Chapter 3 - Characteristics and behavior of nanoparticles and its dispersion systems

Abstract

For nanometer-scaled devises, it is necessary to develop nanoparticle dispersion in suspension without aggregation, nanoparticles assemble on the circuit, drying and sintering technology to cause neither disconnection nor deformation. The aggregation/dispersion behavior control, which is the first process for the preparation of new functional materials using nanoparticles, is very difficult for nanoparticles with less than 100 nm in diameter. This chapter discusses the reason why the aggregation and dispersion behavior control of nanoparticles is very difficult, and reviews the basic concept and method for the aggregation and dispersion control. By using DLVO theory, it is possible to discuss the dispersion and aggregation behavior of particles in aqueous suspension. If it is possible to control the aggregation and dispersion behavior of nanoparticles in liquid by the adjustment of electrostatic interaction, the dispersion behavior can be designed by using DLVO theory. However, non-DLVO type interaction, steric, bridging, and depletion force, is generally important to control dispersion behavior of nanoparticles.