材料期刊网

采用X射线衍射（XRD）、Fourier红外吸收光谱（FT-IR）、扫描电子显微镜（SEM）分析了热活化坡缕石晶体结构及显微形貌,并采用Zeta（ζ）电位分析仪、比表面积分析仪及原子吸收光谱仪（AAS）测定了热活化坡缕石的ζ电位、比表面积及饱和Cu2＋交换吸附量。结果表明热活化温度对坡缕石ζ电位无显著影响。当热活化温度低于250℃时,坡缕石脱出吸附水及部分配位水,比表面积显著增大,但晶体结构无明显变化;热活化温度为350~650℃时,坡缕石将脱出配位水和结构水,并发生“折叠作用”,使得坡缕石表面活性中心增加,至750℃时晶体结构完全破坏,而比表面积则随热活化温度的升高依次降低。坡缕石饱和Cu2＋交换吸附量仅与热活化温度密切相关,当热活化温度为450℃时,坡缕石饱和Cu2＋交换吸附量最大。

The effect of thermal treatment temperature on the crystal structure and microtopography of palygorskite were studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electronic microscopy (SEM). The zeta (ξ) potential, specific surface area and the saturation ion exchange capacity to Cu2+ of thermal activated palygorskite were also measured by zeta potential analyzer, specific surface area analyzer, atomic absorption spectrometer (AAS). The results indicate that the zeta potential of palygors- kite is not distinct changed by thermal activation temperature. The adsorbed water and partial coordinated wa- ter are dehydrated, and the specific surface area is distinct increasing, but the change of crystal structure is un- conspicuous when the thermal activation temperature is below 250℃. The coordinated water and constitution water are dehydrated, the folded structure appears and the surface activated center of palygorskite was increased with the thermal activated temperature increasing from 350 to 650℃, the crystal structure of palygorskite was completely destructed at 750℃. The specific surface area is regularly decreasing along with the thermal activated temperature increasing from 350 to 750℃. The saturation ion exchange capacity to Cu2+ of thermal activated palygorskite is only related with the thermal treatment temperature and reaches the maximum at 450℃.