A Langevin Dynamics Study of Depletion Forces in Binary Hard-Sphere System

• Main Authors: Kao, Chun-Hsiang, 高俊翔
• Other Authors: 華繼中
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/16212708227506006449

碩士 === 國立中正大學 === 化學工程研究所 === 101 === Depletion interaction plays an important role in colloidal solutions, and the study of such phenomena can help elucidate the mechanism of the oscillation of pair interaction potential between two colloidal particles. In the past, researchers utilized the concept of small spheres which lead to the formation of "shell" around the large spheres to explain the oscillation of interaction potential of the latter, but the resulting change of interaction and its mechanism are barely discussed. The fluctuations of small colloidal particles between two large probe particles separated by various distances have been investigated using Brownian dynamics simulation. By dividing the area inside and outside of two big colloidal particles, respectively, and analyzing the radial distribution function between large and small particles separately, we found that the small particles outside two particles, hardly affect the interaction between them. On the other hand, analyses on the density and number fluctuation in the inner tube and the outer shell between two large particles suggested that the variation of number fluctuation in small particles result in a notable change of interaction potential between the large particles.