Fe3O4 suspension, derived from chemical coprecipitation and subsequent ultrasonic treatment, was embedded into calcium alginate to form complex gel. Both gel beads and injectable gel floc were obtained by slightly tai...Fe3O4 suspension, derived from chemical coprecipitation and subsequent ultrasonic treatment, was embedded into calcium alginate to form complex gel. Both gel beads and injectable gel floc were obtained by slightly tailoring the preparation condition. SEM analysis showed that the iron oxide was dispersed homogenously in nanometer. TGA profiles revealed that the content of Fe3O4 in beads was about 7.2%.展开更多
In this manuscript, a series of catalyst SG n-[VVO2-PAMAM-MSA] (SG silica gel, PAMAM polyamidoamine, MSA 5-methyl salicylaldehyde, n=0, 1, 2, 3) was prepared and their structures were fully characterized by Fourier tr...In this manuscript, a series of catalyst SG n-[VVO2-PAMAM-MSA] (SG silica gel, PAMAM polyamidoamine, MSA 5-methyl salicylaldehyde, n=0, 1, 2, 3) was prepared and their structures were fully characterized by Fourier transform-infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and inductive coupled plasma emission spectrometer (ICP) etc. XPS revealed that the metal V and SG n-PAMAM-MSA combined more closely after the formation of Schiff base derivatives. Their catalytic activities for oxidation of dibenzothiophene were evaluated using tert-butyl hydroperoxide as oxidant. The results showed that the catalyst SG 2.0-[VVO2-PAMAM-MSA] presented good catalytic activity and recycling time. Meanwhile, the optimal condition for the catalytic oxidation of SG 2.0-[VVO2-PAMAM-MSA] was also investigated, which showed that when the oxidation temperature was 90 °C, time was 60 min, the O/S was 3:1, and the mass content of catalyst was 1%, the rate of desulfurization could reach 85.2%. Moreover, the catalyst can be recycled several times without significant decline in catalytic activity.展开更多
Both silica and boron-silica glass materials doped with terbium organic complex were prepared by in situ sol-gel method respectively. XRD and SEM measurements were performed to verify the non-crystalline structure of ...Both silica and boron-silica glass materials doped with terbium organic complex were prepared by in situ sol-gel method respectively. XRD and SEM measurements were performed to verify the non-crystalline structure of the glass. The influence of the glass contents on the structure of the glass and the erwrgy level of the doped Tb （Ⅲ） ions was analyzed by the emission spectra and IR spectra. The effect of B2O3 on the photolumirwscence properties of rare earth organic complex in silica- based glass was investigated. The IR spectra indicate that the in situ sylthesized rare earth complex molecule was confined to the micropores of the bost and the vibration of the ligands was frozen. When B2O3 was added into the silica host gel, B2O3 had little influence on the noncrystallirw structure of the glass, and BO3 triangle, which had a layer structure different from the silica framework, could form. So the silica network became more inhomogenous, and the luminescence of terbium complexes was quenched with the increase of the B2O23 amount.展开更多
Nanometer ZrO2 - 8% Y2O3 (mole fraction, % ) powders were prepared by the EDTA (ethylenediaminetetraacetic acid) sol-gel process. Effects of the addition of ethylene glycol on agglomerate control was investigated. The...Nanometer ZrO2 - 8% Y2O3 (mole fraction, % ) powders were prepared by the EDTA (ethylenediaminetetraacetic acid) sol-gel process. Effects of the addition of ethylene glycol on agglomerate control was investigated. The results showed that because of the replacement of hydrogen bonds with ethylene glycol in the polymerized gel, gel stabilization and homogeneity were improved and close approach of gel particles was prevented, which led to reduction of hard agglomerates to some extent. Calcined at 4OO t for 2 h and 700 C for 2 h, the powders had a specific surface area of 35 m2/g, average particle size of 28 nm, and median particle size (d50) of 0. 44um with very sharp distribution, mostly being soft agglomerates.展开更多
