Surface Modification Of Ultrafine Silicon Dioxide And Preparation Of Multi-porous Structure Materials

This paper mainly investigated that surface modification of ultrafine silicon dioxide is carried out in view of recycle byproduct. By the surface modification to ultrafine silicon dioxide, Si-OH bonds on the surface decrease; another hydroxide groups react with modifying reagent by chemical bond, and become hydrophobe groups. So we may regard the modified ultrafine silicon dioxide as analogous cation surfactant. In the process of porous structure materials synthesis, the modified ultrafine silicon dioxide acts as silicon resource. The tradition idea of silicon resource choice is changed; on the other hand, the hybrid self-assembly capacity is enhanced.The first, the surface modification with silicon coupling reagent to ultrafine silicon dioxide, which roots in byproduct in fiber manufacturing, is investigated in this paper. The experimental results show that infrared intensity of Si-OH bonds on the surface is decreased and thermo-gravimetric (TG) loss is increased by using Fourier infrared (FTIR) spectroscopy and thermo-gravimetric analyzer, which indicates Si-OH bonds on the surface of ultrafine silicon dioxide has reacted with silicon coupling reagent by chemical bonds; By using dynamic laser light scattering (DLS) and scanning electron microscopy (SEM) techniques, particle sizes of ultrafine silicon dioxide is minished and the congeries dispersibility is obvious improved, which indicates the hydrophobic property of ultrafine silicon dioxide after being modified has been much more strengthened, and gain surface modification's ends. Then we synthesize multi-porous structure materials with the modified ultrafine silicon dioxide as silica resource, cetyltrimethyl ammonium bromide (CTAB) as template and H2O as solvent medium according to method of mesoporous materials prefabricating through superamolecular assembly or cooperative effect, and investigate its structure and characters by using FTIR, X-ray diffraction (XRD), TEM, Nitrogen adsorption-desorption techniques, etc. The results show that material framework possesses tropism crystal silica-based structure, and the material has multi-porous distribution and ordinary surface areas;Surface area of BET is 5.0194 m2/g, surface area of Langmuir is 6.5364 m2/g, porous areas is 0.7042 m2/g, out surface areas is 4.3872 m2/g;adorption average porous diameter is 51.6 nm, desorption average porous diameter is 50.2 nm after the sampler is calcined at room temperature.In addition, relations between morphology of multi-porous materials and crystallization temperature of multi-porous materials synthetic process are studied. The results show high-temperature crystallization leads to the form of regulation sphericity particle, then the room temperature crystallization forms club-shaped or other irregular shapes by using SEM technique analysis.Multi-porouse structure materials have many unique properties. Surface of mesoporous channel may be modified by physical adsorption or chemical modification. Those methods also have lot of advantage for the functionalization and applied research, which provides wide market to reuse ultrafine silicon dioxide waste material.