Preparation And Characterization Of Nanoparticle-sized Agl Powders And Its Composite

Drought and water shortage has always been a problem in our nation and evenworldwide.It has been an important method for human beings to relieve watershortage by weather modification. When there is a shortage of natural ice nuclei in theclouds,it can be improved by sowing artificial ice nuclei,which is the artificialcatalyst,in the supercooled area of the clouds.The concentration of ice nuclei can beincreased by heterogeneous nucleation effect of the artificial ice nuclei,thus rainfallcan be established.Both of silver iodide (AgI) and ice crystal (H2O) belong to thehexagonal system,and the lattice parameter of the two is very approximate,as a resultsilver iodide (AgI)has been widely used as the artificial catalyst in the field of weathermodification at home and abroad. But the catalyst which has been widely used isalways in the micron level,so there is still a long way to go on nucleationrate,nucleation temperature and so on. The particular characteristics of nanometermaterials give rise to certain application prospect for nano-silver iodide powders inthe area of weather modification. Because of the surface effect of nanometermaterials,their surface area is far outweigh the one of the micron powders.Thephysical property of nano-silver iodide powders is somehow different from that of thecommercial silver iodide,which is widely used nowadays,counting on the volumeeffect and the size effect of nanometer materials.So the nucleation rate of nano-silveriodide powders could improve a lot.This article has prepared nanoscaled catalyst powders.The whole experiment consistsof two parts: The preparation and characterization of nanoparticle-sized AgI powdersis the first part. We research on such factors as the concentration of AgNO3solutionand KI solution, reaction temperature, titrate speed,stirring speed, different surfactantagents, different titration way, drying temperature and drying time do to the catalystpowders and determine the optimal technological parameters. In the second part,we changed the mole percent of Cu and synthetized Ag1-XCuXI(X=0,0.1,0.2,0.3,0.4,0.5,1.0)solid solution powders. We use the X-ray diffractometer (XRD),transmissionelectron microscope(TEM),scanning electron microscope(SEM), surface area andpore size analyzer (BET), differential scanning calorimetry(DSC) to characterize andanalyze the microstructure and the crystal structure of the nano-silver iodide powdersand solid solution powders.The research results and conclusions we have got are asfollows:1.0.05mol/l of the concentration of AgNO3solution and KI solution,25℃of thereaction temperature,40drops/min of the titrate speed,800r/min of the stirringspeed are the optimal technological parameters.2. B is the optimal surfactant agent,and the dosage of SLS is4.1×10-3mol/l.Theoptimal drying temperature of the nano-silver iodide powders is80℃～100℃.The drying time and titration way have little influence on the nano-silver iodidepowders.3. The crystallite dimension of the solid solution powders decreases with the dosageof CuI increases. The crystallite dimension of the solid solution powders reachedthe bottom line when the mole percent of the dosage of CuI is50%. The differentcomponent of the solid solution may result in the different nucleation rate, andthus result in the difference of the crystallite dimension. According to the XRDresult, both of the lattice parameter and the lattice volume decrease as the dosage ofCuI increases,and reach to the bottom line when the dosage is50%.