Thermal investigation of the coconut husk aerogel for enhanced insulation properties

Thermal investigation of the coconut husk aerogel for enhanced insulation properties | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Thermal investigation of the coconut husk aerogel for enhanced insulation properties Nursyafawati Bakhari, Fatin Zafirah Mansur This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5696159/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Insulating buildings effectively is critical for energy conservation. Traditionally, insulation materials have been composed of synthetic polymers or mineral fibers. Recent research has explored the potential of biomass materials, leveraging their inherent insulative properties. To advance these capabilities, converting biomass into aerogel forms offers a promising approach due to their low density and thermal conductivity. This study focuses on producing coconut husk aerogel to assess its thermal insulation performance. The fabrication process involved blending sodium alginate, phytic acid, and coconut husk to create the aerogel. The influence of varying sodium alginate volumes on the fabrication of coconut husk aerogel was systematically investigated, given its crucial role in gelation. The produced aerogels were comprehensively characterized using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDX), Brunauer–Emmett–Teller specific surface area analysis (BET) and Fourier-transform infrared spectroscopy (FTIR). Thermal conductivity measurements were conducted to evaluate their insulation effectiveness. Results demonstrate that the coconut husk aerogel exhibits good insulation properties, characterized by significantly low thermal conductivity. Coconut husk freeze dying sodium alginate phytic acid SEM-EDX Scanning Electron Microscopy Thermal conductivity BET Brunauer – Emmett - Teller FTIR Fourier – transform infrared spectroscopy Aerogel Biomass Insulating Building Energy Conservation Figures Figure 1 Figure 2 Figure 3 1. Introduction During the last decade, rising urbanization and population growth have generated a continuous need for energy. The alternative to choosing the most environmentally friendly insulation materials is critical to reducing heat transfer. Therefore, the use of thermal insulation materials is essential to managing this issue, which contributes to environmental concerns. Thermal insulation materials have gained the world’s interest as a new alternative to overcome this excessive energy use (Shahee et al. 2024 ). There are several types of insulation materials, such as natural, synthetic, and recycled (Rojas et al. 2019 ). Traditional synthetic insulation materials such as fiberglass and polystyrene have been widely used in construction for many years due to their insulation characteristics and availability. However, this material presents health and environmental issues due to its non-recyclable and high energy production process (Abu-Jdayil et al. 2019 ). Natural fibers such as coconut husk, an abundant organic waste, present a promising option for creating bio-based insulation materials (Stelte et al. 2022 ). According to the Food and Agriculture Organization, Malaysia has become the world’s top 10 coconut producer, with production increasing from 536,606 metric tonnes in 2014 to 2019 (Zakaria et al. n.d.). This fiber presents some unique properties, including the ability to maintain thermal comfort and improve energy efficiency, along with outstanding internal properties without any treatment (Iwaro and Mwasha 2019). Formulation of the sodium alginate-based aerogels through the sol-gel process has emerged as a promising innovation within the construction industry, owing to their unique combination of advantageous properties (Gu & Ling, 2024 ). Sodium alginate, a biopolymer derived from brown seaweed, forms hydrogels in the presence of divalent cations, such as calcium ions, which are subsequently dried to produce highly porous, lightweight aerogels (Wang & Lu, 2023 ). The porous nature of sodium alginate aerogels reduces the rate of heat transfer, thereby contributing to energy savings in heating and cooling systems (Giuma et al,2024) while their biodegradable materials sourced from renewable feedstocks, making the sodium alginate aerogels as a more sustainable and environmentally friendly alternative to conventional synthetic materials typically used in construction (Deng et al., 2023 ) This paper highlights the thermal properties of coconut husk-based aerogel and identifies their potential as more effective insulators. Coconut husk, known for its natural insulating properties, can be combined with aerogel technology to create environmentally friendly, highly efficient insulation. Aerogels were identified for their excellent thermal insulation, and when derived from organic waste such as coconut husk, these are additionally beneficial for the environment. However, challenges remain in using coconut husk alone due to its limited mechanical strength, moisture susceptibility, and scalability. The purpose of this study is to improve these properties by combining coconut husk with other materials and evaluate the thermal properties of coconut husk aerogel through thermal analysis to identify its potential for use in energy-efficient buildings. 2. Methodology 2.1 Materials and chemicals Coconut husk was collected from the local market (Ketereh, Kelantan). The samples were oven-dried to remove any remaining water and processed into a powder, approximately 125 g. Then, the sample has been stored without additional treatment at room temperature for further analysis. Phytic acid and sodium alginate were purchased from Tiongnam Logistic Solution Sdn. Bhd. All solutions were prepared in distilled water (DW). The sodium alginate was ranged from 5 to 25% while the volume of coconut husk and phytic acid was fixed at 5%, respectively. 2.2 Preparation of the coconut husk aerogel In this study, coconut husk aerogels are produced using a freeze-drying method adapted by (Ho Kim H. et al. 2021 ).The raw coconut husk has been dried in the oven at 60°C for 1 hour to remove any impurities (Obeng et al. 2020 ). The dried coconut husk was then ground into a powder using a Panasonic dry mill grinder for 2 minutes before further steps. After that, the coconut husk (5g), phytic acid (5 ml), and sodium alginate (20–40 g) at varying concentrations were prepared and mixed using a magnetic stirrer for 3 minutes to ensure complete blending of each component. The mixture was then placed in a 100-ml beaker and fermented in a desiccator for 5 days to allow the gelling and cross-linking agents to interact with the untreated husk to form a solid gel. Finally, the mixture was then incubated for 5 days at -55°C in a freeze-dyer machine to allow moisture to be removed from the mixture. 2.3 Characterization of the coconut husk aerogel A scanning electron microscope (SEM-EDX) was conducted at 10 kV and a working distance (WD) of 9.7 mm to investigate the morphology of the coconut husk aerogel. Furthermore, the standard less ZAF qualification method was used, with signal detection via SED (secondary electron detector). In addition, the porosity and surface properties were evaluated using standard adsorption (N₂) at 77.248 K. The Brunaer-Emmett-Teller (BET) method was used to determine specific surface area, the t-plot method to determine micropore surface area, and the Barrett-Joyner-Halenda (BJH) analysis for identifying pore distribution. The chemical structure of the coconut husk aerogel was determined using a Fourier transform infrared (FTIR) spectrometer with a wavenumber range focuses of 400 cm − 1 to 4000 cm − 1 . Data were collected at room temperature using standard FTIR settings using the potassium bromide (KBr) palette method. Furthermore, this study on the thermal investigation and characterization of the prepared coconut husk aerogel. 