少量CuCl2·2H2O作用下制备高长径比α-半水硫酸钙晶须

摘要

In order to produce α-calcium sulfate hemihydrate (α-CaSO4·0.5H2O) whiskers with high aspect ratios, a minor amount of CuCl2·2H2O was used as the modifying agent in the process of hydrothermal treatment of calcium sulfate dihydrate (CaSO4·2H2O) precursor. The presence of 2.60×10-3mol/L CuCl2·2H2O resulted in the increase of the aspect ratios of α-CaSO4·0.5H2O whiskers from 81 to 253. The preferential adsorption of Cu2+on the negative {110}and {100} facets of α-CaSO4·0.5H2O crystal structures was confirmed by EDS and XPS. And ATR-FTIR demonstrated the ligand adsorption of Cu2+on the surface of α-CaSO4·0.5H2O whiskers. The experimental results reveal that the whiskers with high aspect ratios are attributed to the adsorption of Cu2+, which promotes the 1-D growth of α-CaSO4·0.5H2O whiskers along thecaxis.%为了制备高长径比的α-半水硫酸钙(α-CaSO4·0.5H2O)晶须,在以二水硫酸钙(CaSO4·2H2O)前驱体为原料的水热反应过程中加入CuCl2·2H2O作为媒晶剂.当反应体系中加入2.60×10-3mol/L的CuCl2·2H2O时可以使产物α-半水硫酸钙晶须的长径比由81增加到253.EDS和XPS检测结果表明, CuCl2·2H2O能够显著增加α-半水硫酸钙晶须的长径比主要是因为Cu2+优先吸附于α-CaSO4·0.5H2O晶体带负电的{110}和{100}面,从而阻碍了侧面的生长,最终导致晶体长径比的增加.ATR-FTIR 进一步证实了Cu2+主要通过配位吸附的形式与α-CaSO4·0.5H2O晶体表面进行作用.