Preparation And Properties Of Carbon Aerogels And Carbon Aerogels/Polyaniline Composites

The carbon aerogels were prepared from the sol-gel polymerization of resorcinol andformaldehyde by using calcium acetate monohydrate as template and malonic acid as acatalyst. Then the structure properties of carbon aerogels were studied by X-raydiffraction, scanning electron microscope and N2adsorption isotherm, and the influenceof calcium acetate monohydrate on the electrochemical performances of carbon aerogelswas also investigated. Then mesoporous carbon aerogels and polyaniline compositeswere prepared by in situ polymerization. Last, the high specific surface area carbonaerogels were used as adsorbent for the adsorption of Cd2+from aqueous solution.The results demonstrated that the mass of calcium acetate monohydrate have an effecton the specific surface area of carbon aerogels. The specific surface area of carbonaerogels decreased with increasing mass of calcium acetate monohydrate. The CVcurves of carbon aerogels show a rectangular shape, which was characteristic of anelectric double-layer capacitor. The carbon aerogels that were prepared with templateexhibited much larger specific capacitances ca275.4F/g at the current density of0.5A/g in6.0mol/L KOH aqueous and the impedance of the carbon aerogels is smaller.Surface modified carbon aerogels and polyaniline composites were prepared by insitu polymerization. It was found that carbon aerogels and polyaniline compounds wellthrough chemical bond by XPS and FTIR analysis. From electrochemical text, twocouples of redox peaks were observed from the CV curve, and high specific capacitanceof carbon aerogels/polyaniline composites can reach486.81F/g.Succinic acid-catalyzed carbon aerogels with high surface areas of1510.83m2/gwere used for the adsorption of Cd2+. The adsorption performance for Cd2+usingdifferent process parameters like the dose of adsorbent, contact time, temperature andsolution pH were investigated. The results indicates that there was an increase of thepercentage of adsorption with increasing the dose of carbon aerogels. The adsorptioncapacity increased with the enhancement of temperature, revealing that the adsorptionreaction was endothermic in nature. And the pseudo-second order correlated well withthe experimental data, indicating that adsorption process involved chemical sorption.The maximum adsorption capacity of Cd2+onto carbon aerogels was90.01mg/gaccording to the Langmuir isotherm model.