一种纳米纯AgI气溶胶的制备方法及其成冰核活性的检测

Preparation of Pure AgI Nano-Aerosol and Its Efficiency of Ice Nucleation in Laboratory Experiment

将100mg纯AgI粉末置于一个气氛炉的汽化管内加热到1600℃使之汽化,再利用高压空气将气态AgI爆冲到一个容积为2m^3的金属容器里,骤冷后形成AgI气溶胶。用碳支持膜对形成的AgI气溶胶粒子自然沉降取样,然后用X射线衍射仪和电镜检测其成分和粒子尺度。检测表明:粉末状纯AgI经汽化—冷凝产生的气溶胶其成分仍为纯AgI,粒子尺度在0.84～34.6nm,峰值直径约为2.17nm。为了验证产生的纳米纯AgI气溶胶在冰核化中是否具有成冰核活性,用15L混合云室分别在云室中有冷雾和无冷雾两种条件下定量注入纳米纯AgI气溶胶,检测了它们在不同温度下的成冰核效率,检测结果是:在云室中有-10℃冷雾时,成核率为1.1×10^(11)个·g^(-1),在云室中-10℃无冷雾时,成核率约为3.4×10^(10)个·g^(-1)。

The 100 mg pure AgI powder was placed in a vaporization tube of an electrical heating furnace and heated to 1600℃ for gasification. Then, the gaseous AgI was burst into a 2 m^3 metal container by high-pressure air, and AgI aerosols were formed after suddenly cooled afterward. AgI aerosols were sampled by natural sedimentation using the formvar stabilized with carbon support films. The results indicated that the aerosol composition maintains pure AgI and the size spectrum width is 0.84-34.6 nm with 2.17 nm peaking diameter. The ice nucleation efficiency of the quantitative pure AgI nano aerosol was detected by a 15 L mixed cloud chamber, with and without fog, respectively. The preliminary results were that the efficiency of ice nucleation is little more than 1.1 × 10^11 g^-1 under the condition of - 10℃ with cold fog, and 3.4×10^10 g^-1 without cold fog.