Controllable Preparation And Application Of Nano-Silica

Carbon black has been used as rubber filler for nearly 150 years until the development of white carbon black (silica) in 1990s. white carbon black has a small particle size with the surface containing the active silicon hydroxyl group. Especially bridging effect of silane coupling agent with silica enhances the properties of rubber material. For example the rubber material's anti-slippery performance, hysteresis loss, had been significantly improved. More significantly, rolling resistance of the rubber is greatly reduced. In recent years, especially the green tire or high performance tire production all cannot do without the use of nano-silica. International famous chemical enterprises, Rhodia and Degussa, successfully developed the easily dispersed and highly dispersed silica (i.e. easily dispersed silica, EDS and highly dispersed silica, HDS),and a various types of products are widely used in the green tire, however, our country there is still not the advent of high quality silica products. Therefore, development of high performance silica is currently an important topic. In this thesis, two different methods for the synthesis of high performance silica products had been developed:(1)Water glass working as raw material by sulfuric acid precipitation method, strong electrolyte, sodium chloride, is introduced in the liquid environment, using sodium dodecyl benzene sulfonate as surface active agent for preparing white carbon black products of high performance. In the experiment, the experimental parameters such as the concentration of substrate, reaction temperature, concentration of sodium chloride and the addition of sulfuric acid were studied and the optimum technics of preparation was obtained. Transmission electron microscope, scanning electron microscope and oil absorption value, BET, laser particle size analysis test had clearly showed that:the prepared silica particles have a narrow size distribution, the particle size 25.37nm, aggregate particle diameter 130.6nm, BET specific surface area 136.0m2/g, oil absorption value 2.3mL/g, dispersion index 2.98, representing a good dispersion.(2)Orthogonal experimental was designed, using PEG as dispersant, in sulfuric acid precipitation method, preparating of high performance silica products. Experiments explored the effects of concentration of water glass, dispersing agent content on oil absorption value and diameter of the white carbon black particles. By optimizing the experimental conditions we had obtained the optimum preparation parameter.the concentration of water glass was 0.35mol/L, polyethylene glycol (PEG) quality for 10%of the quantity of water glass; obtained silica particle size is 11.96nm, DBP reached a maximum value of 3.0 mL/g. Infrared spectroscopy showed the successful modification of polyethylene glycol on the surface of silica and the EDS spectrum indicated that the content of silica is more than 85 percent in the white carbon black production we had prepared in the optimum preparation condition.