木薯淀粉磁性微球的制备及表征

Preparation and characterization of magnetic cassava starch microspheres

采用一步共沉淀法制备木薯淀粉磁性微球,以磁含量为考察目标,考察料液比(Fe3+:Fe2+)、淀粉乳浓度、反应温度、搅拌速率、起始pH值、反应时间对木薯淀粉磁性微球磁含量的影响。通过正交实验得到最佳制备条件为:料液比(Fe3+:Fe2+)30:20,淀粉乳浓度5%,反应温度50℃,搅拌速率250 r/min,起始pH值11.5,反应时间75 min;最佳制备条件下获得木薯淀粉磁性微球磁含量为20.66%。采用傅立叶变换红外光谱、X射线衍射、扫描电镜、激光粒度仪、磁天平等对其进行表征,结果表明:木薯淀粉磁性微球中位径约为29μm,磁化率为1.192×10-3 cm3/g,产品呈现球形状态、形貌规整。

Cassava starch magnetic microsphere was prepared by one step co-precipitation. Based on magnetic content measurement, the effect of the solid-liquid ratio, starch content, reaction temperature, agitation rate, initial pH and reaction time have been investigated, and the optimal process conditions was found from orthogonal experiment as： ratio of feed liquid 30：20 （ferric iron： ferrous iron）, starch milk concentration 5%, reaction temperature 50 ℃, stirring speed 250 r/min, initial pH 11.5 and react for 75 min. The product was characterized by laser granulometer, fourier transform infrared spectrum, X-ray diffraction, scanning electron microscope and magnetic balance. The results shows that its D50 （median diameter） is 29 μm, magnetic susceptibility is 1.192×10^-3cm^3/g.