Extraction and characterization of cellulose nanocrystals from brown seaweed Dictyota bartayreisana, J.V.Lamouroux

Extraction and characterization of cellulose nanocrystals from brown seaweed Dictyota bartayreisana, J.V.Lamouroux | 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 Extraction and characterization of cellulose nanocrystals from brown seaweed Dictyota bartayreisana, J.V.Lamouroux Sobiya Murugesan, Radhika Rajasree S R, Roopa Rajan This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4099221/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 10 You are reading this latest preprint version Abstract For the first time, cellulose nanocrystal (CNC) was derived from the biomass of brown seaweed Dictyota bartayresiana , undergoing a comprehensive process of extraction and transformation. The structural analysis, conducted via Transmission Electron Microscopy (TEM), affirmed that the resulting CNCs displayed an average width of approximately 26 nm and a length extending to 520nm long. X-ray Diffraction (XRD) analysis indicated that these extracted CNCs constituted around 62%. Fourier Transform Infrared (FTIR) spectral analysis confirmed the successive removal of non-cellulosic components through chemical treatments. Elemental analysis (CHNS) validated the presence of sulphate groups, accounting for 0.59%. Thermogravimetric Analysis (TGA) results unveiled the superior thermal stability of the extracted CNCs. Marine Macroalgae Brown seaweed Dictyota bartayresiana Cellulose nanocrystals Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 1. Introduction Cellulose is an abundant macromolecular polysaccharide made up of glucose units and it is recognized as the most extensively dispersed polysaccharide in the nature. It accounts more than half the carbon content within the plant community [ 21 ]. In recent years, there has been a significant surge in interest concerning sustainable raw materials with potential applications in nanotechnology. The utilization of nanotechnology in synthesizing nanoparticles has gained significant attention across various fields, including packaging, biomedical, electronic, and optical industries. Silver, Gold, Titanium dioxide, and Zinc oxide are among the diverse nanoparticles applied in different domains. Currently, cellulose nanocrystal (CNC) has emerged as a focal point for numerous researchers. Nanocellulose, a nanostructured form of cellulose found either in the form of nanocrystals or nanofibers typically possesses dimensions in the micrometer range with a diameter of around 100 nm [ 33 ]. It includes cellulose nanofibers (CNF), also known as Micro fibrillated cellulose (MFC) and cellulose nanocrystals (CNC), or bacterial nanocellulose (BNC) produced by bacteria to form nano-structured cellulose. This nanomaterial boasts exceptional properties, including a high surface area-to-volume ratio, higher Young's modulus and tensile strength, a reduced thermal expansion coefficient, hydrogen-bonding capacity, biocompatibility, eco-friendliness, and non-toxicity [ 30 ]. The physical and chemical properties of nanocellulose, as well as its unique behaviour at the nanoscale, have created an opportunity in several industries especially in biomedical applications [ 13 , 23 ]. The cellulose nanomaterials market is predicted to expand from $ 271.26 million in 2017 to $ 1076.43 million by 2025, along with a Compound Annual Growth Rate (CAGR) of 18.8 percent [ 34 ]. Nanosized cellulose has gained significant attraction, particularly in the industrial and biomedical applications [ 12 ]. Nanocrystalline cellulose (NCC), also known as cellulose nanocrystals, whiskers, or nanowhiskers, exhibits a rod-like shape. The well-ordered crystalline regions of cellulose i.e., the CNCs are isolated from the amorphous disordered region via selective hydrolysis process comprising chemical treatment, mechanical treatment, or enzymatic action [ 18 ]. Acid hydrolysis employed by H 2 SO 4 which produced a highly ordered crystalline cellulose when compared to other acid techniques [ 7 , 12 ]. These CNCs possess outstanding physical and mechanical properties, with a Young's modulus value empirically stronger than steel, a superior elastic modulus, low density, and a large aspect ratio [ 28 – 29 , 37 ]. Additionally, CNCs demonstrate biocompatibility, non-abrasiveness, and biodegradability. In the past decade, researchers have turned their attention to the use of lignocellulosic biomass, marine animal tunicate [ 31 ], particularly seaweeds, to extract cellulose nanocrystals. Seaweeds, serving as a sustainable source of bioactive compounds, have found applications in nutrition, fuel, pharmaceutical and industrial areas [ 17 , 19 & 20 ]. The CNCs derived from seaweed have emerged as potential new materials for polymer reinforcement, possessing an ordered crystalline structure and excellent physical properties. In the paper and pulp industry for paper production, wood materials were most commonly used, in pulping and bleaching process to break the lignin and hemicelluloses, harsh chemicals were used which emitted air pollutants primarily made up of hydrogen sulphide, Oxides of sulphur and oxides of nitrogen [ 5 ]. The algal purification process, which is essential for extracting cellulose from seaweeds, offers advantages over traditional terrestrial plants, including a cheaper and rapidly growing biological source, year-round multiple harvesting options, high cellulose content, and cultivation without the need for water, productive land, manure, fertilizers, or defoliants [ 38 ]. Dictyota bartayresiana , a brown seaweed abundantly available in the tropical western Indo-pacific region and the Gulf of Mexico, has been considered as a promising source for deriving cellulose nanocrystals. D. bartayresiana is distributed in Indian waters, especially on south east coast of India. Previous studies have reported a high cellulose content of 9.3% in D. bartayresiana [ 35 ]. Despite successful manufacturing of CNCs from red and brown macroalgal biomass in previous studies [ 15 , 24 ], there is a lack of research on extracting cellulose nanocrystals from D. bartayresiana . Hence, this study aims to fill this gap by extracting cellulose nanocrystals from brown seaweed D. bartayreisana through acid hydrolysis followed mechanical dispersion mechanism. The properties of these cellulose nanocrystals will be thoroughly investigated by means of various techniques including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Transmission electron microscopy (TEM), and Thermogravimetry (TG). This comprehensive exploration aims to assess the potential of D. bartayresiana -derived CNCs as bio-nanofillers for sustainable food packaging applications. 2. Materials and methods 2.1. Extraction of CNCs from D. bartayresina The CNCs were extracted from the brown seaweed D. bartayresiana through a four-step procedure as described by [ 12 ]. Firstly, depolymerization by acid-base pretreatment was carried out by treating the dried seaweed powder with 0.2M of HCl (1:10 (w/v)) and stirred for 2 hours at 30 0 C. After centrifugation, the colloid suspension was neutralized to pH 7 with distilled water. The colloidal suspension was soaked in distilled water at 1:60 (w/v) ratio and stirred for 3 hours at 75 ᵒC during which, the pH was adjusted to 10.5 ± 0.5 using 4% sodium hydroxide solution. The suspension was centrifuged (Sorvall ST 8R centrifuge, Thermo Scientific, Germany) at 15000 xg for 10 minutes. Following the supernatants removal, solid residues were dried at 65 ᵒC for three days. In the second step, Cellulose was extracted using a seaweed bleaching procedure from the dried residues. To remove polysaccharide barriers, the dried solid residue was stirred with 10% of KOH for 3 hours. By using distilled water, the residue was washed 3 times and treated with 6.5% of sodium hypochlorite. The pH of the mixture was adjusted to 5 by adding glacial acetic acid and subjected to stirring for 2 hours at 75 ᵒC. For the second bleaching step, the samples were treated with 10% hydrogen peroxide for 70minutes at 80 ºC. After discarding the supernatant, the samples were centrifuged (Sorvall ST 8R centrifuge, Thermo Scientific, Germany) at 22000 xg to obtain cellulose. Next, an acid hydrolysis was carried out to breakdown the seaweed cellulose to CNCs. The extracted cellulose