Di(2-ethylhexyl)phosphoric acid (D2EHPA) in acetone was supported on the Amberlite XAD-1180 polystyrene divinylbenzene copolymer resin. The use of XAD-1180 impregnated with D2EHPA for the extraction of bismuth(III) fr...Di(2-ethylhexyl)phosphoric acid (D2EHPA) in acetone was supported on the Amberlite XAD-1180 polystyrene divinylbenzene copolymer resin. The use of XAD-1180 impregnated with D2EHPA for the extraction of bismuth(III) from nitrate medium was carried out using batch technique. Various parameters affecting the uptake of this metal ion were described in the previous paper (Belkhouche and Didi, 2010) and the capacity of the impregnated resin for bismuth(III) was found to be 490.7 mg/g of resin. Effect of temperature on the values of distribution equilibrium was studied to evaluate the changes in standard thermodynamic quantities. A comparison of Langmuir forms I, II and Freundlich sorption isotherms was realized and the kinetic models applied to the adsorption rate data were evaluated for Lagergren first order, the pseudo second order and Morris–Weber models. From the results, the adsorption of Bi(III) onto D2EHPA/XAD-1180 resin shown the exothermic character and followed the Langmuir form II isotherm. Thus, the capacity of monolayer adsorption of Bi(III) was equal to 769.23 mg/g of resin. Both the Lagergren pseudo first order and film-diffusion models were found to best describe the experimental rate data.展开更多
A membrane process for metal recovery from aqueous solutions was studied. Metal ions diffused from the feed compartment to the stripping compartment through an hybrid Donnan dialysis which consists to combine two ion ...A membrane process for metal recovery from aqueous solutions was studied. Metal ions diffused from the feed compartment to the stripping compartment through an hybrid Donnan dialysis which consists to combine two ion exchange membranes with solvent impregnated resin (SIR). The aim of this work is to study the recovery of Pb(II), Ag(I) and Cu(II) from nitrate solutions by using SIR combined with classical Donnan dialysis. The resin has been prepared by impregnating the Amberlite XAD-4 using three different extractants namely: di-2-ethyl hexyl phosphine acide (D2EHPA), tris-octyl phosphine oxide (TOPO) and Diphenylthiourea (DPT). Experiments were performed as a function of nature of the extractant impregnated on the XAD-4 resin as well as the concentration in the resin phase, the stripping pH, the concentration ratio of metal ions in the feed compartment and the nature of the counter ions in strip compartment. The results show that the D2EHPA is the better extractant for the metal ions used in this work, and it’s shown a good selectivity for the separation between ions.展开更多
Two-dimensional nanosheets are highly effective tougheners for vinyl ester resins.The toughening effect is related to the high specific surface area and unique two-dimensional planar structure of the nanosheets.In thi...Two-dimensional nanosheets are highly effective tougheners for vinyl ester resins.The toughening effect is related to the high specific surface area and unique two-dimensional planar structure of the nanosheets.In this study,a coupling agentγ-(2,3-epoxypropoxy)propytrimethoxysilane(Kh-560)was used to modify MXene nanosheets(M-MXene)for use in toughening vinyl ester resin.The mechanical properties,including the tensile strength,flexural strength,Young’s modulus and elongation,of neat vinyl ester resin and vinyl ester resin modified with MXene and M-MXene were investigated.The results showed that modification significantly improved the mechanical properties of the vinyl ester resin.The tensile and flexural strengths of the MXene-nanosheet-modified vinyl ester resin were 27.20%and 25.32%higher,respectively,than those of the neat vinyl ester resin.The coupling agent improved the interfacial compatibility between the MXene nanosheets and vinyl ester resin,which resulted in the tensile and flexural strengths of the M-MXene-nanosheet-modified vinyl ester resin being 52.57%and 54.60%higher,respectively,than those of the neat vinyl ester resin for a loading quantity of nanosheets of only 0.04 wt%,which is economically viable.The main mechanisms by which the nanosheets toughen the resin are crack deflection and crack pinning.展开更多
