Go Stable Pickering Emulsion And Its Aggregation

Pickering emulsion is a novel emulsion system, it uses inorganic or organic solid particles instead of the conventional surfactant to stabilize the emulsion. It has a very important value in the field of separation technology, FMCG products, bio-medicine, composite materials and so on. In this paper, we use nano graphite oxide sheets (GO) prepared according to Hummers method as the stabilizer to prepare the Pickering emulsion using methyl methacrylate (MMA) as the oil phase. Also Pickering polymerization was conducted.According to Hummers method, we use natural graphite, KMnO4, NaN03and sulfuric acid to prepare graphite oxide (GO), and we carried out the characterization by means of FTIR,TGA,XRD,XPS,TEM and so on. It turns out that the graphite oxide (GO) we obtained has a excellent degree of oxidation, and it’s thickness was nano-size. Also it can be dispersed in the water to form a uniform and stable dispersion.We prepared the MMA/water Pickering emulsion using graphite oxide sheets (GO) dispersed in the water as stabilizer. And we studied the influence to the stability and the droplet size of the GO sheet in contrast to the traditional emulsifier sodium dodecyl benzene sulfonate (SDBS). We found that Pickering emulsion stabilized by GO sheets showed well stability, and the size distribution was uniform. Also we studied the impact to the stability and the size of the droplet of the concentration of GO, pH, ratio of oil-water. The increase of the concentration of GO can improve the stability of the emulsion, however high concentration of GO will make the viscosity of the emulsion too large, so suitable concentration is very important. Acid environment is more favorable for GO sheets absorbing to the interface of oil-water. Also suitable ratio of oil-water is very crucial to forming a stable Pickering emulsion, phase inversion may occur when the volume of the oil phase is large enough.Polymerization of the Pickering emulsion using water soluble initiator KPS and oil soluble initiator AIBN was conducted individually. Each mechanism of polymerization was discussed, on the other hand, we studied the polymerization kinetics of the Pickering emulsion polymerization, also detailed characterization of the product of the Pickering polymerization was conducted, the results showed that we can obtained GO/PMMA composite material with good performance by using Pickering polymerization.