{"paper_id":"42a1ee32-668a-4f4d-ac6e-47c2183d5e3f","body_text":"Semi-Reversible Thermochromism in Polydiacetylene–PDMS Hybrid Structures | 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 Semi-Reversible Thermochromism in Polydiacetylene–PDMS Hybrid Structures Inwoong Heo, Seung Soo Shin, Binglun Tu, Boyoung Yoon, Jong-Man Kim, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8811543/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 11 You are reading this latest preprint version Abstract Thermochromic materials that change color in response to temperature have been extensively explored in point-of-use temperature indicators, smart textiles, energy-saving coatings and biomedical monitoring devices. Polydiacetylene (PDA) undergoes a thermally induced blue-to-red transition that is typically irreversible, limiting its use in temperature-responsive sensing. Here, we examine the origin of semi-reversible thermochromism in PDA–PDMS hybrid structures by comparing four architectures: core–shell PDA@PDMS particles, nested-PDAs|PDMS particles, PDA/PDMS composites, and PDA|PDMS laminates. The observed reversibility arises from the melting of residual unpolymerized 10,12-pentacosadiynoic acid (PCDA), its migration into the PDMS matrix, and UV-induced formation of new PDA domains. Systems containing larger PCDA reservoirs show clearer semi-reversible behavior, whereas limited PCDA content results in weak or negligible recovery. Laminate experiments further reveal that PDMS thickness and PDA polymerization time influence thermochromic kinetics through their effects on heat transport and PCDA availability. These results clarify the mechanism of semi-reversible thermochromism in PDA-based materials and offer practical considerations for designing thermally responsive PDA systems. polydiacetylene (PDA) thermochromism PDA–PDMS hybrid structures reversibility Full Text Additional Declarations No competing interests reported. Supplementary Files Supplementarymaterial.docx Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 13 May, 2026 Reviews received at journal 11 May, 2026 Reviews received at journal 08 May, 2026 Reviewers agreed at journal 02 May, 2026 Reviewers agreed at journal 27 Apr, 2026 Reviews received at journal 09 Mar, 2026 Reviewers agreed at journal 02 Mar, 2026 Reviewers invited by journal 02 Mar, 2026 Editor assigned by journal 24 Feb, 2026 Submission checks completed at journal 06 Feb, 2026 First submitted to journal 06 Feb, 2026 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. 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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-8811543\",\"acceptedTermsAndConditions\":true,\"allowDirectSubmit\":false,\"archivedVersions\":[],\"articleType\":\"Research Article\",\"associatedPublications\":[],\"authors\":[{\"id\":600908289,\"identity\":\"e1e57bca-b0cf-4f27-960a-4bb2c6eb79fd\",\"order_by\":0,\"name\":\"Inwoong Heo\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Kyung Hee University\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Inwoong\",\"middleName\":\"\",\"lastName\":\"Heo\",\"suffix\":\"\"},{\"id\":600908292,\"identity\":\"c3906252-8d2a-48b7-a9d0-dc41982a20ff\",\"order_by\":1,\"name\":\"Seung Soo 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