Preparation of Magnetite Nanofluids in Water Phase by Wet Beads Milling

• Main Authors: Lin,Tsung-Hsing, 林宗興
• Other Authors: 江禎立
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/05755552911464560114

碩士 === 南台科技大學 === 化學工程與材枓工程系 === 98 === With regard to the state-of-the-art of the chemical, paint- and printing inks industries, it becomes clear that further development of wet grinding technology is necessary in order to satisfy the requirements of the production of nanoparticles with specific functional properties in the future. This investigation deals with a comprehensive analysis of the dispersion behavior of magnetite(Fe3O4) powders in order to determine accurate conditions for mixing and grinding dense superparamagnetic nanofluids by the novel wet beads mill.During the grinding procedure, due to the high surface energy of particles, it is easy for particles to flocculate and difficult to disperse in aqueous solution. To avoid the phenomena of flocculation of particles, adding dispersants which tend to attach on particle surface is an effective method to solve this problem. The effect of dispersant, including PAA, PMAA and PEI, on the dispersion phenomena of Fe3O4 powders in aqueous solution was investigated. The effect of polymer molecular weight on dispersion was also studied. The degree of dispersion of powders was evaluated from the measurements of average particles size and zeta potential. The size and morphology of nanoparticles were observed by TEM and DLS. In all dispersed systems, the flocculation of Fe3O4 particles was decreased obviously after grinding procedure. The dispersion phenomena of Fe3O4 particles were explained by the adsorption of the polymer on particle surface and the increase of zeta potential. The size of nanoparticles was decreased after the grinding procedure. Furthermore, using the dispersant PEI dispersion effect is limited, we speculated that the main reason for its molecular structure has a large number of amine, so that powder aggregation caused by hydrogen bond forces. The optical properties of nanoparticles were also observed by FT-IR. Magnetic measurement revealed the fluids were superparamagnetic with a saturation of 19~22 emu/g(Fe3O4).