Ternary complexes of europium and terbium with benzoic acid and 1, 10 phenanthroline [RE(BA) 3phen] (BA=benzoate phen=1,10 phenanthroline) were introduced into a silica matrix by sol gel method. The thermal stabil...Ternary complexes of europium and terbium with benzoic acid and 1, 10 phenanthroline [RE(BA) 3phen] (BA=benzoate phen=1,10 phenanthroline) were introduced into a silica matrix by sol gel method. The thermal stability and luminescence behavior of the complexes in silica gels were studied in comparison with the corresponding solid state complexes by thermal decomposition, excitation and emission spectra. The thermal stability of the complexes is enhanced in silica gel matrix and the luminescence remaines unchanged.展开更多
Ethyl methacrylate (EMA) doped with luminescent ternary terbium complex (Tb(acac) 3·dam) with acetylacetone (Hacac) and diantipylmethane (dam) was incorporated into the microporous silica gel. With the polymeriz...Ethyl methacrylate (EMA) doped with luminescent ternary terbium complex (Tb(acac) 3·dam) with acetylacetone (Hacac) and diantipylmethane (dam) was incorporated into the microporous silica gel. With the polymerization of EMA, the hybrid material containing Tb(acac) 3·dam was obtained. The hybrid material exhibited good toughness and transparency and higher thermal stability than that of the pure complex and pure polymer matrix. In the range of doping concentration of Tb(acac) 3·dam (0.05%, 0.1%, 0.2%, 0.5%, 1.0%, 2.0% and 5.0%), emission intensity increases with the increasing of corresponding doping concentration and concentration quenching effect has not taken place.展开更多
Silica gel luminophors containing 1, 10-phenanthroline-tris(M-Methylbenzoate) europium (or terbium) com- plexes were prepared bysol-gel method. The thermal decomposition, excitation and emissionspectra for the gel pho...Silica gel luminophors containing 1, 10-phenanthroline-tris(M-Methylbenzoate) europium (or terbium) com- plexes were prepared bysol-gel method. The thermal decomposition, excitation and emissionspectra for the gel phos- phors were measured and compared with thatof solid complex powders. The thermal stability of the complexes wasen- hanced in SiO_2 host matrix and the luminescence intensityremained unchanged.展开更多
A process for in situ synthesis of terbium complex with salicylic acid by a two-step solgel method in silica matrix has been proposed. The luminescence properties of the silica gelscodoped with terbium and salicylic a...A process for in situ synthesis of terbium complex with salicylic acid by a two-step solgel method in silica matrix has been proposed. The luminescence properties of the silica gelscodoped with terbium and salicylic acid have also been discussed with respect to that of the geldoped with terbium and that of pure terbium complex with salicylic acid.展开更多
A novel pyridine-phenol boron complex[（dppy）BF] was encapsulated into polymer/silica composite matrix by sol-gel process. UV-Vis absorption spectra show that this process can control the aggregation structure of com...A novel pyridine-phenol boron complex[（dppy）BF] was encapsulated into polymer/silica composite matrix by sol-gel process. UV-Vis absorption spectra show that this process can control the aggregation structure of complex （dppy）BF. The results of photoluminescence of （dppy）BF in sol-gel composite film indicate that both fluorescence intensity and photostability are markedly increased using this method compared with other methods, which increases the practical significance of such composite film.展开更多
The transparent luminescent thin films of doped terbium complex were obtained by sol gel method. The result indicates that rare earth carboxylates with poor solubility can be homogeneously doped into sol matrix in si...The transparent luminescent thin films of doped terbium complex were obtained by sol gel method. The result indicates that rare earth carboxylates with poor solubility can be homogeneously doped into sol matrix in situ. The fluorescence spectra show that the thin film material emits the characteristic narrow band emission of Tb 3+ under the UV excitation.展开更多
A facile EDTA （ethylene diamine tetraacetic acid） complexing technique has been successfully employed to prepare La2Mo2O9 nanoparticles. The as-synthesized products are characterized by X-ray diffraction （XRD）, sc...A facile EDTA （ethylene diamine tetraacetic acid） complexing technique has been successfully employed to prepare La2Mo2O9 nanoparticles. The as-synthesized products are characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and Fourier transform infrared spectroscopy （FT-IR）. The results show that a homogeneous transparent gel can be obtained with EDTA as the organic complexing reagent under the pH value of 3.0. Further thermal decomposition of the as-synthesized transparent gel by increasing the temperature up to 600℃ for 3 h results in the formation of La2Mo2O9 nanoparticles with a crystal size of about 30 nm. Moreover, the nanoparticles tend to form micrometer-sized aggregates with a three-dimensional network structure, which shows promising applications in solid oxide fuel cells （SOFC）, catalysts and so on.展开更多
