Surface enrichment in a miscible random copolymer blend : Influence of polydispersity and architecture
Surface enrichment in a miscible random copolymer blend : Influence of polydispersity and architecture
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可混溶的无规共聚物共混物中的表面富集：多分散性和结构的影响
DOI：
10.1021/ma980601z
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发表时间：
1999
期刊：
影响因子：
5.5
通讯作者：
P. Garrett
中科院分区：
文献类型：
--
作者：
R. Oslanec;J. Genzer;A. Faldi;R. Composto;P. Garrett
同时使用中子反射率和低能前向反冲光谱法来监测聚（苯乙烯-丙烯腈），dSAN 23和SAN 27，分别具有23和27重量% AN的共混物中的表面偏析。由于其较低的AN含量，发现dSAN 23在聚合物/空气界面处分配，这与曼斯菲尔德等人（Physica B 1991，173，207）和Kim等人（Polymer 1995，36，2427）的工作一致。与以前的研究相比，这项工作探讨了在高dSAN 23体积分数φ∞（即，φ∞ > 0.50）。新的结果包括观察到最大dSAN 23表面过量（1075 A）接近φ∞ <$0.35，并且当φ∞增加到1时，dSAN 23表面体积分数接近1，而不是0.75。dSAN 23曲线偏离了施密特-宾德和自洽平均场（SCMF）模型预测的指数曲线。当φ∞ > 0.50时，剖面显示出在低φ∞时未观察到的表面平坦。SCMF模型扩展到占聚合物p…
Neutron reflectivity and low-energy forward-recoil spectrometry were used simultaneously to monitor surface segregation in blends of poly(styrene-ran-acrylonitrile), dSAN23 and SAN27, having 23 and 27 wt % AN, respectively. Because of its lower AN content, dSAN23 was found to partition at the polymer/air interface, in agreement with the work of Mansfield et al. (Physica B 1991, 173, 207) and Kim et al. (Polymer 1995, 36, 2427). In contrast to the previous studies, this work explores surface segregation at high dSAN23 bulk volume fractions, φ∞ (i.e., φ∞ > 0.50). New results include the observation of a maximum dSAN23 surface excess (∼75 A) near φ∞ ≈ 0.35 and a dSAN23 surface volume fraction that approaches 1, rather than 0.75, as φ∞increases to 1. The dSAN23 profile deviates from the exponential profile predicted by Schmidt−Binder and self-consistent mean-field (SCMF) models. For φ∞ > 0.50, the profile displays a surface flattening not observed at low φ∞. The SCMF model is extended to account for polymer p...