Titanium matrix composites reinforced with ceramic particles are considered a promising engineering material due to their combination of high specific strength,low density,and high modulus.In this study,the TA15-based...Titanium matrix composites reinforced with ceramic particles are considered a promising engineering material due to their combination of high specific strength,low density,and high modulus.In this study,the TA15-based composites reinforced with a volume fraction of 10% to 25%(TiB+TiC)were prepared using powder metallurgy and casting technique.Microstructural characterization and phase constitution were examined using optical microscopy(OM),scanning electron microscopy(SEM),and X-ray diffraction(XRD).In addition,the microhardness,room temperature(RT)and high temperature(HT)tensile properties of the composites were evaluated.Results revealed that the reinforcements are distributed uniformly even in the composites with a high volume of TiB and TiC.However,as the volume fraction exceeds 15%,TiB and TiC particles become coarsening and exhibit rod-like and dendritic-like morphology.Microhardness increases gradually from 321.2 HV for the base alloy to a maximum of 473.3 HV as the reinforcement increases to 25vol.%.Tensile test results indicate that a reinforcement volume fraction above 20% is beneficial for enhancing tensile strength and yield strength at high temperatures,but it has an adverse effect on room temperature elongation.Conversely,if the reinforcement volume fraction is below 20%,it can improve high-temperature elongation when the temperature exceeds 600℃.展开更多
The addition of 2,5-pyridinedicarboxylic acid(2,5-PDCA)to the Mg-Al LDH coating,which was prepared by one-step hydrothermal synthesis,had extremely enhanced the corrosion protection of AZ31 Mg alloy,although the 2,5-P...The addition of 2,5-pyridinedicarboxylic acid(2,5-PDCA)to the Mg-Al LDH coating,which was prepared by one-step hydrothermal synthesis,had extremely enhanced the corrosion protection of AZ31 Mg alloy,although the 2,5-PDCA could not be intercalated into the interlayer spacing.The corrosion current density of 0.05 mol L^(−1)2,5-PDCA LDH containing LDH coating is 3.18 nA cm^(−2),reduced by two orders of magnitude compared to the LDH coating without inhibitor,and the corrosion inhibition efficiency of the coating is 98.05%.The coating formed on the surface of AZ31 was peeled off from the substrate by using a mechanical method and SEM observation of the cross-section showed that the coating consisted of three different layers.The innermost layer is a thick layer that consists of Mg(OH)_(2)and the intermediate layer is LDH,which is vertical to the substrate and the outmost layer is a thin but very dense deposit layer of LDH agglomerates with complexes of 2,5-PDCA and Mg.This kind of sediment/LDH/Mg(OH)_(2)three-layer composite structure was accountable for the increase in the corrosion resistance of AZ31 Mg alloy.展开更多
Tetragonal barium titanate was synthesized from barium hydroxide octahydrate and titanium tetrachloride through a simple one-step hydrothermal method.The effect of different solvents on the crystal structure and morph...Tetragonal barium titanate was synthesized from barium hydroxide octahydrate and titanium tetrachloride through a simple one-step hydrothermal method.The effect of different solvents on the crystal structure and morphology of barium titanate nanoparticles during the hy-drothermal process was investigated.Except for ethylene glycol/water solvent,impurity-free barium titanate was synthesized in pure water,methanol/water,ethanol/water,and isopropyl alcohol/water mixed solvents.Compared with other alcohols,ethanol promotes the formation of a tetragonal structure.In addition,characterization studies confirm that particles synthesized in methanol/water,ethanol/water,and isopropyl al-cohol/water mixed solvents are smaller in size than those synthesized in pure water.In the case of alcohol-containing solvents,the particle size decreases in the order of isopropanol,ethanol,and methanol.Among all the media used in this study,ethanol/water is considered the optimum reaction media for barium titanate with high tetragonality(defined as the ratio of two lattice parameters c and a,c/a=1.0088)and small aver-age particle size(82 nm),which indicates its great application potential in multilayer ceramic capacitors.展开更多