A ternary Sm（ Ⅲ ） complex with salicylate （sal-） and o-phenanthroline （phen） was synthesized and incorporated in silica matrix by sol-gel method. The luminescence behavior of the complex in silica gel was studi...A ternary Sm（ Ⅲ ） complex with salicylate （sal-） and o-phenanthroline （phen） was synthesized and incorporated in silica matrix by sol-gel method. The luminescence behavior of the complex in silica gel was studied compared with that of the pure complex by means of emission, excitation spectra and thermogravimetic analysis. The results indicate that the fluorescence intensity ratio of the ^4G5/2→^6H9/2 transition to the ^4G5/2→^6H5/2 transition in silica gel doped with Sm（sal）3 （phen） is lower than that of the pure Sm（sal）3（phen）. The thermal stability of Sm（sal）3（phen） is enhanced greatly by the introduction of the complex into silica matrix. An isolated and chemical inert environment of the complex appears to be responsible for the thermal stability enhancement in silica gel.展开更多
Transparent thin films of ZnO have been prepared on ordinary glass substrates by the inorganic sol-gel method using citric acid as chelating agent and zinc nitrate as the starting material. A novel structure on zinc c...Transparent thin films of ZnO have been prepared on ordinary glass substrates by the inorganic sol-gel method using citric acid as chelating agent and zinc nitrate as the starting material. A novel structure on zinc citrate complex was put forward by using DTA-TG and FT-IR absorbanee spectrum of citrate gels. Phase formation, morphology and optical properties of ZnO films are investigated by XRD, AFM and UV-vis transmittance spectra. The experimental results show that ZnO thin films derived from zinc citrate sol-gel method showed a （002） oriented hexagonal wurtzite structure, good crystalline property, a uniform range of grain size （40 nm）, smooth surface of films, band gap of 3.28 eV and optical transmittances ratio over 90% in the visible range.展开更多
Binary and ternary terbium complexes were synthesized: Tb(N PA) 3·4H 2O and Tb(N PA) 3(phen·2H 2O (N HPA = N phenyl 2 aminobenzoic acid and phen = 1,10 phenanthroline). These complexes were introd...Binary and ternary terbium complexes were synthesized: Tb(N PA) 3·4H 2O and Tb(N PA) 3(phen·2H 2O (N HPA = N phenyl 2 aminobenzoic acid and phen = 1,10 phenanthroline). These complexes were introduced into inorganic polymeric porous silica matrix by the sol gel method. The luminescence behavior of the complexes in silica gels was compared with the corresponding solid state complexes by means of emission, excitation spectra and luminescence lifetimes. The result indicates that the terbium ions show fewer emission lines and lower emission intensities in the silica gel than those in pure terbium complexes. The lifetimes of terbium ions in silica gel doped with terbium complexes become longer than those of terbium complexes.展开更多
To establish a immobilization method of oxygen sensitive dye, a dissolved oxygen sensor based on a sol-gel matrix doped with ruthenium complex ([Ru(bpy)3]2+) as the oxygen-sensitive material is reported. The results i...To establish a immobilization method of oxygen sensitive dye, a dissolved oxygen sensor based on a sol-gel matrix doped with ruthenium complex ([Ru(bpy)3]2+) as the oxygen-sensitive material is reported. The results indicate that the I0 /I100 value of the [Ru(bpy)3]2+-doped in tetraethylorthosilane (TEOS) composite films are estimated to be 10.6, where I0 and I100 correspond to the detected fluorescence intensities in pure nitrogen saturated water and pure oxygen saturated water, respectively. Also, the Stern-Volmer plot shows a very good linearity at low dissolved oxygen concentrations. The response time of the composite films is 5 s upon switching from nitrogen saturated water to oxygen saturated water and 10 s from oxygen saturated water to nitrogen saturated water. The dissolved oxygen sensors based on the ruthenium complex/TEOS composite films exhibit greater sensitivity, stability and faster response time as compared to the existing ones. Furthermore, the thin films possess greatly minimized dye leaching effect.展开更多
