微乳液耦合微波辐照制备β-半水硫酸钙

Preparation ofβ-hemihydrate calcium sulfate by microemulsion coupled and microwave irradiation

该文以表面活性剂SDS为晶型控制剂,正辛烷为油相,正戊醇为助表面活性剂,把硫酸配制成微乳液,与氯化钙溶液进行反应,在微波加热条件下快速合成β-半水硫酸钙,并探究了反应温度、反应时间、原料浓度、SDS用量、搅拌速率对产物相态及形貌的影响.使用TG-DSC、XRD、SEM、FT-IR仪器对部分样品进行表征,初步探讨了β-半水硫酸钙形成机理.结果表明,增加反应时间、反应温度、SDS用量可促使二水硫酸钙转化为β-半水硫酸钙,样品形貌多为长棒状,尺寸较大,且存在颗粒状物质,可能为未转化的二水硫酸钙,同时增大SDS用量使硫酸钙长径比减小.

In this paper,surfactant SDS was used as crystalline control agent,n-octane was in the oil phase and n-amyl alcohol was a co-surfactant.Sulfuric acid was prepared into microemulsion and reacted with calcium chloride solution,β-hemihydrate calcium sulfate was synthesized under microwave heating conditions.To explore the influence of reaction temperature,reaction time,concentration of raw materials,dosage of SDS and stirring speed on the phase state and morphology of product.TG-DSC,XRD,SEM and FT-IR were used to characterize some samples.The formation mechanism ofβ-hemihydrate calcium sulfate was discussed.The results show that increasing the reaction time,temperature and SDS mass can promote the conversion of calcium sulfate dihydrate intoβ-hemihydrate calcium.The morphology of the samples is mostly in the shape of long bar and large size.There is also a granular substance which may be unconverted calcium sulfate dihydrate.Meanwhile increasing the SDS mass can reduce the length-diameter ratio of calcium sulfate.