Study On Preparation Of Silk Fibroin Microspheres And Silk Fibroin Stabilized Silver Nanoparticles/PVA Composite Microfibers By Microfluidic

Microfluidics is an emerging technique that studies the design,fabrication and operation of fluids at the microscale within microscopic channels.Microfluidic technology has the potential to prepare high monodispersed structure,structure of double and high order emulsion/particle and complex composition new materials full of combined functions.At the same time,microfluidic technology can also use fluids to produce fibers with various morphology controllability.It is a kind of fiber preparation technology without high voltage current,energy saving,safety and easy operation,which facilitates the production and processing of biomedical materials.Based on the microfluidic technology,this paper explores a method for preparing highly efficient monodisperse silk microspheres.The effect of silk fibroin concentration,Span-80 content in the external phase,stirring speed,cross-linking time,and flow velocity of the internal and external phases on the morphology and particle size of silk fibroin microspheres were studied.Characterized the silk microsphere emulsions and particles.The result shows that when the concentration of silk fibroin was 5wt%,the weight of Span-80 in the external phase was 4%,stirring speed was 160 rpm and cross-linking time was 2 h,the silk fibroin microspheres has high sphericity,uniform particle size distribution and high monodispersity(CV= 3.43%).The silk fibroin structure changes from an irregular crimp state to a b folded state.In this paper,the silk fibroin stabilized silver nanoparticles/PVA microfibers were reported by microfluidic spinning for the first time,and the effect of different spinning conditions on microfibers were investigated.The results shown that the morphology of microfibers were uniform and neat when the ratio of silk fibroin stabilized silver nanoparticles/PVA was 1:5,concentration of PVA solution was 25wt%,injection pump advance rate was 0.5 mL/h,stepping translation frequency was 30 Hz,and the rotating motor speed was 200 rpm.SEM and DLS characterizations shown that the silver nanoparticles were 30-50 nm and dispersed uniformly in the microfibers.X-ray diffraction(XRD)displayed the characteristic diffraction peaks of silver nanoparticles in microfibers and FTIR test proved that there was an interaction between PVA and silk fibroin stabilized silver nanoparticles after blending.