Host-vip supramolecular gels were developed via the self-assembly of inclusion complexes(ICs) ofβ-cyclodextrins/phenylboronic acid gelator(PBA).Salts and current were involved in the self-assembly to stabilize the ...Host-vip supramolecular gels were developed via the self-assembly of inclusion complexes(ICs) ofβ-cyclodextrins/phenylboronic acid gelator(PBA).Salts and current were involved in the self-assembly to stabilize the host-vip gels.The stability of the gels was greatly improved after salts were added.The stable time of gels was extended from 2.5 h to 120 h with the addition of NH_4 NO_3 at the concentration of 2.5×10^(-2) g/mL.The morphology of the gel was affected by the concentrations of NH_4NO_3.SEM images revealed that the gels were three-dimensional nanofibrous networks,the sizes of fibers decreased with decreasing NH_4NO_3 concentrations,which affected the stability of gels,further proved by the rheological properties of gels.More stable gels were obtained with current stimulation,the stable time of the gel was increased from 2.5 h to 55 h with current by adding NaBF_4.The current also exhibited significant influence on the aggregation as the voltage varied(0-500 mV) with a constant concentration of salts.The result showed the self-assembly process of host-vip gel could be well controlled via the addition of salts and current to desired morphology and stability.展开更多
A series of (SrNa)2-xEux(MoO4)3 red phosphors have been synthesized by using the sol-gel method. X-ray diffraction, used to characterize the crystallization process of the phosphor precursors, indicates that the (SrNa...A series of (SrNa)2-xEux(MoO4)3 red phosphors have been synthesized by using the sol-gel method. X-ray diffraction, used to characterize the crystallization process of the phosphor precursors, indicates that the (SrNa)2-xEux(MoO4)3 phosphors had an SrMoO4 structure. The properties of these resulting phosphors have also been characterized by using photoluminescence (PL) spectra. The PL results indicate that all of the (SrNa)2-xEux(MoO4)3 phosphors exhibit intense red emissions under 275, 395, and 465-nm excitation. The two strongest lines at 395 and 465 nm in the excitation spectra of these phosphors match well with the two popular emissions from near-UV and blue GaN-based light-emitting diodes. Some process parameters for Eu3+ concentration, (C6H8O7)·H2O concentration, and solution pH value were also investigated. For (SrNa)2-xEux(MoO4)3 phosphors, there are two maximum emission intensities appearing with x = 0.6 and x = 1.4, respectively. When the molar ratio of citric acid is equal to that of metal cations and the solution pH is almost 4, (SrNa)2-xEux(MoO4)3 shows the strongest emission intensity compared to those under other conditions.展开更多
The CeTi 2O 6, which is formed above 1300 ℃ by ceramic method, was obtained at 700 ℃ using sol gel synthesis method. XRD analysis shows that there is 8% deficient of Ce in the structure. The chemical formula is C...The CeTi 2O 6, which is formed above 1300 ℃ by ceramic method, was obtained at 700 ℃ using sol gel synthesis method. XRD analysis shows that there is 8% deficient of Ce in the structure. The chemical formula is Ce 0.92 Ti 2O 5.84 , which has a monoclinic structure with space group of C 2/ m . Its cell parameters are a =0.9811(8) nm, b =0.3726(3) nm, c =0.6831(6) nm, and β =118.84°. After being treated at 1300 ℃ for 3 h, the system keeps stable but the deficient disappears, while the chemical formula change to the normal CeTi 2O 6, and the cell parameters are a =0.9813(3) nm, b =0.3752(4) nm, c =0.6883(5) nm, β =119.05°. The key to synthesis the precursors of CeTi 2O 6 is that Ti 4+ and Ce 3+ ions must reach the atomistic distributing state and prevent the oxidation of Ce 3+ during sol gel process.展开更多
基金Funded by the University Special Item of Natural Science Foundation of Fujian Province (No. 2006J0441)
文摘Fe3O4 suspension, derived from chemical coprecipitation and subsequent ultrasonic treatment, was embedded into calcium alginate to form complex gel. Both gel beads and injectable gel floc were obtained by slightly tailoring the preparation condition. SEM analysis showed that the iron oxide was dispersed homogenously in nanometer. TGA profiles revealed that the content of Fe3O4 in beads was about 7.2%.
