Experimental Studies of Cluster-Size Distributions During Colloidal Aggregation

这个项目是在一般地区的分析和表面 化学和胶体聚集的子领域。 这 研究继续首席研究员的应用， 光学粒度脉冲分析表征动力学 胶体聚集过程和结构 在不同条件下形成的聚集体。 这种方法允许 胶体基本理论的直接检验 絮凝。 将系统地研究两个模型系统： 1)盐诱导的胶体聚苯乙烯微球的凝聚; 2)抗原抗体凝集反应。 时间演变 的集群大小分布将被记录为一个函数 诸如电解质溶液的离子强度和pH的因素 来验证不可逆聚合的理论 的 将改进粒度分析仪， 比目前可能的颗粒更小。 此外，光 将不仅在小角度收集，而且在 更大的散射角。 这将使决心不仅 还有旋转半径和分形 集群的维度。 团簇结构关系 集群增长和集群规模分布将是 表征了 小颗粒聚集形成较大的结构， 在空气和水污染等不同领域具有重要意义， 材料加工、催化、医学和生物学。 两 实验和理论研究是必要的，以推进我们的 了解胶体聚集。 光学粒度 脉冲分析能够直接测量颗粒尺寸 分布和时间演变，并直接测试 集群增长的基本理论。

This project is in the general area of analytical and surface chemistry and in the subfield of colloidal aggregation. This research continues the Principal Investigator's application of optical particle size pulse analysis to characterize the kinetics of colloidal aggregation processes and the structure of aggregates formed under different conditions. This method permits direct testing of the fundamental theories of colloid flocculation. Two model systems will be studied systematically: 1) salt-induced coagulation of colloidal polystyrene microspheres; 2) antigen-antibody agglutination reactions. Temporal evolution of the cluster-size distribution will be recorded as a function of such factors as ionic strength and pH of the electrolyte solution in order to test theories of irreversible aggregation. The particle size analyzer will be improved to enable analysis of smaller particles than currently possible. In addition, light will be collected not only at small angles but also at a range of larger scattering angles. This will enable determination not only of the mass but also the radius of gyration and hence the fractal dimensionality of the clusters. The relation of cluster structure to cluster growth and cluster-size distribution will be characterized. The aggregation of small particles to form larger structures is of major importance in such diverse areas as air and water pollution, materials processing, catalysis, medicine and biology. Both experimental and theoretical studies are necessary to advance our understanding of colloidal aggregation. Optical particle size pulse analysis enables direct measurement of the particle size distribution and temporal evolution, and direct testing of the fundamental theories of cluster growth.