恒温低能量乳化法制备水包油纳米乳液及其稳定性研究

Preparation and stability of oil in water nanoemulsions by low-energy emulsification method at constant temperature

25℃下用恒温低能量乳化法在水/复配壬基酚聚氧乙烯醚/生物柴油的系统中,制备了稳定的水包油纳米乳液。通过体系的相行为研究得到了纳米乳液的形成条件;用动态光散射(DLS)与透射电镜(TEM)测试纳米乳液的颗粒形貌、粒径大小及分布;并通过DLS测试纳米乳颗粒粒径随时间的变化,探索了纳米乳不稳定机制。结果表明:纳米乳液是通过双连续微乳液稀释得到,颗粒粒径主要被双连续相结构所控制,而与乳液中最终水的质量分数无关;纳米乳液体系的颗粒为球形,多分散系数小于0.2,粒径分布主要在20 nm^35 nm;纳米乳液不稳定机制符合絮凝作用。

Stable oil in water（O/W） nanoemulsions was prepared at constant temperature 25 ℃ in water/blended nonylphenol ethoxylate nonionic surfactant/biodiesel system by using the low-energy emulsification method.The formation condition of O/W nanoemulsions was found through study of phase behavior of the system.Particle morphology,particle size and distribution were determined by dynamic light scattering（DLS） and transmission electron microscopy（TEM）.Through DLS test,change of particle diameter as a function of time and the unstability mechanism of nanoemulsions were explored.The results obtained showed that the O/W nanoemulsions are obtained during the dilution of double continuous phase microemulsion.Particles size of the O/W nanoemulsions is primarily controlled by the structure of double continuous phase,and is independent on the mass fraction of water in the final emulsion.Shape of the particles of nanoemulsions is spherical.Poly-dispersivity coefficient is less than 0.2 and the distribution of particles size is concentrated in a range of 20 nm~ 35 nm.The unstability mechanism of O/W nanoemulsions fundamentally coincides with flocculation.