Preparation Of Activated Carbon Fiber Based Composites And Their Application In Gas Purification

With the rapid development of economy,the use of fossil fuels and chemical products has showed the increasing tendency year by year,and it led to air pollution that had a serious impact on people's breathing and health.In our work,a series of composite materials were prepared by modification methods with activated carbon fiber?ACF?as the carrier and the prepared materials were used in fresh air generating system.The main research contents are as follows:Firstly,with ACF as carriers,MnOx/ACF composite materials were prepared by in situ reduction with potassium permanganate on the surface of ACF.The structure and morphology of MnOx/ACF were characterized by Scanning electron microscope?SEM?,Energy dispersive spectrum?EDS?,and X-ray diffraction?XRD?.The results showed that,the immersion time of 40min was the appropriate option.Through catalytic performance evaluation,it obtained that the advisable loading amounts was Mn/ACF with 5.0%MnOx and the best processing temperature is 450?.Secondly,TiO₂/ACF composites were prepared by a sol-gel method assisted with ultrasonic at a constant temperature,with tetrabutyl titanate as a titanium source.TiO₂/Al₂O₃ composites were prepared by extrusion molding and high-temperature calcinations,with intended boehmite and titanium dioxide as precursors and the aqueous solution of citric acid,nitric acid and acetic acid as kneading agent.The obtained composites were characterized by Scanning electron microscope?SEM?,X-ray diffraction?XRD?and so on.The results showed that,the surface of ACF loaded with TiO₂ was covered with a layer of film.It indicated that PEI had been loaded onto the surface of ACF.The photocatalytic performances of two composite materials were evaluated by photocatalytic reaction device.The photocatalytic properties of the TiO₂/ACF with powder form in water were much better than that of the TiO₂/ACF wrapped in UV lamp,but when the latter wrapped in UV lamp was used five times,photocatalytic degradation of methylene blue was still was 65.93%.The TiO₂/Al₂O₃ composites with 90%TiO₂ did not only have a higher photocatalytic performance,but also can be recycled.Then,different loading of PEI/ACF composite materials were prepared by amino surface modification of PEI with ACF as the carrier.The structure and morphology of PEI/ACF were characterized by Fourier transform infrared spectroscopy?FTIR?,thermal gravity analysis?TGA?,and X-ray diffraction?XRD?.The results showed that after being loaded with PEI,the surface of ACF was covered with a layer of film.It indicated that PEI had been loaded onto the surface of ACF.Device of PEI/ACF adsorbent performance evaluation was adopted to the performance evaluation of the adsorption of CO₂ on composite materials.The CO₂ removal effect by the composite materials modified with ACF was significantly superior to that by the pure ACF.The CO₂ removal effect by the PEI/ACF with 5%PEI obtained the best result.Finally,in fresh air generating system,the two composites of MnOx/ACF,TiO₂/ACF can completely removing organic contaminants,by exploiting the synergy effect of composite materials.CO₂ was removed by using PEI/ACF composite materials,and composite materials with adsorption saturation can be reused by heat treatment.The unit of dehumidifying may obtain the results of the outlet gas humidity below 40%.The unit of oxygen generation may adjust the oxygen content of the air outlet from 30%to 90%.