Preparation And Characterization Of Novel Carbon Dioxide Adsorbents Based On Polymer-modified Halloysite Nanotubes

In this thesis,carbon dioxide adsorbent of polyethyleneimine modified halloysite nanotubes was synthesized and characterized on carbon dioxide adsorption properties.With impregnation method,different PEI loading adsorption based on HNTs support was prepared and probed into carbon dioxide adsorption conditions thoroughly.In order to get HNTs with structural integrity and uniform size,purchased HNTs were processed through chemical wash and centrifugal separation.The purified HNTs was determined negative potential by Zeta potential analyser.This would be beneficial to the stability of adsorption under high temperature.Determined by Fourier transform infrared spectrum,HNTs were of integrated structure and through transmission electron microscopy the inner hollows and tubular structure of purified halloysite nanotubes were observed directly.By impregnation method,new nano carbon dioxide adsorbents were synthesized by loading polyethyleneimine onto in inexpensive halloysite nanotubes.The obtained adsorbents exhibit excellent carbon dioxide adsorption efficiency at room temperature.The structure of the adsorption were conformed by Fourier transform infrared instrument.The adsorption temperature and rate were determined by thermal gravimetric analysis analytical instrument.The desorption process was analytical with thermal gravimetric analysis combined with Fourier transform infrared spectrum.The specific surface area and aperture capacity were measured by BET method.The influence of aperture capacity on the adsorption capacity of the adsorbent was also investigated.In this work,adsorbent with polyethyleneimine content of 5%,10%,15%,20%,25%,30%,35%,40%,45%were prepared.The surface features of the different content adsorbents were directly observed.A comprehensive analysis of the effects of PEI content on the pore size of the adsorbent and the impact on the final carbon dioxide adsorption capacity were clarified.The desorption time,saturated adsorption capacity under different concentrations of carbon dioxide and related parameters have been explored.The results indicated that for the saturated adsorption system,the increasing concentration of carbon dioxide will not influence the adsorption capacity of the adsorbent very much.Using adsorbent with polyethyleneimine content of 30%to adsorb carbon dioxide,the maximum carbon dioxide adsorption capacity per gram of polyethyleneimine was was 156.6 mg/g-PEI,for the saturated adsorption of adsorbent with polyethyleneimine content of 35%,the maximum adsorption capacity was 54.8 mg/g-adsorbent.The experimental results show that this new type of carbon dioxide adsorbent has a high stability at 80 ?,multiple adsorption-desorption recycle experiments reveal that it has a stable performance for repeated use.