聚四氟乙烯包覆纳米铜颗粒的热熔化行为的研究

固态物质在宏观尺寸时,其熔点是固定的,超细微化后熔点显著降低,当粒径小于20nm时尤为显著。纳米铜颗粒是一种热力学上处于亚稳态的粒子,在程序升温过程中受热会发生团聚,结构向更稳定的状态转变,同时放出潜热,其特性就会随之变化,因此,用常规热分析测试方法无法测得纳米铜的熔点。文章将纳米铜均匀涂在聚四氟乙烯薄膜上进行动态热机械性能测试,得到纳米铜（小于20nm）的熔点大约在341℃左右。

Studies on the Thermal Melting Behavior of Nano-copper Particles Coated with Uniform Polytetrafluoroethylene

The solid material in block size has the fixed melting point, but the melting point of super-fine powder, especially to particle with diameter less than 20 nm would be significantly decreased.Nano-copper particles are thermody-namically metastable particles, and easily changes into big particles with stable state and the features disappear with releasing latent heat.Therefore, there are many difficulties to measure melting point of nanometer copper partials with con-ventional testing methods.In the paper, nanometer copper powders are evenly coated with PTFE thin film and the dynamic thermal mechanical performance test are carried out, and the corresponding melting point of about 341 ℃ is obtained.