A novel and selective method for the fast determination of trace amounts of chromium species in water samples has been developed. The procedure is based on the selective formation of chromium diethyldithiocarbamate co...A novel and selective method for the fast determination of trace amounts of chromium species in water samples has been developed. The procedure is based on the selective formation of chromium diethyldithiocarbamate complexes at different pH in the presence of Mn（Ⅱ） as an enhancement agent of chromium signals followed by elution with organic eluents and determination by atomic flame absorption spectrometry. The maximum capacity of the employed disks was found to be （396±3） pg and （376±2） pg for Cr（Ⅲ） and Cr（Ⅵ）, respectively. The detection limit of the proposed method is 49 and 43 ng·L^-1 for Cr（Ⅲ） and Cr（Ⅵ）, respectively. The proposed method was successfully applied for determination of chromium species Cr（Ⅲ） and Cr（Ⅵ） in different water samples.展开更多
Porous membrane separation is a competitive hydrogen purification technology due to the advantages of environmental friendliness,energy-saving,simple operation,and low cost.Benefiting from the booming development of m...Porous membrane separation is a competitive hydrogen purification technology due to the advantages of environmental friendliness,energy-saving,simple operation,and low cost.Benefiting from the booming development of materials science and chemical science,great progress has been made in H_(2) separation with porous membranes.This review focuses on the latest advances in the design and fabrication of H_(2) separation inorganic microporous membranes,with emphasis on the synthetic strategies to achieve structural integrity,continuity and stability.This review starts with a brief introduction to the membrane separation mechanisms,followed by an elaboration on the synthetic challenges and corresponding solutions of various high-performance inorganic microporous membranes based on zeolites,silica,carbon,and metal-organic frameworks(MOFs).At last,by highlighting the prospects of ultrathin two-dimensional(2D)porous membranes,we wish to shed some light on the further development of new materials and membranes for highly efficient hydrogen separation.展开更多
A kind of octanol-modifded silica nanoparticle was fabricated and employed as a framework to form‘‘soggy sand’’electrolyte along with 1-butyl-3-methylimidazolium tetrafluoroborate.‘‘Soggy sand’’and poly（vinyl...A kind of octanol-modifded silica nanoparticle was fabricated and employed as a framework to form‘‘soggy sand’’electrolyte along with 1-butyl-3-methylimidazolium tetrafluoroborate.‘‘Soggy sand’’and poly（vinylidene fluoride-hexafluoropropylene）composite electrolyte membranes were electrospun for the frst time.The properties of this membrane electrolyte have been evaluated by the mechanical test and electrochemical test.The Young’s modulus increased by 275%from 6.8 MPa to 25.5 MPa and the electrical conductivity increased to 7.6 10à5S/cm at 290.15 K when compared to pristine P（VdF-HFP）membrane electrolyte.The conductivity is 3.1 10à4S/cm at 323.15 K.展开更多
文摘A novel and selective method for the fast determination of trace amounts of chromium species in water samples has been developed. The procedure is based on the selective formation of chromium diethyldithiocarbamate complexes at different pH in the presence of Mn（Ⅱ） as an enhancement agent of chromium signals followed by elution with organic eluents and determination by atomic flame absorption spectrometry. The maximum capacity of the employed disks was found to be （396±3） pg and （376±2） pg for Cr（Ⅲ） and Cr（Ⅵ）, respectively. The detection limit of the proposed method is 49 and 43 ng·L^-1 for Cr（Ⅲ） and Cr（Ⅵ）, respectively. The proposed method was successfully applied for determination of chromium species Cr（Ⅲ） and Cr（Ⅵ） in different water samples.
基金This work was supported by the National Key Research and Development Program of China(No.2021YFB4000601)the National Natural Science Foundation of China(Nos.21975010,U21A20328,and 51731002)the Natural Science Foundation of Beijing Municipality(No.Z200012).
文摘Porous membrane separation is a competitive hydrogen purification technology due to the advantages of environmental friendliness,energy-saving,simple operation,and low cost.Benefiting from the booming development of materials science and chemical science,great progress has been made in H_(2) separation with porous membranes.This review focuses on the latest advances in the design and fabrication of H_(2) separation inorganic microporous membranes,with emphasis on the synthetic strategies to achieve structural integrity,continuity and stability.This review starts with a brief introduction to the membrane separation mechanisms,followed by an elaboration on the synthetic challenges and corresponding solutions of various high-performance inorganic microporous membranes based on zeolites,silica,carbon,and metal-organic frameworks(MOFs).At last,by highlighting the prospects of ultrathin two-dimensional(2D)porous membranes,we wish to shed some light on the further development of new materials and membranes for highly efficient hydrogen separation.
基金supported by National Key Basic Research Program of China, 973 Program (Nos. 2012CB932800 and 2011CB93570)
文摘A kind of octanol-modifded silica nanoparticle was fabricated and employed as a framework to form‘‘soggy sand’’electrolyte along with 1-butyl-3-methylimidazolium tetrafluoroborate.‘‘Soggy sand’’and poly（vinylidene fluoride-hexafluoropropylene）composite electrolyte membranes were electrospun for the frst time.The properties of this membrane electrolyte have been evaluated by the mechanical test and electrochemical test.The Young’s modulus increased by 275%from 6.8 MPa to 25.5 MPa and the electrical conductivity increased to 7.6 10à5S/cm at 290.15 K when compared to pristine P（VdF-HFP）membrane electrolyte.The conductivity is 3.1 10à4S/cm at 323.15 K.
