Li 2+ x RE x Si 1- x O 3(RE=Pr, Nd, Sm, Gd; x =0～0 15) samples were prepared by the sol gel method. DTA TG, XRD, TEM and A C impedance techniques were used to investigate the structure, sha...Li 2+ x RE x Si 1- x O 3(RE=Pr, Nd, Sm, Gd; x =0～0 15) samples were prepared by the sol gel method. DTA TG, XRD, TEM and A C impedance techniques were used to investigate the structure, shape, and ionic conductivity of these samples. The results show that the range of solid solution formation is in 0< x ≤0 09, in which the conductivity of these samples raises with the increasing amount of RE 2O 3 (RE=Pr, Nd, Sm, Gd) added, and the diameter of the powders is about 100 nm. Compared with the conventional solid state reaction, the sol gel method needs low temperature and presents high ionic conductivity.展开更多
In this study, a modified silica gel surface with a hydrophobic ionic liquid (SG-1,10-PhenanNTf2) was used as an adsorbent for a selective extraction of coumarin prior to its determination by use of high performance l...In this study, a modified silica gel surface with a hydrophobic ionic liquid (SG-1,10-PhenanNTf2) was used as an adsorbent for a selective extraction of coumarin prior to its determination by use of high performance liquid chromatography. Results demonstrated that SG-1,10-PhenanNTf2 phase had a good adsorption capacity up to 85.29 mg?g?1, high selectivity, good site accessibility and fast binding kinetics toward coumarin. The adsorption capacity for coumarin was improved by 62.33% with the SG-1,10-PhenanNTf2 phase as compared to activated silica gel. Adsorption isotherm data displayed that the adsorption process was mainly monolayer on a homogeneous adsorbent surface, confirming the validity of Langmuir adsorption isotherm model. The adsorption of coumarin on the SG-1,10-PhenanNTf2 phase was accomplished after only 60 min contact time. Results of kinetic models showed that the adsorption of coumarin on the SG-1,10-PhenanNTf2 phase obeyed a pseudo second-order kinetic model. Finally, the efficiency of this methodology was confirmed by applying it to real water samples.展开更多
Systematic analysis about the exploitation of imidazolium based ionic liquids （ILs）, [BMIM] BF4 [ILl], [EMIM] BF4 ILL2] and [BMIM] PF6 [IL3] as the morphological template on the basic sol-gel method adopted synthesi...Systematic analysis about the exploitation of imidazolium based ionic liquids （ILs）, [BMIM] BF4 [ILl], [EMIM] BF4 ILL2] and [BMIM] PF6 [IL3] as the morphological template on the basic sol-gel method adopted synthesis of nanostructured zinc oxide （ZnO） is presented. X-ray diffraction （XRD）, particle size analysis （PSA） and scanning electron microscopy （SEM） have been employed for the characterization of structure and morphology of the synthesized ZnO particles. Well-defined capsule like shaped morphology with lower nanosize is observed for the ZnO nanoparticles with ILl than those with IL2 and IL3. This confirms that ILl served as an effective templating material due to their unique properties. Especially the effective aggregation of ZnO particles with a self-organized frame of ILl was the essential factor to produce the lower nanosized ZnO with capsule shaped structure. The synthesized ZnO samples with IL2 and IL3 fabricated the flake like shaped and rod like shaped morphologies in the range of nanoscale. The formed ZnO nanoparticles with IL2 exhibit higher nanosize than the ZnO nanoparticles produced by ILl, owing to shorter length of alkyl group in its cation which restricts steric effect and permits the nanoparticles to grow longer. Even though IL3 produced the discrete ZnO nanorods, the hydrophobic nature of IL3 created the higher nanosize than the ZnO nanoparticles formed by other two ionic liquids. Antibacterial properties of the synthesized ZnO nanostructures were investigated against Staphylococcus aureus （gram positive） and Escherichia coil （gram negative） bacteria by Agar diffusion test method. Microbial experiments indicate that the synthesized ZnO samples show a wide spectrum of antimicrobial activities and performed better against S. aureus than E. coil with the same concentration of ZnO.展开更多
The Li_(4+x)Al_xSi_(1-x)O_(4-y)Al_2O_3 (x = 0 to 0.5, y = 0 to 0.5) ionconductors were prepared by the Sol-Gel method and examined in detail. The powder and sinteredsamples were characterized by TG-DTA, XRD, SEM, and ...The Li_(4+x)Al_xSi_(1-x)O_(4-y)Al_2O_3 (x = 0 to 0.5, y = 0 to 0.5) ionconductors were prepared by the Sol-Gel method and examined in detail. The powder and sinteredsamples were characterized by TG-DTA, XRD, SEM, and AC impedance techniques. The experimentalresults show that the conductivity and sinterability increase with the amount of excess Al_2O_3 inthe silicate. The particle size of the powder samples is about 0.13 μm. The maximum conductivity at18 ℃ is 3.057 * 10^(-5) s/cm for Li_(4.4)Al_(0.4)Si_(0.6)O_4-0.3 Al_2O_3.展开更多
The Li 4.4Al 0.4Si 0.6O 4-xLi 3BO 3 (x=0 to 0.5) ion conductors were prepared by the sol-gel method. The powder and sintered samples were characterized by DTA-TG, XRD, SEM and ac impedance techniqu...The Li 4.4Al 0.4Si 0.6O 4-xLi 3BO 3 (x=0 to 0.5) ion conductors were prepared by the sol-gel method. The powder and sintered samples were characterized by DTA-TG, XRD, SEM and ac impedance techniques. The temperature of the preparation of powder patterns decreased by this method as compared to that of the preparation in solid state reaction. The conductivity and sinterability increased with Li 3BO 3 increasing from x=0 to 0.2 in the Li 4.4Al 0.4Si 0.6O 4-xLi 3BO 3 solid electrolytes. The particle size of the sintered pellets is about 0.12 μm. The maximum conductivity at 20 ℃ is 3.165×10 -5 S·cm -1 for Li 4.4Al 0.4Si 0.6O 4-0.2Li 3BO 3.展开更多
文摘Li 2+ x RE x Si 1- x O 3(RE=Pr, Nd, Sm, Gd; x =0～0 15) samples were prepared by the sol gel method. DTA TG, XRD, TEM and A C impedance techniques were used to investigate the structure, shape, and ionic conductivity of these samples. The results show that the range of solid solution formation is in 0< x ≤0 09, in which the conductivity of these samples raises with the increasing amount of RE 2O 3 (RE=Pr, Nd, Sm, Gd) added, and the diameter of the powders is about 100 nm. Compared with the conventional solid state reaction, the sol gel method needs low temperature and presents high ionic conductivity.
