Preparation Of PEG Nanogel By 532 Nm Laser-induced Photopolymerization

Polymer nanogels have been widely used in the field of medical treatment.So far,a variety of nanogel preparation methods have been developed.Compared with traditional preparation methods,laser-controlled polymerization has obvious advantages,such as no addition of large amounts of emulsifiers and surfactants,normal temperature reaction,and fast polymerization rate.Polyethylene glycol(PEG)based monomer has good biocompatibility and water solubility,there is little loss of laser light energy during the polymerization due to polyethylene glycol diacrylate(PEGDA)is a transparent liquid at room temperature.PEGDA nanogels were prepared by combining the self-emulsifying of PEGDA and the 532 nm laser polymerization technology,the polymerization parameters were optimized and the mechanism was clarified.The main research contents are as follows:?.The self-emulsifying behavior of PEGDA400 was explored.The critical micelle concentration(CMC)of PEGDA400 in water was determined using the fluorescent probe method and surface tension method,the CMC is about 10^-0.3 mg/m L.The formation of micelle aggregates in water was showed in cryo-electron microscopy when the concentration of PEGDA400 was higher than CMC,the PEGDA400 micelle aggregates with a good spherical structure were showed in scanning electron microscopy.?.The visible light polymerization device was designed and optimized.Combining the self-emulsifying behavior of PEGDA400 monomer with the characteristics of laser energy distribution to achieve the spatiotemporal control of polymerization.Using eosin(EY)/triethanolamine(TEOA)as an initiator,monomer polymerization was carried out under continuous laser irradiation at 532 nm.The process parameters of preparing PEGDA nanogels were optimized,and the effect of reaction conditions(laser power,monomer concentration,initiator concentration and reaction time)on the average particle size of nanogels were investigated.The results show that the average particle size and the dispersion index(PDI)increase with the increase of laser power,initiator concentration and reaction time,the homogeneity and the double bond residual rate of the nanogel decreases,at the same time,small-sized nanogels can be generated due to the increased crosslink density of nanogels.The number of large-sized nanogels increases with the PEGDA400 concentration increasing from 10%g/m L to 30%g/m L while the number of small-sized nanogels increases with increasing the concentration to 50%g/m L.?.According to the characteristics of the laser energy distribution,the reaction area can be precisely controlled.nanogels with uniform particle sizes of 20.3±3.7 nm and 37.9±7.6 nm were prepared by balancing the double bond crosslinking between micelle aggregates and inside micelle,and their elastic modulus was 794.2 MPa?1.169MPa measured by atomic force microscope.?.Uniform nanogels of PEGDA700 and bovine serum albumin(BSA)were prepared,the encapsulation of catechin by PEGDA700 was achieved by one-pot method,and the particle size of catechin-loaded PEGDA700 nanogels increased.