基金Supported by the National Natural Science Foundation of China （20901063） the Natural Science Foundation of Hubei Province （2011CDB221）
文摘In this manuscript, a series of catalyst SG n-[VVO2-PAMAM-MSA] (SG silica gel, PAMAM polyamidoamine, MSA 5-methyl salicylaldehyde, n=0, 1, 2, 3) was prepared and their structures were fully characterized by Fourier transform-infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and inductive coupled plasma emission spectrometer (ICP) etc. XPS revealed that the metal V and SG n-PAMAM-MSA combined more closely after the formation of Schiff base derivatives. Their catalytic activities for oxidation of dibenzothiophene were evaluated using tert-butyl hydroperoxide as oxidant. The results showed that the catalyst SG 2.0-[VVO2-PAMAM-MSA] presented good catalytic activity and recycling time. Meanwhile, the optimal condition for the catalytic oxidation of SG 2.0-[VVO2-PAMAM-MSA] was also investigated, which showed that when the oxidation temperature was 90 °C, time was 60 min, the O/S was 3:1, and the mass content of catalyst was 1%, the rate of desulfurization could reach 85.2%. Moreover, the catalyst can be recycled several times without significant decline in catalytic activity.
基金Funded bythe National Natural Science Fundation of China(No.90206047)
文摘Both silica and boron-silica glass materials doped with terbium organic complex were prepared by in situ sol-gel method respectively. XRD and SEM measurements were performed to verify the non-crystalline structure of the glass. The influence of the glass contents on the structure of the glass and the erwrgy level of the doped Tb （Ⅲ） ions was analyzed by the emission spectra and IR spectra. The effect of B2O3 on the photolumirwscence properties of rare earth organic complex in silica- based glass was investigated. The IR spectra indicate that the in situ sylthesized rare earth complex molecule was confined to the micropores of the bost and the vibration of the ligands was frozen. When B2O3 was added into the silica host gel, B2O3 had little influence on the noncrystallirw structure of the glass, and BO3 triangle, which had a layer structure different from the silica framework, could form. So the silica network became more inhomogenous, and the luminescence of terbium complexes was quenched with the increase of the B2O23 amount.
文摘Nanometer ZrO2 - 8% Y2O3 (mole fraction, % ) powders were prepared by the EDTA (ethylenediaminetetraacetic acid) sol-gel process. Effects of the addition of ethylene glycol on agglomerate control was investigated. The results showed that because of the replacement of hydrogen bonds with ethylene glycol in the polymerized gel, gel stabilization and homogeneity were improved and close approach of gel particles was prevented, which led to reduction of hard agglomerates to some extent. Calcined at 4OO t for 2 h and 700 C for 2 h, the powders had a specific surface area of 35 m2/g, average particle size of 28 nm, and median particle size (d50) of 0. 44um with very sharp distribution, mostly being soft agglomerates.
文摘Ternary complexes of europium and terbium with benzoic acid and 1, 10 phenanthroline [RE(BA) 3phen] (BA=benzoate phen=1,10 phenanthroline) were introduced into a silica matrix by sol gel method. The thermal stability and luminescence behavior of the complexes in silica gels were studied in comparison with the corresponding solid state complexes by thermal decomposition, excitation and emission spectra. The thermal stability of the complexes is enhanced in silica gel matrix and the luminescence remaines unchanged.
文摘Ethyl methacrylate (EMA) doped with luminescent ternary terbium complex (Tb(acac) 3·dam) with acetylacetone (Hacac) and diantipylmethane (dam) was incorporated into the microporous silica gel. With the polymerization of EMA, the hybrid material containing Tb(acac) 3·dam was obtained. The hybrid material exhibited good toughness and transparency and higher thermal stability than that of the pure complex and pure polymer matrix. In the range of doping concentration of Tb(acac) 3·dam (0.05%, 0.1%, 0.2%, 0.5%, 1.0%, 2.0% and 5.0%), emission intensity increases with the increasing of corresponding doping concentration and concentration quenching effect has not taken place.
基金This project is financially supported by Natural Science Foundation of Hebei Province, China (No. 299193)
文摘Silica gel luminophors containing 1, 10-phenanthroline-tris(M-Methylbenzoate) europium (or terbium) com- plexes were prepared bysol-gel method. The thermal decomposition, excitation and emissionspectra for the gel phos- phors were measured and compared with thatof solid complex powders. The thermal stability of the complexes wasen- hanced in SiO_2 host matrix and the luminescence intensityremained unchanged.
