ROW: Surface and Interfacial Properties of Polymer Blends

多组分聚合物体系表现出丰富多样的有用的性能。 机械、电学和光学性能。 的性质 界面和自由表面边界区域是中心 问题的认识和预测其复杂的 行为 该ROW研究启动补助金将处理 模型系统中的成分与距离曲线 部分混溶聚合物;（a）聚苯乙烯/聚溴苯乙烯 (b)聚苯乙烯/氘代聚苯乙烯。 测量结果将是 通过几种互补技术进行;（a）二次离子 质谱，（B）前向反冲弹性散射， 飞行时间和能量同时测量 （c）中子和X射线反射率， 荧光。 前两种技术的分辨率为120 A 和240 A，以及测量的 能谱可以简单地、明确地转换成 浓度分布 反射率技术具有 分辨率约但是在逆空间中获得数据， 如果没有初步资料， 从其他方法。 该实验计划将重点研究 界面和表面的平衡和动力学性质 作为链长、相互作用参数、链段 氘化和共混物组成。 特别感兴趣的是 表面润湿和预润湿相变及其 与各种预测的体临界现象的关系 理论模型。

Multi-component polymer systems exhibit a rich variety of useful mechanical, electrical, and optical properties. The nature of the interface and free surface boundary regions is a central problem to the understanding and predicting of their complex behavior. This ROW research-initiation grant will deal with composition-vs-distance profiles in the model systems of partially miscible polymers; (a) polystyrene/polybromostyrene (b) polystyrene/deuterated polystyrene. The measurements will be performed by several complementary techniques; (a) secondary ion mass spectroscopy, (b) forward recoil elastic scattering with simultaneous measurement of time-of-flight and energy measurements, (c) neutron and x-ray reflectivity and fluorescence. The first two techniques have resolutions of 120A and 240A, respectively, and the advantage that the measured energy spectra can be converted simply and unambiguously into concentration profiles. The reflectivity techniques have resolutions of approx. 20A but obtain data in inverse space and the interpretation is difficult without preliminary information from other methods. The experimental program will focus on investigation of the equilibrium and dynamical properties of interfaces and surfaces as functions of chain length, interaction parameter, segment deuteration, and blend composition. Of special interest are surface wetting and pre-wetting phase transitions and their relationship to bulk critical phenomena as predicted by various theoretical models.