Preparation And Propetries Study Of Guanidinium Antibacterial Polymer Composite Materials

With the rapid increase of life quality, people pay much more attention to theirhealth, and thus interest in the antibacterial polymer materials has been driven frommany fields. The traditional antibacterial agents mainly include inorganic antibacterialagent and organic antibacterial agent. Inorganic antibacterial agents have manyadvantages such as high efficiency, nearly innocuity, and durability, but most of themare too expensive and easily oxidated upon long-term exposure. In contrast, organicantibacterial agents can reach satisfied antibacterial efficiency in short time, but theyhave poor stability and toxicity more or less. Polymer antibacterial agent cansuccessfully overcome these defects through the immobilization of antibacterialgroups on polymer chains. They possess strong stability, high durablity, and easy tostore. The reaction of guanidine salt with polymer provides a guanidine salt polymer,which has excellent anti-fungal and anti-bacterial property, thermal stablity, and highwashability.Composite materials with core/shell structure have aroused the increasinginterest. They can show different chemical and physical property because of theirdifferent chemical composition, and superior to single core or shell component.Polymer-inorganic core/shell nanoparticles can present extraordinary properties whichderive from the synergism between the properties of an inorganic core, such as optical,electronic, and magnetic, combined with those of polymer shell which include easyprocessing and good mechanical strength. Therefore, encapsulation of inorganicnanoparticles with polymer can effectively widen materials’ actual and potentialapplication.Guanidine hydrochloride is a common used antibacterial agent, but itsapplication is badly restricted because it is easily hydrolyzed. Silica is chemical inert,stable, hard, and beneficial to the mechanical processing. Epoxy group modified silicacan easily react with guanidinium polymer to produce antibacterial polymer materialswith core/shell structure. The optimal conditions were obtained by tuning reactiontime and temperature （the optimal reaction temperature for70℃and reaction time for 14h）. By adjusting reactant ratio, the shell thickness can be well controlled. Theexcellent antibacterial activity of SiO₂/PHGH against E. coli, P. aeruginosa, B.subtilis, and S. aureus was assayed via the minimum inhibition concentration （MIC）method。Polyglycidyl methacrylate （PGMA） is aciduric, heat-proof, weather-proof, andsolvent-proof, and the surfacial epoxy group has a good reactivity. In situ depositionof Fe3O4nanoparticles in the amino functionalized PGMA was performed firstly, andmagnetic/antibacterial bifunctional microspheres were obtained through theintroduction of guanidine hydrochloride polymer, and finally quantum dot CdTe wasdeposited on polymer surface through electrostatic adsorption. The multi-functionalcomposite microspheres with magnetic, fluorescent and antimicrobial performancewere fabricated.MIC method showed that the as-synthesized polymer microspheres havepowerful antibacterial activity against E. coli, P. aeruginosa, S. aureus, and B. subtilis.The existence of magnetisum is good for materials’ magnetic recovery under anexternal magnetic field condition. The introduction of magnetic component facilitatesthe recovery, which greatly widen their application. Due to the existence of thequantum dots, the microspheres have a targeted positioning function, and expand itsmedical application.