Application Of Membrane Technology To Classify Nano-meter Titanium Dioxide And Ferric Oxide

Nano materials arised from 1980s, as a new functional material, which has important value in theory and broad prospect in application, and is regarded as the most promising material in the 21st century. For their small particle size, high special surface, nano materials have very fantastic characteristics, such as surface effects, small dimension effects and the macroscopic quantum tunnel effects. In this paper, we primarily study the application of membrane technology in classifying and obtaining single distribution nano particles. The main work contents are summarized four parts as follows:In the first chapter of my paper, we primary introduce the synthesis and application of the two nano-particles. As a new kind of inorganic function materials, For their outstanding chemical stability and great photochemical activity, nano Titanium dioxide and nano Ferric oxide are widely used in many kinds of areas, such as nano ceramic, plastic, dope, catalyst. So it is also widely used in physic and biological engineering.In the second chapter, the preparation of titanium dioxide hydrates was prepared by TiCl₄, and urea as the precipitant. Different nano-meter titanium dioxide were prepared by 5μCA MF membrane by full circulation cross-flow model and purified by application of ultrafiltration (UF)and microfiltration (MF)in order to remove lots of ammonium chloride, the effects of chloride ion on the calcined titanium dioxide nanoparticles have been investigated. The different nano-meter titanium dioxide hydrates were characterized by ZetaPlus apparatus, the polydispersivities of permeated sample and blocked sample are smaller than the primal sample, and the average particle size of permeated sample is smaller than that of blocked sample, that of primal sample is among of them. Titanium dioxide hydrates were distilled with n-Butyl alcohol and calcinated at 500℃in a Lindberg furnace for 2h.the titanium dioxide were characterized by X-ray diffraction (XRD),specific surface area (BET), scanning electron microscopy observation (SEM) and transmission electron microscopy observation. The characterization results indicate different nano-meter particle size. The photocatalytic activity of all of the specimens was tested by carrying out the phenol and methylene blue degradation. The tests showed that the surface area and photocatalytic activities of the permeated sample were always higher than that of the blocked sample.In the third chapter, we primarily - discussed the concentration of chloride influence on the agglomeration, particle size and so on. We discovered that the existence of chloride can strongly affect the crystal size and agglomeration situation. Wide dispersivity ferric oxide hydrates were easily abtained during the preparation since changes of adding precipitant speed and stirring speed, Different nano-meter ferric oxide were prepared by 5μCA MF membrane by full circulation cross-flow model and purified by application of ultrafiltration (UF) and microfiltration (MF) in order to remove lots of ammonium chloride, The different nano-meter ferric oxide hydrates were characterized by ZetaPlus apparatus, the polydispersivities of permeated sample and blocked sample are smaller than the primal sample, and the average particle size of permeated sample is smaller than that of blocked sample, that of primal sample is among of them. Ferric oxide hydrates were dried under vacuum and calcinated at 500℃in a Lindberg furnace for 3h. The ferric oxide was characterized by X-ray diffraction (XRD), specific surface area (BET), scanning electron microscopy observation (SEM) and transmission electron microscopy observation.In the fourth chapter, we firstly applied the ultra-filtration membrane technology to purify the ferric oxide hydrates. After a series of experiments we got the optimal operation parameter. The best operation parameter is 0.48 MPa and back flux rate 15. Then we began to choose the right membrane materials by experiment, and maintain the flux. Research indicated that the PES membrane with the MWCO of 100 kDa perform the best separation effect. In the following experiment, considering the control of contamination and reuse of membrane, we study the contamination and cleanout of membrane.After all, we firstly study the application of membrane technology in separating nano titanium dioxide and nano ferric oxide. The results of two systems show the feasibility of membrane technology in obtaining single distribution nano particles, and the titanium dioxide with different size distribution shows difference in performance aspect, so apply membrane technology in separating nano particles, bring a new solution for the procedure.