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用光子相关光谱研究了四臂星形聚苯乙烯在良溶剂(四氢呋喃THF)和θ溶剂(环己烷CH)中扩散系数与溶剂的浓度和温度的依赖关系。用累积量方法分析光子相关数据给出了多分散样品的Z均扩散系数。在θ溶剂中,高于或低于θ温度时,聚合物在溶液中的分子扩散分别表现出具有在良溶剂与不良溶剂中的行为。外推浓度至零,得到无限稀时不同温度的分子扩散系数,借助Stokes-Einstein方程,给出了聚合物的流体力学半径。通过InD对I/T作图,得到了星形聚苯乙烯在THF与CH中的扩散活化能。
The dependence of the diffusion coefficient of the four-arm star polystyrene on the concentration and temperature of the solvent in good solvent (tetrahydrofuran THF) and θ solvent (cyclohexane CH) was studied by photon correlation spectroscopy. Using the cumulant method to analyze the photon correlation data gives the Z diffusion coefficient of the polydisperse sample. Molecular diffusion of a polymer in solution at or above the θ temperature in the θ solvent, respectively, shows behavior in good and poor solvents. By extrapolating the concentration to zero, the molecular diffusion coefficient of infinite temperature at different temperatures was obtained. The hydrodynamic radius of the polymer was given by Stokes-Einstein equation. By InD I / T mapping, obtained star polystyrene diffusion activation energy in THF and CH.