was stirred with 51% sulphuric acid at 45 ᵒC for 30 minutes. The reaction was further stopped for 15 minutes, by diluting the suspension with ice distilled water at the ratio of 1:6 (v/v). To discard the sulphuric acid, the suspensions were centrifuged at 15000 xg (Sorvall ST 8R centrifuge, Thermo Scientific, Germany) for 25 minutes. After which the supernatant was discarded and the residues were treated with 4% sodium hydroxide solution with the pH adjusted to 7. The mechanical disruption was carried out by homogenizing the suspension a probe-type sonicator (750w, Frontline sonicator, Frontline Electronics & M/C P Ltd, Ahmedabad) for 15 minutes. The CNC suspension was then lyophilized to powdered form. A schematic diagram for the extraction of CNCs shown in Fig. 1 . The yield obtained were calculated as follows; $$\text{Y}\text{i}\text{e}\text{l}\text{d} \text{o}\text{f} \text{C}\text{N}\text{C}=\frac{\text{W}\text{e}\text{i}\text{g}\text{h}\text{t} \text{o}\text{f} \text{e}\text{x}\text{t}\text{r}\text{a}\text{c}\text{t}\text{e}\text{d} \text{C}\text{N}\text{C}}{\text{W}\text{e}\text{i}\text{g}\text{h}\text{t} \text{o}\text{f} \text{s}\text{e}\text{a}\text{w}\text{e}\text{e}\text{d}}*100$$ 2.2. Characterization of extracted cellulose nanocrystals 2.2.1. Fourier Transmission Infra-red spectroscopic (FTIR) analysis The presence of different functional groups in the extracted cellulose nanocrystals and cellulose were analysed with an ATR-FTIR. The samples were observed with Perkin Elmer FTIR spectrophotometer at a scan range of 4000 to 400 cm − 1 and resolution of 0.2 cm − 1 with 64 scans for each sample. 2.2.2. Elemental analysis (CHNS) Elemental analysis was conducted using a CHNS analyser (Elementar vario EL III, Germany) to determine the percentage of carbon, hydrogen, nitrogen and sulphur. 2.2.3. X-ray Diffraction The crystallinity of cellulose nanocrystals was measured with an analytical X-ray diffractometer (Bruker model D 8 Advance A 25 ). The sample was placed on the sample stage of the goniometer after being spread out over the low background sample holder (amorphous silica holder). The B-B geometry was configured on the instrument. In order to record the XRD pattern, the voltage and current were set to 40mV and 40mA. The CNC’s crystallinity index was computed using the following equation [ 32 ]; Where Ic = crystallinity index; I 200 = Cellulose crystalline region intensity; I am = amorphous region intensity. 2.2.4. Thermogravimetric analysis A thermogravimetric analyser (TGA) was used to examine the thermal characteristics of the CNC (Hitachi STA 7300). A small portion of the sample is weighed and heated in the temperature range RT to 700 ºC at a heating rate of 10 ºC/minute in Nitrogen atmosphere. 2.2.5. Transmission Electron microscope (TEM) CNC morphological characteristics was analysed by Transmission electron microscope (TEM) (JOEL-JEM 2100). An aqueous suspension of a small quantity of CNC material was prepared and to disperse the particles well, the solution was ultrasonically treated. Then using a pipette, a drop of the solution was applied to 200 mesh carbon-coated grids at 200 kV acceleration voltage. 3. Result and Discussion 3.1. Yield of cellulose and cellulose nanocrystals The yield of seaweed cellulose extracted was about 30% and CNC yield from D. bartayresiana accounts 10%, found to be on lower in comparison with previous reports based on brown seaweeds Laminaria japonica (26.7%) and Sargassum natans (42.7%) [ 12 ]. The red seaweed Gelidium amansii also revealed that higher yield for CNC extracted (15.5%) [ 10 ]. 3.2. FTIR analysis The FTIR analysis performed to define functional groups present in untreated seaweed, alkali-treated, Cellulose, and CNC during the isolation treatment from seaweed D. bartayresiana . The spectra showed prominent peaks at 3400cm − 1 , 1428.08cm − 1 , 1315.26cm − 1 , 1161.37cm − 1 , 1055.53cm − 1 , 1108.60cm − 1 , 898.02cm − 1 . The broad peak absorption band obtained at 3400cm − 1 in all four samples assigned represents -OH stretching vibration of the hydrogen bond, which confirms that nature of cellulosic components has a strong affinity to water. Due to the formation and evaporation of water molecules during acid hydrolysis and freeze drying, the -OH stretching vibrations in CNC were less intense than in cellulose. The peaks at 1428.08cm − 1 and 1315.26cm − 1 in bleached cellulose and CNC confirm the presence of cellulose, which is assigned to the vibration of the cellulose major chains [ 8 , 9 ]. The peak at 1161.37cm − 1 in both cellulose and CNC indicates the C-O-C asymmetric stretching of cellulose. This peak was clearly visible as it is the reduction of the amorphous region in the polysaccharide matrix happened during the acid hydrolysis process [ 11 ]. The spectra revealed presence of an absorption band at 1055.53cm − 1 which may have been attributed to the skeletal vibration of C-O-C pyranose ring in the cellulose fiber as clearly shown in Fig. 2 [ 39 ]. According to [ 8 , 9 ], the strong absorption band at 898.0cm − 1 -1108.60cm − 1 indicated that presence of ß-glucosidic ether linkages (COC) related to the vibration modes of anhydro-glucopyranose ring skeleton, and to the ß glycosidic linkages between the anhydro glucose rings in the cellulose chains. This peak was more intense in CNC. This data confirmed that most of the non-cellulosic polysaccharides were eliminated during the bleaching and acid hydrolysis treatment. The FTIR spectra of extracted CNC and cellulose from D. bartayresiana showed similar absorption bands at 3400cm − 1 and 1108cm − 1 , 1428cm − 1 , and 1055cm − 1 but, the peaks were weaker in CNC. These observations corroborate with the findings of [ 10 , 16 ], that the above peaks were lesser and weaker in the FTIR spectra due to the acid extraction treatment. 3.3. X-Ray Diffraction analysis X-ray diffraction analysis (XRD) is a technique used to ascertain the material’s crystallinity. The cellulose and cellulose nanocrystals from D. bartayresiana exhibit diffraction patterns, as depicted in Fig. 3 . The crystalline structure and crystallinity index of cellulose and CNC from D. bartayresiana was analysed from XRD patterns collected from 3° to 80° (2θ). The peaks were seen at 14.5°, 21.14°, 22.6°, 26.74°, and 34.86°. The CNC showed a distinctive crystal peak related to the crystal structure of cellulose I [ 8 , 9 ] at around 2θ = 22.6° which corresponded to the lattice plane (200), and one broad peak at 2θ = 14.5°, which corresponded to the lattice plan (110) related to the amorphous domains of cellulose. From Fig. 3 I C is the crystallinity index; I 200 is the cellulose crystalline region’s intensity (22.6°); I am is the amorphous region’s intensity (14.5°). The Crystallinity index of the cellulose & CNC was around 45% and 62%. The degree of crystallinity of CNC is important as a filler to strengthen the mechanical and barrier properties of biopolymer composites in industrial applications [ 4 ]. During the acid hydrolysis process, hydronium ions diffuse into the cellulose chains in the amorphous encouraging the hydrolysis process of the glycosidic linkages and liberating individual crystal compounds after mechanical treatment (sonication) [ 3 ]. The non- cellulosic components were removed, as explained earlier in FTIR, and the results here confirm this. As a result, the XRD graph confirmed that acid hydrolysis mostly eliminated the cellulose’s amorphous region and the crystalline peak regions in the graph represent cellulose nanocrystals. The crystallinity index of cellulose nanocrystals from D. bartayresiana as lower than that of Laminaria japonica (69.4%) [ 24 ] and Cladophora rupestris (94%) [ 36 ] and Gelidium elegans (73%) [ 10 ]. 