氨基改性过程引入去离子水对层状双氢氧化物CO_2吸附性能的影响规律研究

Absorption capacity of carbon dioxide on Mg/Al layered double hydroxide with deionized water adding during amine modified process

以共沉淀方法合成了十二烷基磺酸钠插层的Mg/Al层状双氢氧化物,并采用超声剥落方法进行氨基改性。利用元素分析、X射线衍射技术和扫描电镜表征所得样品的成分、结构以及形貌特征,利用热重分析技术表征样品在30℃、1.013×105 Pa下对CO2的吸附能力以及吸附-脱附循环再生性能。在氨基改性过程的超声剥落环节引入一定量的去离子水,重点考察了去离子水对氨基改性层状双氢氧化物的氨基负载量和CO2吸附性能的影响规律。结果表明,当改性过程中加入的去离子水量为0.1 mL/g时,样品Mg/Al 0.1N1和Mg/Al 0.1N2的CO2吸附容量均为最大,分别为1.21和1.02 mmol/g(30℃,纯CO2环境)。

The preparation of the organic surfactant (sodium laurylsulfonate)intercalated Mg/Al layered double hydroxides (Mg/Al LDH)were prepared via a co-precipitation method.Then an exfoliation and grafting meth-od was utilized for synthesizing amine modified Mg/Al LDH.The materials were characterized by element anal-ysis,X-ray diffraction,scanning electron microscopy and thermogravimetric analysis.The adsorption behavior and the adsorption-desorption regeneration experiments for these layered double hydroxides was investigated by TGA at 30 ℃ and one bar pressure.In the process of amine modified,a amount of deionized water was aided during exfoliation.The influence rule of the amount of water with amine loading and CO2 absorption capacity were particularly studied.The results show that the optimum amount of deionized water of 3-(trimethoxysilyl) propylamine and N-(amino-ethyl)-amino-propyl trimethoxy silane was both 0.1 mL/g with the adsorption ca-pacity of 1.21 and 1.02 mmol/g for sample Mg/Al 0.1 N1 and Mg/Al 0.1 N2 in pure CO2 at 30 ℃.