微波强化掺Al-TiO_2改性膨润土的制备及其结构表征

Preparation of bentonite modified by Al-TiO_2 with microwave radiation and its structure characterization

为制备一种新型水处理吸附剂复合材料,在微波作用下,采用掺Al-TiO2作为改性剂制备改性膨润土,考察了最佳微波辐射条件,利用EDS、SEM、FTIR、XRD、N2吸附-脱附和差热热重(DSC-TGA)等手段对样品进行表征。结果表明:辐射功率260 W,辐射时间8min为最佳微波辐射条件;改性膨润土中的改性剂已进入到膨润土层间,与蒙脱石骨架发生成键反应,形成Ti—O—Si键;改性膨润土的层间距由1.280nm增大至1.533nm,比表面积由39.66m2·g-1增大至72.05m2·g-1,孔隙体积由0.103 4cm3·g-1增大至0.140 5cm3·g-1,对亚甲基蓝的饱和吸附量也由32.56g/100g增大至57.96g/100g,且热稳定性较改性前明显提高。

In order to prepare a new composite of water treatment adsorbent,modified bentonite was prepared under microwave radiation by using doped Al-TiO2 as modifier.The best condition of microwave radiation was investigated.The samples were characterized by EDS,SEM,FTIR,XRD,N2adsorption-desorption,differential scanning calorimetry and thermal gravity analysis(DSC-TGA).The results show that the best condition of microwave radiation are microwave power 260 Wand microwave time 8min.The modifier enters into the interlayer of bentonite and Ti—O—Si bond is formed between the framework of bentonite in the modified bentonite.The interlayer spacing increases from 1.280 nm to 1.533 nm,the surface area increases from 39.66m2·g-1 to 72.05m2·g-1,the pore volume increases from 0.103 4cm3·g-1 to 0.140 5cm3·g-1,while the saturated adsorption capacity of methylene blue increases from 32.56g/100 g to 57.96g/100 g,and the thermal stability is evidently improved by modification.