PVA/AgNO3低温原位固相反应制备银泡沫及机理研究

Silver foam is one kind of new functional material with excellent performance and wide application. Thisproject is aimed to explore a novel theory and methodto prepare the silver foam. PVA/AgNO3 composite foam will be firstly obtained by using the self-developed polyvinyl alcohol (PVA) thermoplastic processing and the supercritical carbon dioxide (Sc-CO2) foaming technologies. And then the silver foam will be prepared through in situ solid-state reaction between PVA and AgNO3 in PVA/AgNO3 composite foam at low temperature.Thermoplastic composite mechanism of PVA and AgNO3 and thermoplastic processing properties of PVA/AgNO3 system will be investigated. The study will be carried out on the interactions between AgNO3, PVA and Sc-CO2 and the foaming mechanism of PVA/AgNO3composite foam.The kinetics and thermodynamics of in situ solid state reaction during the heat treatment of PVA/AgNO3 composite foam will investigated, to reveal the evolution mechanism of silver nanoparticles structure.This project will provide aclean, simple and controllable novel principle, method and technologyto prepare silver foam and help to develop the theory of solid state chemical reaction, which is of great theoretical and practical significance.

银泡沫是一种新型功能材料，性能优异，应用广泛。本项目拟研究一种新型银泡沫的制备方法和理论；拟通过自行发展的聚乙烯醇（PVA）热塑加工和超临界二氧化碳（Sc-CO2）发泡技术制备PVA/AgNO3复合泡沫，再利用PVA与AgNO3之间的原位固态反应特性，在低温下制备金属银泡沫。研究PVA与AgNO3的热塑复合机理和PVA/AgNO3体系的热塑加工性能；研究AgNO3与Sc-CO2、PVA等的相互作用和PVA/AgNO3复合泡沫的发泡机理；探索PVA/AgNO3复合泡沫热处理过程中原位固态反应动力学和热力学过程，揭示银纳米粒子的结构演变机理；考察银泡沫的多层次结构以及影响因素，建立银泡沫结构性能调控耦合机制；为银泡沫制备提供一种清洁、简便、可控的新原理、新方法和新技术，发展固相化学反应理论，具有重要的理论和实际意义。

银泡沫作为一种将金属银和泡沫特性相结合的新型三维多孔功能材料，具有催化、抗菌、传感、散热储热、电磁屏蔽、吸声降噪等多种功能，在石油化工、航空航天、能源及生物医学等领域具有广阔的应用前景。但现有的银泡沫大多采用烧结、腐蚀、电解等方法制备，工艺繁琐、条件苛刻、结构调控困难，极大地限制了银泡沫的发展及应用，亟待开发绿色高效的银泡沫制备新方法、新技术。本项目采用AgNO3和水共增塑PVA，制备了高AgNO3含量的PVA/AgNO3复合材料，进一步借助超临界二氧化碳发泡技术得到PVA/AgNO3复合泡沫，最后通过热诱导在较低温度下引发原位固相反应制得性能优异的银泡沫。系统研究了PVA/AgNO3的相互作用机理、PVA/AgNO3复合泡沫的结构调控机理以及低温原位固相反应机理，并探索了银泡沫在催化、表面增强拉曼光谱等领域的应用。项目执行期间发表SCI论文11篇，授权中国发明专利5项，申请中国发明专利2项。