This study aims to improve the value of fast-growing wood and extend the heat-treated wood utilization using inorganic calcium carbonate(CaCO_(3))crystals via an in-situ synthesis method.CaCl_(2)and Na 2CO_(3)solution...This study aims to improve the value of fast-growing wood and extend the heat-treated wood utilization using inorganic calcium carbonate(CaCO_(3))crystals via an in-situ synthesis method.CaCl_(2)and Na 2CO_(3)solutions with a concentration ratio of 1:1 were successively introduced into the thermally modified poplar wood obtained by steam heat treatment(HT)at 200℃for 1.5 and 3 h,resulting in the in-situ synthesis of CaCO_(3)crystals inside the heat-treated wood.The filling effect was best at the concentration of 1.2 mol/L.CaCO_(3)was uniformly distributed in the cell cavities of the heat-treated wood,and some of the crystals were embedded in the fissures of the wood cell walls.The morphology of CaCO_(3)crystals was mainly spherical and rhombic polyhedral.Three main types of CaCO_(3)crystals were calcite,vaterite,and aragonite.The HT of poplar wood at 200℃resulted in degrading the chemical components of the wood cell wall.This degradation led to reduced wood mechanical properties,including the surface hardness(HD),modulus of rupture(MOR),and modulus of elasticity(MOE).After CaCO_(3)was in-situ synthesized in the heat-treated wood,the HD increased by 18.36%and 16.35%,and MOR increased by 14.64%and 8.89%,respectively.Because of the CaCO_(3)synthesization,the char residue of the 200℃heat-treated wood samples increased by 9.31%and the maximum weight loss rate decreased by 19.80%,indicating that the filling with CaCO_(3)cannot only improve the mechanical properties of the heat-treated wood but also effectively enhance its thermal stability.展开更多
A metal-organic coordination polymer [ZnE.s(phen)(BDC)2(OH)]2 (phen = 1,10- phenanthroline, BDC = benzene-1,4-dicarboxylic acid) 1 has been hydrothermally synthesized and structurally characterized by single-c...A metal-organic coordination polymer [ZnE.s(phen)(BDC)2(OH)]2 (phen = 1,10- phenanthroline, BDC = benzene-1,4-dicarboxylic acid) 1 has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analyses and IR spectroscopy. The complex crystallizes in the triclinic system, space group PI with a = 11.199(2), b = 11.593(2), c = 11.865(3)/A, α= 99.330(1), β = 111.506(1), γ = 104.804(1)^o, V= 1328.4(5)A^3, Dc= 1.722 g/cm^3, Z = 1, Mr = 1377.82, F(000) = 692,μ(MoKa) = 2.306 mm^-1, S = 1.093, R= 0.0281 and wR = 0.0756 for 4179 observed reflections (I 〉 2σ(/)). The coordination polyhedron around Zn(II) can be described as a tetrahedron, trigonal bipyramid and octahedron. It is worth noting that the crystal structure of 1 is composed of tetranuclear zinc clusters linked by {ZnO6} units.展开更多
The title complex (C26H18CuN206, Mr= 517.96) has been synthesized by the reaction of α-furanacrylic acid with 1,10-phenanthroline (phen) in the solvent mixture of water and methanol. Crystal data: monoclinic, sp...The title complex (C26H18CuN206, Mr= 517.96) has been synthesized by the reaction of α-furanacrylic acid with 1,10-phenanthroline (phen) in the solvent mixture of water and methanol. Crystal data: monoclinic, space group C2/c with a = 2.2927(4), b = 1.01248(18), c = 1.05061(18) nm, β = 111.188(3)°, V= 2.274(7) nm^3, Dc = 1.513 g/cm^3, Z = 4, F(000) = 1060,μ = 1.007mm^-1, R = 0.0320 and ωR = 0.0781. The crystal structural analysis shows that the copper atom is coordinated with four oxygen atoms from two α-furacrylic acids and two nitrogen atoms from 1,10-phenanthroline, giving a distorted octahedral coordination geometry. The result of electrochemical analysis shows that the electron transfer in the electrode reaction is quasi-reversible.展开更多
