| 초록 |
Using water-in-oil-in-water (W/O/W) double emulsions as template, ultrathin-shell microcapsules loading aqueous water cores are formed in the capillary microfluidic device. Owing to the electrostatic interaction between carboxyl-functionalized shellac nanoparticles and diamino-terminated NH2-PDMS-NH2, which are dispersed in inner water phase and dissolved in middle oil phase of n-hexane, respectively, the microcapsules are endowed with ultrathin shell after the evaporation of n-hexane. The parameters of flow fluxes of inner, middle, and outer phases that determine the diameter of microcapsules are investigated in detail. Cross-sectional images obtained from scanning electronic microscopy (SEM) reveal the porous surface morphology of ultrathin shell, which allows the transmembrane transport of small-sized nanoparticles such as rhodamine B, quantum dot，but not large-sized PLLA nanoparticle. Due to the permeability of membrane, microcapsules could rupture under osmotic shock. And the shell can also response to pH trigger and release the encapsulants, due to carboxyl groups of shellac nanoparticles deprotonated under alkaline condition. Combining the versatile performances of high-efficiency loading, selective permeability, controlled release of the generated microcapsule, it presents a promising platform for various applications, such as drug delivery and release. |
