Self-assembled Structures And Antibacterial Properties Of Silver-based Coordination Polymers

Metal and metal-based composites have been widely used in many antibacterial fields such as surgical devices, cosmetics and ceramics due to their long-term stability and high safety. However, the metal ion release rations have always been limited by loading structures, which could reduce the antibacterial activities and restrict the application of these materials. Coordination polymers as antibacterial agents exhibit unique advantage of tunable structures, which could control the ion release ration to improve their antibacterial activity. Herein, this dissertation is focused on constructing silver, nickel, zinc and cadmium coordinationpolymers, and the effects of chemical structures and particle sizes on Ag+release abilities and antibacterial activities for silver-based coordination polymers were analyzed as well. Furthermore, self-assembled film of silver-based coordination polymers exhibits excellent bactericidal activity for practical application, The main points and contents in this thesis are summarized as follows:(1) Coordination polymers with different metal centers were synthesized and their antibacterial properties were analyzed. A series ofNi(Ⅱ), Zn(Ⅱ), Cd(Ⅱ)and Ag(Ⅰ) coordination polymers have been synthesized under hydrothermal conditions using similar organic ligands, and their antibacterial properties were analyzes as well. They exhibit fascinating structures from one-dimension (1-D) to three-dimension (3-D) due to different metal centers. Among these compounds, silver-based coordination polymers exhibit excellent antibacterial activity.(2) Silver-based coordination polymers with different frameworks and micro-/nano-particles were synthesized, and their thermal-photo stabilities were analyzed. A series of silver-based coordinationpolymers have been synthesized by using silver salts and N-/O-donor ligands via a hydrothermal reaction. The micro-/nano-particles of silver-based coordination polymers with different morphologies have been fabricated by reflux and hydrothermal methods, respectively. And the thermal-photo stabilities of these samples have been tested as well. It is shown that there are great effects of coordination modes for different ligands on constructing mononuclear or polynuclear silver building blocks with1-D to3-D frameworks. The particle sizes are ranging from0.1-0.3μm by varying the reaction methods and conditions. All of these coordinationpolymers exhibit good thermal-photo stabilities.(3) The Ag+release abilities and antibacterial properties of silver-based coordination polymers were explored. A large number of Ag+release tests and antibacterial tests have been carried out to analyze the relationship between chemical structures and Ag+release abilities. And the antibacterial activities and toxicity of silver-based coordination polymers have been explored for further discussion The tests of Ag+release ration proved that ions release capabilities of coordination polymers are closely related to their antibacterial activies. Furthermore, there are no obviously effect of particle sizes on their antibacterial activities in the range of0.1-0.3μm, Hematological study shows that silver-based coordination polymers exhibit good biocompatibility under the concentration of100ppm.(4) The self-assembled films of silver-based coordination polymer were prepared and their antibacterial performances were studied. The silver-based coordination polymers were uniformly self-assembled on glass substrates with its thickness ranging from200nm to300nm, which exhibits good chemical structure and morphobgy stabilities. There were hardly any Escherichia coli and Staphylococcus aureus sticking on it, which proved that the self-assembled film of silver-based coordination polymers is suit for further antibacterial application.