Preparing Nano-Particles Using Hollow Fiber Membrane Dispersion Technology

Nano-materials have many outstanding capabilities, which have wider application in every field. Using membrane dispersion technology to prepare nano-materials is the hotspot of the study in field of materials in recent years. Which uses microporous membrane or micro-filtration membrane as dispersion medium. With the effect of pressure, the solution is forced to get through the membrane into another phase. Membrane dispersion makes the solution disperse to the scale of membrane pore and intensifies the process of mass transfer in different phases. Using submerged hollow fiber membrane module to prepare nano-particles comparing with traditional method of direct precipitation, membrane dispersion technology can solve the problem on saturation controlling of the reaction system very well, It makes advantage for the full blast of nucleating. Comparing with flat membrane dispersion technology, it can improve membrane area. Comparing with tube-and-shell hollow fiber membrane module, it can avoid ditch flow effect and improve the shear force, it makes advantage for preparing high quality nano-particles.The experiment uses sodium sulfate solution as the continuous phase, barium chloride solution is dispersed into the sodium sulfate solution through the hollow fiber membrane. The microcosmic mixing of the two kinds of solutions with the liquid drops and the barium sulfate particles are created through the reaction. The influences of membrane model, membrane pore size, the reactant concentrations, disperse phase flux, dispersant for particle morphology, particle size and size distribution were investigated. The results indicate that the spherical barium sulfate with narrow size distribution and fine dispersibility could be prepared with submerged membrane module and the average size in the range of 10-30nm.