基于纳米氢氧化铝颗粒的Pickering乳液制备

Preparation of Pickering emulsion based on alumina hydroxide nanoparticles

以异丙醇铝为原料,采用醇盐水解-水热法制备勃姆石型纳米氢氧化铝颗粒,优化制备条件;以所制颗粒为稳定剂、角鲨烯为油相,通过超声破碎法制备Pickering乳液,考察了颗粒浓度、水相成分、超声时间及功率对Pickering乳液粒径及稳定性的影响。结果表明,水热温度200℃、水热时间2 h条件下,可制得结晶度高且均一的勃姆石型纳米氢氧化铝颗粒,平均粒径为55.70±9.20 nm,多分散性指数(PDI)为0.187±0.011;所制Pickering乳液平均粒径为1 870±55 nm,PDI=0.120±0.010,可在室温下稳定储存120 d以上,且生物相容性良好,有望应用于生物医药领域。

Pickering emulsion is a new type of emulsion stabilized by solid particles instead of traditional organic surfactants. Compared to the traditional surfactantstabilized emulsion, Pickering emulsion has the advantages of strong interfacial stability, regeneration, low toxicity and low cost, and has broad application value in the fields of food, medicine and cosmetics. The size of solid particle for stabilizing Pickering emulsion is in the nanometer range. The particles used to prepare Pickering emulsion are generally inorganic particles and polymer particles, most of which are not biocompatible or easily degradable. It is important to choose materials that have both good biocompatibility and stability. In this work, the boehmite-type aluminium hydroxide nanoparticles were prepared from aluminum isopropoxide by hydrolysis-hydrothermal method. Pickering emulsion was prepared by using boehmitetype aluminium hydroxide nanoparticles as stabilizer and squalene as oil phase. The effects of preparation conditions on size distribution and stability of Pickering emulsion were examined, including the concentration of nanoparticles, aqueous phase and dispersion condition. The results showed that two main factors affected the formation of nanoparticles were hydrothermal temperature and time. When the hydrothermal temperature was set to 200 ℃ for 2 h, the boehmite-type aluminium hydroxide nanoparticles were spherical with good dispersibility, uniform size distribution and high crystallinity. The average size of boehmite-type aluminium hydroxide nanoparticles was 55.70±9.20 nm and the polydispersity index was 0.187±0.011. The average size of Pickering emulsion was 1 870±55 nm and the polydispersity index was 0.120±0.010. The Pickering emulsion could be stored stably at room temperature for more than 120 d. Based on this study, Pickering emulsion with uniform size distribution and good dispersibility was prepared, which provided a new material for biomedical area.