Synthesis of environmental multi-responsive microcapsules

PNIPAAm and ALG were introduced into the shell of microcapsules based on the layer-by-layer technique via hydrogen bond.This render the microcapsules have biocompatibility,thermosensitivity and pH-sensitivity.To improve the dispersity and stability of microcapsules,extra bilayer of PAH/PSS was deposited on the outmost layer of microcapsules.Afterward,Ag nanoparticles were synthesized in the shell of microcapsules by in-situ reduction due to abundant of functional groups.The heat from the nanoparticles after radiated by 420 nm light will affect the permeability of microcapsules,which endows the microcapsules with light-sensitivity.Besides,the structure and surface morphology of microcapsules were assayed by TEM,SEM and AFM,which showed that the microcapsules had a good dispersity and integrality.This method couples multi-sensitivity in one microcapsule,which will extend the application of microcapsules in drug release and sensor.