3.4. CHNS Analysis CHNS analysis is used to determine the percentage of carbon, hydrogen, nitrogen and sulphur content of a sample. The CHNS percentage of Cellulose nanocrystals is shown in the Table 1 . This elemental composition is due to the result of the cellulose fibre’s acid hydrolysis process and persisted after its centrifugation washing of CNC containing sulphate groups to some extent. The sulphur content thus primarily demonstrated the crystal’s surface charge and it’s critical to the characterization and comprehension of material’s properties. Due to the insertion of charged sulphate ester groups onto the crystallite surface during the process, CNC from sulphuric acid hydrolysis is electrostatically stabilised in aqueous suspension [ 1 ]. The percentage of sulphur measured for CNC was found to be 0.59%. Similar observations have been reported as in [ 1 ]. In the present study, the sulphur content of D. bartayresiana was around 0.59% which was lower than that of (64% H 2 SO 4 ) concentration at different times of acid hydrolysis CNC30 (1.23%), CNC40 (1.47%), CNC80 (1.95%) from the red algae waste [ 15 ] as a result of addition of polar sulphate groups during acid hydrolysis [ 14 ]. Carbon and Sulphur values are somewhat similar to the previous literature [ 22 ], CNC from sugarcane bagasse agro-waste. Table 1 CHNS analysis of CNC CHNS CNC %C %H %N %S 36.58 5.18 0.50 0.59 3.5. TGA, DTG and DSC Analysis Thermal stability and fraction of the volatile components of the material was determined by Thermogravimetric analyser, through the weight change of the sample when continuously heated at a constant rate. Cellulose nanocrystals weight loss is depicted in the figures by the TGA and DTG curves. Thermogravimetric analysis (TGA) is a useful tool for obtaining a thorough understanding of the thermodynamics of nanocrystals in order to determine the oxidative and thermal performances of CNCs, as they have remarkably different thermal profiles than the original cellulose. TGA, derivative thermogram (DTG), and DSC curves of CNC were shown in Figs. 4 and 5 . The first stage of reduction (80–110 ℃) corresponded to the vaporization of water molecules. The second stage reduction of CNC occurred in the range of 195 ℃ to 200 ℃, which was due to the degradation of the cross-linked carbon skeleton. The third weight loss occurred in the range of 220 ℃ to 470 ℃, indicated degradation of glycosidic bonds in cellulose. The CNC showed two step degradations in the DTG graph, at 293.3 ℃ and 416.1 ℃. [ 4 ] reported findings were similar to these. Due to the presence of carbonaceous materials, the CNC lost 40% of their mass, with the progressive loss occurring between 150 ℃ and 330 ℃ and at the end, 15% decomposition of residual char remaining between 470 ℃ and 750 ℃, and the results are consistent with previous literature [ 25 ]. [ 10 ] reported T on at 261℃ and T max at 334 ℃, with a char yield of about 8.2%, which differed slightly from our findings. D. bartayresiana CNC showed higher T on and T max obtained higher char yield (15%). This results which indicated that CNC had higher thermal stability. The reason for this is due to the high content of crystalline domains in nanocellulose as a result of CNC reorientation and rearrangement following amorphous region dissolution [ 26 ]. 3.6.TEM Analysis The CNC’s sample dimensions and morphology were examined using the TEM. The TEM image of CNC comprised of rod or needle like particles, exhibited a homogeneous and dense structure with evenly dispersed mostly averages 26 nm wide and several hundred nanometres long and spectral images similar to the previous studies. Despite their long lengths, the fibres were well dispersed into near-elementary fibril levels. Individual cellulose nanocrystals were formed in a porous network with a spider web-like structure as a result of acid hydrolysis. These results are similar to previous literature [ 10 , 39 ] where the nano-sized cellulose were fibre network arrangements or spider web-like structure. Some aggregates were found in the CNC TEM image Fig. 6 . These aggregates formed as a result of the sample preparation method of freeze drying that resulted in the formation of strong intermolecular hydrogen bonding between the particles [ 2 ]. Different structures were seen in the various types of cellulose sources. Acid hydrolysis process or catalyst may alter the length but some non-crystalline regions may remain same after acid treatment of cellulose [ 27 ]. The D. bartayresiana CNC is comparable in length to CNC isolated from Laminaria [ 12 ] and Laminaria japonica waste [ 24 ]. According to [ 6 ] the cellulose source characteristics and the acid hydrolysis procedure determine the CNC’s general dimensions and shape. 4. Conclusion Cellulose nanocrystals were successfully isolated from the brown seaweed D. bartayresiana for the first time, employing sulfuric acid hydrolysis and subsequent processing. The physico-chemical characterization of the extracted cellulose nanocrystals confirmed the effective removal of non-cellulosic components from the raw material, as evidenced by FTIR. The XRD data revealed a crystallinity index of approximately 62%, and TGA data demonstrated enhanced thermal stability. The cellulose nanocrystals exhibited an average width of 26 nm and extended to 520 nm in length. Given the observed high crystallinity of these cellulose nanocrystals, this study strongly recommends further investigation into their potential to be used as an effective reinforcement material for strengthening different polymeric matrices to enhance the structural attributes of packaging materials especially biopolymer-based ones. The unique properties identified in this research make these cellulose nanocrystals promising candidates for applications requiring robust and thermally stable materials. Declarations Acknowledgement This work was supported by the Indian Council of Agricultural Research to the first author and the authors express their gratitude to Kerala University of Fisheries and Ocean Studies for providing necessary lab facilities. Author contributions These authors contributed equally to this work and share first authorship. Competing interests: The authors declare that they have no competing interest. Data availability: The data will be made available on request. Ethical approval: Not applicable. References Abitbol, T., Kloser, E., &Gray, D. G. Cellulose. (2013) https://doi.org/10.1007/s10570-013-9871-0 Agustin, M. B., Ahmmad, B., Alonzo, S. M. M., &Patriana, F. M, J. Reinf. Plast. Compos. (2014) https://doi.org/10.1177/0731684414558325 Alain Dufresne, Materials Today (2014) https://doi.org/10.1016/j.mattod.2013.06.004 Andrade, M. S., Ishikawa, O. H., Costa, R. S., Seixas, M. V., Rodrigues, R. C., & Moura, E. A,Food Packag. Shelf Life (2022). https://doi.org/10.1016/j.fpsl.2021.100807 Bajpai P, Green chemistry and sustainability in pulp and paper industry (Springer, Cham International Publishing, 2015), pp. 65-84 Beck-Candanedo, S., Roman, M., &Gray, D. G, Biomacromolecules (2005) https://doi.org/10.1021/bm049300p Cao, Xiaodong, Hua Dong, and Chang Ming Li, Biomacromolecules (2007) https://doi.org/10.1021/bm0610368 Chen, Y. W., Lee, H. V., &Abd Hamid, S. B, Bio Resources (2016) 10.15376/biores.11.2.4645-4662 Chen, Y. W., Lee, H. V., &Abd Hamid, S. B, Journal of Nano Research (2016) https://doi.org/10.4028/www.scientific.net/JNanoR.41.96 Chen, Y. W., Lee, H. V., Juan, J. C., &Phang, S. M,Carbohydr.Polym. (2016) https://doi.org/10.1016/j.carbpol.2016.06.083 Chirayil, C. J., Joy, J., Mathew, L., Mozetic, M., Koetz, J., & Thomas, S, Ind. Crops Prod. (2014) https://doi.org/10.1016/j.indcrop.2014.04.020 Doh, H., Lee, M. H., & Whiteside, W. S. Food Hydrocoll. (2020) https://doi.org/10.1016/j.foodhyd.2019.105542 Dong, S., & Roman, M. J. Am. Chem. Soc. (2007) https://doi.org/10.1021/ja076196l El Achaby, M., El Miri, N., Aboulkas, A., Zahouily, M., Bilal, E., Barakat, A., &Solhy, A,Int. J. Biol. Macromol. (2017). https://doi.org/10.1016/j.ijbiomac.2016.12.040 El Achaby, M., Kassab, Z., Aboulkas, A., Gaillard, C., &Barakat, A, Int. J. Biol. Macromol. (2018) https://doi.org/10.1016/j.ijbiomac.2017.08.067 Fortunati, E., Puglia, D., Monti, M., Peponi, L., Santulli, C., Kenny, J. M., & Torre, L, J. Polym. Environ. (2013) https://doi.org/10.1007/s10924-012-0543-1 Goswami, G., Bang, V., & Agarwal, S. (2015). Diverse applications of algae. Int. J. Adv. Res. Sci. Eng, 4(1), 1102-1109. Habibi, Y., Lucia, L. A., & Rojas, O. J. Chemical reviews (2010) https://doi.org/10.1021/cr900339w Ismail, M. M., El Zokm, G. M., & El-Sayed, A. A. Environ. Monit. Assess. (2017) https://doi.org/10.1007/s10661-017-6366-8 Ismail, M. M., Ismail, G. A., & El-Sheekh, M. M. Energy Sources A: Recovery, Util. Environ. Eff. (2020) https://doi.org/10.1080/15567036.2020.1758853 Klemm, D., Heublein, B., Fink, H. P., & Bohn, A. Angew. Chem., Int. Ed. Engl. (2005) https://doi.org/10.1002/anie.200460587 Kumar, A., Negi, Y. S., Choudhary, V., & Bhardwaj, N. K. Journal of materials physics and chemistry. (2014) DOI: 10.12691/jmpc-2-1-1 Lin, N., & Dufresne, A. Eur.Polym. J. (2014) https://doi.org/10.1016/j.eurpolymj.2014.07.025 Liu, Z., Li, X., Xie, W., & Deng, H. Carbohydr. Polym. (2017) https://doi.org/10.1016/j.carbpol.2017.05.079 Mali, P., &Sherje, A. P. Carbohydr. Polym. (2022) https://doi.org/10.1016/j.carbpol.2021.118668 Mandal, A., &Chakrabarty, D. Carbohydr. Polym.