A metal-organic coordination polymer {[Zn(Pht)(4,4'-bipy)(H2O)2]·2H2O}n (Pht = phthalate, 4,4'-bipy = 4,4'-bipyridine) 1 has been hydrothermally synthesized and characterized by elemental analysis, IR,...A metal-organic coordination polymer {[Zn(Pht)(4,4'-bipy)(H2O)2]·2H2O}n (Pht = phthalate, 4,4'-bipy = 4,4'-bipyridine) 1 has been hydrothermally synthesized and characterized by elemental analysis, IR, TG, fluorescence spectrum and single-crystal X-ray diffraction. Yellow crystals crystallize in the monoclinic system, space group P2/n, a = 7.6346(14), b = 11.316(2), c = 10.8133(19) ,A, β = 92.A.A,A.(3)°, V = 933.3(3) A^3, C18H20N2O8Zn, Mr = 457.73, Dc = 1.629 g/cm^3, F(000) = 472, Z = 2,μ(MoKa) = 1.367 mm^-1, the final R = 0.0323 and wR = 0.0821 for 1859 observed reflections (Ⅰ〉 2σ(Ⅰ)). The structure of 1 exhibits a two-dimensional bilayer framework formed by hydrogen bonding interactions. Furthermore, 1 shows yellow photoluminescent property at room temperature.展开更多
Olivine LiFePO 4 , as a cathode material for lithium ion batteries, was prepared by a novel optimized hydrothermal method; afterwards, the product mixed with glucose was two-step (350℃ and 700℃) calcinated under h...Olivine LiFePO 4 , as a cathode material for lithium ion batteries, was prepared by a novel optimized hydrothermal method; afterwards, the product mixed with glucose was two-step (350℃ and 700℃) calcinated under high-purity N 2 atmosphere to obtain the LiFePO 4 /C composite. The study on the hydrothermal preparation method, which focused on the influences of molar ratios, initial pH value, reaction temperature, and duration, was made to promote the resultant performances and to investigate the relations between the performances and the reaction conditions. The resultant samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical tests, which include charge-discharge, electrochemical impedance spectroscopy, and cyclic voltammetry. The result shows that the optimal hydrothermal condition is to set the Li:Fe:P molar ratio at 3:1:1 and the reaction temperature at 180℃ for 5 h duration with an initial pH value of 7. The optimized sample, with an average particle size of 100 to 300 nm and a discharge capacity of 118.2 mAh·g-1 at 0.1C, exhibits a stable and narrow-gapped charge-discharge platform and small capacity losses after cycles.展开更多
High quality Sb-doped SnO2 electrode, with high oxygen evolution potential of 3.0 V, was successfully synthesized on the Ti substrates by in situ hydrothermal synthesis method.
A new metal-organic coordination polymer [Zn(ipt)(im)2]2n·3nH2O 1 has been obtained by using hydrothermal synthesis and characterized by elemental analysis, IR, TG, fluorescence spectrum and single-crystal X-...A new metal-organic coordination polymer [Zn(ipt)(im)2]2n·3nH2O 1 has been obtained by using hydrothermal synthesis and characterized by elemental analysis, IR, TG, fluorescence spectrum and single-crystal X-ray diffraction. The complex crystallizes in monoclinic, space group P2(1/n) with a = 10.653(3), b = 17.891(6), c = 10.743(4)A^°,β= 117.093(5)°, V= 1822.9(10) A^°3, Mr= 413.65, Dc = 1.507 g/cm^3,/t(MoKa) = 1.390 mm^-1, F(000) = 840, Z = 4, the final R = 0.0444 and wR = 0.1066 for 2434 observed reflections (I〉 2σ(I)). Furthermore, compound 1 shows blue photoluminescent property at room temperature.展开更多
A novel supramolecular compound, [Co(IN)_2(H_2O)_4](1), was synthesized by means of the hydrothermal method and its structure was characterized with elemental analysis, FT-IR spectrum, TGA and X-ray diffraction. Thoug...A novel supramolecular compound, [Co(IN)_2(H_2O)_4](1), was synthesized by means of the hydrothermal method and its structure was characterized with elemental analysis, FT-IR spectrum, TGA and X-ray diffraction. Though the unit cell structure of the title compound is only monomeric, all these units as building blocks are assembled into a novel three-dimensional supramolecular network via the widely hydrogen-bonding and π-π stacking interactions.展开更多
The phase and morphology transformation during the hydrothermal treating process of Y2O3 was evaluated with X-ray difference (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), particle ...The phase and morphology transformation during the hydrothermal treating process of Y2O3 was evaluated with X-ray difference (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), particle size and specific surface area determination. The results showed that the cubic Y2O3 did not transfer into hexagonal Y(OH)3 in pure water. Therefore, pure hexagonal Y(OH)3 with nanotube and microrod morphologies were obtained by hydrothermal treating Y2O3 at 150 oC for 12 h in 15 ml of 2 mol/L NaOH solution with and without PVA or PEG. It was suggested that the characteristic preferential growth of Y(OH)3 was attributed to the structure anisotropy of hexahedron Y(OH)3. The addition of PVA or PEG could promote the forming process of nanotubes by selective adsorption on different crystal planes, which altered the growth rate along different directions and resulted in the diffusion limit of constructing ions in the center top of rods. Finally, Y(OH)3:Eu and Y2O3:Eu nanotubes were also synthesized by using this method, and their photoluminescence properties were evaluated.展开更多
