Study On Preparation,Self-assembly And Application Of P(NIPAm-AA-NMA-ABC) Microgels

Poly(N-isopropylacrylamide)(PNIPAm)is one of the most studied temperature-sensitive materials.Taking full advantage of the temperature sensitive properties of PNIPAm,it was copolymerized with fluorescence,glucose sensitive and ion sensitive monomers to obtain intelligent polymer materials with multiple response characteristics.These smart polymer materials have very important application value in p H and glucose fluorescence response,drug loading and controlled release,temperature sensing and heavy metal ion detection.In this paper,two kinds of smart polymer P(NIPAm-NMA-AABC)self-assembled colloidal crystal films and POSS-P(NIPAM-NBDAE-AAPBA)hybrid macromolecules were prepared by free radical polymerization,and their responses to environmental stimuli were studied.The specific contents of this paper are as follows:1.P(NIPAm-AA-NMA)microgels were synthesized by free radical polymerization of N-isopropylacrylamide(NIPAm),acrylic acid(AA)and N-hydroxymethylacrylamide(NMA),then via coupling effect of N-(3-dimethylaminopropyl)-N’-ethyl-carbodiimide hydrochloride(EDC),4’-aminobenzo-18-crown-6(ABC)decorated P(NIPAm-AA-NMA)microgels and P(NIPAm-AABC-NMA)microgels were fabricated.Finally,the colloidal crystal film was prepared by the solvent evaporation method.Fourier transform infrared spectroscopy(FTIR),scanning electron microscope(SEM)and dynamic light scattering(DLS)were used to characterize the microstructure of microgels and self-assembled films;Moreover,the temperature-sensitive properties of self-assembled films and their selective response to metal ions were investigated by Ultraviolet-visible spectrum(UV-Vis).The results indicated that the particle size of the microgels before and after modification by ABC was about 240 nm and 300 nm,respectively.With variation of environmental temperature or concentration of heavymetal ions,the particle size of the microgels in the self-assembled film changed accordingly,the incident light could be diffractedby the self-assembled film,and different structural colors of the film could be observed.2.POSS-P(NIPAm-NBDAE-AA)hybrid macromolecules were synthesized by reversible addition-fragmentation transfer(RAFT)polymerization of N-isopropylacrylamide(NIPAm),4-(2-aminoethyl acrylate)-7-nitro-2,1,3-benzoxazole(NBDAE)and acrylic acid(AA),then via coupling effect of N-(3-dimethylaminopropyl)-N’-ethyl-carbodiimide hydrochloride(EDC),3-aminophenylboronic acid(3-PBA)decorated POSS-P(NIPAm-NBDAE-AA)hybrid macromolecules and POSS-P(NIPAm-NBDAE-AAPBA)hybrid macromolecules were fabricated.Fourier transform infrared spectroscopy(FTIR),superconducting nuclear magnetic resonance spectroscopy(~1H NMR)and differential scanning calorimetry(DSC)were used to characterize the microstructure of hybrid macromolecules;Fluorescence spectrum(PL)studied the p H and glucose sensitivity of hybrid macromolecules.In addition,the drug loading and release behavior of polymer micelles were studied using insulin as a model drug.The results showed that the changes of p H value and glucose concentration in aqueous solution have obvious effects on the fluorescence emission intensity of hybrid macromolecules.The fluorescence intensity of drug loaded polymer micelles decreased with the release of insulin,and the drug release rate of drug loaded polymer micelles depended on the concentration of glucose in the release medium.