(2011)https://doi.org/10.1016/j.carbpol.2011.06.030 Miao, C., & Hamad, W.Y. Cellulose (2013) https://doi.org/10.1007/s10570-013-0007-3 O'sullivan, A. C. Cellulose (1997) https://doi.org/10.1023/A:1018431705579 Rusli, R., &Eichhorn, S. J. Applied Physics Letters (2008) https://doi.org/10.1063/1.2963491 Salimi, S., Sotudeh-Gharebagh, R., Zarghami, R., Chan, S. Y., & Yuen, K. H. ACS Sustain. Chem. Eng. (2019) https://doi.org/10.1021/acssuschemeng.9b02744 Samir, M. A. S. A., Alloin, F., Sanchez, J. Y., & Dufresne, A. Polymer (2004) https://doi.org/10.1016/j.polymer.2004.03.094 Segal, L. G. J. M. A., Creely, J. J., Martin Jr, A. E., & Conrad, C. M. Text. Res. J. (1959) https://doi.org/10.1177/004051755902901003 Sharma, A., Thakur, M., Bhattacharya, M., Mandal, T., & Goswami, S. Biotechnol. Rep. (2019)https://doi.org/10.1016/j.btre.2019.e00316 Shojaeiarani, J., Bajwa, D. S., &Chanda, S. Compos. C: Open Access (2021) https://doi.org/10.1016/j.jcomc.2021.100164 Siddhanta, A. K., Chhatbar, M. U., Mehta, G. K., Sanandiya, N. D., Kumar, S., Oza, M. D., ... &Meena, R. J. Appl. Phycol. (2011) https://doi.org/10.1007/s10811-010-9599-2 Sucaldito, M. R., & Camacho, D. H. Carbohydr. Polym. (2017) https://doi.org/10.1016/j.carbpol.2017.04.031 Tashiro, K., & Kobayashi, M. Polymer (1991) https://doi.org/10.1016/0032-3861(91)90435-L Trivedi, N., Gupta, V., Reddy, C. R. K., &Jha, B. Bioresour.Technol. (2013) https://doi.org/10.1016/j.biortech.2013.09.103 Yahya, M. B., Lee, H. V., & Hamid, S. B. A. Bio Res. (2015). 10.15376/biores.10.4.7627-7639. Additional Declarations No competing interests reported. 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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-4099221","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":283166930,"identity":"5642b415-c2de-4798-b630-3c0aaaa14d39","order_by":0,"name":"Sobiya Murugesan","email":"","orcid":"","institution":"Kerala University of Fisheries and Ocean Studies","correspondingAuthor":false,"prefix":"","firstName":"Sobiya","middleName":"","lastName":"Murugesan","suffix":""},{"id":283166931,"identity":"cfffe35d-aff0-4906-b19b-41b7764cb65a","order_by":1,"name":"Radhika Rajasree S R","email":"data:image/png;base64,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","orcid":"","institution":"Kerala University of Fisheries and Ocean Studies","correspondingAuthor":true,"prefix":"","firstName":"Radhika","middleName":"Rajasree S","lastName":"R","suffix":""},{"id":283166932,"identity":"453b25c8-788b-41f1-b635-a33e18206cbc","order_by":2,"name":"Roopa Rajan","email":"","orcid":"","institution":"Kerala University of Fisheries and Ocean Studies","correspondingAuthor":false,"prefix":"","firstName":"Roopa","middleName":"","lastName":"Rajan","suffix":""}],"badges":[],"createdAt":"2024-03-14 09:23:48","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4099221/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4099221/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":53417870,"identity":"4096ea25-66f7-4d22-9a79-f61c52bc06ca","added_by":"auto","created_at":"2024-03-25 18:05:16","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":134609,"visible":true,"origin":"","legend":"\u003cp\u003eSteps involved in the isolation of cellulose nanocrystals from \u003cem\u003eDictyotabartayresiana\u003c/em\u003e\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-4099221/v1/1b46d37265aa0c19a429de24.png"},{"id":53417868,"identity":"45fba55c-d521-4f14-96bc-7d5df5193be7","added_by":"auto","created_at":"2024-03-25 18:05:16","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":73941,"visible":true,"origin":"","legend":"\u003cp\u003eFTIR spectra of A) Seaweed powder B) NaOH Alkali treated C) Cellulose D) Cellulose nanocrystals\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4099221/v1/6bc0de3a675c058257a521c5.png"},{"id":53417873,"identity":"0e431320-0789-4fc2-b06b-bd28557a3252","added_by":"auto","created_at":"2024-03-25 18:05:19","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":149488,"visible":true,"origin":"","legend":"\u003cp\u003eSee image above for figure legend\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-4099221/v1/f1edcb750cb5a8567dd290d7.png"},{"id":53417869,"identity":"cbbb0016-ce0f-4f12-8c63-083a96cc7540","added_by":"auto","created_at":"2024-03-25 18:05:16","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":45188,"visible":true,"origin":"","legend":"\u003cp\u003eTGA and DTG of isolated CNC\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-4099221/v1/f2c82a845071ea377451fb98.png"},{"id":53417872,"identity":"711bf110-e8e4-48ec-a6c5-c606e9eda743","added_by":"auto","created_at":"2024-03-25 18:05:17","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":36447,"visible":true,"origin":"","legend":"\u003cp\u003eTGA and DSC of isolated CNC\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-4099221/v1/6be7ec5227af860f687b0646.png"},{"id":53417871,"identity":"8fb68bee-cc67-4ba5-a07f-fc61ebc8354f","added_by":"auto","created_at":"2024-03-25 18:05:16","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":174969,"visible":true,"origin":"","legend":"\u003cp\u003eTEM images of CNC\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-4099221/v1/1924d12e4c6498a9917edc6c.png"},{"id":53417945,"identity":"1c45cc27-ac94-4fb7-8c83-dd7a07768794","added_by":"auto","created_at":"2024-03-25 18:05:27","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":962740,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4099221/v1/414f96ba-09a8-4635-a157-992642fc749b.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Extraction and characterization of cellulose nanocrystals from brown seaweed Dictyota bartayreisana, J.V.Lamouroux","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eCellulose is an abundant macromolecular polysaccharide made up of glucose units and it is recognized as the most extensively dispersed polysaccharide in the nature. It accounts more than half the carbon content within the plant community [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. In recent years, there has been a significant surge in interest concerning sustainable raw materials with potential applications in nanotechnology. The utilization of nanotechnology in synthesizing nanoparticles has gained significant attention across various fields, including packaging, biomedical, electronic, and optical industries. Silver, Gold, Titanium dioxide, and Zinc oxide are among the diverse nanoparticles applied in different domains. Currently, cellulose nanocrystal (CNC) has emerged as a focal point for numerous researchers.\u003c/p\u003e \u003cp\u003eNanocellulose, a nanostructured form of cellulose found either in the form of nanocrystals or nanofibers typically possesses dimensions in the micrometer range with a diameter of around 100 nm [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. It includes cellulose nanofibers (CNF), also known as Micro fibrillated cellulose (MFC) and cellulose nanocrystals (CNC), or bacterial nanocellulose (BNC) produced by bacteria to form nano-structured cellulose. This nanomaterial boasts exceptional properties, including a high surface area-to-volume ratio, higher Young's modulus and tensile strength, a reduced thermal expansion coefficient, hydrogen-bonding capacity, biocompatibility, eco-friendliness, and non-toxicity [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. The physical and chemical properties of nanocellulose, as well as its unique behaviour at the nanoscale, have created an opportunity in several industries especially in biomedical applications [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. The cellulose nanomaterials market is predicted to expand from \u003cspan\u003e$\u003c/span\u003e271.26\u0026nbsp;million in 2017 to \u003cspan\u003e$\u003c/span\u003e1076.43\u0026nbsp;million by 2025, along with a Compound Annual Growth Rate (CAGR) of 18.8 percent [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eNanosized cellulose has gained significant attraction, particularly in the industrial and biomedical applications [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Nanocrystalline cellulose (NCC), also known as cellulose nanocrystals, whiskers, or nanowhiskers, exhibits a rod-like shape. The well-ordered crystalline regions of cellulose i.e., the CNCs are isolated from the amorphous disordered region via selective hydrolysis process comprising chemical treatment, mechanical treatment, or enzymatic action [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Acid hydrolysis employed by H\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e4\u003c/sub\u003e which produced a highly ordered crystalline cellulose when compared to other acid techniques [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. These CNCs possess outstanding physical and mechanical properties, with a Young's modulus value empirically stronger than steel, a superior elastic modulus, low density, and a large aspect ratio [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. Additionally, CNCs demonstrate biocompatibility, non-abrasiveness, and biodegradability.