Adsorption of carbon dioxide on amine-modified TiO2 nanotubes

TiO2 nanotubes (TiNT) were prepared by a hydrothermal treatment and modified by three kinds of amines,namely ethylenediamine,polyetherimide and tetraethylenepentamine (TEPA),to study their CO2 adsorption properties from gas streams.The resultant samples were characterized by X-ray diffraction,transmission electron microscopy,and infrared spectroscopy,as well as low temperature N 2 adsorption.CO2 capture was investigated in a dynamic packed column at 30℃.TEPA-modified TiO2 nanotubes showed the highest adsorption capacity of 167.64 mg/g because it had the highest amino-group content among the three amines.CO2 fixation on TiNT impregnated by TEPA was investigated at 30,50,and 70℃,and the adsorption capacity increased slightly with temperature.Following the adsorption step,the sorbents were regenerated by temperature programmed desorption,and the TiNT-TEPA sample,as CO2 sorbent,was found to be readily regenerated and energy-efficient.The cycle test also revealed that the TiNT-TEPA adsorbent is fairly stable,with only a 5% drop in the adsorption capacity after 10 adsorption/desorption cycles.In addition,the CO2 adsorption behavior was investigated with the deactivation model,and which showed an excellent prediction for the TiNT-TEPA breakthrough curves.     

基于改性石墨烯固相萃取-液相色谱法测定联苯菊酯

以石墨粉末为原料通过Hummers法逐步合成磁性胺基化石墨烯(Fe3O4-NH2-G),分别用扫描电镜和FTIR对其表面形貌和化学结构进行表征,并对Fe3O4-NH2-G用于实际样品中联苯菊酯的吸附性能进行了研究.以高效液相色谱为检测手段,对洗脱液和淋洗液的选择、萃取时间和洗脱时间、离子强度、溶液p H、吸附剂总量等相关参数进行优化.实验结果表明,用1%乙酸乙腈溶液做洗脱液,50%甲醇水溶液作为淋洗液,吸附时间洗脱时间都是20 min,溶液p H值为7,不加Na Cl时吸附效果最好.在293 K下改性石墨烯的平衡吸附量136 mg·g-1.实验表明最优条件下检出限达到1.7 ng·m L-1,线性范围为0.005—10μg·m L-1,方法对实际样品的加标回收率91.8%—101.6%,可应用于痕量联苯菊酯的测定.该实验研究表明Fe3O4-NH2-G对联苯菊酯有很好的吸附能力.