| The broad-spectrum and highly-effective anti-bacterial agent has gained increasing interest in recent years due to the improvement on health consciousness and raising requirement on living and medical condition. Ag NPs is an excellent inorganic anti-bacterial agent that was intensively studied recently. However, there are also some disadvantages for Ag NPs colloids such as agglomeration due to its thermodynamic instability, difficult to separation and purification and high toxicity. Recently, Ag NPs loaded on various matrice were intensively studied, in order to reduce the toxicity, to improve the dispersity and to enhance the antimicrobial properties. Herein, Ag NPS/polymer composite particles were prepared using amine functionalized spheres and self-assemblies as carriers for Ag NPS loading and their antibacterial properties were studied.Amine functionalized poly glycidyl methacrylate spheres(am-PGMA) prepared via soap-free emulsion polymerization were served as polymeric matrices to loading Ag NPs for anti-bacterial agent. The amine and hydroxyl enriched am-PGMA spheres served as both matrix for Ag+ absorbance through coordination bond and reduce agent under hydrothermal condition in a high-pressure steam sterilization. Am-PGMA/Ag NPs composite spheres with ultra-fine Ag nanoparticles in high loading level were formed in-situ which was characterized by SEM, TEM, UV-Vis, TGA and XRD. The antibacterial activity of am-PGMA/Ag-NPs were studied and discussed in detail.Results show that the best reaction condition is: the concentration of matrix is 2 mg/m L, the concentration of silver nitrate is 2 mg/m L, water/alcohol ratio is 7:3, the reaction temperature is 128 ℃(0.26 MPa), TGA analysis showed that the count of Ag NPs up to 24.5%. The minimal inhibitory concentration for E. coli is 15 mg/L, S. aureus is 20 mg/L, is equal to the concentration of Ag NPs with 3.7, 4.9mg/L. The minimal bactericidal concentration for E. coli is 20 mg/L, S. aureus is 160mg/L, is equal to the concentration of Ag-NPs with 4.9mg/L, 39.3mg/L. In conclusion, the antibacterial Property of loading Ag NPs is better than the same size colloid Ag-NPs that others had reported, so we have solved the uneasy separation and purification, agglomeration shortcomings of silver nanoparticles.PGMA self-assemblies were prepared via the reversible addition-breaking chain transfer(RAFT) dispersion polymerization. The influence of morphology and size of self-assemblies obtained by RAFT polymerization in different conversion with various amount of chain transfer agent were studied. The as-prepared vesicles functionalized by EDA were used as carrier for silver NPs loading. The optimized conditions for silver NPs loading was as follows: the water/alcohol ratio is 7:3(v/v), reaction temperature is 128 ℃(0.26 MPa), the concentration is 1 mg/m L for matrix and 0.3 mg/m L(Ⅰ), or 1 g/m L(Ⅲ) for silver nitrate. TG analysis indicated that the content of Ag NPs is 12.55%, 20.91%, respectively. Antibacterial test results show that MIC of the sampleⅠand samples Ⅲ is 5, 5 mg/L, against E. coli and 2.5, 5 mg/L against S. aureus, respectively, which is equal to 0.63, 1.05, 0.31, 0.52 mg/L of Ag NPs respectively. MBC is 10, 10 mg/L against E. coli, and 80,80 mg/L against S. aureus respectively, which is equal to 1.26,2.10,10.04,16.73 mg/L of Ag NPs respectively. In conclusion, its antibacterial performance of Ag NPs loaded vesicles is better than that of colloid Ag-NPs in the same size as reported in other work, which could be concluded as synergistic effect of vesicles and Ag NPs. |
PDF Full Text Request