Study On Preparation And Properties Of New Polymer-Activated Carbon Functional Compound Materials

Activated carbon material is a kind of typic porous adsorption materials which has many excellent properties such as high specific surface area and pore volume ,high temperature and corrosion resistance, high electrical conductivity, high acid and alkali resistance, good chemical resistance and biocompatibility. It has been mainly applied to gas and liquid adsorption separation process, which has been widely used and become one of the research hot spots. Now activated carbon is widely used in gas masks, gas separation refining, organic recovery, inorganic ions and heavy metal ions removal, sewage purification and so on.At present, the research on activated carbon adsorption primarily focuses on the porosity which is mainly related to physisorption. Activated carbon adsorption characteristic is not only depended on the porous structure, but also on the surface chemistry nature. Therefore, chemical modification was carried out of the surface to improve adsorption performance. In this article, functional polymer was polymerized in the activated carbon holes to prepared polymer-activated carbon composite materials. The modified activated carbon material combined with functional polymer with special groups has advantages in pore structure and could adsorb heavy metal ions in waste water. So these materials have broad application prospects in electricity, optics, biology, medicine and environmental protection field.Firstly, activated carbon was prepared using rice husk which is low in price and rich in resources, and NaOH as chemical activator. The factors on activated carbon iodine adsorption value and the activated carbon production rate were discussed by soaked proportion, the activation method, the activation temperature and the activation time. We prepared activated carbon as follow: the drying rice husk was carbonized at 450℃in nitrogen atmosphere for 4h.Then, the carbonized product was heated in the presence of sodium hydroxide (NaOH: C=3:1) at 400℃for 30 min to dehydrate the mixture. Thereafter the temperature was raised to 800℃and this temperature was held for 2 hours to activate the combination. At last the activated product was washed with water and dried. Then we found that its nitrogen adsorption/desorption isothermal isâ…£, The specific surface 1200m²/g, the average hole diameter 3.8nm, and the holes volume 0.8cm³ /g.Secondly, we explored the method of synthesizing the polymer in the activated carbon holes, and then we successfully made methyl methacrylate (MMA) in-situ polymerization in activated carbon holes with freezing aeration. The results of test methods showed that methyl methacrylate (MMA) was in-situ polymerized in activated carbon holes.Through analyzing, there is about 15% MMA polymerizing in activated carbon holes. The specific surface and pore volume before and after polymerization has decreased significantly (from 848.4 m²/g to 479 m²/g, from 0.5022 cm³/g to 0.3405 cm³/g respectively). The adsorption isotherm belongs to typeâ…£with type C hysteretic curve (or type H4 hysteretic curve).Thirdly, acrylic acid was in-situ directly polymerized in activated carbon holes with ultrasonic vibration. The porous polymer-inorganic composite was prepared and analyzed by IR, nitrogen adsorption measurement and TG The results showed that: the optimum proportion of polymeric monomer was 1:1,the temperature 80℃, the reaction time 24h. The adsorption of Cu²⁺ on activated carbon and porous polymer-inorganic composite were carried out and compared with each other. The factors on activated carbon Cu²⁺ adsorption were discussed by polymer content and the vibration time.And we found that the adsorption of Cu²⁺ on activated carbon mainly belongs to chemical adsorption. The maximum adsorption was achieved when the polymer content is approximately 20%. The adsorption was increased as reaction time until 20h. The adsorption is suitable Langmuir equation, Freundlich equation and the Pseudo-second equation dynamic equation.Finally, we prepared poly (2-acrylamido-2-methyl propane sulfuric acid) -activated carbon composite materials using ultrasonic vibration and freezing aeration. then we analyzed the effects of adsorption properties and the selective adsorption of Pb²⁺,Cu²⁺ and Zn²⁺ on PAMPS-RAC.PAMPS-RAC still remains high specific surface of 838 m²/g and high pore volume of 0.56cm³/g.The result showed that adsorption capacity became fast with time,and reached equilibrium at about two hours.The equilibrium adsorptions of are 275,92å’Œ83mg/g respectively,and fitting data with Pseudo-second order kinetics equation.The results showed that Pseudo-second order kinetics equation could explain the adsorption process and the rules of them are same with each other.The results of adsorption isotherm experiment showed that adsorptions of Pb²⁺,Cu²⁺ and Zn²⁺ became higer as bigger as the initial concentration of Pb(NO₃)₂,Cu(NO₃)₂å’ŒZn(NO₃)₂ finally, and approached equilibrium.we fitted data with Langmuir equation and Freundlich equation,and found both of them could fit data well.The results of pH experiment showed that adsorptions of Pb²⁺,Cu²⁺ and Zn²⁺ became higer as bigger as the pH value, and approached equilibrium at last.The optimum pH value are 5.5,5.5 and 6.5 respectively. The results of selective adsorption of Pb²⁺,Cu²⁺ and Zn²⁺ on PAMPS-RAC showed that the order of adsorption is : Pb²⁺＞Cu²⁺ >Zn2²⁺.The selective adsorption of Pb²⁺ on PAMPS-RAC is very good,and we can use PAMPS-RAC to selectively remove Pb²⁺ in solution containing Pb²⁺,Cu²⁺å’ŒZn²⁺ simultaneously.