文摘Di(2-ethylhexyl)phosphoric acid (D2EHPA) in acetone was supported on the Amberlite XAD-1180 polystyrene divinylbenzene copolymer resin. The use of XAD-1180 impregnated with D2EHPA for the extraction of bismuth(III) from nitrate medium was carried out using batch technique. Various parameters affecting the uptake of this metal ion were described in the previous paper (Belkhouche and Didi, 2010) and the capacity of the impregnated resin for bismuth(III) was found to be 490.7 mg/g of resin. Effect of temperature on the values of distribution equilibrium was studied to evaluate the changes in standard thermodynamic quantities. A comparison of Langmuir forms I, II and Freundlich sorption isotherms was realized and the kinetic models applied to the adsorption rate data were evaluated for Lagergren first order, the pseudo second order and Morris–Weber models. From the results, the adsorption of Bi(III) onto D2EHPA/XAD-1180 resin shown the exothermic character and followed the Langmuir form II isotherm. Thus, the capacity of monolayer adsorption of Bi(III) was equal to 769.23 mg/g of resin. Both the Lagergren pseudo first order and film-diffusion models were found to best describe the experimental rate data.
文摘A membrane process for metal recovery from aqueous solutions was studied. Metal ions diffused from the feed compartment to the stripping compartment through an hybrid Donnan dialysis which consists to combine two ion exchange membranes with solvent impregnated resin (SIR). The aim of this work is to study the recovery of Pb(II), Ag(I) and Cu(II) from nitrate solutions by using SIR combined with classical Donnan dialysis. The resin has been prepared by impregnating the Amberlite XAD-4 using three different extractants namely: di-2-ethyl hexyl phosphine acide (D2EHPA), tris-octyl phosphine oxide (TOPO) and Diphenylthiourea (DPT). Experiments were performed as a function of nature of the extractant impregnated on the XAD-4 resin as well as the concentration in the resin phase, the stripping pH, the concentration ratio of metal ions in the feed compartment and the nature of the counter ions in strip compartment. The results show that the D2EHPA is the better extractant for the metal ions used in this work, and it’s shown a good selectivity for the separation between ions.
基金We gratefully acknowledge the fundings from the National Natural Science Foundation of China(Grant Nos.22022805,22078107)National Key Research and Development Program(Grant No.2021YFB3802500)+2 种基金the Special Project for Scienceand Technology Commissioner of Enterpriseof Guangdong Province(Grant No.GDKTP2021045700)the General Project of Department of Natural Resources of Guangdong Province(Grant No.GDNRC[2021]47)the Science&Technology Programof Qingyuan City(Grant No.2021DZX026).
文摘Two-dimensional nanosheets are highly effective tougheners for vinyl ester resins.The toughening effect is related to the high specific surface area and unique two-dimensional planar structure of the nanosheets.In this study,a coupling agentγ-(2,3-epoxypropoxy)propytrimethoxysilane(Kh-560)was used to modify MXene nanosheets(M-MXene)for use in toughening vinyl ester resin.The mechanical properties,including the tensile strength,flexural strength,Young’s modulus and elongation,of neat vinyl ester resin and vinyl ester resin modified with MXene and M-MXene were investigated.The results showed that modification significantly improved the mechanical properties of the vinyl ester resin.The tensile and flexural strengths of the MXene-nanosheet-modified vinyl ester resin were 27.20%and 25.32%higher,respectively,than those of the neat vinyl ester resin.The coupling agent improved the interfacial compatibility between the MXene nanosheets and vinyl ester resin,which resulted in the tensile and flexural strengths of the M-MXene-nanosheet-modified vinyl ester resin being 52.57%and 54.60%higher,respectively,than those of the neat vinyl ester resin for a loading quantity of nanosheets of only 0.04 wt%,which is economically viable.The main mechanisms by which the nanosheets toughen the resin are crack deflection and crack pinning.