One novel metal-organic framework(MOF), [Ba(L)(HO)](1, HL =aniline-2,5-disulfonic acid), has been synthesized by hydrothermal method. Each barium atom is eleven-coordinated into a distorted monocapped pentagonal antip...One novel metal-organic framework(MOF), [Ba(L)(HO)](1, HL =aniline-2,5-disulfonic acid), has been synthesized by hydrothermal method. Each barium atom is eleven-coordinated into a distorted monocapped pentagonal antiprismatic arrangement. Compound 1 shows an interesting 3 D pillar-layered structure constructed from 2 D inorganic layers[Ba(SO)(HO)]and organic pillars of phenyl moieties of L2-linkages. The inorganic layers are supported by the organic pillars, generating a novel 3 D open framework structure with {3, 4~6, 5~5, 6~5,7~4}2{3}{5} topology. The result of fluorescence measurement can reveal that the decayed emission band centered at 492 nm may be caused by the interactions of the ligands and the metal ions.Compound 1 exhibits selective toward the adsorption of COover Nat 273 K.展开更多
One novel binuclear copper(Ⅱ) complex [Cu 2 (Hpt) 2 (CO 3) 2 (H 2 O) 2 ]·H 2 O with copper carbonate and 3-(pyridin-2-yl)-1,2,4-triazole (Hpt) was hydrothermally synthesized and characterized by IR a...One novel binuclear copper(Ⅱ) complex [Cu 2 (Hpt) 2 (CO 3) 2 (H 2 O) 2 ]·H 2 O with copper carbonate and 3-(pyridin-2-yl)-1,2,4-triazole (Hpt) was hydrothermally synthesized and characterized by IR and X-ray diffraction analysis.The complex crystallizes in triclinic,space group P2 1 /n with a=0.6862(1),b=0.7805(1),c=1.1983(2) nm,α=72.03(2),β=107.72(3),γ=75.28(2)o,V=0.5884 nm 3,D c=2.105 g/cm 3,Z=1,F(000)=357,GOOF=1.041,the final R=0.01859 and wR=0.04348.The whole molecule is composed of two cooper ions,two Hpt molecules,two carbonate and three water molecules,forming a binuclear structure.The crystal structure shows that the cooper ion is coordinated with three nitrogen atoms from two Hpt molecules,two oxygen atoms from one carbonic acid and one water molecule,forming a distorted square pyramidal geometry.The TG analysis result shows that the title complex is stable under 131.0 ℃.展开更多
It was focused on the applications and developments of microwave hydrothermal synthesis piezoelectric ceramic powder. The microwave hydrothermal vessel was designed and manufactured. The microwave hydrothermal synthes...It was focused on the applications and developments of microwave hydrothermal synthesis piezoelectric ceramic powder. The microwave hydrothermal vessel was designed and manufactured. The microwave hydrothermal synthesis system was established and the PZT piezoelectric ceramic powder was synthesized. XRD and TEM have been used to characterize the products in detail. The diameter of the PZT powder particle is from 40 to 60 nm.展开更多
The title complex (C26H24CuN2O5, Mr = 508.01) has been synthesized by o-methylbenzoic acid, 2,2'-bipyridine (bipy) and copper perchlorate in the mixed solvent of water and methanol. It crystallizes in orthorhombi...The title complex (C26H24CuN2O5, Mr = 508.01) has been synthesized by o-methylbenzoic acid, 2,2'-bipyridine (bipy) and copper perchlorate in the mixed solvent of water and methanol. It crystallizes in orthorhombic, space group P212121 with a = 0.70814(10), b = 1.6953(3), c = 1.9539(3) nm, V= 2.3457(6) nm^3, De= 1.439 g/cm^3, Z = 4,μ = 0.971 mm^-1, F(000) = 1052, R = 0.0432 and wR = 0.0860. The structural determination shows that the copper atom is coordinated by three oxygen atoms from two o-methylbenzoic acids and one water molecule together with two nitrogen atoms from 2,2'-bipyridine, giving a distorted square-pyramidal coordination geometry. The cyclic voltammetric behavior of the complex is also discussed.展开更多