\u003c/p\u003e \u003cp\u003eIn the past decade, researchers have turned their attention to the use of lignocellulosic biomass, marine animal tunicate [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e], particularly seaweeds, to extract cellulose nanocrystals. Seaweeds, serving as a sustainable source of bioactive compounds, have found applications in nutrition, fuel, pharmaceutical and industrial areas [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e \u0026amp; \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. The CNCs derived from seaweed have emerged as potential new materials for polymer reinforcement, possessing an ordered crystalline structure and excellent physical properties. In the paper and pulp industry for paper production, wood materials were most commonly used, in pulping and bleaching process to break the lignin and hemicelluloses, harsh chemicals were used which emitted air pollutants primarily made up of hydrogen sulphide, Oxides of sulphur and oxides of nitrogen [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. The algal purification process, which is essential for extracting cellulose from seaweeds, offers advantages over traditional terrestrial plants, including a cheaper and rapidly growing biological source, year-round multiple harvesting options, high cellulose content, and cultivation without the need for water, productive land, manure, fertilizers, or defoliants [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003cem\u003eDictyota bartayresiana\u003c/em\u003e, a brown seaweed abundantly available in the tropical western Indo-pacific region and the Gulf of Mexico, has been considered as a promising source for deriving cellulose nanocrystals. \u003cem\u003eD. bartayresiana\u003c/em\u003e is distributed in Indian waters, especially on south east coast of India. Previous studies have reported a high cellulose content of 9.3% in \u003cem\u003eD. bartayresiana\u003c/em\u003e [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]. Despite successful manufacturing of CNCs from red and brown macroalgal biomass in previous studies [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e], there is a lack of research on extracting cellulose nanocrystals from \u003cem\u003eD. bartayresiana\u003c/em\u003e. Hence, this study aims to fill this gap by extracting cellulose nanocrystals from brown seaweed \u003cem\u003eD. bartayreisana\u003c/em\u003e through acid hydrolysis followed mechanical dispersion mechanism. The properties of these cellulose nanocrystals will be thoroughly investigated by means of various techniques including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Transmission electron microscopy (TEM), and Thermogravimetry (TG). This comprehensive exploration aims to assess the potential of \u003cem\u003eD. bartayresiana\u003c/em\u003e-derived CNCs as bio-nanofillers for sustainable food packaging applications.\u003c/p\u003e"},{"header":"2. Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\n \u003ch2\u003e2.1. Extraction of CNCs from \u003cem\u003eD. bartayresina\u003c/em\u003e\u003c/h2\u003e\n \u003cp\u003eThe CNCs were extracted from the brown seaweed \u003cem\u003eD. bartayresiana\u003c/em\u003e through a four-step procedure as described by [\u003cspan class=\"CitationRef\"\u003e12\u003c/span\u003e]. Firstly, depolymerization by acid-base pretreatment was carried out by treating the dried seaweed powder with 0.2M of HCl (1:10 (w/v)) and stirred for 2 hours at 30 \u003csup\u003e0\u003c/sup\u003eC. After centrifugation, the colloid suspension was neutralized to pH 7 with distilled water. The colloidal suspension was soaked in distilled water at 1:60 (w/v) ratio and stirred for 3 hours at 75 ᵒC during which, the pH was adjusted to 10.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5 using 4% sodium hydroxide solution. The suspension was centrifuged (Sorvall ST 8R centrifuge, Thermo Scientific, Germany) at 15000 xg for 10 minutes. Following the supernatants removal, solid residues were dried at 65 ᵒC for three days.\u003c/p\u003e\n \u003cp\u003eIn the second step, Cellulose was extracted using a seaweed bleaching procedure from the dried residues. To remove polysaccharide barriers, the dried solid residue was stirred with 10% of KOH for 3 hours. By using distilled water, the residue was washed 3 times and treated with 6.5% of sodium hypochlorite. The pH of the mixture was adjusted to 5 by adding glacial acetic acid and subjected to stirring for 2 hours at 75 ᵒC. For the second bleaching step, the samples were treated with 10% hydrogen peroxide for 70minutes at 80 \u0026ordm;C. After discarding the supernatant, the samples were centrifuged (Sorvall ST 8R centrifuge, Thermo Scientific, Germany) at 22000 xg to obtain cellulose.\u003c/p\u003e\n \u003cp\u003eNext, an acid hydrolysis was carried out to breakdown the seaweed cellulose to CNCs. The extracted cellulose was stirred with 51% sulphuric acid at 45 ᵒC for 30 minutes. The reaction was further stopped for 15 minutes, by diluting the suspension with ice distilled water at the ratio of 1:6 (v/v). To discard the sulphuric acid, the suspensions were centrifuged at 15000 xg (Sorvall ST 8R centrifuge, Thermo Scientific, Germany) for 25 minutes. After which the supernatant was discarded and the residues were treated with 4% sodium hydroxide solution with the pH adjusted to 7.\u003c/p\u003e\n \u003cp\u003eThe mechanical disruption was carried out by homogenizing the suspension a probe-type sonicator (750w, Frontline sonicator, Frontline Electronics \u0026amp; M/C P Ltd, Ahmedabad) for 15 minutes. The CNC suspension was then lyophilized to powdered form. A schematic diagram for the extraction of CNCs shown in Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e. The yield obtained were calculated as follows;\u003c/p\u003e\n \u003cdiv id=\"Equa\" class=\"Equation\"\u003e\n \u003cdiv class=\"mathdisplay\" id=\"FileID_Equa\" name=\"EquationSource\"\u003e$$\\text{Y}\\text{i}\\text{e}\\text{l}\\text{d} \\text{o}\\text{f} \\text{C}\\text{N}\\text{C}=\\frac{\\text{W}\\text{e}\\text{i}\\text{g}\\text{h}\\text{t} \\text{o}\\text{f} \\text{e}\\text{x}\\text{t}\\text{r}\\text{a}\\text{c}\\text{t}\\text{e}\\text{d} \\text{C}\\text{N}\\text{C}}{\\text{W}\\text{e}\\text{i}\\text{g}\\text{h}\\text{t} \\text{o}\\text{f} \\text{s}\\text{e}\\text{a}\\text{w}\\text{e}\\text{e}\\text{d}}*100$$\u003c/div\u003e\n \u003c/div\u003e\n \u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\n \u003ch2\u003e2.2. Characterization of extracted cellulose nanocrystals\u003c/h2\u003e\n \u003cdiv id=\"Sec5\" class=\"Section3\"\u003e\n \u003ch2\u003e2.2.1. Fourier Transmission Infra-red spectroscopic (FTIR) analysis\u003c/h2\u003e\n \u003cp\u003eThe presence of different functional groups in the extracted cellulose nanocrystals and cellulose were analysed with an ATR-FTIR. The samples were observed with Perkin Elmer FTIR spectrophotometer at a scan range of 4000 to 400 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and resolution of 0.2 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003ewith 64 scans for each sample.