The magnetic nitrogen-doped carbon (MNC) was prepared from polypyrrole by a simple high temperature calcination process in this paper. The structure and properties of MNC were analyzed by scanning electron microscope,...The magnetic nitrogen-doped carbon (MNC) was prepared from polypyrrole by a simple high temperature calcination process in this paper. The structure and properties of MNC were analyzed by scanning electron microscope, Fourier transform infrared spectroscopy, X-ray diffraction, Brunner-Emmet-Teller, vibrating sample magnetometer, and X-ray photoelectron spectroscopy. The capacity of MNC to adsorb Cr(Ⅵ) and Pb(Ⅱ) was evaluated. The effects of the initial pH, dosage, concentration and temperature on the adsorption capacity of MNC were measured. MNC had a large specific surface area and a special porous structure. Its nitrogen and carbon sources were rich, and the ratio of carbon to nitrogen was fixed. The maximum Cr(Ⅵ)-adsorption capacity and maximum Pb(Ⅱ) adsorption capacity of MNC could reach 456.63 and 507.13 mg·g^(−1) at 318 K, respectively. The pseudo-second-order model was used to describe the adsorption kinetics of MNC, and the Freundlich model was employed to discuss its isotherms. The adsorption process was affected by the electrostatic force, the reducing reaction, pores and chelation. The results of this study suggest that MNC is a material with superior performance, and is very easily regenerated, reused, and separated in the adsorption process.展开更多
As an imitation of genuine leather,polyvinyl chloride(PVC)artificial materials are versatile,but suffers from being flammable due to the presence of large amounts of combustible plasticizers.Under such circumstance,in...As an imitation of genuine leather,polyvinyl chloride(PVC)artificial materials are versatile,but suffers from being flammable due to the presence of large amounts of combustible plasticizers.Under such circumstance,intrinsically flame-retardant plasticizers displaying dual functions have been a subject of intensive research interest.However,previous strategies attempting to covalently attach flame-retardant moiety to plasticizers invariably required either expensive starting materials or laborious and tedious procedures,ultimately limiting their scale-up application in industry.In addition,driven by escalating demand of halogen-free flame retardants worldwide from an environmental health perspective,previously reported intrinsically flame-retardant plasticizers were mainly halogenfree,less attractive in PVC artificial material industry simply because PVC itself is a halogen-containing polymer.Here,we report an approach to introduce chlorine moieties into unsaturated fatty acid methyl ester by a simple addition reaction occurring on carbon-carbon double bonds,yielding a chlorine-containing,intrinsically flameretardant bio-plasticizer.When combined with di-(2-ethylhexyl)phthalate(DOP)in PVC formulations,the chlorinated fatty acid methyl ester is qualified as a co-plasticizer while conferring flame retardancy upon the PVC coatings.This approach involves only a one-step procedure that employs renewable fatty acid methyl esters and cheap chlorine gas as raw materials,thus being of great potential to enable intrinsically flame-retardant bioplasticizers on a large scale to manufacture functional PVC artificial materials for application in fire-prone scenarios.展开更多
基金the Applied Basic Research Programs of Science and Technology Department of Sichuan Province(Grant No.2018JY0115)the Application Technology Research and Development Special Project of Nanchong,China(Grant No.18YFZJ0035)the Meritocracy Research Funds of China West Normal University(Grant Nos.17YC013 and 17YC139).
文摘The magnetic nitrogen-doped carbon (MNC) was prepared from polypyrrole by a simple high temperature calcination process in this paper. The structure and properties of MNC were analyzed by scanning electron microscope, Fourier transform infrared spectroscopy, X-ray diffraction, Brunner-Emmet-Teller, vibrating sample magnetometer, and X-ray photoelectron spectroscopy. The capacity of MNC to adsorb Cr(Ⅵ) and Pb(Ⅱ) was evaluated. The effects of the initial pH, dosage, concentration and temperature on the adsorption capacity of MNC were measured. MNC had a large specific surface area and a special porous structure. Its nitrogen and carbon sources were rich, and the ratio of carbon to nitrogen was fixed. The maximum Cr(Ⅵ)-adsorption capacity and maximum Pb(Ⅱ) adsorption capacity of MNC could reach 456.63 and 507.13 mg·g^(−1) at 318 K, respectively. The pseudo-second-order model was used to describe the adsorption kinetics of MNC, and the Freundlich model was employed to discuss its isotherms. The adsorption process was affected by the electrostatic force, the reducing reaction, pores and chelation. The results of this study suggest that MNC is a material with superior performance, and is very easily regenerated, reused, and separated in the adsorption process.
基金financial support of this work by National Key Research and Development Program of China(2017YFB0308600)Science and Technology Planning Project of Sichuan Province(20YYJC3727)+1 种基金National Natural Science Foundation of China(21878196)Fundamental Research Funds for the Central Universities,China(20826041C4159).
文摘As an imitation of genuine leather,polyvinyl chloride(PVC)artificial materials are versatile,but suffers from being flammable due to the presence of large amounts of combustible plasticizers.Under such circumstance,intrinsically flame-retardant plasticizers displaying dual functions have been a subject of intensive research interest.However,previous strategies attempting to covalently attach flame-retardant moiety to plasticizers invariably required either expensive starting materials or laborious and tedious procedures,ultimately limiting their scale-up application in industry.In addition,driven by escalating demand of halogen-free flame retardants worldwide from an environmental health perspective,previously reported intrinsically flame-retardant plasticizers were mainly halogenfree,less attractive in PVC artificial material industry simply because PVC itself is a halogen-containing polymer.Here,we report an approach to introduce chlorine moieties into unsaturated fatty acid methyl ester by a simple addition reaction occurring on carbon-carbon double bonds,yielding a chlorine-containing,intrinsically flameretardant bio-plasticizer.When combined with di-(2-ethylhexyl)phthalate(DOP)in PVC formulations,the chlorinated fatty acid methyl ester is qualified as a co-plasticizer while conferring flame retardancy upon the PVC coatings.This approach involves only a one-step procedure that employs renewable fatty acid methyl esters and cheap chlorine gas as raw materials,thus being of great potential to enable intrinsically flame-retardant bioplasticizers on a large scale to manufacture functional PVC artificial materials for application in fire-prone scenarios.
