Methods of colloid vibration imaging for characterisation of nano-particle suspensions

M. Wang, M. Hosseini, L. Bramson, J.I. Khan
University of Leeds, UK

Keywords: colloid vibration potential imaging, physiochemical feature, theoretical models, nano-particles, ions, characterisation

Summary:

This paper addresses various aspects in the development of the new imaging technique, colloid vibration potential imaging. Two theoretical models are introduced, including an extended (2D) slab model and a 3D electric dipole model. These models are well meeting the experimental observations. A new test cell is reported, which provides a convenient access to the cell for testing various colloid simples. New sensing electronics and Moving Window Matched Filter Demodulation were applied to enhance signal quality and process methods. Various samples were tested and results are reported in the paper, including colloids “sandwich” samples with silica particles size-ranged from 18 nm to 220 nm and concentration-ranged from 0.5 wt% to 5 wt%, and various electrolytes “sandwich” samples, including NaCl, KCl, RbCl, CsCl, and MgCl2, CaCl2, SrClo2, BaCl2, and VCl3, MnCl2, CuCl2, FeCl2, FeCl3. The non-structural features, e.g. the effects of particle size and molecular weights of ionic species are discussed and reported in the paper.