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec6\" class=\"Section3\"\u003e\n \u003ch2\u003e2.2.2. Elemental analysis (CHNS)\u003c/h2\u003e\n \u003cp\u003eElemental analysis was conducted using a CHNS analyser (Elementar vario EL III, Germany) to determine the percentage of carbon, hydrogen, nitrogen and sulphur.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec7\" class=\"Section3\"\u003e\n \u003ch2\u003e2.2.3. X-ray Diffraction\u003c/h2\u003e\n \u003cp\u003eThe crystallinity of cellulose nanocrystals was measured with an analytical X-ray diffractometer (Bruker model D\u003csub\u003e8\u003c/sub\u003e Advance A\u003csub\u003e25\u003c/sub\u003e). The sample was placed on the sample stage of the goniometer after being spread out over the low background sample holder (amorphous silica holder). The B-B geometry was configured on the instrument. In order to record the XRD pattern, the voltage and current were set to 40mV and 40mA.\u003c/p\u003e\n \u003cp\u003eThe CNC\u0026rsquo;s crystallinity index was computed using the following equation [\u003cspan class=\"CitationRef\"\u003e32\u003c/span\u003e];\u003c/p\u003e\n \u003cdiv id=\"Equb\" class=\"Equation\"\u003e\n \u003cdiv class=\"mathdisplay\" id=\"FileID_Equb\" name=\"EquationSource\"\u003e\u003cimg src=\"https://myfiles.space/user_files/122228_c8a1650c59388082/122228_custom_files/img1711388269.png\"\u003e\u003cbr\u003e\u003c/div\u003e\n \u003c/div\u003e\n \u003cp\u003eWhere Ic\u0026thinsp;=\u0026thinsp;crystallinity index; I\u003csub\u003e200\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;Cellulose crystalline region intensity; I\u003csub\u003eam\u003c/sub\u003e= amorphous region intensity.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec8\" class=\"Section3\"\u003e\n \u003ch2\u003e2.2.4. Thermogravimetric analysis\u003c/h2\u003e\n \u003cp\u003eA thermogravimetric analyser (TGA) was used to examine the thermal characteristics of the CNC (Hitachi STA 7300). A small portion of the sample is weighed and heated in the temperature range RT to 700 \u0026ordm;C at a heating rate of 10 \u0026ordm;C/minute in Nitrogen atmosphere.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e\n \u003ch2\u003e2.2.5. Transmission Electron microscope (TEM)\u003c/h2\u003e\n \u003cp\u003eCNC morphological characteristics was analysed by Transmission electron microscope (TEM) (JOEL-JEM 2100). An aqueous suspension of a small quantity of CNC material was prepared and to disperse the particles well, the solution was ultrasonically treated. Then using a pipette, a drop of the solution was applied to 200 mesh carbon-coated grids at 200 kV acceleration voltage.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e"},{"header":"3. Result and Discussion","content":"\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003e3.1. Yield of cellulose and cellulose nanocrystals\u003c/h2\u003e \u003cp\u003eThe yield of seaweed cellulose extracted was about 30% and CNC yield from \u003cem\u003eD. bartayresiana\u003c/em\u003e accounts 10%, found to be on lower in comparison with previous reports based on brown seaweeds \u003cem\u003eLaminaria japonica\u003c/em\u003e (26.7%) and \u003cem\u003eSargassum natans\u003c/em\u003e (42.7%) [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. The red seaweed \u003cem\u003eGelidium amansii\u003c/em\u003e also revealed that higher yield for CNC extracted (15.5%) [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003e3.2. FTIR analysis\u003c/h2\u003e \u003cp\u003eThe FTIR analysis performed to define functional groups present in untreated seaweed, alkali-treated, Cellulose, and CNC during the isolation treatment from seaweed \u003cem\u003eD. bartayresiana\u003c/em\u003e. The spectra showed prominent peaks at 3400cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 1428.08cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 1315.26cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 1161.37cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 1055.53cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 1108.60cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 898.02cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. The broad peak absorption band obtained at 3400cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in all four samples assigned represents -OH stretching vibration of the hydrogen bond, which confirms that nature of cellulosic components has a strong affinity to water. Due to the formation and evaporation of water molecules during acid hydrolysis and freeze drying, the -OH stretching vibrations in CNC were less intense than in cellulose.\u003c/p\u003e \u003cp\u003eThe peaks at 1428.08cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 1315.26cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in bleached cellulose and CNC confirm the presence of cellulose, which is assigned to the vibration of the cellulose major chains [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. The peak at 1161.37cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in both cellulose and CNC indicates the C-O-C asymmetric stretching of cellulose. This peak was clearly visible as it is the reduction of the amorphous region in the polysaccharide matrix happened during the acid hydrolysis process [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. The spectra revealed presence of an absorption band at 1055.53cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e which may have been attributed to the skeletal vibration of C-O-C pyranose ring in the cellulose fiber as clearly shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e]. According to [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], the strong absorption band at 898.0cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e -1108.60cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e indicated that presence of \u0026szlig;-glucosidic ether linkages (COC) related to the vibration modes of anhydro-glucopyranose ring skeleton, and to the \u0026szlig; glycosidic linkages between the anhydro glucose rings in the cellulose chains. This peak was more intense in CNC. This data confirmed that most of the non-cellulosic polysaccharides were eliminated during the bleaching and acid hydrolysis treatment. The FTIR spectra of extracted CNC and cellulose from \u003cem\u003eD. bartayresiana\u003c/em\u003e showed similar absorption bands at 3400cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 1108cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 1428cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, and 1055cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e but, the peaks were weaker in CNC. These observations corroborate with the findings of [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e], that the above peaks were lesser and weaker in the FTIR spectra due to the acid extraction treatment.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003e3.3. X-Ray Diffraction analysis\u003c/h2\u003e \u003cp\u003eX-ray diffraction analysis (XRD) is a technique used to ascertain the material\u0026rsquo;s crystallinity. The cellulose and cellulose nanocrystals from \u003cem\u003eD. bartayresiana\u003c/em\u003e exhibit diffraction patterns, as depicted in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. The crystalline structure and crystallinity index of cellulose and CNC from \u003cem\u003eD. bartayresiana\u003c/em\u003e was analysed from XRD patterns collected from 3\u0026deg; to 80\u0026deg; (2θ). The peaks were seen at 14.5\u0026deg;, 21.14\u0026deg;, 22.6\u0026deg;, 26.74\u0026deg;, and 34.86\u0026deg;. The CNC showed a distinctive crystal peak related to the crystal structure of cellulose I [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] at around 2θ\u0026thinsp;=\u0026thinsp;22.6\u0026deg; which corresponded to the lattice plane (200), and one broad peak at 2θ\u0026thinsp;=\u0026thinsp;14.5\u0026deg;, which corresponded to the lattice plan (110) related to the amorphous domains of cellulose.