文摘A process for in situ synthesis of terbium complex with salicylic acid by a two-step solgel method in silica matrix has been proposed. The luminescence properties of the silica gelscodoped with terbium and salicylic acid have also been discussed with respect to that of the geldoped with terbium and that of pure terbium complex with salicylic acid.
基金Supported by the National Basic Research Program of China(No2007CB80800)
文摘A novel pyridine-phenol boron complex[（dppy）BF] was encapsulated into polymer/silica composite matrix by sol-gel process. UV-Vis absorption spectra show that this process can control the aggregation structure of complex （dppy）BF. The results of photoluminescence of （dppy）BF in sol-gel composite film indicate that both fluorescence intensity and photostability are markedly increased using this method compared with other methods, which increases the practical significance of such composite film.
文摘The transparent luminescent thin films of doped terbium complex were obtained by sol gel method. The result indicates that rare earth carboxylates with poor solubility can be homogeneously doped into sol matrix in situ. The fluorescence spectra show that the thin film material emits the characteristic narrow band emission of Tb 3+ under the UV excitation.
基金the Opening Subject of the State Key Laboratory of Powder Metallurgy of China (Nos. 200506123105A and 20070620090631B14)
文摘A facile EDTA （ethylene diamine tetraacetic acid） complexing technique has been successfully employed to prepare La2Mo2O9 nanoparticles. The as-synthesized products are characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and Fourier transform infrared spectroscopy （FT-IR）. The results show that a homogeneous transparent gel can be obtained with EDTA as the organic complexing reagent under the pH value of 3.0. Further thermal decomposition of the as-synthesized transparent gel by increasing the temperature up to 600℃ for 3 h results in the formation of La2Mo2O9 nanoparticles with a crystal size of about 30 nm. Moreover, the nanoparticles tend to form micrometer-sized aggregates with a three-dimensional network structure, which shows promising applications in solid oxide fuel cells （SOFC）, catalysts and so on.
基金Project supported bythe Science and Research Planning Project of Zhejiang Provincial Education Department (0424XP18)
文摘A ternary Sm（ Ⅲ ） complex with salicylate （sal-） and o-phenanthroline （phen） was synthesized and incorporated in silica matrix by sol-gel method. The luminescence behavior of the complex in silica gel was studied compared with that of the pure complex by means of emission, excitation spectra and thermogravimetic analysis. The results indicate that the fluorescence intensity ratio of the ^4G5/2→^6H9/2 transition to the ^4G5/2→^6H5/2 transition in silica gel doped with Sm（sal）3 （phen） is lower than that of the pure Sm（sal）3（phen）. The thermal stability of Sm（sal）3（phen） is enhanced greatly by the introduction of the complex into silica matrix. An isolated and chemical inert environment of the complex appears to be responsible for the thermal stability enhancement in silica gel.
基金Supported by the Natural Science Foundation of Hebei Province(B2008000758) and Overseas Training for Outstanding Experts in Hebei Province
文摘Transparent thin films of ZnO have been prepared on ordinary glass substrates by the inorganic sol-gel method using citric acid as chelating agent and zinc nitrate as the starting material. A novel structure on zinc citrate complex was put forward by using DTA-TG and FT-IR absorbanee spectrum of citrate gels. Phase formation, morphology and optical properties of ZnO films are investigated by XRD, AFM and UV-vis transmittance spectra. The experimental results show that ZnO thin films derived from zinc citrate sol-gel method showed a （002） oriented hexagonal wurtzite structure, good crystalline property, a uniform range of grain size （40 nm）, smooth surface of films, band gap of 3.28 eV and optical transmittances ratio over 90% in the visible range.
文摘Binary and ternary terbium complexes were synthesized: Tb(N PA) 3·4H 2O and Tb(N PA) 3(phen·2H 2O (N HPA = N phenyl 2 aminobenzoic acid and phen = 1,10 phenanthroline). These complexes were introduced into inorganic polymeric porous silica matrix by the sol gel method. The luminescence behavior of the complexes in silica gels was compared with the corresponding solid state complexes by means of emission, excitation spectra and luminescence lifetimes. The result indicates that the terbium ions show fewer emission lines and lower emission intensities in the silica gel than those in pure terbium complexes. The lifetimes of terbium ions in silica gel doped with terbium complexes become longer than those of terbium complexes.