2.4 Thermal conductivity measurement Preparations have been made for thermal measurements after preparing 15 samples. A thermal conductivity tool (Hot Disc TPS 2500S) has been used to measure the thermal conductivity of coconut husk aerogel. The sensor TPS 2500S Hot Disc was chosen due to the size of the sample, which was created with a thickness of 20 mm, the standard minimum insulation thickness in buildings (Huang et al. 2020 ). The sensor is then placed between two sections of coconut husk aerogel to provide a more precise reading in which the sample thickness of 20 mm exceeds the sensor diameter of 13 mm. The samples were calibrated, and the measurement was performed using Hot Disc software, which has used the transient heat pulse method to determine the thermal conductivity of the sample. When the measurements were completed, the software produced the findings, including thermal conductivity and specific heat capacity. Thus, in this study, the sample was examined three times, and the average value was calculated. 3. Result and Discussion 3.1 Characterization of coconut husk – based aerogel 3.1.1 Surface Morphology Analysis Considering the attempts to develop coconut husk as an insulating material, the porosity of the treated coconut husk aerogel has been investigated further using SEM-EDX. Figures 1 (a) and 1(b) present the SEM images of coconut husk aerogel at two magnification scales, 100x and 500x, respectively. Also, the asymmetric porosity of the aerogel can be clearly seen in these SEM images. Besides, Table 1 presents the results of the respective EDX analysis. From the two magnification scales selected, the results show that the coconut husk aerogel has a slightly porous structure, which indicates this material is suitable for thermal insulation applications. The changes in the surface morphology of coconut husk aerogels can be linked to the gelling agent's function, sodium alginate, which allows for the creation of a stable and porous structure with controlled porosity (Cao et al. 2021 ). Furthermore, blending coconut husk, phytic acid, and sodium alginate in the formation of aerogels could result in high-performance coconut husk aerogels with good thermal insulation, mechanical strength, and durability. Table 1 presents the elemental composition of coconut husk, which contains a high concentration of carbon (54.54%) and oxygen (45.46%), suggesting that this material has a solid carbon structure and chemical reactivity potential. These findings have shown that coconut husk has a high carbon concentration, which, when formed into an aerogel, can improve and influence its material's properties. Furthermore, previous research indicates that the optimal carbon content for selecting raw materials is between 50% and 71% (Xu et al. 2020 ). However, compared to coconut husk aerogel, the concentrations of carbon (34.13%) and oxygen (38.10%) have decreased. This situation is caused by improper processing factors, such as drying methods, temperature or pressure conditions during gelation or drying, or inappropriate precursor treatment. Nevertheless, coconut husk aerogel has been considered a sustainable thermal insulation ideal for use in the building sector. Table 1 EDX analysis of raw coconut husk and coconut husk aerogel Sample Element Mass% Atom% Raw coconut husk C 54.54 61.51 O 45.46 38.49 Coconut Husk Aerogel C 34.13 46.31 O 38.10 38.81 3.1.2 Textural analysis Table 2 displays the texture analysis of coconut husk aerogel, which includes pore structure and surface area. The study's findings show that coconut husk aerogel has a surface area of 5.1283 m²/g, which is lower than raw coconut husk. From previous studies, coconut husk aerogels generally range between 200 and 700 m²/g, depending on processing elements and aerogel production methods (Azadi and Dinari 2023). This lower than expected surface area could be due to adjustments in the processing methods or aerogel fabrication methods used in the study. Despite this, SEM investigations showed the strong porous structure, indicating that coconut husk aerogels may still have significant insulating properties. In addition, the total pore volume and average pore widths of the coconut husk aerogel obtained were 0.00365 cm2/g and 2.8511 nm. These findings indicate the existence of mesoporous elements, which are effective in thermal insulation. Table 2 Textural analysis of the raw coconut husk and coconut husk aerogel Parameters Coconut husk aerogel BET Surface Area (m²/g) 5.1283 Total pore volume (cm³/g) 0.00365 Average pore width (nm) 2.8511 3.1.3 Identification of functional groups The functional groups in the coconut husk aerogel were located using Fourier transform infrared (FTIR) spectroscopy. Figure 2 presents the KBr spectrum of coconut husk aerogel. Based on Fig. 2 , the analysis has identified the existence of several functional groups that indicate lignin content in coconut husk aerogel. The broad absorption at 3323.86 cm⁻¹ shows significant hydroxyl (-OH) groups found in cellulose, hemicellulose, and remaining moisture in aerogels. These hydroxyl bonds might be contributing to the aerogels hydrophilic nature, potentially improving its capacity to absorb moisture and other polar substances (Franco et al. 2021 ). Furthermore, the strong peak at 2919.23 cm⁻¹ indicates C-H stretching from the hydrophobic boundary, suggesting the existence of cellulose and hemicellulose. Besides, small peak values appear at 142.51 cm⁻¹ and 1370.0 cm⁻¹, indicating C-H bending, which is often found in lignocellulose materials, highlighting the importance of the aerogel's structure and flexibility. Additionally, the peak between 867.35 cm⁻¹ and 816.67 cm⁻¹ demonstrates the existence of aromatic C-H bending, showing that lignin chemical structure was kept during the formation process. It further indicates that coconut husk aerogel maintains its lignin content, which contributes to its thermal stability and mechanical strength. 3.2 Thermal conductivity of coconut husk aerogel Thermal conductivity is an important indicator to evaluate the thermal insulation properties of energy-efficient building materials (Cao et al. 2021 ). Therefore, the results of thermal data measurements were presented and analyzed graphically in this study. The thermal performance was measured for all samples at a constant temperature of 25.5°C, as indicated in Table 3 . As shown in the table, integrating various ratios of sodium alginate from 5–25% resulted in diverse thermal data. Table 3 shows the thermal conductivity of sodium alginate is lowest at a 10% concentration at 0.1130 ± 0.002 W/m.K, making it the most effective for insulation. At both lower (5%) and higher concentrations (15%, 20%, and especially 25%), thermal conductivity increases, reducing insulation efficiency with the higher thermal conductivity recorded at 0.1979 ± 0.0018 W/m.K. This suggests that 10% sodium alginate is the optimal concentration for minimizing heat transfer, while higher concentrations may change the material’s structure, leading to poorer insulation performance . Table 3 Thermal conductivity of coconut husk aerogel with various sodium alginate contents (5–25%) and coconut husk and phytic acid that fixed