\u003c/p\u003e \u003cp\u003eFrom Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e I\u003csub\u003eC\u003c/sub\u003e is the crystallinity index; I\u003csub\u003e200\u003c/sub\u003e is the cellulose crystalline region\u0026rsquo;s intensity (22.6\u0026deg;); I\u003csub\u003eam\u003c/sub\u003e is the amorphous region\u0026rsquo;s intensity (14.5\u0026deg;). The Crystallinity index of the cellulose \u0026amp; CNC was around 45% and 62%. The degree of crystallinity of CNC is important as a filler to strengthen the mechanical and barrier properties of biopolymer composites in industrial applications [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. During the acid hydrolysis process, hydronium ions diffuse into the cellulose chains in the amorphous encouraging the hydrolysis process of the glycosidic linkages and liberating individual crystal compounds after mechanical treatment (sonication) [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. The non- cellulosic components were removed, as explained earlier in FTIR, and the results here confirm this.\u003c/p\u003e \u003cp\u003eAs a result, the XRD graph confirmed that acid hydrolysis mostly eliminated the cellulose\u0026rsquo;s amorphous region and the crystalline peak regions in the graph represent cellulose nanocrystals. The crystallinity index of cellulose nanocrystals from \u003cem\u003eD. bartayresiana\u003c/em\u003e as lower than that of \u003cem\u003eLaminaria japonica\u003c/em\u003e (69.4%) [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e] and \u003cem\u003eCladophora rupestris\u003c/em\u003e (94%) [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e] and \u003cem\u003eGelidium elegans\u003c/em\u003e (73%) [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003e3.4. CHNS Analysis\u003c/h2\u003e \u003cp\u003eCHNS analysis is used to determine the percentage of carbon, hydrogen, nitrogen and sulphur content of a sample. The CHNS percentage of Cellulose nanocrystals is shown in the Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. This elemental composition is due to the result of the cellulose fibre\u0026rsquo;s acid hydrolysis process and persisted after its centrifugation washing of CNC containing sulphate groups to some extent. The sulphur content thus primarily demonstrated the crystal\u0026rsquo;s surface charge and it\u0026rsquo;s critical to the characterization and comprehension of material\u0026rsquo;s properties. Due to the insertion of charged sulphate ester groups onto the crystallite surface during the process, CNC from sulphuric acid hydrolysis is electrostatically stabilised in aqueous suspension [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. The percentage of sulphur measured for CNC was found to be 0.59%. Similar observations have been reported as in [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. In the present study, the sulphur content of \u003cem\u003eD. bartayresiana\u003c/em\u003e was around 0.59% which was lower than that of (64% H\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e4\u003c/sub\u003e) concentration at different times of acid hydrolysis CNC30 (1.23%), CNC40 (1.47%), CNC80 (1.95%) from the red algae waste [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] as a result of addition of polar sulphate groups during acid hydrolysis [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Carbon and Sulphur values are somewhat similar to the previous literature [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e], CNC from sugarcane bagasse agro-waste.\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\u003eCHNS analysis of CNC\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=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eCHNS\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eCNC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e%C\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e%H\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e%N\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e%S\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e36.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.59\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=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003e3.5. TGA, DTG and DSC Analysis\u003c/h2\u003e \u003cp\u003eThermal stability and fraction of the volatile components of the material was determined by Thermogravimetric analyser, through the weight change of the sample when continuously heated at a constant rate. Cellulose nanocrystals weight loss is depicted in the figures by the TGA and DTG curves. Thermogravimetric analysis (TGA) is a useful tool for obtaining a thorough understanding of the thermodynamics of nanocrystals in order to determine the oxidative and thermal performances of CNCs, as they have remarkably different thermal profiles than the original cellulose. TGA, derivative thermogram (DTG), and DSC curves of CNC were shown in Figs.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e and \u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e. The first stage of reduction (80\u0026ndash;110 ℃) corresponded to the vaporization of water molecules. The second stage reduction of CNC occurred in the range of 195 ℃ to 200 ℃, which was due to the degradation of the cross-linked carbon skeleton. The third weight loss occurred in the range of 220 ℃ to 470 ℃, indicated degradation of glycosidic bonds in cellulose. The CNC showed two step degradations in the DTG graph, at 293.3 ℃ and 416.1 ℃. [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] reported findings were similar to these. Due to the presence of carbonaceous materials, the CNC lost 40% of their mass, with the progressive loss occurring between 150 ℃ and 330 ℃ and at the end, 15% decomposition of residual char remaining between 470 ℃ and 750 ℃, and the results are consistent with previous literature [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] reported T\u003csub\u003eon\u003c/sub\u003e at 261℃ and T\u003csub\u003emax\u003c/sub\u003e at 334 ℃, with a char yield of about 8.2%, which differed slightly from our findings. \u003cem\u003eD. bartayresiana\u003c/em\u003e CNC showed higher T\u003csub\u003eon\u003c/sub\u003e and T\u003csub\u003emax\u003c/sub\u003e obtained higher char yield (15%). This results which indicated that CNC had higher thermal stability. The reason for this is due to the high content of crystalline domains in nanocellulose as a result of CNC reorientation and rearrangement following amorphous region dissolution [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003e3.6.TEM Analysis\u003c/h2\u003e \u003cp\u003eThe CNC\u0026rsquo;s sample dimensions and morphology were examined using the TEM. The TEM image of CNC comprised of rod or needle like particles, exhibited a homogeneous and dense structure with evenly dispersed mostly averages 26 nm wide and several hundred nanometres long and spectral images similar to the previous studies. Despite their long lengths, the fibres were well dispersed into near-elementary fibril levels. Individual cellulose nanocrystals were formed in a porous network with a spider web-like structure as a result of acid hydrolysis. These results are similar to previous literature [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e] where the nano-sized cellulose were fibre network arrangements or spider web-like structure. Some aggregates were found in the CNC TEM image Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e. These aggregates formed as a result of the sample preparation method of freeze drying that resulted in the formation of strong intermolecular hydrogen bonding between the particles [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Different structures were seen in the various types of cellulose sources. Acid hydrolysis process or catalyst may alter the length but some non-crystalline regions may remain same after acid treatment of cellulose [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. The \u003cem\u003eD. bartayresiana\u003c/em\u003e CNC is comparable in length to CNC isolated from \u003cem\u003eLaminaria\u003c/em\u003e [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] and \u003cem\u003eLaminaria japonica\u003c/em\u003e waste [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. According to [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] the cellulose source characteristics and the acid hydrolysis procedure determine the CNC\u0026rsquo;s general dimensions and shape.