基金Funded by the Open Project of State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials of Sichuan Province (No.10zxfk23)Scientific Research Project of Sichuan Normal University (No.11KYL06)
文摘To establish a immobilization method of oxygen sensitive dye, a dissolved oxygen sensor based on a sol-gel matrix doped with ruthenium complex ([Ru(bpy)3]2+) as the oxygen-sensitive material is reported. The results indicate that the I0 /I100 value of the [Ru(bpy)3]2+-doped in tetraethylorthosilane (TEOS) composite films are estimated to be 10.6, where I0 and I100 correspond to the detected fluorescence intensities in pure nitrogen saturated water and pure oxygen saturated water, respectively. Also, the Stern-Volmer plot shows a very good linearity at low dissolved oxygen concentrations. The response time of the composite films is 5 s upon switching from nitrogen saturated water to oxygen saturated water and 10 s from oxygen saturated water to nitrogen saturated water. The dissolved oxygen sensors based on the ruthenium complex/TEOS composite films exhibit greater sensitivity, stability and faster response time as compared to the existing ones. Furthermore, the thin films possess greatly minimized dye leaching effect.
基金financial support from the National Natural Science Foundation of China(No.21672164)Wenzhou Science and Technology Bureau(No.Y20170162)Graduate Innovation Fund of Wenzhou University(No.3162018031)。
文摘Host-vip supramolecular gels were developed via the self-assembly of inclusion complexes(ICs) ofβ-cyclodextrins/phenylboronic acid gelator(PBA).Salts and current were involved in the self-assembly to stabilize the host-vip gels.The stability of the gels was greatly improved after salts were added.The stable time of gels was extended from 2.5 h to 120 h with the addition of NH_4 NO_3 at the concentration of 2.5×10^(-2) g/mL.The morphology of the gel was affected by the concentrations of NH_4NO_3.SEM images revealed that the gels were three-dimensional nanofibrous networks,the sizes of fibers decreased with decreasing NH_4NO_3 concentrations,which affected the stability of gels,further proved by the rheological properties of gels.More stable gels were obtained with current stimulation,the stable time of the gel was increased from 2.5 h to 55 h with current by adding NaBF_4.The current also exhibited significant influence on the aggregation as the voltage varied(0-500 mV) with a constant concentration of salts.The result showed the self-assembly process of host-vip gel could be well controlled via the addition of salts and current to desired morphology and stability.
文摘A series of (SrNa)2-xEux(MoO4)3 red phosphors have been synthesized by using the sol-gel method. X-ray diffraction, used to characterize the crystallization process of the phosphor precursors, indicates that the (SrNa)2-xEux(MoO4)3 phosphors had an SrMoO4 structure. The properties of these resulting phosphors have also been characterized by using photoluminescence (PL) spectra. The PL results indicate that all of the (SrNa)2-xEux(MoO4)3 phosphors exhibit intense red emissions under 275, 395, and 465-nm excitation. The two strongest lines at 395 and 465 nm in the excitation spectra of these phosphors match well with the two popular emissions from near-UV and blue GaN-based light-emitting diodes. Some process parameters for Eu3+ concentration, (C6H8O7)·H2O concentration, and solution pH value were also investigated. For (SrNa)2-xEux(MoO4)3 phosphors, there are two maximum emission intensities appearing with x = 0.6 and x = 1.4, respectively. When the molar ratio of citric acid is equal to that of metal cations and the solution pH is almost 4, (SrNa)2-xEux(MoO4)3 shows the strongest emission intensity compared to those under other conditions.
文摘The CeTi 2O 6, which is formed above 1300 ℃ by ceramic method, was obtained at 700 ℃ using sol gel synthesis method. XRD analysis shows that there is 8% deficient of Ce in the structure. The chemical formula is Ce 0.92 Ti 2O 5.84 , which has a monoclinic structure with space group of C 2/ m . Its cell parameters are a =0.9811(8) nm, b =0.3726(3) nm, c =0.6831(6) nm, and β =118.84°. After being treated at 1300 ℃ for 3 h, the system keeps stable but the deficient disappears, while the chemical formula change to the normal CeTi 2O 6, and the cell parameters are a =0.9813(3) nm, b =0.3752(4) nm, c =0.6883(5) nm, β =119.05°. The key to synthesis the precursors of CeTi 2O 6 is that Ti 4+ and Ce 3+ ions must reach the atomistic distributing state and prevent the oxidation of Ce 3+ during sol gel process.
