Three Unusual Techniques for the Analysis of Surface Modification of Clays and Nanocomposites

Abstract

Abstract Three relatively unusual techniques that might deliver interesting information about the surface modifications performed on clay minerals are described here. The instruments used and the techniques were: (1) a streaming current detector (more commonly known as particle-charge detector) to monitor changes in the colloidal charge of the surfaces of modified particles; (2) a dispersion analyzer to monitor sedimentation/ dispersion behavior as a function of the modification, and in several cases even to yield a very good estimate of size of the particles (as long as they are between 10 nm and 10 mm); and (3) nuclear magnetic resonance-based specific surface area measurements, that yield information on the area and in some cases even on changes in the hydrophobic-hydrophillic surfaces formed due to the modification. As with all analytical techniques, these methods have advantages accompanied by problems, interesting research opportunities coupled with severe limitations that might lead to misinterpretation of the results. A few examples for each technique are presented here.