Direct Observation of Early-Stage Polymer Crystallization Driven by Surface Wrinkling and Compressive Stress in Thin Films  

作　　者：Peng Zhang Stephan V.Roth Peter Muller-Buschbaum Tian-Bai He 

机构地区：[1]School of Materials Science and Engineering,Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education,Institute of Green Chemistry and Molecular Engineering,Sun Yat-sen University,Guangzhou,510275,China [2]Deutsches Elektronen-Synchrotron(DESY),Notkestrasse 85,22607,Hamburg,Germany [3]Department of Fibre and Polymer Technology,KTH Royal Institute of Technology,Teknikringen 56-58,Stockholm,SE-10044,Sweden [4]TUM School of Natural Sciences,Department of Physics,Chair for Functional Materials,Technical University of Munich,James-Franck-Str.1,Garching,85748,Germany [5]Heinz Maier-Leibnitz-Zentrum(MLZ),Technical University of Munich,Lichtenbergstr.1,Garching,85748,Germany [6]State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,Graduate University of Chinese Academy of Sciences,Chinese Academy of Sciences,Changchun,130022,China

出　　处：《Chinese Journal of Polymer Science》2025年第2期360-367,共8页高分子科学(英文版)

基　　金：the National Natural Science Foundation of China(Nos.U2032101 and 11905306);the National Key Research and Development Project of China(No.2022YFB2402602).

摘　　要：The early stages of crystallization and occurrence of surface wrinkling were investigated using poly(butadiene)-block-poly(ε-caprolactone)with an ordered lamellar structure.Direct evidence has demonstrated that surface wrinkling precedes nucleation and crystal growth.This study examined the relationship between surface wrinkling,nucleation,and the formation of crystalline supramolecular structures using atomic force microscopy(AFM)and X-ray scattering measurements.Surface wrinkling is attributed to curving induced by accumulated stresses,including residual stress from the sample preparation and thermal stress during cooling.These stresses cause large-scale material flow and corresponding changes in the molecular conformations,potentially reducing the nucleation barrier.This hypothesis is supported by the rapid crystal growth observed following the spread of surface wrinkles.Additionally,the surface curving of the polymer thin film creates local minima of the free energy,facilitating nucleation.The nuclei subsequently grow into crystalline supramolecular structures by incorporating polymer molecules from the melt.This mechanism highlights the role of localized structural inhomogeneity in the early stages of crystallization and provides new insights into structure formation processes.

关 键 词：Polymer crystallization NUCLEATION Surface wrinkling Stress Thin film 

分 类 号：O34[理学—固体力学]