{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T05:04:54Z","timestamp":1790053494145,"version":"4.0.1"},"reference-count":39,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T00:00:00Z","timestamp":1789603200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Natural Science Foundation of China","award":["52373024"],"award-info":[{"award-number":["52373024"]}],"id":[{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"crossref"}]},{"award":["52373024"],"award-info":[{"award-number":["52373024"]}],"id":[{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"publisher"}]},{"name":"Fundamental Research Funds for Central Universities","award":["226-2025-00031"],"award-info":[{"award-number":["226-2025-00031"]}]},{"name":"Doctoral Research Start-up Fund Project of Liaoning Province","award":["2026-BS-0973"],"award-info":[{"award-number":["2026-BS-0973"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Introducing charged groups into comb-like copolymers significantly enhances the incompatibility between the main chain and side chains, enabling sub-5 nm microphase separation. In this work, a series of charged comb-like copolymers with imidazolium ionic junctions and mixed alkyl side chains (C18\/C8, C20\/C12, C22\/C12) were synthesized. The regulation of microphase separation behavior via side-chain composition and length were investigated. The crystallization of long alkyl side chains could disrupt pre-formed microphase-separated structures, rendering a disordered state at low temperatures. The systems underwent a lower disorder\u2013order transition (LDOT) that was closely correlated with the melting of side-chain crystallites, forming lamellar (LAM) or hexagonally packed cylindrical (HEX) nanostructures. By adjusting the side-chain length and feed ratio (r) of long\/short chains, both the LDOT and closed-loop sequence of transitions (LDOT at low temperatures and upper order\u2013disorder transition (UODT) at high temperatures) were achieved, with transition temperatures shifting accordingly. Notably, the SAXS data at a specific composition are consistent with the Frank\u2013Kasper (F-K) A15 complex spherical phase. Moreover, the domain spacing showed an approximately linear dependence on the nominal long-chain feed ratio within the investigated range. This work demonstrates that statistical side-chain functionalization is an effective strategy for tuning microphase separation in charged comb-like copolymers with ultra-small self-assembled dimensions.<\/jats:p>","DOI":"10.3390\/ma19183955","type":"journal-article","created":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T16:06:51Z","timestamp":1790006811000},"page":"3955","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Microphase Separation and Temperature-Dependent Structural Transitions of Mixed-Side-Chain Comb-like Copolymers"],"prefix":"10.3390","volume":"19","author":[{"given":"Yuan-Hao","family":"Yao","sequence":"first","affiliation":[{"name":"State Key Laboratory of Biobased Transportation Fuel Technology, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310058, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7788-9026","authenticated-orcid":false,"given":"Jun-Ting","family":"Xu","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Biobased Transportation Fuel Technology, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310058, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"funding-acquisition","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"given":"Ze-Kun","family":"Zhang","sequence":"additional","affiliation":[{"name":"Dalian Changfeng Industrial Corporation, Dalian 116038, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"funding-acquisition","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"113","DOI":"10.1016\/S0169-409X(00)00124-1","article-title":"Block Copolymer Micelles for Drug Delivery: Design, Characterization and Biological Significance","volume":"47","author":"Kataoka","year":"2001","journal-title":"Adv. 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