Donselaar LN, Philipse AP
Debye Research Institute, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands
J Colloid Interface Sci. 1999 Apr 1;212(1):14-23. doi: 10.1006/jcis.1998.5931.
The magnetic and Van der Waals attraction between uncharged silica spheres with a magnetic core has been studied using sedimentation and static and dynamic light scattering techniques. Specifically the effect of the interactions on the concentration dependence of the sedimentation velocity, diffusion, and the apparent radius of gyration was investigated. It was found experimentally that the concentration dependence is decreased significantly as a result of the Van der Waals and magnetic attractions and even may change sign in comparison to the hard-sphere case. Calculations of the (linear) concentration dependence for weak interactions predict this decrease and also indicate that for the silica-magnetite particles the second virial coefficient passes a maximum with increasing silica layer thickness. Copyright 1999 Academic Press.
利用沉降法以及静态和动态光散射技术，对具有磁芯的不带电二氧化硅球体之间的磁吸引力和范德华吸引力进行了研究。具体而言，研究了这些相互作用对沉降速度、扩散以及表观回转半径浓度依赖性的影响。实验发现，由于范德华力和磁吸引力，浓度依赖性显著降低，与硬球情况相比甚至可能改变符号。对弱相互作用的（线性）浓度依赖性计算预测了这种降低，并且还表明，对于二氧化硅 - 磁铁矿颗粒，第二维里系数随二氧化硅层厚度的增加而通过一个最大值。版权所有1999年，学术出版社。
