Herein,copper ion doped calcium alginate(Cu^(2+)/CaAlg)composite hydrogel filtration membranes were prepared by using natural polymer sodium alginate(NaAlg)as raw material.The thermal stability and structure of the co...Herein,copper ion doped calcium alginate(Cu^(2+)/CaAlg)composite hydrogel filtration membranes were prepared by using natural polymer sodium alginate(NaAlg)as raw material.The thermal stability and structure of the composite membranes were characterized by thermogravimetric analysis and infrared spectroscopy.The mechanical strength,anti-fouling performance,hydrophilicity and filtration performance of the membrane were studied.The results show that Cu^(2+)/CaAlg hydrogel membrane has excelle nt mechanical properties and thermal stability.The anti-swelling ability of the membrane was greatly enhanced by doping Cu^(2+).After three alternate filtration cycles,the flux recovery rate of Cu^(2+)/CaAlg hydrogel membrane can still reach 85%,indicating that the membrane has good antipollution performance.When the operation pressure was 0.1 MPa,the rejection of coomassie brilliant blue G250 reached 99.8%with a flux of 46.3 L m^(-2)h^(-1),while the Na_(2)SO_(4) rejection was less than 10.0%.The Cu^(2+)/CaAlg membrane was recycled after 24 h in the filtration process,and its flux and rejection rate did not decrease significantly,indicating that the hydrogel membrane has long-term application potential.The Cu^(2+)/CaAlg membrane has a wide range of applications prospect in dye desalination,fine separation and biopharmaceutical technology fields.展开更多
Cu^2＋-doped nanostructured TiO2-coated SiO2 （TiO2/SiO2） particles were prepared by the layer-by-layer assembly technique and their photocatalytic property was studied. TiO2 colloids were synthesized by the sol-gel ...Cu^2＋-doped nanostructured TiO2-coated SiO2 （TiO2/SiO2） particles were prepared by the layer-by-layer assembly technique and their photocatalytic property was studied. TiO2 colloids were synthesized by the sol-gel method using TiOSO4 as a precursor. The experimental results showed that TiO2 nanopowders on the surface of SiO2 particles were well distributed and compact. The amount of TiO2 increased with the increase in coating layers. The shell structure appeared to be composed of anatase titania nanocrystals at 550℃. The 2-layer coated TiO2 particles on the surface showed a higher degradation rate compared with all the different-layer samples. The photocatalytic activity of Cu^2＋-doped TiO2/SiO2 was higher than that ofundoped TiO2/SiO2. The optimum dopant content was about 0.10wt%.展开更多
Un-doped and Cu-doped ZnS（ZnS：Cu） thin films were synthesized by Successive Ion Layer Absorption and Reaction（SILAR） method. The UV–visible absorption studies have been used to calculate the band gap values of t...Un-doped and Cu-doped ZnS（ZnS：Cu） thin films were synthesized by Successive Ion Layer Absorption and Reaction（SILAR） method. The UV–visible absorption studies have been used to calculate the band gap values of the fabricated ZnS：Cu thin films. It was observed that by increasing the concentration of Cu^2＋ ions, the Fermi level moves toward the edge of the valence band of ZnS. Photoluminescence spectra of un-doped and Cu-doped ZnS thin films was recorded under 355 nm. The emission spectrum of samples has a blue emission band at 436 nm.The peak positions of the luminescence showed a red shift as the Cu^2＋ C ion concentration was increased, which indicates that the acceptor level（of Cu^2＋） is getting close to the valence band of ZnS.展开更多
基金supported by National Natural Science Foundation of China(Nos.51678409,51708406,51708407)Tianjin Science Technology Research Funds of China(Nos.16JCZDJC37500,15JCZDJC38300)Tianjin Science and Technology Plan Project(No.18ZXJMTG00120)。
文摘Herein,copper ion doped calcium alginate(Cu^(2+)/CaAlg)composite hydrogel filtration membranes were prepared by using natural polymer sodium alginate(NaAlg)as raw material.The thermal stability and structure of the composite membranes were characterized by thermogravimetric analysis and infrared spectroscopy.The mechanical strength,anti-fouling performance,hydrophilicity and filtration performance of the membrane were studied.The results show that Cu^(2+)/CaAlg hydrogel membrane has excelle nt mechanical properties and thermal stability.The anti-swelling ability of the membrane was greatly enhanced by doping Cu^(2+).After three alternate filtration cycles,the flux recovery rate of Cu^(2+)/CaAlg hydrogel membrane can still reach 85%,indicating that the membrane has good antipollution performance.When the operation pressure was 0.1 MPa,the rejection of coomassie brilliant blue G250 reached 99.8%with a flux of 46.3 L m^(-2)h^(-1),while the Na_(2)SO_(4) rejection was less than 10.0%.The Cu^(2+)/CaAlg membrane was recycled after 24 h in the filtration process,and its flux and rejection rate did not decrease significantly,indicating that the hydrogel membrane has long-term application potential.The Cu^(2+)/CaAlg membrane has a wide range of applications prospect in dye desalination,fine separation and biopharmaceutical technology fields.
基金the Department of Education of Hebei Province, China (No.2005362)
文摘Cu^2＋-doped nanostructured TiO2-coated SiO2 （TiO2/SiO2） particles were prepared by the layer-by-layer assembly technique and their photocatalytic property was studied. TiO2 colloids were synthesized by the sol-gel method using TiOSO4 as a precursor. The experimental results showed that TiO2 nanopowders on the surface of SiO2 particles were well distributed and compact. The amount of TiO2 increased with the increase in coating layers. The shell structure appeared to be composed of anatase titania nanocrystals at 550℃. The 2-layer coated TiO2 particles on the surface showed a higher degradation rate compared with all the different-layer samples. The photocatalytic activity of Cu^2＋-doped TiO2/SiO2 was higher than that ofundoped TiO2/SiO2. The optimum dopant content was about 0.10wt%.
文摘Un-doped and Cu-doped ZnS（ZnS：Cu） thin films were synthesized by Successive Ion Layer Absorption and Reaction（SILAR） method. The UV–visible absorption studies have been used to calculate the band gap values of the fabricated ZnS：Cu thin films. It was observed that by increasing the concentration of Cu^2＋ ions, the Fermi level moves toward the edge of the valence band of ZnS. Photoluminescence spectra of un-doped and Cu-doped ZnS thin films was recorded under 355 nm. The emission spectrum of samples has a blue emission band at 436 nm.The peak positions of the luminescence showed a red shift as the Cu^2＋ C ion concentration was increased, which indicates that the acceptor level（of Cu^2＋） is getting close to the valence band of ZnS.
