聚乙烯亚胺修饰的氧化硅纳米管基吸附剂的制备及其CO_2吸附应用

以P123为模板,1,2-二(三甲氧基硅基)乙烷(BTME)为硅源合成了介孔氧化硅纳米管(E-SNTs).将ESNTs经过聚乙烯亚胺(PEI)修饰后制得吸附剂用于捕捉CO2.对吸附剂进行了透射电镜(TEM)、物理吸附、傅里叶变换红外(FTIR)光谱、热重分析(TGA)等表征.E-SNTs-PEI吸附剂的最佳CO2吸附温度为75°C.吸附剂的CO2吸附量随着PEI负载量的增加呈现先增大后减小的趋势,其中50%为最佳负载量,此时吸附剂的吸附量最大为3.32 mmol·g-1.相比较SBA-15基吸附剂,E-SNTs基吸附剂具有更优异的吸附性能.在有水汽的存在下,吸附剂E-SNTs-50的CO2吸附量达到3.75 mmol·g-1.经过四次循环吸脱附实验测试E-SNTs-PEI吸附剂的稳定性能,结果表明其CO2吸附量基本不变,该吸附剂表现出较好的稳定性和可再生能力.

Preparation of Polyethylenimine-Functionalized Silica Nanotubes and Their Application for CO2 Adsorption

Mesoporous ethane-silica nanotubes (E-SNTs) were synthesized using P123 as a template and 1,2-bis(trimethoxysilyl)ethane (BTME) as a silica source. E-SNTs were modified with polyethylenimine (PEI) as sorbents for CO₂ adsorption. These new composite sorbents were characterized by transmission electron microscopy (TEM), nitrogen adsorption/desorption, Fourier transform infrared (FTIR) spectroscopy, and thermal gravimetric analysis (TGA). We found that 75 ℃ is the optimal temperature for CO₂ adsorption. E-SNTs with a 50% (w) PEI loading (E-SNTs-50) exhibited a higher CO₂ adsorption capacity (3.32 mmol·g^-1) than the other materials. The E-SNTs-based sorbents show better CO₂ capture performance than the SBA-15-based sorbents. Additionally, CO₂ uptake was further enhanced to 3.75 mmol·g^-1 in the presence of moisture. Cyclic CO₂ adsorption-desorption test results indicated that the composite sorbents are stable and can be regenerated.