关键词: 丝素, 超临界流体强制分散溶液, 纳米颗粒, 制备, 表征

Abstract: Using silk fibroin as raw material and 1,1,1,3,3,3-hexafluoro-2-propanol as solvent，the solution-enhanced dispersion by supercritical fluid (SEDS) process was used to prepare silk fibroin nanoparticles. The influences of pressure，solution concentration，solution velocity and CO2 velocity on particle size and particle size distribution of nanoparticles were investigated；the Zeta potential，Headspace gas chromatography (HS-GC)，Fourier transform infrared spectroscopy (FTIR)，X-ray diffraction (XRD) and Differential scanning calorimetry (DSC) were also used to characterize the resulting nanoparticles. The results of dynamic laser light scattering detection show that the particle size of silk fibroin nanoparticles increases with the increase of pressure，solution concentration and solution velocity；while the opposite phenomenon is observed for the CO2 velocity，and the minimum particles size is 298nm. The Zeta potential of silk nanoparticles is ?39mV. The results of HS-GC show the organic solvent residue of silk nanoparticles is 20μg/L. After SEDS process，the results of FTIR show that chemical structure and functional group of the silk fibroin do not change，however，the results of XRD and DSC indicate that the secondary structure shifts from random coil to β-sheet.

Key words: silk fibroin, solution-enhanced dispersion by supercritical fluid, nanoparticles, preparation, characterization