Structural, Optical, Dielectric and Nonlinear Properties of PVA/Na-Alg/ITO Nanocomposite Films

Structural, Optical, Dielectric and Nonlinear Properties of PVA/Na-Alg/ITO Nanocomposite Films | 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 Structural, Optical, Dielectric and Nonlinear Properties of PVA/Na-Alg/ITO Nanocomposite Films Martin Ouma Osemba, Adrián Chávez Huerta, justin Kambale Maghanga This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9366243/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 Flexible and optically active polymer nanocomposites have attracted significant attention for next-generation optoelectronic and photonic applications. In this study, PVA/Na-Alg/ITO nanocomposite films were successfully fabricated via a solution casting method, and the effect of indium tin oxide (ITO) nanoparticle incorporation (2–5 wt%) on their structural, optical, dielectric, and nonlinear optical properties was systematically investigated. X-ray diffraction (XRD), Fourier-transform infrared (FTIR), and Raman analyses confirmed good miscibility between polyvinyl alcohol (PVA) and sodium alginate (Na-Alg), along with uniform dispersion of ITO nanoparticles with an average crystallite size of 21.7 nm. Morphological analysis revealed homogeneous films with minimal agglomeration. UV–visible spectroscopy showed a red shift in the absorption edge accompanied by a systematic reduction in optical band gap from 3.59 eV (pristine PVA) to 3.18 eV (5 wt% ITO), indicating enhanced electronic interactions and charge delocalization. The refractive index increased from 1.47 to 1.78, while the dispersion energy (Ed) improved from 8.28 eV to 12.17 eV with increasing ITO content, reflecting enhanced electronic polarizability. The dielectric constant (ε∞) also increased from 2.37 to 3.46, confirming strengthened interfacial polarization effects. Photoluminescence (PL) analysis revealed significant quenching of emission intensity with increasing ITO concentration, indicating efficient charge transfer and suppression of radiative recombination. Furthermore, the nonlinear refractive index (n₂) increased from 0.675 × 10⁻¹² to 4.83 × 10⁻¹², while the third-order nonlinear susceptibility (χ⁽³⁾) increased from 0.314 × 10⁻¹³ to 2.84 × 10⁻¹³ (esu) as ITO content increased from 0 to 5 wt%. These results demonstrate that controlled incorporation of ITO nanoparticles significantly enhances the structural disorder, optical tunability, dielectric response, and nonlinear optical performance of PVA/Na-Alg films. The developed nanocomposites show strong potential as environmentally friendly, flexible materials for advanced optoelectronic, photonic, and nonlinear optical device applications. Nanoscience Polymer Science Materials Chemistry Optical Materials and Devices Polyvinyl alcohol Sodium alginate Indium tin oxide Optical band gap Dielectric properties Nonlinear optics Nanocomposites Full Text Additional Declarations The authors declare no competing interests. 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. 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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-9366243","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":620194023,"identity":"f1c9e4f3-d913-4456-8251-55af89f9e75a","order_by":0,"name":"Martin Ouma Osemba","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABCklEQVRIiWNgGAWjYNCCCgh1AEKxQSgJvFrOwLQkEKuFsQ3GIkaLbnuP6Yaf8+zs5dubHx74+cPGnkHsWJoEQ40dg2R7A1YtZmfOmN3s3ZacuOHMMYODPQlpiQ3SacckGI4lM0jzHMCu5UaO2Q3ebcwJBhI5DAd4Eg4nMEint0kwsB1gkJNIwKnl5t859fbyM3IYDv5J+G8P0fIPqEX+AU4tt3kbDjM23MhhOMyTcIAR7DDGtgMM0jj8b3bmWNltmWPHwX45LJOWnNgmnZZskdiXzCPZg8Nhx5u33XxTUw0Ksccf39jY2fNLpxne+PDNTk7iOHbvYwJwrADN5yFS/SgYBaNgFIwCLAAAyTFdk+mKoW0AAAAASUVORK5CYII=","orcid":"https://orcid.org/0009-0007-2045-4746","institution":"Mount Kenya University","correspondingAuthor":true,"prefix":"","firstName":"Martin","middleName":"Ouma","lastName":"Osemba","suffix":""},{"id":620195289,"identity":"d78bb02c-dae1-4872-b2de-a650efcc6c9b","order_by":1,"name":"Adrián Chávez Huerta","email":"","orcid":"","institution":"Zulian Institute of Technological Research (INZIT), Venezuela","correspondingAuthor":false,"prefix":"","firstName":"Adrián","middleName":"Chávez","lastName":"Huerta","suffix":""},{"id":620195290,"identity":"bff2d9df-55c8-4028-a678-2d26844a3b08","order_by":2,"name":"justin Kambale Maghanga","email":"","orcid":"","institution":"TTU","correspondingAuthor":false,"prefix":"","firstName":"justin","middleName":"Kambale","lastName":"Maghanga","suffix":""}],"badges":[],"createdAt":"2026-04-09 09:25:17","currentVersionCode":1,"declarations":{"humanSubjects":false,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":false,"humanSubjectConsent":false,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-9366243/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9366243/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":106726493,"identity":"82389acc-8b64-4c7f-96df-d20abd6ed11d","added_by":"auto","created_at":"2026-04-12 18:36:19","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":841637,"visible":true,"origin":"","legend":"","description":"","filename":"StructuralOpticalDielectricACADEMIA.