In the particle technology, it is fundamentally important to know the interaction and adhesive forces between particles and to find the correlation of those forces with the microscopic characteristics of particle surface, because these forces are the origin of many phenomena which particles exhibit. Most investigations on these forces reported so far have been carried out using macroscopic and statistical techniques. Hence it is impossible to clarify the relationship of these forces with the local and microscopic characteristics of the surfaces by which the interaction forces are influenced greatly.
There are two kinds of devices to obtain in-situ information of molecular level on the interaction forces between surfaces; Surface Force Apparatus (SFA) and Atomic Force Microscope(AFM). In the case of SFA, the interaction forces can be measured accurately, but transparent, smooth and large surfaces must be employed. The advantages of AFM are as follows: (1) the interaction and adhesive forces between surfaces of any kind are possibly measured if the surfaces are able to be glued on the probe, (2) the local microscopic features of the surface are obtained and they can be correlated with the interaction force, and (3) the device is simple and easy to handle.
The aim of this research is to clarify on the molecular scale the interaction and adhesive forces between surfaces in various solutions and correlate those with the micro-structure of the surfaces, using an AFM. The following figure illustrates the whole map of experiments which we are going to do in this program.
In this report the experiments of the interaction and adhesive forces between SiOz and Mica surfaces in alcohol-water solutions and in dioxane-water solutions which are non- aqueous but miscible with water are reported, and the correlation of those forces with the microstructure on the surfaces is discussed, The effects of the addition of a surfactant, AOT, are also examined. The abstracts for these investigations are given below.