Structure and thermodynamics of bulk homopolymer/solid interfaces: a site lattice model approach
Structure and thermodynamics of bulk homopolymer/solid interfaces: a site lattice model approach
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DOI：
10.1021/ma00183a036
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发表时间：
1988-09
期刊：
影响因子：
5.5
通讯作者：
D. Theodorou
中科院分区：
文献类型：
--
作者：
D. Theodorou
基于Scheutjens和Fleer的聚合物溶液模型，导出了纯均聚物界面的原位晶格模型.技术开发的界面键取向特性的探索。该模型是实现各种分子量的单分散均聚物系统。发现表面自由能随着链长的增加而增加，作为界面处的熵约束的结果。键取向仅在一个狭窄的界面区域内偏离各向同性，大约6个晶格层（25埃）厚;它在相对于表面的平行和垂直排列之间交替层与层之间。高分子链的形状在表面附近是扁平的，而远离表面则呈现出无扰动的整体特征。我们的网站模型收敛到Helfand的债券模型在无限长链的限制。
Asite lattice model for pure homopolymers at interfaces is derived, based on Scheutjens and Fleer’s formulation for polymersolutions. Techniques are developed for the exploration of bond orientational characteristics at the interface. The model is implemented for monodisperse homopolymer systems of various molecular weights. Surface free energy is found to increase with chain length, as a result of entropic constraints at the interface. Bond orientation deviates from isotropy only within a narrow interfacial region, approximately six lattice layers (25 Á) thick; it alternates from layer to layer between a parallel and a perpendicular arrangement with respect to the surface. The shape of polymerchains is flattened in the vicinity of the surface, whilefar from the surface it assumes unperturbed bulk characteristics. Our site model is shown to converge to Helfand’s bond model in the limit of infinitely long chains.