at 5%, respectively. Sample percentage Temperature(°C) Thermal Conductivity (W/mK) Min Max Average Sodium Alginate 5 25.5 0.1573 0.1593 0.1582 10 25.5 0.1110 0.1150 0.1130 15 25.5 0.1832 0.1889 0.1864 20 25.5 0.1360 0.1400 0.1376 25 25.5 0.1957 0.1990 0.1979 Figure 3 illustrates the relationship between the volume of sodium alginate and the thermal conductivity of the material. It also includes benchmarks for two reference materials: wood (with thermal conductivity between 0.15 and 0.4 W/m·K) and glass wool (with a thermal conductivity between 0.03 and 0.05 W/m·K) signify as the good and excellent insulator (Mededji et al., 2024 ). At a 5% concentration of sodium alginate, the thermal conductivity is slightly above 0.15 W/m·K, placing it within the thermal conductivity range typical for wood materials, which are known for moderate insulation properties. As the sodium alginate concentration increases to 10% and 20%, a notable decrease in thermal conductivity is observed, approaching the upper limit of glass wool’s thermal conductivity range, which is known for superior insulation. However, at a 25% concentration, thermal conductivity increases again to a level similar to that at 5%, suggesting an optimal concentration range between 10% and 20% for minimizing thermal conductivity and maximizing insulation performance. This improvement in insulation efficiency at intermediate concentrations (10–20%) is likely due to structural changes that reduce heat transfer within the material by increasing the porous structure of the biomass. It have been discovered that enhanced porosity can trap air pockets, which act as thermal barriers and contribute to lower thermal conductivity in bio-based insulation materials (Li et al., 2024 & Wang et al., 2018 ). In contrast, at concentrations of 5% and 25%, the thermal conductivity aligns more closely with that of wood, indicating comparatively lower insulation effectiveness. Overall, the results indicate that the insulation properties of the wood material have been enhanced by incorporating aerogel characteristics. 4. Conclusions This study is aimed at investigating coconut husk aerogel to enhance its functional insulation properties by producing a blend using sodium alginate and phytic acid, which has offered promising thermal insulation properties. The various mixture of the sodium alginate was investigated. A comprehensive characterization, including SEM-EDX, BET, and FTIR, demonstrated that the coconut husk aerogel has a porous structure, particular thermal insulation boundaries, and functional groups indicating lignocellulosic content. Thermal conductivity analysis has found that samples treated with 10% of sodium alginate have a great thermal measurement ability for use in energy-saving structure. In a nutshell, coconut husk aerogel has great potential as a renewable and environmentally friendly alternative to conventional insulation materials. However, future research could enhance the fabrication method to increase surface area and explore long-term strength in a wide range of environmental conditions. Declarations Author Contribution N.B contributed to the conceptualization, investigation, methodology, formal analysis, and the original drafting of the manuscript. F.Z.M. was responsible for supervision, methodology, data analysis, and writing—review and editing. Acknowledgement This study was supported by the Universiti Malaysia Pahang Al-Sultan Abdullah’s internal grant (RDU220319). Data Availability The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request. References Abu-Jdayil, Basim, Abdel-Hamid Mourad, Waseem Hittini, Muzamil Hassan, and Suhaib Hameedi.2019. ‘Traditional, State-of-the-Art and Renewable Thermal Building Insulation Materials: An Overview’. Construction and Building Materials 214: 709–35.doi: 10.1016/j.conbuildmat.2019.04.102 . Azadi, Elham, and Mohammad Dinari. 2023. ‘Green Synthesis, Characterization, and Properties of Carbon Aerogels’. In ACS Symposium Series, eds. Shahid Ul Islam and Chaudhery Mustansar Hussain. Washington, DC: American Chemical Society, 1–23. doi: 10.1021/bk-2023-1441.ch001 . Cao, Min, Bo-Wen Liu, Lin Zhang, Zi-Chen Peng, Yi-Ying Zhang, Han Wang, Hai-Bo Zhao, and YuZhong Wang. 2021. ‘Fully Biomass-Based Aerogels with Ultrahigh Mechanical Modulus, EnhancedFlame Retardancy, and Great Thermal Insulation Applications’. Composites Part B: Engineering 225: 109309. doi: 10.1016/j.compositesb.2021.109309 . Deng, T., Li, H., Li, Y., Jiang, C., He, Y., Yang, T., Zhu, L. and Xie, L., 2023. Environment friendly biomass composite aerogel with reinforced mechanical properties for thermal insulation and flame retardancy application. Polymer Engineering & Science, 63(12), pp.4084–4097. Franco, Paola, Stefano Cardea, Antonio Tabernero, and Iolanda De Marco. 2021. ‘Porous Aerogels and Adsorption of Pollutants from Water and Air: A Review’. Molecules 26(15): 4440. doi: 10.3390/molecules26154440 . Giuma, A., Khalil, H.A., Yahya, E.B., Sukeksi, L., Alfatah, T., Nurazzi, N.M., Jaber, M. and Surya, I., 2024. Green thermal insulators: A review into the role of biopolymer-based aerogels in thermal insulation applications. Polymer Engineering & Science, 64(10), pp.4611–4629. Gu, X. and Ling, Y., 2024. Research progress of aerogel materials in the field of construction. Alexandria Engineering Journal, 91, pp.620–631. Hasan, K. M. Faridul, Péter György Horváth, Miklós Bak, and Tibor Alpár. 2021. ‘A State-of-the Art Review on Coir Fiber-Reinforced Biocomposites’. RSC Advances 11(18): 10548–71.doi: 10.1039/D1RA00231G . Ho Kim H., Nguyen Phuong X. T., Do Nga H. N., Le Kien A., and Le Phung K. 2021. ‘Green Fabrication of Bio-Based Aerogels from Coconut Coir for Heat Insulation and Oil Removal’. Chemical Engineering Transactions 88: 709–14. doi: 10.3303/CET2188118 . Huang, Huakun, Yijun Zhou, Renda Huang, Huijun Wu, Yongjun Sun, Gongsheng Huang, and TaoXu. 2020. ‘Optimum Insulation Thicknesses and Energy Conservation of Building Thermal Insulation Materials in Chinese Zone of Humid Subtropical Climate’. Sustainable Cities and Society52: 101840. doi: 10.1016/j.scs.2019.101840 . Iwaro, Joseph, and Abrahams Mwasha. 2019. ‘Effects of Using Coconut Fiber–Insulated Masonry Walls to Achieve Energy Efficiency and Thermal Comfort in Residential Dwellings’. Journal ofArchitectural Engineering 25(1): 04019001. doi: 10.1061/(ASCE)AE.1943-5568.0000341 . Li, M., Wang, F., Ouyang, S., Liu, Y., Hu, Z., Wu, Y., Qian, J., Li, Z., Wang, L. and Ma, S., 2024. A comprehensive review on preparation and functional application of the wood aerogel with natural cellulose framework. International Journal of Biological Macromolecules, p.133340. Mededji, D.S., Sogbochi, E., Djossou, A.A., Cherkaoui, O., Fagbemi, L.A. and Sohounhloue, D.C.K., 2024. Characteristics of Insulating Panels Realised from Coconut Palm Fibres for Low-Temperature Thermal Insulation. International Journal of Environment and Climate Change, 14(5), pp.324–335. Obeng, George Yaw, Derrick Yeboah Amoah, Richard Opoku, Charles K. K. Sekyere, Eunice Akyereko Adjei, and Ebenezer Mensah. 2020. ‘Coconut Wastes as Bioresource for Sustainable Energy: Quantifying Wastes, Calorific Values and Emissions in Ghana’. Energies 13(9): 2178. doi: 10.3390/en13092178 . Rojas, Carlos, Mara Cea, Alfredo Iriarte, Gonzalo Valdés, Rodrigo Navia, and Juan Pablo Cárdenas R. 2019. ‘Thermal Insulation Materials Based on Agricultural Residual Wheat Straw and Corn Husk Biomass, for Application in Sustainable Buildings’. Sustainable Materials and Technologies 20:e00102. doi: 10.1016/j.susmat.2019.e00102 . Shahee, Arash, Mahmood Abdoos, Alireza Aslani, and Rahim Zahedi. 