Generalization of Surface Freezing in P3AT Thin Films

IF 5.1 1区化学 Q1 POLYMER SCIENCE Macromolecules Pub Date : 2025-06-11 DOI:10.1021/acs.macromol.5c00384

Jesse Kuebler, Sunil Dhapola, Trygve Santelman, Lucia Fernandez-Ballester

引用次数: 0

Abstract

We directly observe surface freezing in 90–95% regioregular poly(3-alkylthiophene)s (P3ATs) of different molecular weights and side-chain lengths, i.e., a free surface-induced crystallization event occurs at temperatures 25–50 °C above bulk crystallization. For all studied P3ATs, surface freezing involves the development of highly edge-on oriented crystallites within 20 nm of the air–polymer interface; however, nucleation and growth of 2D spherulites (“circulites”) during surface freezing can be optically resolved only in P3ATs with relatively low circulite nucleation densities. For poly(3-hexylthiophene) (P3HT), molecular weight and regioregularity impact circulite nucleation density as well as surface and bulk crystallization kinetics. Both free surface and bulk crystallization temperatures are nearly insensitive to molecular weight for 95% regioregular P3HT but strongly decrease with increasing chain length for 90% regioregular P3HT. Overall, the results indicate that surface freezing and high edge-on orientation at the free surface are general phenomena in P3ATs, but circulites are not always observable.

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P3AT薄膜表面冻结的推广

我们直接观察到90-95%不同分子量和侧链长度的区域规则聚（3-烷基噻吩）s （P3ATs）的表面冻结，即在体结晶以上25-50℃的温度下发生自由表面诱导结晶事件。对于所有被研究的p3at，表面冻结涉及在空气-聚合物界面20 nm内形成高度边缘取向的晶体；然而，在表面冻结过程中，二维球晶（“圆晶”）的成核和生长只能在圆晶成核密度相对较低的p3at中进行光学分辨。对于聚（3-己基噻吩）（P3HT），分子量和区域规则性影响环核密度以及表面和体结晶动力学。对于95%区域规则P3HT，自由表面和大块结晶温度对分子量几乎不敏感，而对于90%区域规则P3HT，自由表面和大块结晶温度随着链长的增加而显著降低。总体而言，结果表明，表面冻结和自由表面的高边缘取向是p3at的普遍现象，但并非总是可以观察到圆形。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Macromolecules 工程技术-高分子科学

CiteScore

9.30

自引率

16.40%

发文量

942

审稿时长

2 months

期刊介绍： Macromolecules publishes original, fundamental, and impactful research on all aspects of polymer science. Topics of interest include synthesis (e.g., controlled polymerizations, polymerization catalysis, post polymerization modification, new monomer structures and polymer architectures, and polymerization mechanisms/kinetics analysis); phase behavior, thermodynamics, dynamic, and ordering/disordering phenomena (e.g., self-assembly, gelation, crystallization, solution/melt/solid-state characteristics); structure and properties (e.g., mechanical and rheological properties, surface/interfacial characteristics, electronic and transport properties); new state of the art characterization (e.g., spectroscopy, scattering, microscopy, rheology), simulation (e.g., Monte Carlo, molecular dynamics, multi-scale/coarse-grained modeling), and theoretical methods. Renewable/sustainable polymers, polymer networks, responsive polymers, electro-, magneto- and opto-active macromolecules, inorganic polymers, charge-transporting polymers (ion-containing, semiconducting, and conducting), nanostructured polymers, and polymer composites are also of interest. Typical papers published in Macromolecules showcase important and innovative concepts, experimental methods/observations, and theoretical/computational approaches that demonstrate a fundamental advance in the understanding of polymers.

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