\u003c/p\u003e \u003c/div\u003e"},{"header":"4. Conclusion","content":"\u003cp\u003eCellulose nanocrystals were successfully isolated from the brown seaweed \u003cem\u003eD. bartayresiana\u003c/em\u003e for the first time, employing sulfuric acid hydrolysis and subsequent processing. The physico-chemical characterization of the extracted cellulose nanocrystals confirmed the effective removal of non-cellulosic components from the raw material, as evidenced by FTIR. The XRD data revealed a crystallinity index of approximately 62%, and TGA data demonstrated enhanced thermal stability. The cellulose nanocrystals exhibited an average width of 26 nm and extended to 520 nm in length.\u003c/p\u003e \u003cp\u003eGiven the observed high crystallinity of these cellulose nanocrystals, this study strongly recommends further investigation into their potential to be used as an effective reinforcement material for strengthening different polymeric matrices to enhance the structural attributes of packaging materials especially biopolymer-based ones. The unique properties identified in this research make these cellulose nanocrystals promising candidates for applications requiring robust and thermally stable materials.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by the Indian Council of Agricultural Research to the first author and the authors express their gratitude to Kerala University of Fisheries and Ocean Studies for providing necessary lab facilities.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThese authors contributed equally to this work and share first authorship.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests:\u0026nbsp;\u003c/strong\u003eThe authors declare that they have no competing interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability:\u0026nbsp;\u003c/strong\u003eThe data will be made available on request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval:\u0026nbsp;\u003c/strong\u003eNot applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAbitbol, T., Kloser, E., \u0026amp;Gray, D. G. Cellulose. (2013) https://doi.org/10.1007/s10570-013-9871-0 \u003c/li\u003e\n\u003cli\u003eAgustin, M. B., Ahmmad, B., Alonzo, S. M. M., \u0026amp;Patriana, F. M, J. Reinf. Plast. Compos. (2014) https://doi.org/10.1177/0731684414558325\u003c/li\u003e\n\u003cli\u003eAlain Dufresne, Materials Today (2014) https://doi.org/10.1016/j.mattod.2013.06.004\u003c/li\u003e\n\u003cli\u003eAndrade, M. S., Ishikawa, O. H., Costa, R. S., Seixas, M. V., Rodrigues, R. C., \u0026amp; Moura, E. A,Food Packag. Shelf Life (2022). https://doi.org/10.1016/j.fpsl.2021.100807\u003c/li\u003e\n\u003cli\u003eBajpai P, Green chemistry and sustainability in pulp and paper industry (Springer, Cham International Publishing, 2015), pp. 65-84\u003c/li\u003e\n\u003cli\u003eBeck-Candanedo, S., Roman, M., \u0026amp;Gray, D. G, Biomacromolecules (2005) https://doi.org/10.1021/bm049300p\u003c/li\u003e\n\u003cli\u003eCao, Xiaodong, Hua Dong, and Chang Ming Li, Biomacromolecules (2007) https://doi.org/10.1021/bm0610368\u003c/li\u003e\n\u003cli\u003eChen, Y. W., Lee, H. V., \u0026amp;Abd Hamid, S. B, Bio Resources (2016) 10.15376/biores.11.2.4645-4662\u003c/li\u003e\n\u003cli\u003eChen, Y. W., Lee, H. V., \u0026amp;Abd Hamid, S. B, Journal of Nano Research (2016) https://doi.org/10.4028/www.scientific.net/JNanoR.41.96\u003c/li\u003e\n\u003cli\u003eChen, Y. W., Lee, H. V., Juan, J. C., \u0026amp;Phang, S. M,Carbohydr.Polym. (2016) https://doi.org/10.1016/j.carbpol.2016.06.083\u003c/li\u003e\n\u003cli\u003eChirayil, C. J., Joy, J., Mathew, L., Mozetic, M., Koetz, J., \u0026amp; Thomas, S, Ind. Crops Prod. (2014) https://doi.org/10.1016/j.indcrop.2014.04.020\u003c/li\u003e\n\u003cli\u003eDoh, H., Lee, M. H., \u0026amp; Whiteside, W. S. Food Hydrocoll. (2020) https://doi.org/10.1016/j.foodhyd.2019.105542\u003c/li\u003e\n\u003cli\u003eDong, S., \u0026amp; Roman, M. J. Am. Chem. Soc. (2007) https://doi.org/10.1021/ja076196l\u003c/li\u003e\n\u003cli\u003eEl Achaby, M., El Miri, N., Aboulkas, A., Zahouily, M., Bilal, E., Barakat, A., \u0026amp;Solhy, A,Int. J. Biol. Macromol. (2017). https://doi.org/10.1016/j.ijbiomac.2016.12.040\u003c/li\u003e\n\u003cli\u003eEl Achaby, M., Kassab, Z., Aboulkas, A., Gaillard, C., \u0026amp;Barakat, A, Int. J. Biol. Macromol. (2018) https://doi.org/10.1016/j.ijbiomac.2017.08.067\u003c/li\u003e\n\u003cli\u003eFortunati, E., Puglia, D., Monti, M., Peponi, L., Santulli, C., Kenny, J. M., \u0026amp; Torre, L, J. Polym. Environ. (2013) https://doi.org/10.1007/s10924-012-0543-1\u003c/li\u003e\n\u003cli\u003eGoswami, G., Bang, V., \u0026amp; Agarwal, S. (2015). Diverse applications of algae. Int. J. Adv. Res. Sci. Eng, 4(1), 1102-1109.\u003c/li\u003e\n\u003cli\u003eHabibi, Y., Lucia, L. A., \u0026amp; Rojas, O. J. Chemical reviews (2010) https://doi.org/10.1021/cr900339w\u003c/li\u003e\n\u003cli\u003eIsmail, M. M., El Zokm, G. M., \u0026amp; El-Sayed, A. A. Environ. Monit. Assess. (2017) https://doi.org/10.1007/s10661-017-6366-8\u003c/li\u003e\n\u003cli\u003eIsmail, M. M., Ismail, G. A., \u0026amp; El-Sheekh, M. M. Energy Sources A: Recovery, Util. Environ. Eff. (2020) https://doi.org/10.1080/15567036.2020.1758853\u003c/li\u003e\n\u003cli\u003eKlemm, D., Heublein, B., Fink, H. P., \u0026amp; Bohn, A. Angew. Chem., Int. Ed. Engl. (2005) https://doi.org/10.1002/anie.200460587\u003c/li\u003e\n\u003cli\u003eKumar, A., Negi, Y. S., Choudhary, V., \u0026amp; Bhardwaj, N. K. Journal of materials physics and chemistry. (2014) DOI: 10.12691/jmpc-2-1-1\u003c/li\u003e\n\u003cli\u003eLin, N., \u0026amp; Dufresne, A. Eur.Polym. J. (2014) https://doi.org/10.1016/j.eurpolymj.2014.07.025\u003c/li\u003e\n\u003cli\u003eLiu, Z., Li, X., Xie, W., \u0026amp; Deng, H. Carbohydr. Polym. (2017) https://doi.org/10.1016/j.carbpol.2017.05.079\u003c/li\u003e\n\u003cli\u003eMali, P., \u0026amp;Sherje, A. P. Carbohydr. Polym. (2022) https://doi.org/10.1016/j.carbpol.2021.118668\u003c/li\u003e\n\u003cli\u003eMandal, A., \u0026amp;Chakrabarty, D. Carbohydr. Polym.(2011)https://doi.org/10.1016/j.carbpol.2011.06.030\u003c/li\u003e\n\u003cli\u003eMiao, C., \u0026amp; Hamad, W.Y. Cellulose (2013) https://doi.org/10.1007/s10570-013-0007-3\u003c/li\u003e\n\u003cli\u003eO\u0026apos;sullivan, A. C. Cellulose (1997) https://doi.org/10.1023/A:1018431705579\u003c/li\u003e\n\u003cli\u003eRusli, R., \u0026amp;Eichhorn, S. J. Applied Physics Letters (2008) https://doi.org/10.1063/1.2963491\u003c/li\u003e\n\u003cli\u003eSalimi, S., Sotudeh-Gharebagh, R., Zarghami, R., Chan, S. Y., \u0026amp; Yuen, K. H. ACS Sustain. Chem. Eng. (2019) https://doi.org/10.1021/acssuschemeng.9b02744\u003c/li\u003e\n\u003cli\u003eSamir, M. A. S. A., Alloin, F., Sanchez, J. Y., \u0026amp; Dufresne, A. Polymer (2004) https://doi.org/10.1016/j.polymer.2004.03.094\u003c/li\u003e\n\u003cli\u003eSegal, L. G. J. M. A., Creely, J. J., Martin Jr, A. E., \u0026amp; Conrad, C. M. Text. Res. J. (1959) https://doi.org/10.1177/004051755902901003\u003c/li\u003e\n\u003cli\u003eSharma, A., Thakur, M., Bhattacharya, M., Mandal, T., \u0026amp; Goswami, S. Biotechnol. Rep. (2019)https://doi.org/10.1016/j.btre.2019.e00316\u003c/li\u003e\n\u003cli\u003eShojaeiarani, J., Bajwa, D. S., \u0026amp;Chanda, S. Compos. C: Open Access (2021) https://doi.org/10.1016/j.jcomc.2021.100164\u003c/li\u003e\n\u003cli\u003eSiddhanta, A. K., Chhatbar, M. U., Mehta, G. K., Sanandiya, N. D., Kumar, S., Oza, M. D., ... \u0026amp;Meena, R. J. Appl. Phycol. (2011) https://doi.org/10.1007/s10811-010-9599-2\u003c/li\u003e\n\u003cli\u003eSucaldito, M. R., \u0026amp; Camacho, D. H. Carbohydr. Polym. (2017) https://doi.org/10.1016/j.carbpol.2017.04.031\u003c/li\u003e\n\u003cli\u003eTashiro, K., \u0026amp; Kobayashi, M. Polymer (1991) https://doi.org/10.1016/0032-3861(91)90435-L\u003c/li\u003e\n\u003cli\u003eTrivedi, N., Gupta, V., Reddy, C. R. K., \u0026amp;Jha, B. Bioresour.Technol. (2013) https://doi.org/10.1016/j.biortech.2013.09.103\u003c/li\u003e\n\u003cli\u003eYahya, M. B., Lee, H. V., \u0026amp; Hamid, S. B. A. Bio Res. 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The structural analysis, conducted via Transmission Electron Microscopy (TEM), affirmed that the resulting CNCs displayed an average width of approximately 26 nm and a length extending to 520nm long. X-ray Diffraction (XRD) analysis indicated that these extracted CNCs constituted around 62%. Fourier Transform Infrared (FTIR) spectral analysis confirmed the successive removal of non-cellulosic components through chemical treatments. Elemental analysis (CHNS) validated the presence of sulphate groups, accounting for 0.59%. 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