半水硫酸钙晶须水化质量分数对其水化能力的影响研究

半水硫酸钙晶须的水化能力对其应用有较大影响,为掌握半水硫酸钙晶须水化质量分数对其水化能力的影响规律,对半水硫酸钙晶须在不同水化质量分数下的水化过程进行了研究。在此基础上,采用XRD、SEM等对晶须水化产物进行了表征,结果表明:随着半水硫酸钙晶须水化质量分数的增大,其水化速度减慢;当半水硫酸钙晶须水化质量分数为1.0%时,水化产物的长径比为6;当水化质量分数为10.0%时,水化产物的长径比为30左右。水化质量分数的增大不利于半水硫酸钙晶须水化的原因在于:随着水化质量分数的增大,溶液的黏度也增大,不仅阻碍了水分子向晶须表面的扩散,还增大了晶须表面钙离子和硫酸根离子向溶液中扩散的阻力,这不利于晶须的断裂。此外,水化质量分数的增大还不利于溶液中水分子进入晶须内部与晶须发生水合反应,最终不利于晶须体积的膨胀。研究结果对调控半水硫酸钙晶须的水化能力有一定的参考意义。

Study on the effect of hydration concentration on hydration capacity of hemihydrate calcium sulfate whiskers

The hydration capacity of hemihydrate calcium sulfate whiskers has a great influence on its application.In order to comprehend the effect of the hydration concentration on the hydration capacity of hemihydrate calcium sulfate whiskers,the hydration process of hemihydrate calcium sulfate whiskers at different hydration concentrations was studied.On this base,the hydration product was characterized by means of XRD and SEM.The results shown that as the hydration concentration increased,the hydration of hemihydrate calcium sulfate whiskers slowed down.When the hydration concentration was 1.0%or 10.0%,the aspect ratio of the hydrated product was 6 or about 30 respectively.The reason why the increase of hydration concentration made against the hydration of calcium sulfate hemihydrate whiskers was that the increase of hydration concentration resulted in the increase of viscosity of the solution,which not only prevented water molecules from spreading onto the whisker surface,but also increased the resistance for Ca 2+and SO 42-on the whisker surface to diffuse into the solution,which was to the disadvantage of breakage of the whisker.In addition,the increase of the hydration concentration was not helpful for water molecules in the solution to enter into the whisker for hydration reaction and ultimately went against the swelling of the whisker.This study has reference significance for regulating the hydration capacity of hemihydrate calcium sulfate whiskers.