2024. ‘Reducing the Energy Consumption of Buildings by Implementing Insulation Scenarios and Using Renewable Energies’. Energy Informatics 7(1): 18. doi: 10.1186/s42162-024-00311-9 . Stelte, Wolfgang, Narendra Reddy, Søren Barsberg, and Anand Ramesh Sanadi. 2022. ‘Coir from Coconut Processing Waste as a Raw Material for Applications beyond Traditional Uses’. BioResources 18(1). doi: 10.15376/biores.18.1.Stelte . Wang, Y. and Lu, Y., 2023. Sodium alginate-based functional materials toward sustainable applications: Water treatment and energy storage. Industrial & Engineering Chemistry Research, 62(29), pp.11279–11304. Wang, X., Liu, H., Wang, L., Liu, B. and Wang, L., 2018. Optimization of thermal insulation performance for the porous materials. Heat Transfer Engineering, 39(17–18), pp.1573–1581. Xu, Yongjian, Yan Liu, Shenglin Chen, and Yonghao Ni. 2020. ‘Current Overview of Carbon Fiber: Toward Green Sustainable Raw Materials’. BioResources 15(3): 7234–59.doi: 10.15376/biores.15.3.Xu . Zakaria, Mohd Hafizudin, Mohd Zaffrie Mat Amin, Muhammad Faireal Ahmad, and Muhammad Syafiq Ahmad Dani. ‘Market Potential and Competitiveness Assessment of Malaysian Coconut Based Products’. Additional Declarations No competing interests reported. Supplementary Files GA.png Graphical Abstract Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5696159","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":396167606,"identity":"729889cb-198a-4e40-813d-6ee82898e7cc","order_by":0,"name":"Nursyafawati Bakhari","email":"","orcid":"","institution":"Universiti Malaysia Pahang Al-Sultan Abdullah","correspondingAuthor":false,"prefix":"","firstName":"Nursyafawati","middleName":"","lastName":"Bakhari","suffix":""},{"id":396167607,"identity":"6f39d65c-20ef-4a16-8da4-e1a456b4fbd8","order_by":1,"name":"Fatin Zafirah Mansur","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABEklEQVRIiWNgGAWjYBAC9gYGhgNAmp+NgYGN4QNMmAePFp4DzGAtkm1ALYwziNUCApJA29iY4SrxamE/f/BwwR87CT7pw88e27Zty5NvP8D44G0bQ7TBARxaeJIZDs/gSZZg40szN85tu11scCaB2XBuG0PuBhxa7BmAWngkmOvYeBjMpIFaEjcwJLBJ8+LRwsP/GKjFoF6CjYf9m7QlUMv8/gfsv/FqkQDZknAYqIXHTJoRqKXhRgIbM34tjw0O8xw4DtJSJtlzDuiXGw+bJeeck8ididNhiY8/8/yplpDvYd8m8aPsdp58f/LBD2/KbHL7cGjBAAkMDIwNQFqCQYEELVAg30CkllEwCkbBKBjuAAATy1jkK/J3yQAAAABJRU5ErkJggg==","orcid":"","institution":"Universiti Malaysia Pahang Al-Sultan Abdullah","correspondingAuthor":true,"prefix":"","firstName":"Fatin","middleName":"Zafirah","lastName":"Mansur","suffix":""}],"badges":[],"createdAt":"2024-12-23 03:23:15","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5696159/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5696159/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":72778459,"identity":"399397c1-046b-4da3-85fe-6a2ded55b515","added_by":"auto","created_at":"2025-01-02 05:29:39","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1269786,"visible":true,"origin":"","legend":"\u003cp\u003eSEM image of coconut husk aerogel at (a) 100x magnification and (b) 500x magnification\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-5696159/v1/e2058b019f19fbc92bd313bc.png"},{"id":72778417,"identity":"e165c964-1c9c-47d5-8115-600bde92861d","added_by":"auto","created_at":"2025-01-02 05:29:37","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":43049,"visible":true,"origin":"","legend":"\u003cp\u003eFTIR spectra of coconut husk aerogel\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-5696159/v1/dbd441dfa3773485739dc271.png"},{"id":72778728,"identity":"7f0b2900-467a-40c9-b9bf-eece26c20938","added_by":"auto","created_at":"2025-01-02 05:37:37","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":76413,"visible":true,"origin":"","legend":"\u003cp\u003eThermal conductivity measurement at various volume of sodium alginate comparing with the thermal conductivity value for the wood material and glass wool.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-5696159/v1/ca529aca1a5faecd6db961d4.png"},{"id":77135426,"identity":"87c269ac-ba32-4910-a6b2-828a7baf16ee","added_by":"auto","created_at":"2025-02-25 12:53:32","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1897207,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5696159/v1/15a3b0dc-ee67-4d95-8c93-ba9a34a3095d.pdf"},{"id":72778416,"identity":"5f7a9f38-6afa-4683-b13c-947d09ab26fc","added_by":"auto","created_at":"2025-01-02 05:29:37","extension":"png","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":311323,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eGraphical Abstract\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"GA.png","url":"https://assets-eu.researchsquare.com/files/rs-5696159/v1/648de21f4570397295ca6af2.png"}],"financialInterests":"No competing interests reported.","formattedTitle":"Thermal investigation of the coconut husk aerogel for enhanced insulation properties","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eDuring the last decade, rising urbanization and population growth have generated a continuous need for energy. The alternative to choosing the most environmentally friendly insulation materials is critical to reducing heat transfer. Therefore, the use of thermal insulation materials is essential to managing this issue, which contributes to environmental concerns. Thermal insulation materials have gained the world\u0026rsquo;s interest as a new alternative to overcome this excessive energy use (Shahee et al. \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). There are several types of insulation materials, such as natural, synthetic, and recycled (Rojas et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Traditional synthetic insulation materials such as fiberglass and polystyrene have been widely used in construction for many years due to their insulation characteristics and availability. However, this material presents health and environmental issues due to its non-recyclable and high energy production process (Abu-Jdayil et al. \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2019\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eNatural fibers such as coconut husk, an abundant organic waste, present a promising option for creating bio-based insulation materials (Stelte et al. \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). According to the Food and Agriculture Organization, Malaysia has become the world\u0026rsquo;s top 10 coconut producer, with production increasing from 536,606 metric tonnes in 2014 to 2019 (Zakaria et al. n.d.). This fiber presents some unique properties, including the ability to maintain thermal comfort and improve energy efficiency, along with outstanding internal properties without any treatment (Iwaro and Mwasha 2019). Formulation of the sodium alginate-based aerogels through the sol-gel process has emerged as a promising innovation within the construction industry, owing to their unique combination of advantageous properties (Gu \u0026amp; Ling, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). Sodium alginate, a biopolymer derived from brown seaweed, forms hydrogels in the presence of divalent cations, such as calcium ions, which are subsequently dried to produce highly porous, lightweight aerogels (Wang \u0026amp; Lu, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). The porous nature of sodium alginate aerogels reduces the rate of heat transfer, thereby contributing to energy savings in heating and cooling systems (Giuma et al,2024) while their biodegradable materials sourced from renewable feedstocks, making the sodium alginate aerogels as a more sustainable and environmentally friendly alternative to conventional synthetic materials typically used in construction (Deng et al., \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2023\u003c/span\u003e)\u003c/p\u003e \u003cp\u003eThis paper highlights the thermal properties of coconut husk-based aerogel and identifies their potential as more effective insulators. Coconut husk, known for its natural insulating properties, can be combined with aerogel technology to create environmentally friendly, highly efficient insulation. Aerogels were identified for their excellent thermal insulation, and when derived from organic waste such as coconut husk, these are additionally beneficial for the environment. However, challenges remain in using coconut husk alone due to its limited mechanical strength, moisture susceptibility, and scalability. The purpose of this study is to improve these properties by combining coconut husk with other materials and evaluate the thermal properties of coconut husk aerogel through thermal analysis to identify its potential for use in energy-efficient buildings.