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9366243/v1_covered_b08a91d3-517f-47f2-84f7-e7ec6678d01c.pdf"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003e\u003cstrong\u003eStructural, Optical, Dielectric and Nonlinear Properties of PVA/Na-Alg/ITO Nanocomposite Films\u003c/strong\u003e\u003c/p\u003e","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"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":"Polyvinyl alcohol, Sodium alginate, Indium tin oxide, Optical band gap, Dielectric properties, Nonlinear optics, Nanocomposites","lastPublishedDoi":"10.21203/rs.3.rs-9366243/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9366243/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eFlexible and optically active polymer nanocomposites have attracted significant attention for next-generation optoelectronic and photonic applications. In this study, PVA/Na-Alg/ITO nanocomposite films were successfully fabricated via a solution casting method, and the effect of indium tin oxide (ITO) nanoparticle incorporation (2\u0026ndash;5 wt%) on their structural, optical, dielectric, and nonlinear optical properties was systematically investigated. X-ray diffraction (XRD), Fourier-transform infrared (FTIR), and Raman analyses confirmed good miscibility between polyvinyl alcohol (PVA) and sodium alginate (Na-Alg), along with uniform dispersion of ITO nanoparticles with an average crystallite size of 21.7 nm. Morphological analysis revealed homogeneous films with minimal agglomeration. UV\u0026ndash;visible spectroscopy showed a red shift in the absorption edge accompanied by a systematic reduction in optical band gap from 3.59 eV (pristine PVA) to 3.18 eV (5 wt% ITO), indicating enhanced electronic interactions and charge delocalization. The refractive index increased from 1.47 to 1.78, while the dispersion energy (Ed) improved from 8.28 eV to 12.17 eV with increasing ITO content, reflecting enhanced electronic polarizability. The dielectric constant (ε\u0026infin;) also increased from 2.37 to 3.46, confirming strengthened interfacial polarization effects. Photoluminescence (PL) analysis revealed significant quenching of emission intensity with increasing ITO concentration, indicating efficient charge transfer and suppression of radiative recombination. Furthermore, the nonlinear refractive index (n₂) increased from 0.675 \u0026times; 10⁻\u0026sup1;\u0026sup2; to 4.83 \u0026times; 10⁻\u0026sup1;\u0026sup2;, while the third-order nonlinear susceptibility (χ⁽\u0026sup3;⁾) increased from 0.314 \u0026times; 10⁻\u0026sup1;\u0026sup3; to 2.84 \u0026times; 10⁻\u0026sup1;\u0026sup3; (esu) as ITO content increased from 0 to 5 wt%. These results demonstrate that controlled incorporation of ITO nanoparticles significantly enhances the structural disorder, optical tunability, dielectric response, and nonlinear optical performance of PVA/Na-Alg films. The developed nanocomposites show strong potential as environmentally friendly, flexible materials for advanced optoelectronic, photonic, and nonlinear optical device applications.\u003c/p\u003e","manuscriptTitle":"Structural, Optical, Dielectric and Nonlinear Properties of PVA/Na-Alg/ITO Nanocomposite Films","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-10 12:51:23","doi":"10.21203/rs.3.rs-9366243/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":"5d14f81d-949c-4edf-8687-aff0cf3f9240","owner":[],"postedDate":"April 10th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":65998533,"name":"Nanoscience"},{"id":65998534,"name":"Polymer Science"},{"id":65998535,"name":"Materials Chemistry"},{"id":65998536,"name":"Optical Materials and Devices"}],"tags":[],"updatedAt":"2026-04-10T12:51:23+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-10 12:51:23","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9366243","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9366243","identity":"rs-9366243","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}