用探针粒子示踪微流变法测量明胶的动态不均匀性

发布时间：2018-06-05 03:37

本文选题：凝胶化 + 动态不均匀性　；参考：《高分子学报》2017年09期

【摘要】：利用探针粒子示踪微流变法对明胶溶液等温凝胶化过程的动态不均匀性进行了观测.通过向体系中引入探针粒子,利用广义的Stokes-Einstein关系由探针粒子的位移建立了体系结构的空间分布.进而利用van Hove函数和非高斯因子描述了凝胶化转变前后动态不均匀性的变化,结果表明在凝胶化后体系动态在空间和时间尺度上都是不均匀的,与凝胶化前相比,凝胶化后的快动态有更高的贡献.为了进一步探究这种动态不均匀性在空间和时间上相关的变化,本工作在粒子示踪技术的基础上,实现了四点相关函数和极化率的测量.实验结果表明,凝胶化前体系的快松弛可以原位独立完成,而慢松弛则需要周围的结构单元协同完成;凝胶化后体系的快松弛和慢松弛均需要协同完成.
[Abstract]:The dynamic inhomogeneity during isothermal gelation of gelatin solution was observed by using probe particle tracing microrheology method. By introducing probe particles into the system, the spatial distribution of the system structure is established by using the generalized Stokes-Einstein relation. Van Hove function and non-Gao Si factor are used to describe the change of dynamic inhomogeneity before and after gelation transition. The results show that the dynamics of the system are not uniform in space and time scale after gelation, compared with those before gelation. The quick dynamic after gelation has a higher contribution. In order to further explore the spatial and temporal variations of the dynamic inhomogeneity, the four-point correlation function and the measurement of polarizability are realized on the basis of particle tracing technique. The experimental results show that the rapid relaxation of the system before gelation can be completed independently in situ, while the slow relaxation requires the coordination of the surrounding structural units, and the rapid relaxation and the slow relaxation of the gelatinized system need to be completed in cooperation.
【作者单位】：华南理工大学材料科学研究所;
【基金】：国家自然科学基金(基金号21427805,21574047)资助项目
【分类号】：O648.17

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