文摘In this study, a modified silica gel surface with a hydrophobic ionic liquid (SG-1,10-PhenanNTf2) was used as an adsorbent for a selective extraction of coumarin prior to its determination by use of high performance liquid chromatography. Results demonstrated that SG-1,10-PhenanNTf2 phase had a good adsorption capacity up to 85.29 mg?g?1, high selectivity, good site accessibility and fast binding kinetics toward coumarin. The adsorption capacity for coumarin was improved by 62.33% with the SG-1,10-PhenanNTf2 phase as compared to activated silica gel. Adsorption isotherm data displayed that the adsorption process was mainly monolayer on a homogeneous adsorbent surface, confirming the validity of Langmuir adsorption isotherm model. The adsorption of coumarin on the SG-1,10-PhenanNTf2 phase was accomplished after only 60 min contact time. Results of kinetic models showed that the adsorption of coumarin on the SG-1,10-PhenanNTf2 phase obeyed a pseudo second-order kinetic model. Finally, the efficiency of this methodology was confirmed by applying it to real water samples.
基金Department of Science and Technology (DST) for the financial support from DST-PURSE programme
文摘Systematic analysis about the exploitation of imidazolium based ionic liquids （ILs）, [BMIM] BF4 [ILl], [EMIM] BF4 ILL2] and [BMIM] PF6 [IL3] as the morphological template on the basic sol-gel method adopted synthesis of nanostructured zinc oxide （ZnO） is presented. X-ray diffraction （XRD）, particle size analysis （PSA） and scanning electron microscopy （SEM） have been employed for the characterization of structure and morphology of the synthesized ZnO particles. Well-defined capsule like shaped morphology with lower nanosize is observed for the ZnO nanoparticles with ILl than those with IL2 and IL3. This confirms that ILl served as an effective templating material due to their unique properties. Especially the effective aggregation of ZnO particles with a self-organized frame of ILl was the essential factor to produce the lower nanosized ZnO with capsule shaped structure. The synthesized ZnO samples with IL2 and IL3 fabricated the flake like shaped and rod like shaped morphologies in the range of nanoscale. The formed ZnO nanoparticles with IL2 exhibit higher nanosize than the ZnO nanoparticles produced by ILl, owing to shorter length of alkyl group in its cation which restricts steric effect and permits the nanoparticles to grow longer. Even though IL3 produced the discrete ZnO nanorods, the hydrophobic nature of IL3 created the higher nanosize than the ZnO nanoparticles formed by other two ionic liquids. Antibacterial properties of the synthesized ZnO nanostructures were investigated against Staphylococcus aureus （gram positive） and Escherichia coil （gram negative） bacteria by Agar diffusion test method. Microbial experiments indicate that the synthesized ZnO samples show a wide spectrum of antimicrobial activities and performed better against S. aureus than E. coil with the same concentration of ZnO.
基金theNaturalScienceFoundationofHebeiProvince (No .2 96 16 9)
文摘The Li_(4+x)Al_xSi_(1-x)O_(4-y)Al_2O_3 (x = 0 to 0.5, y = 0 to 0.5) ionconductors were prepared by the Sol-Gel method and examined in detail. The powder and sinteredsamples were characterized by TG-DTA, XRD, SEM, and AC impedance techniques. The experimentalresults show that the conductivity and sinterability increase with the amount of excess Al_2O_3 inthe silicate. The particle size of the powder samples is about 0.13 μm. The maximum conductivity at18 ℃ is 3.057 * 10^(-5) s/cm for Li_(4.4)Al_(0.4)Si_(0.6)O_4-0.3 Al_2O_3.
文摘The Li 4.4Al 0.4Si 0.6O 4-xLi 3BO 3 (x=0 to 0.5) ion conductors were prepared by the sol-gel method. The powder and sintered samples were characterized by DTA-TG, XRD, SEM and ac impedance techniques. The temperature of the preparation of powder patterns decreased by this method as compared to that of the preparation in solid state reaction. The conductivity and sinterability increased with Li 3BO 3 increasing from x=0 to 0.2 in the Li 4.4Al 0.4Si 0.6O 4-xLi 3BO 3 solid electrolytes. The particle size of the sintered pellets is about 0.12 μm. The maximum conductivity at 20 ℃ is 3.165×10 -5 S·cm -1 for Li 4.4Al 0.4Si 0.6O 4-0.2Li 3BO 3.
