Preparation And Characterization Of Inorganic Polymer Composite Antibacterial Agents Based On Phosphate

At present, prevailing silver-loaded antibacterial agents have shortcomings suchas high cost, easy discolor and poor mouldproof effect, so it is important to developnew antibacterial agents instead of them. Therefore, novel inorganic polymercomposite antibacterial agents based on phosphate carriers which contained dualactive component of the antimicrobial metal ions were prepared in this paper. And thepreparation, structure, morphology and antibacterial activity of the antibacterialagents were investigated.Firstly, α-zirconium phosphate (ZrP) was prepared by cycle hydrothermalmethod, then a series of zinc ions (Zn²⁺) or/and cerium ions (Ce3+) co-doped ZrP(Zn-Ce/ZrPs) were prepared. The novel Zn-Ce/ZrPs were characterized by EDX,ICP,XRD,SEM,TEM, and the antibacterial activity on Gram-negative E. coli andGram-positive S. aureus were tested. The results showed that the basal spacing of themodified ZrP increased after exchanged with Zn²⁺, while the Ce3+does not. Therefore,the Ce³⁺was adsorbed on the surface of ZrP through hydrogen bonds, while Zn²⁺intercalated into the interlayer of ZrP. Following the import of Zn²⁺or/and Ce3+, theZeta potential and Z-average size of Zn-Ce/ZrPs slightly increased and the granularityof the Zn-Ce/ZrPs were more agglomeration.When Zn²⁺/Ce³⁺atomic ratio was0.6(Zn-Ce/ZrP3), the sample killing rate against E. coli and S. aureus after contact24.0hwere88.73%and97.98%, showed obvious synergistic antibacterial effect.Secondly, zirconium phosphate sodium (NZP) was prepared by hydrothermalmethod. Inorganic polymer composite antibacterial agents (Cu-Nd/NZPs) wereprepared by introducing copper ions (Cu²⁺ and neodymium ions (Nd³⁺) into NZPthrough ion-exchange method. The Cu-Nd/NZPs were characterized by EDX,ICP,XRD,SEM,TEM etc, and the antibacterial activity were tested. The results showedthat Nd³⁺exchange of Na+in NZP was significantly greater than the Cu2+. With thecontent of Nd³⁺increased, the crystallinity of the Cu-Nd/NZPs decreased, particle sizebecame smaller, specific surface area increased. When Cu²⁺/Nd³⁺atomic ratio was1.72(Cu-Nd/NZP1),the sample killing rate against E. coli and S. aureus after contact 24.0h were99.06%and99.93%, showed certain synergistic antibacterial effect.Finally, the impact of Cu-Nd/NZPs on cell wall/membrane and the metal ionscontent of E. coli in vivo were investigated. When Cu-Nd/NZPs and E. coli aftercontact24.0h, the cell wall and membrane of E. coli became blurred, dissolvedamaged signs and suspected inclusions leak. When Cu-Nd/NZPs contact with E. colifor3.0h, cell membrane of E. coli was damaged, result in DNA, RNA and protein inthe cytoplasm constantly leaking to the bacteria in vitro. When Cu-Nd/NZPs and E.coli after contact3.0h, a large number of K⁺and Na⁺of E. coli in vivo free to thebacteria in vitro, Mg²⁺content of E. coli in vivo was significantly reduced, andcompared to the Cu/NZP and Nd/NZP, Cu-Nd/NZP1lower Ca2+content of E. coli invivo more significant, Cu²⁺and Nd³⁺content of E. coli in vivo increased.