Preparation Of Polypyrrole Composites And Their Adsorption Properties

Although polypyrrole has many characteristics such as high thermal stability,low cost,easy availability and non-toxicity,it also has a wide range of applications in the field of environmental restoration.However,the single polypyrrole material has the disadvantages of small specific surface area,poor surface properties,limited adsorption active sites and limited surface functional groups,which makes the adsorption capacity and range of polypyrrole to dyes limited.Therefore,it is necessary to utilize the synergy between different materials to enhance the adsorption removal ability of polypyrrole to dyes.In this paper,polypyrrole-chitosan?PPy-CS?and polypyrrole-chitosan-sodiumdodecylbenzenesulfonate?PPy-CS-SDBS?were prepared by using polypyrrole?PPy?as the backbone.Materials,and then studied the effects of various influencing factors on the adsorption properties of the composites,such as the pH value of the solution,the dosage of the adsorbent,the initial concentration of the dye,etc.,and studied the thermodynamics,kinetics and adsorption mechanism of the adsorption process.The main research contents are as follows:?1?The PPy-CS composite was prepared by chemical oxidative polymerization and then used to remove acid red 18?AR-18?.The structure and morphology of the composites were analyzed by means of scanning electron microscopy?SEM?,Brunauer-Emmett-Teller?BET?and infrared spectroscopy?FT-IR?.The thermodynam-ics and kinetics of the adsorption process were studied.Explore its adsorption mechanism and elution regeneration performance.The research shows that the adsorption process is spontaneous and endothermic.The maximum adsorption capacity of the Langmuir equation is 285.71 mg/g,and the adsorption kinetics accords with the quasi-second-order kinetic equation.The adsorption mechanism indicates that electrostatic attraction and hydrogen bonding play an important role in the removal process.In addition,the type and amount of dye molecular functional groups also have an effect on the removal process.Moreover,the PPy-CS composite still has a removal efficiency of 70.83%after the sixth regeneration cycle,which will contribute to the practical application of the composite.?2?PPy-CS-SDBS composites were prepared by chemical oxidative polymeriza-tion and used to remove naphthol green B?NGB?and alizarin yellow R?AYR?.The structure and morphology of the composites were analyzed by means of SEM,BET and Zata potentials.Then,the influencing factors of naphthol green B and alizarin yellow R were optimized by response surface methodology.The results show that the PPy-CS-SDBS composite has the best removal effect on AYR and NGB when the mass ratio of CS to SDBS is 1:2.The optimal adsorption conditions for the removal of AYR from the composites were pH=4.00,m=0.064 g,C₀=100 mg/L,and the optimal adsorption conditions for removing NGB were pH=4.00,m=0.041 g and C₀=50 mg/L.And the experimental results of the two response values are consistent with the predicted results,indicating that the optimal adsorption conditions predicted by the response surface model are accurate.?3?The adsorption effect of NGB and AYR in mixed dyes was studied by PPy-CS-SDBS composites.Then the influencing factors of the mixed dyes were optimized by the response surface model,and the removal rules of the adsorbents in the mixed system were investigated.The results show that the optimal adsorption conditions for mixed dye removal by response surface method are pH=4.05,m=0.081g,C₀=94.43 mg/L.The calcination results of the PPy-CS-SDBS material after removing the mixed dye showed that the removal rates of cationic dyes such as malachite green,crystal violet and methylene blue were 97.60%,96.16%and91.20%,respectively,when the calcination temperature was 400?.Moreover,PCD-2-AYR-NGB and PCD-2-AYR-NGB?400°C?materials all have a certain specific capacitance,which can be used for the preparation of electrode materials in supercapacitors,and has certain waste utilization value.