Effect of different drying techniques on silaning efficiency

Abstract

Colloidal drying is a method that is used in many areas but leads to particle agglomeration. In this study, the effects of drying methods on the agglomeration, dispersion, and silanization efficiency of silica nanoparticles (NSp) were investigated using vacuum oven dryer (VOD), rotary evaporator (RE), and freeze-dryer (FD) methods. In addition, dried silica nanoparticles were mechanically ground using a conventional ball mill system, and the relationship between grinding effect and agglomeration was investigated. The results of the SEM analysis showed that the surface energy, which increased with the reduction of the grain size as a result of the prolon-gation of the grinding time, caused the agglomeration of the grains. BET analysis, it was observed that the surface areas of silica nanoparticles vary depending on the drying method. Contact angle measurement was performed to investigate the silanization ability of silica nanoparticles and it was determined that silica nanoparticles with the low surface area had the lowest contact angle. Therefore, the silanization ability of silica nanoparticles was observed to increase with the reduction of agglomeration. As a result, the VOD technique, which allows the production of low surface area silica nanoparticles, was chosen as the best method for increasing the silanization efficiency.