\u003c/p\u003e"},{"header":"2. Methodology","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1 Materials and chemicals\u003c/h2\u003e \u003cp\u003eCoconut husk was collected from the local market (Ketereh, Kelantan). The samples were oven-dried to remove any remaining water and processed into a powder, approximately 125 g. Then, the sample has been stored without additional treatment at room temperature for further analysis. Phytic acid and sodium alginate were purchased from Tiongnam Logistic Solution Sdn. Bhd. All solutions were prepared in distilled water (DW). The sodium alginate was ranged from 5 to 25% while the volume of coconut husk and phytic acid was fixed at 5%, respectively.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2 Preparation of the coconut husk aerogel\u003c/h2\u003e \u003cp\u003eIn this study, coconut husk aerogels are produced using a freeze-drying method adapted by (Ho Kim H. et al. \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2021\u003c/span\u003e).The raw coconut husk has been dried in the oven at 60\u0026deg;C for 1 hour to remove any impurities (Obeng et al. \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). The dried coconut husk was then ground into a powder using a Panasonic dry mill grinder for 2 minutes before further steps. After that, the coconut husk (5g), phytic acid (5 ml), and sodium alginate (20\u0026ndash;40 g) at varying concentrations were prepared and mixed using a magnetic stirrer for 3 minutes to ensure complete blending of each component. The mixture was then placed in a 100-ml beaker and fermented in a desiccator for 5 days to allow the gelling and cross-linking agents to interact with the untreated husk to form a solid gel. Finally, the mixture was then incubated for 5 days at -55\u0026deg;C in a freeze-dyer machine to allow moisture to be removed from the mixture.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.3 Characterization of the coconut husk aerogel\u003c/h2\u003e \u003cp\u003eA scanning electron microscope (SEM-EDX) was conducted at 10 kV and a working distance (WD) of 9.7 mm to investigate the morphology of the coconut husk aerogel. Furthermore, the standard less ZAF qualification method was used, with signal detection via SED (secondary electron detector).\u003c/p\u003e \u003cp\u003eIn addition, the porosity and surface properties were evaluated using standard adsorption (N₂) at 77.248 K. The Brunaer-Emmett-Teller (BET) method was used to determine specific surface area, the t-plot method to determine micropore surface area, and the Barrett-Joyner-Halenda (BJH) analysis for identifying pore distribution.\u003c/p\u003e \u003cp\u003eThe chemical structure of the coconut husk aerogel was determined using a Fourier transform infrared (FTIR) spectrometer with a wavenumber range focuses of 400 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to 4000 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. Data were collected at room temperature using standard FTIR settings using the potassium bromide (KBr) palette method. Furthermore, this study on the thermal investigation and characterization of the prepared coconut husk aerogel.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e2.4 Thermal conductivity measurement\u003c/h2\u003e \u003cp\u003ePreparations have been made for thermal measurements after preparing 15 samples. A thermal conductivity tool (Hot Disc TPS 2500S) has been used to measure the thermal conductivity of coconut husk aerogel. The sensor TPS 2500S Hot Disc was chosen due to the size of the sample, which was created with a thickness of 20 mm, the standard minimum insulation thickness in buildings (Huang et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). The sensor is then placed between two sections of coconut husk aerogel to provide a more precise reading in which the sample thickness of 20 mm exceeds the sensor diameter of 13 mm. The samples were calibrated, and the measurement was performed using Hot Disc software, which has used the transient heat pulse method to determine the thermal conductivity of the sample. When the measurements were completed, the software produced the findings, including thermal conductivity and specific heat capacity. Thus, in this study, the sample was examined three times, and the average value was calculated.\u003c/p\u003e \u003c/div\u003e"},{"header":"3. Result and Discussion","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e3.1 Characterization of coconut husk \u0026ndash; based aerogel\u003c/h2\u003e \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e \u003ch2\u003e3.1.1 Surface Morphology Analysis\u003c/h2\u003e \u003cp\u003eConsidering the attempts to develop coconut husk as an insulating material, the porosity of the treated coconut husk aerogel has been investigated further using SEM-EDX. Figures\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e(a) and 1(b) present the SEM images of coconut husk aerogel at two magnification scales, 100x and 500x, respectively. Also, the asymmetric porosity of the aerogel can be clearly seen in these SEM images. Besides, Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e presents the results of the respective EDX analysis. From the two magnification scales selected, the results show that the coconut husk aerogel has a slightly porous structure, which indicates this material is suitable for thermal insulation applications. The changes in the surface morphology of coconut husk aerogels can be linked to the gelling agent's function, sodium alginate, which allows for the creation of a stable and porous structure with controlled porosity (Cao et al. \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Furthermore, blending coconut husk, phytic acid, and sodium alginate in the formation of aerogels could result in high-performance coconut husk aerogels with good thermal insulation, mechanical strength, and durability.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e presents the elemental composition of coconut husk, which contains a high concentration of carbon (54.54%) and oxygen (45.46%), suggesting that this material has a solid carbon structure and chemical reactivity potential. These findings have shown that coconut husk has a high carbon concentration, which, when formed into an aerogel, can improve and influence its material's properties. Furthermore, previous research indicates that the optimal carbon content for selecting raw materials is between 50% and 71% (Xu et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). However, compared to coconut husk aerogel, the concentrations of carbon (34.13%) and oxygen (38.10%) have decreased. This situation is caused by improper processing factors, such as drying methods, temperature or pressure conditions during gelation or drying, or inappropriate precursor treatment. Nevertheless, coconut husk aerogel has been considered a sustainable thermal insulation ideal for use in the building sector.