银纳米线的控制合成及其对PVB薄膜的拉伸和导热性能的增强

Controllable synthesis of silver nanowire and its enhancement on tensile properties and thermal conductivity of PVB film

采用加热回流的方式合成银纳米线(AgNWs),研究温度对反应时间、聚乙烯吡咯烷酮(PVP)的加入方式对生成AgNWs形貌的影响;并将AgNWs与聚乙烯醇缩丁醛(PVB)混合后制得复合韧性导热薄膜,测试其拉伸强度和热导率。结果表明:在150℃回流35 min,可使AgNWs的还原反应顺利完成;将PVP滴加(速度约为0.1 m L/s)入AgNO_3溶液中可得到高纯度、直径约为40 nm的AgNWs;由AgNWs和PVB制得的韧性导热薄膜,同时具备较高的拉伸强度和热导率。当AgNWs/PVB复合薄膜中AgNWs的质量分数为30%时,其拉伸强度高达25.5 MPa,比PVB薄膜高出20%,此时复合薄膜的热导率为14.1 W/(m·K),高出PVB薄膜63倍。

Silver nanowires（Ag NWs）were synthesized via a modified polyol method in which a reflux heating treatment was employed. The effect of reflux temperature on the polyol reaction,the relationship between the addition methods of polyvinyl pyrrolidone（PVP）and the morphology of the formed Ag NWs were investigated. Afterward,the Ag NWs were mixed with polyvinyl butyl（PVB） solution to prepare ductile and thermal-conductive films,and the tensile strength and thermal conductivity of the composite films were studied. Researches on the synthesis of Ag NWs show that refluxing for 35 min at 150 ℃is helpful to completely finish the polyol reaction,and highly pure Ag NWs with diameters of ~40 nm can be obtained by slowly adding PVP to the AgNO_3 solution at a rate of 0.1 m L/s. Moreover,the ductile and thermal-conductive films with optimal tensile strength and thermal conductivity can be prepared by mixing Ag NWs into PVB solution. When the mass fraction of Ag NWs in the composite film is 30%,a tensile strength of 25.5 MPa and a thermal conductivity of 14.1 W/（m·K）can be achieved,which are20% higher than the tensile strength and 63 times more than the thermal conductivity of pure PVB film, repectively.