Polydispersity effects on diffusion in polymers: Concentration profiles of d‐polystyrene measured by forward recoil spectrometry
Polydispersity effects on diffusion in polymers: Concentration profiles of d‐polystyrene measured by forward recoil spectrometry
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多分散性对聚合物扩散的影响：通过正向反冲光谱法测量 d-聚苯乙烯的浓度分布
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发表时间：
1986
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通讯作者：
E. Kramer
中科院分区：
文献类型：
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作者：
P. Mills;P. Green;C. Palmstrøm;J. Mayer;E. Kramer
前向反冲光谱法是一种测量d-聚合物链在h-聚合物熔体中扩散的有效方法。氘扩散物质的浓度分布可以用80 nm的深度分辨率和h-聚合物中0.1体积% d-聚合物的灵敏度来确定。因此，可以很容易地测量小至10 - 16 cm 2/s的扩散系数。如果聚合物链通过爬行机制扩散，则扩散的多分散聚合物的浓度分布o（x）应该与对于单分散聚合物获得的Fickian解om（x）大不相同。通过测量扩散到h-PS中的多分散d-聚苯乙烯（d-PS）的o（x）来验证这一想法。结果与爬行模型预测的o（x）和实验测定的分子量分布非常一致。
Forward recoil spectrometry is shown to be a useful technique for measuring diffusion of d-polymer chains in h-polymer melts. Concentration profiles of a deuterated diffusing species may be determined with a depth resolution of 80 nm and a sensitivity of 0.1 vol % d-polymer in h-polymer. Consequently diffusion coefficients as small as 10−16 cm2/s can be readily measured. If polymer chains diffuse by a reptation mechanism, the concentration profile o(x) of diffusing polydisperse polymer should be quite different from om(x), the Fickian solution, which one obtains for monodisperse polymer. This idea was tested by measuring o(x) of polydisperse d-polystyrene (d-PS) diffusing into h-PS. The results are in excellent agreement with the o(x) predicted from the reptation model and the experimentally determined molecular weight distribution.