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003e\u003cem\u003eEDX\u003c/em\u003e analysis of raw coconut husk and coconut husk aerogel\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSample\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eElement\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMass%\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAtom%\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRaw coconut husk\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e54.54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e61.51\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e38.49\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCoconut Husk Aerogel\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e34.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e46.31\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e38.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e38.81\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section3\"\u003e \u003ch2\u003e3.1.2 Textural analysis\u003c/h2\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e displays the texture analysis of coconut husk aerogel, which includes pore structure and surface area. The study's findings show that coconut husk aerogel has a surface area of 5.1283 m\u0026sup2;/g, which is lower than raw coconut husk. From previous studies, coconut husk aerogels generally range between 200 and 700 m\u0026sup2;/g, depending on processing elements and aerogel production methods (Azadi and Dinari 2023). This lower than expected surface area could be due to adjustments in the processing methods or aerogel fabrication methods used in the study. Despite this, SEM investigations showed the strong porous structure, indicating that coconut husk aerogels may still have significant insulating properties. In addition, the total pore volume and average pore widths of the coconut husk aerogel obtained were 0.00365 cm2/g and 2.8511 nm. These findings indicate the existence of mesoporous elements, which are effective in thermal insulation.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eTextural analysis of the raw coconut husk and coconut husk aerogel\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParameters\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCoconut husk aerogel\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBET Surface Area (m\u0026sup2;/g)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5.1283\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal pore volume (cm\u0026sup3;/g)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.00365\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAverage pore width (nm)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.8511\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section3\"\u003e \u003ch2\u003e3.1.3 Identification of functional groups\u003c/h2\u003e \u003cp\u003eThe functional groups in the coconut husk aerogel were located using Fourier transform infrared (FTIR) spectroscopy. Figure\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e presents the KBr spectrum of coconut husk aerogel. Based on Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, the analysis has identified the existence of several functional groups that indicate lignin content in coconut husk aerogel. The broad absorption at 3323.86 cm⁻\u0026sup1; shows significant hydroxyl (-OH) groups found in cellulose, hemicellulose, and remaining moisture in aerogels. These hydroxyl bonds might be contributing to the aerogels hydrophilic nature, potentially improving its capacity to absorb moisture and other polar substances (Franco et al. \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Furthermore, the strong peak at 2919.23 cm⁻\u0026sup1; indicates C-H stretching from the hydrophobic boundary, suggesting the existence of cellulose and hemicellulose. Besides, small peak values appear at 142.51 cm⁻\u0026sup1; and 1370.0 cm⁻\u0026sup1;, indicating C-H bending, which is often found in lignocellulose materials, highlighting the importance of the aerogel's structure and flexibility. Additionally, the peak between 867.35 cm⁻\u0026sup1; and 816.67 cm⁻\u0026sup1; demonstrates the existence of aromatic C-H bending, showing that lignin chemical structure was kept during the formation process. It further indicates that coconut husk aerogel maintains its lignin content, which contributes to its thermal stability and mechanical strength.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003e3.2 Thermal conductivity of coconut husk aerogel\u003c/h2\u003e \u003cp\u003eThermal conductivity is an important indicator to evaluate the thermal insulation properties of energy-efficient building materials (Cao et al. \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Therefore, the results of thermal data measurements were presented and analyzed graphically in this study. The thermal performance was measured for all samples at a constant temperature of 25.5\u0026deg;C, as indicated in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. As shown in the table, integrating various ratios of sodium alginate from 5\u0026ndash;25% resulted in diverse thermal data. Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e shows the thermal conductivity of sodium alginate is lowest at a 10% concentration at 0.1130\u0026thinsp;\u0026plusmn;\u0026thinsp;0.002 W/m.K, making it the most effective for insulation. At both lower (5%) and higher concentrations (15%, 20%, and especially 25%), thermal conductivity increases, reducing insulation efficiency with the higher thermal conductivity recorded at 0.1979\u0026thinsp;\u0026plusmn;\u0026thinsp;0.0018 W/m.K. This suggests that 10% sodium alginate is the optimal concentration for minimizing heat transfer, while higher concentrations may change the material\u0026rsquo;s structure, leading to poorer insulation performance .\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThermal conductivity of coconut husk aerogel with various sodium alginate contents (5\u0026ndash;25%) and coconut husk and phytic acid that fixed at 5%, respectively.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eSample percentage\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eTemperature(\u0026deg;C)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003eThermal Conductivity (W/mK)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMin\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMax\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eAverage\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eSodium Alginate\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e25.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.1573\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.1593\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.1582\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e25.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.1110\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.1150\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.1130\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e25.