用于稳定Pickering乳液的氨基化明胶纳米颗粒的制备

Preparation of Aminated Gelatin Nanoparticles Used to Stabilize Pickering Emulsion

摘要:

以氨基化改性的B型明胶为原料，通过二次去溶剂法可制得具有良好单分散性（PDI ≈ 0.068）的氨基化明胶纳米颗粒（Aminated gelatin nanoparticles，AGNPs）,其粒径约为240 nm，表面带正电荷（ζ ≈ 35 mV）。考察了制备过程中溶液pH对AGNPs粒径以及分散性的影响，结果表明，当pH ≈ 4.0时，制备的AGNPs粒径较小（≈ 240 nm），分散较为均匀。SEM、AFM及TEM测试结果表明，AGNPs为一种粒径窄分布的球形纳米颗粒；相比明胶纳米颗粒（Gelatin nanoparticles，GNPs），AGNPs刚性结构特点增强，且质地较为均匀。颗粒表面润湿性测试结果显示，AGNPs的三相接触角（θow = 67° ± 5°）比GNPs（θow = 31° ± 6°）显著增大，表明AGNPs的表面疏水性有所增强。以AGNPs为稳定剂制备的水包油（O/W）型Pickering乳液4 °C下储存9个月未出现分层，表现出较高的稳定性。

Abstract:

Fairly monodispersed aminated gelatin nanoparticles (AGNPs, PDI ≈ 0.068) were prepared by a two-step desolvation method using amino-modified type B as raw material. The particle is positively charged (ζ ≈ 35 mV), with an average size of 240 nm. The effects of pH on the size and dispersity of AGNPs is investigated in the preparation process. It shows that the optimized reaction condition is pH = 4, which can endow the AGNPs with a smaller particle size (≈ 240 nm) and uniform distribution. The results from atomic force microscopy (AFM), scanning electron microscope (SEM) and transmission electron microscopy (TEM) showed that the AGNPs exhibited spherical morphology with a narrow particle size distribution. And compared with gelatin nanoparticles (GNPs), the rigid structure and homogeneity of AGNPs is enhanced. Moreover, the higher three-phase contact angle of AGNPs (θow = 67° ± 5°) than that of GNPs (θow = 31° ± 6°), as evaluated by surface wettability analysis, indicates the increased surface hydrophobicity and capability for the stabilization of O/W Pickering emulsion. Pickering emulsion stabilized by AGNPs can store at 4 ℃ for 9 months without stratification, possessing good storage stability.