Antibacterial Ag-agents are intensively applied as broad spectrum, high-stability, high-efficiency and high-safety inorganic antibacterial agents. We have developed a new kind of antibacterial Ag-agent, namely Ag_2-x(...Antibacterial Ag-agents are intensively applied as broad spectrum, high-stability, high-efficiency and high-safety inorganic antibacterial agents. We have developed a new kind of antibacterial Ag-agent, namely Ag_2-x(NH_4)xMo_3O_(10) ·3H_2O nanowires(NWs). Carrying Ag atoms in the lattice and Ag-rich nanoparticles on the surface, the Ag-doped NWs show strong antibacterial effects for a variety of bacteria including E.coli, Staphylococcus aureus, Candida albicans and Aspergil lus niger. By performing systematic comparison experiments, we have proven that the main antibacterial effects are neither resulted from the tiny amount of Ag+ions released from the Ag-doped NWs in aqueous solutions, nor resulted from Ag-rich nanoparticles of fragments of the NWs when they are slowly dissolved in the Martin broth. Instead, the effects are mainly resulted from a contact mechanism, under which, the Ag-doped NWs need to be physically in contact with the bacteria to be eliminated. This is a novel phenomenon observed in the interactions between nanomaterials and live cells, which is worthy of further investigation at the molecular scale. As the Ag-doped NWs are not dissolved in pure water or weak acids, one may find practical antibacterial applications in textile industry and food storage industry for these unique nanomaterials.展开更多
Tdmercaptotriazine-functionalized polystyrene chelating resin was prepared and employed for the adsorption of Ag（I） from aqueous solution. The adsorbent was characterized according to the following techniques： Four...Tdmercaptotriazine-functionalized polystyrene chelating resin was prepared and employed for the adsorption of Ag（I） from aqueous solution. The adsorbent was characterized according to the following techniques： Fourier transform infrared spectroscopy, elemental analysis, scanning electron microscopy and the Brunauer-Emmet-Teller method. The effects of initial Ag（I） concentration, contact time, solution pH and coexisting ions on the adsorption capacity of Ag（I） were systematically investigated. The maximum adsorption capacity of AgO） was up to 187.1 mg/g resin at pH 0.0 and room temperature. The kinetic experiments indicated that the adsorption rate of Ag（I） onto the chelating resin was quite fast in the first 60 rain and reached adsorption equilibrium after 360 min. The adsorption process can be well described by the pseudo second-order kinetic model and the equilibrium adsorption isotherm was closely fitted by the Langmuir model. Moreover, the chelating resin could selectively adsorb more Ag（I） ions than other heavy metal ions including： Cu（Ⅱ）, Zn（Ⅱ）, Ni（Ⅱ）, Pb（Ⅱ） and Cr（Ⅲ） during competitive adsorption in the binary metal species systems, which indicated that it was a highly selective adsorbent of Ag（I） from aqueous solution.展开更多
基金the NSF of China(Grant No.11074010)the MOST of China(Grant No.2011DFA51450)for financial support
文摘Antibacterial Ag-agents are intensively applied as broad spectrum, high-stability, high-efficiency and high-safety inorganic antibacterial agents. We have developed a new kind of antibacterial Ag-agent, namely Ag_2-x(NH_4)xMo_3O_(10) ·3H_2O nanowires(NWs). Carrying Ag atoms in the lattice and Ag-rich nanoparticles on the surface, the Ag-doped NWs show strong antibacterial effects for a variety of bacteria including E.coli, Staphylococcus aureus, Candida albicans and Aspergil lus niger. By performing systematic comparison experiments, we have proven that the main antibacterial effects are neither resulted from the tiny amount of Ag+ions released from the Ag-doped NWs in aqueous solutions, nor resulted from Ag-rich nanoparticles of fragments of the NWs when they are slowly dissolved in the Martin broth. Instead, the effects are mainly resulted from a contact mechanism, under which, the Ag-doped NWs need to be physically in contact with the bacteria to be eliminated. This is a novel phenomenon observed in the interactions between nanomaterials and live cells, which is worthy of further investigation at the molecular scale. As the Ag-doped NWs are not dissolved in pure water or weak acids, one may find practical antibacterial applications in textile industry and food storage industry for these unique nanomaterials.
基金supported by the Chinese Academy of Science and Technology Project in Support of Gansu (No.XBLZ-2011-013)
文摘Tdmercaptotriazine-functionalized polystyrene chelating resin was prepared and employed for the adsorption of Ag（I） from aqueous solution. The adsorbent was characterized according to the following techniques： Fourier transform infrared spectroscopy, elemental analysis, scanning electron microscopy and the Brunauer-Emmet-Teller method. The effects of initial Ag（I） concentration, contact time, solution pH and coexisting ions on the adsorption capacity of Ag（I） were systematically investigated. The maximum adsorption capacity of AgO） was up to 187.1 mg/g resin at pH 0.0 and room temperature. The kinetic experiments indicated that the adsorption rate of Ag（I） onto the chelating resin was quite fast in the first 60 rain and reached adsorption equilibrium after 360 min. The adsorption process can be well described by the pseudo second-order kinetic model and the equilibrium adsorption isotherm was closely fitted by the Langmuir model. Moreover, the chelating resin could selectively adsorb more Ag（I） ions than other heavy metal ions including： Cu（Ⅱ）, Zn（Ⅱ）, Ni（Ⅱ）, Pb（Ⅱ） and Cr（Ⅲ） during competitive adsorption in the binary metal species systems, which indicated that it was a highly selective adsorbent of Ag（I） from aqueous solution.