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.1832\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.1889\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.1864\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e25.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.1360\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.1400\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.1376\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e25.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.1957\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.1990\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.1979\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e illustrates the relationship between the volume of sodium alginate and the thermal conductivity of the material. It also includes benchmarks for two reference materials: wood (with thermal conductivity between 0.15 and 0.4 W/m\u0026middot;K) and glass wool (with a thermal conductivity between 0.03 and 0.05 W/m\u0026middot;K) signify as the good and excellent insulator (Mededji et al., \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). At a 5% concentration of sodium alginate, the thermal conductivity is slightly above 0.15 W/m\u0026middot;K, placing it within the thermal conductivity range typical for wood materials, which are known for moderate insulation properties. As the sodium alginate concentration increases to 10% and 20%, a notable decrease in thermal conductivity is observed, approaching the upper limit of glass wool\u0026rsquo;s thermal conductivity range, which is known for superior insulation. However, at a 25% concentration, thermal conductivity increases again to a level similar to that at 5%, suggesting an optimal concentration range between 10% and 20% for minimizing thermal conductivity and maximizing insulation performance. This improvement in insulation efficiency at intermediate concentrations (10\u0026ndash;20%) is likely due to structural changes that reduce heat transfer within the material by increasing the porous structure of the biomass. It have been discovered that enhanced porosity can trap air pockets, which act as thermal barriers and contribute to lower thermal conductivity in bio-based insulation materials (Li et al., \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2024\u003c/span\u003e \u0026amp; Wang et al., \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). In contrast, at concentrations of 5% and 25%, the thermal conductivity aligns more closely with that of wood, indicating comparatively lower insulation effectiveness. Overall, the results indicate that the insulation properties of the wood material have been enhanced by incorporating aerogel characteristics.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"4. Conclusions","content":"\u003cp\u003eThis study is aimed at investigating coconut husk aerogel to enhance its functional insulation properties by producing a blend using sodium alginate and phytic acid, which has offered promising thermal insulation properties. The various mixture of the sodium alginate was investigated. A comprehensive characterization, including SEM-EDX, BET, and FTIR, demonstrated that the coconut husk aerogel has a porous structure, particular thermal insulation boundaries, and functional groups indicating lignocellulosic content. Thermal conductivity analysis has found that samples treated with 10% of sodium alginate have a great thermal measurement ability for use in energy-saving structure. In a nutshell, coconut husk aerogel has great potential as a renewable and environmentally friendly alternative to conventional insulation materials. However, future research could enhance the fabrication method to increase surface area and explore long-term strength in a wide range of environmental conditions.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eN.B contributed to the conceptualization, investigation, methodology, formal analysis, and the original drafting of the manuscript. F.Z.M. was responsible for supervision, methodology, data analysis, and writing\u0026mdash;review and editing.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eThis study was supported by the Universiti Malaysia Pahang Al-Sultan Abdullah\u0026rsquo;s internal grant (RDU220319).\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAbu-Jdayil, Basim, Abdel-Hamid Mourad, Waseem Hittini, Muzamil Hassan, and Suhaib Hameedi.2019. \u0026lsquo;Traditional, State-of-the-Art and Renewable Thermal Building Insulation Materials: An Overview\u0026rsquo;. Construction and Building Materials 214: 709\u0026ndash;35.doi:\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.conbuildmat.2019.04.102\u003c/span\u003e\u003cspan address=\"10.1016/j.conbuildmat.2019.04.102\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAzadi, Elham, and Mohammad Dinari. 2023. \u0026lsquo;Green Synthesis, Characterization, and Properties of Carbon Aerogels\u0026rsquo;. In ACS Symposium Series, eds. Shahid Ul Islam and Chaudhery Mustansar Hussain. Washington, DC: American Chemical Society, 1\u0026ndash;23. doi:\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/bk-2023-1441.ch001\u003c/span\u003e\u003cspan address=\"10.1021/bk-2023-1441.ch001\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCao, Min, Bo-Wen Liu, Lin Zhang, Zi-Chen Peng, Yi-Ying Zhang, Han Wang, Hai-Bo Zhao, and YuZhong Wang. 2021. \u0026lsquo;Fully Biomass-Based Aerogels with Ultrahigh Mechanical Modulus, EnhancedFlame Retardancy, and Great Thermal Insulation Applications\u0026rsquo;. Composites Part B: Engineering 225: 109309. doi:\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.compositesb.2021.109309\u003c/span\u003e\u003cspan address=\"10.1016/j.compositesb.2021.109309\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDeng, T., Li, H., Li, Y., Jiang, C., He, Y., Yang, T., Zhu, L. and Xie, L., 2023. Environment friendly biomass composite aerogel with reinforced mechanical properties for thermal insulation and flame retardancy application. Polymer Engineering \u0026amp; Science, 63(12), pp.4084\u0026ndash;4097.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFranco, Paola, Stefano Cardea, Antonio Tabernero, and Iolanda De Marco. 2021. \u0026lsquo;Porous Aerogels and Adsorption of Pollutants from Water and Air: A Review\u0026rsquo;. Molecules 26(15): 4440. doi:\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3390/molecules26154440\u003c/span\u003e\u003cspan address=\"10.3390/molecules26154440\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGiuma, A., Khalil, H.A., Yahya, E.B., Sukeksi, L., Alfatah, T., Nurazzi, N.M., Jaber, M. and Surya, I., 2024. Green thermal insulators: A review into the role of biopolymer-based aerogels in thermal insulation applications. Polymer Engineering \u0026amp; Science, 64(10), pp.4611\u0026ndash;4629.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGu, X. and Ling, Y., 2024. Research progress of aerogel materials in the field of construction. Alexandria Engineering Journal, 91, pp.620\u0026ndash;631.