Study On Polarity-regulating Self-assembly Of 4-vinylbenzoic Acid On Fe₃O₄ Nanoparticles In Ethylene Glycol

In this work,the self-assembly and polymerization of 4-vinylbenzoic acid with magnetic nanoparticles in different solvents were stuided.Ethylene glycol was selected as the best solvent and then preparation conditions were optimized.Finally,adsorption of bovine on nanoparticles was researched.First of all,by using the co-precipitation reaction,adding surface modifier,washing with ethanol/distilled water,monolayer oleic acid coated Fe₃O₄ nanoparticles（Fe₃O₄@OA）was obtained;then ethylene glycol,n-butanol,dioxane and glycerol solvent were chosen as the solvent.The stability of Fe₃O₄@OA nanoparticles in the four solvents was stuided,the results show that the particles can be dispersed stably in the ethylene glycol and glycerol,and the particles were apt to deposit in n-butanol and dioxane after 8h.At the end,the self-assembly and polymerization of 4-vinylbenzoic acid with magnetic nanoparticles in different solvents were stuided.According to the analyses of FT-IR,TGA and conductometric titration curves,the result of self-assembly and polymerization in ethylene glycol was the best.Secondly,factors affecting self assembly system and polymerization process were researched in ethylene glycol solvent system.Three groups of experiments were designed.According to the analysis of FT-IR,TGA,the optimun experimental conditions were discovered.The solvent was pure ethylene glycol,the temperature of self-assembly was 50℃,temperature of polymerization was 80℃ and polymerization time was 4h.Thirdly,after getting the optimal experimental conditions,by increasing content of 4-vinylbenzoic acid,the structure of nanoparticles as core-shell was stuided.Adding 40mg monomer was the best adding monomer,the polymer weightlessness rate was 22.9%,content of carboxyl coated Fe₃O₄@OA nanoparticles was 1.3 87mmol/g.Carboxyl coated Fe₃O₄@OA was core-shell structure.Finally,bovine albumin（BA）adsorption on carboxyl coated nanoparticles was researched.Experimental results show that the maximum adsorption capacity was 152.45mg/g when the pH was 5.2,the initial concentration of BA was 1mg/mL and adsorption time was 2h.