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHasan, K. M. Faridul, P\u0026eacute;ter Gy\u0026ouml;rgy Horv\u0026aacute;th, Mikl\u0026oacute;s Bak, and Tibor Alp\u0026aacute;r. 2021. \u0026lsquo;A State-of-the Art Review on Coir Fiber-Reinforced Biocomposites\u0026rsquo;. RSC Advances 11(18): 10548\u0026ndash;71.doi:\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1039/D1RA00231G\u003c/span\u003e\u003cspan address=\"10.1039/D1RA00231G\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHo Kim H., Nguyen Phuong X. T., Do Nga H. N., Le Kien A., and Le Phung K. 2021. \u0026lsquo;Green Fabrication of Bio-Based Aerogels from Coconut Coir for Heat Insulation and Oil Removal\u0026rsquo;. Chemical Engineering Transactions 88: 709\u0026ndash;14. doi:\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3303/CET2188118\u003c/span\u003e\u003cspan address=\"10.3303/CET2188118\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHuang, Huakun, Yijun Zhou, Renda Huang, Huijun Wu, Yongjun Sun, Gongsheng Huang, and TaoXu. 2020. \u0026lsquo;Optimum Insulation Thicknesses and Energy Conservation of Building Thermal Insulation Materials in Chinese Zone of Humid Subtropical Climate\u0026rsquo;. Sustainable Cities and Society52: 101840. doi:\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.scs.2019.101840\u003c/span\u003e\u003cspan address=\"10.1016/j.scs.2019.101840\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIwaro, Joseph, and Abrahams Mwasha. 2019. \u0026lsquo;Effects of Using Coconut Fiber\u0026ndash;Insulated Masonry Walls to Achieve Energy Efficiency and Thermal Comfort in Residential Dwellings\u0026rsquo;. Journal ofArchitectural Engineering 25(1): 04019001. doi:\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1061/(ASCE)AE.1943-5568.0000341\u003c/span\u003e\u003cspan address=\"10.1061/(ASCE)AE.1943-5568.0000341\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi, M., Wang, F., Ouyang, S., Liu, Y., Hu, Z., Wu, Y., Qian, J., Li, Z., Wang, L. and Ma, S., 2024. A comprehensive review on preparation and functional application of the wood aerogel with natural cellulose framework. International Journal of Biological Macromolecules, p.133340.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMededji, D.S., Sogbochi, E., Djossou, A.A., Cherkaoui, O., Fagbemi, L.A. and Sohounhloue, D.C.K., 2024. Characteristics of Insulating Panels Realised from Coconut Palm Fibres for Low-Temperature Thermal Insulation. International Journal of Environment and Climate Change, 14(5), pp.324\u0026ndash;335.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eObeng, George Yaw, Derrick Yeboah Amoah, Richard Opoku, Charles K. K. Sekyere, Eunice Akyereko Adjei, and Ebenezer Mensah. 2020. \u0026lsquo;Coconut Wastes as Bioresource for Sustainable Energy: Quantifying Wastes, Calorific Values and Emissions in Ghana\u0026rsquo;. Energies 13(9): 2178. doi:\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3390/en13092178\u003c/span\u003e\u003cspan address=\"10.3390/en13092178\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRojas, Carlos, Mara Cea, Alfredo Iriarte, Gonzalo Vald\u0026eacute;s, Rodrigo Navia, and Juan Pablo C\u0026aacute;rdenas R. 2019. \u0026lsquo;Thermal Insulation Materials Based on Agricultural Residual Wheat Straw and Corn Husk Biomass, for Application in Sustainable Buildings\u0026rsquo;. Sustainable Materials and Technologies 20:e00102. doi:\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.susmat.2019.e00102\u003c/span\u003e\u003cspan address=\"10.1016/j.susmat.2019.e00102\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShahee, Arash, Mahmood Abdoos, Alireza Aslani, and Rahim Zahedi. 2024. \u0026lsquo;Reducing the Energy Consumption of Buildings by Implementing Insulation Scenarios and Using Renewable Energies\u0026rsquo;. Energy Informatics 7(1): 18. doi:\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/s42162-024-00311-9\u003c/span\u003e\u003cspan address=\"10.1186/s42162-024-00311-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStelte, Wolfgang, Narendra Reddy, S\u0026oslash;ren Barsberg, and Anand Ramesh Sanadi. 2022. \u0026lsquo;Coir from Coconut Processing Waste as a Raw Material for Applications beyond Traditional Uses\u0026rsquo;. BioResources 18(1). doi:\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.15376/biores.18.1.Stelte\u003c/span\u003e\u003cspan address=\"10.15376/biores.18.1.Stelte\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang, Y. and Lu, Y., 2023. Sodium alginate-based functional materials toward sustainable applications: Water treatment and energy storage. Industrial \u0026amp; Engineering Chemistry Research, 62(29), pp.11279\u0026ndash;11304.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang, X., Liu, H., Wang, L., Liu, B. and Wang, L., 2018. Optimization of thermal insulation performance for the porous materials. Heat Transfer Engineering, 39(17\u0026ndash;18), pp.1573\u0026ndash;1581.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXu, Yongjian, Yan Liu, Shenglin Chen, and Yonghao Ni. 2020. \u0026lsquo;Current Overview of Carbon Fiber: Toward Green Sustainable Raw Materials\u0026rsquo;. BioResources 15(3): 7234\u0026ndash;59.doi:\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.15376/biores.15.3.Xu\u003c/span\u003e\u003cspan address=\"10.15376/biores.15.3.Xu\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZakaria, Mohd Hafizudin, Mohd Zaffrie Mat Amin, Muhammad Faireal Ahmad, and Muhammad Syafiq Ahmad Dani. \u0026lsquo;Market Potential and Competitiveness Assessment of Malaysian Coconut Based Products\u0026rsquo;.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Coconut husk, freeze dying, sodium alginate, phytic acid, SEM-EDX, Scanning Electron Microscopy, Thermal conductivity, BET, Brunauer – Emmett - Teller, FTIR, Fourier – transform infrared spectroscopy, Aerogel, Biomass, Insulating Building, Energy Conservation","lastPublishedDoi":"10.21203/rs.3.rs-5696159/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5696159/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eInsulating buildings effectively is critical for energy conservation. Traditionally, insulation materials have been composed of synthetic polymers or mineral fibers. Recent research has explored the potential of biomass materials, leveraging their inherent insulative properties. To advance these capabilities, converting biomass into aerogel forms offers a promising approach due to their low density and thermal conductivity. This study focuses on producing coconut husk aerogel to assess its thermal insulation performance. The fabrication process involved blending sodium alginate, phytic acid, and coconut husk to create the aerogel. The influence of varying sodium alginate volumes on the fabrication of coconut husk aerogel was systematically investigated, given its crucial role in gelation. The produced aerogels were comprehensively characterized using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDX), Brunauer–Emmett–Teller specific surface area analysis (BET) and Fourier-transform infrared spectroscopy (FTIR). Thermal conductivity measurements were conducted to evaluate their insulation effectiveness. Results demonstrate that the coconut husk aerogel exhibits good insulation properties, characterized by significantly low thermal conductivity.\u003c/p\u003e","manuscriptTitle":"Thermal investigation of the coconut husk aerogel for enhanced insulation properties","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-01-02 05:29:32","doi":"10.21203/rs.3.rs-5696159/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"bc44b0a3-b94b-4d9d-be60-4a8590e7bf13","owner":[],"postedDate":"January 2nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-02-25T12:53:14+00:00","versionOfRecord":[],"versionCreatedAt":"2025-01-02 05:29:32","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5696159","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5696159","identity":"rs-5696159","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}