A metal-organic coordination polymer [Ni(PDB)(bix)(H20)]n (H2PDB = 3,4-pyri- dinedicarboxylic acid, bix = 1,4-bis(imidazol-l-ylmethyl)-benzene) 1 has been hydrothermally synthesized and characterized by elem...A metal-organic coordination polymer [Ni(PDB)(bix)(H20)]n (H2PDB = 3,4-pyri- dinedicarboxylic acid, bix = 1,4-bis(imidazol-l-ylmethyl)-benzene) 1 has been hydrothermally synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. Blue crystals crystallize in the triclinic system, space group PI with a = 9.1849(8), b = 9.2065(9), c = 12.9308(12) °, a = 103.3070(10), β = 104.7160(10), y = 90.5900(10)°, V = 1026.42(16)/k3, C21H19NsNiOs, Mr = 480.12, Dc = 1.553 g/cm3, F(000) = 496, Z = 2,/l(MoKa) = 0.991 mm-1, the final R = 0.0325 and wR = 0.0799 for 3561 observed reflections (I 〉 2σ(I)). The structure of 1 exhibits a two-dimensional network structure.展开更多
A new two-dimensional cobalt coordination polymer has been prepared and fully characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. The compound [Co(C2O4)(bix)]n 1 crystallizes in the m...A new two-dimensional cobalt coordination polymer has been prepared and fully characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. The compound [Co(C2O4)(bix)]n 1 crystallizes in the monoclinic system, space group C2/c, with a = 11.549(3), b = 15.700(3), c = 9.260(2) A, β = 102.984(3)°, V = 1636.0(6) A^3, C16HIaCON4O4, Mr= 383.23, Dc = 1.556 g/cm^3, μ(MoKa) = 1.078 mm^-1, F(000) = 780, Z = 4, the final R = 0.0455 and wR = 0.1286 for 1483 observed reflections (I 〉 2σ(I)). Of the compound, the Co center is octahedrally coordinated with oxalate acting as a tetra-dentate ligand coordinated to the cobalt atom and each bix serving as a bridging ligand by employing two N-donors to coordinate with the Co center. An infinite {Co2(C2O4)2}∞ chain is formed along the α axis. Furthermore, the 1D chains are held together via bix ligands to generate a two-dimensional network structure with 1D coronal-like channels (ca. 5.691A × 15.700A).展开更多
A new 3d-4fheterometallic polymer {[Sm2Cu(PDC)2(SO4)2(H20)6]·2H2O}n 1 has been synthesized by Sm2O3, Cu(SO4)2·5H2O and pyridine-3,5-dicarboxylic acid under hydrothermal conditions. The compound cryst...A new 3d-4fheterometallic polymer {[Sm2Cu(PDC)2(SO4)2(H20)6]·2H2O}n 1 has been synthesized by Sm2O3, Cu(SO4)2·5H2O and pyridine-3,5-dicarboxylic acid under hydrothermal conditions. The compound crystallizes in triclinic system, space group Pi, with a = 6.352(7), b = 10.040(10), c = 10.315(11) A, α = 94.958(14), β = 95.556(7), γ = 99.747(14)°, V = 641.7(12)A3, Z = 1, M, = 1030.63, Dc= 2.651 Mg/m3,μ = 5.615 mm-1, F(000) = 491, the final R = 0.0491 and wR = 0.1345 for 2098 observed reflections with I 〉 2σ(I). The compound is a three-dimensional network structure in which infinite lanthanide-carboxylate chains are linked by [Cu($04)2]2- metalloligands to form a mixed-metal coordination network.展开更多
The properties of aluminosilicate kalsilite have attracted the interest of researchers in chemical synthesis, ceramic industry, biofuels, etc. In this study, kalsilite was hydrothermally synthesized from microcline po...The properties of aluminosilicate kalsilite have attracted the interest of researchers in chemical synthesis, ceramic industry, biofuels, etc. In this study, kalsilite was hydrothermally synthesized from microcline powder in a KOH solution. The microcline powder, rich in potassium, aluminum, and silicon, was collected from Mountain Changling in Northwestem China. The effects of temperature, time, and KOH concentration on the decomposition of microcline were investigated. The kalsilite and intermediate products were characterized by means of wet chemistry analysis, X-ray Diffraction (XRD), infi'ared spectrometry (IR), 29Si magic angle spinning nuclear magnetic resonance (29Si MAS NMR), 27A1 MAS NMR, and scanning electron microscope (SEM). With increasing temperature, the microcline powder transforms into a metastable KAlSiO4 polymorph before transforming further into pure kalsilite. A mixture of both kalsilite and metastable KAlSiO4 polymorph is obtained when the hydrothermal reaction is carried out within 2 h; but after 2 h, kalsilite is the predominant product. The concentration of KOH, which needs to be larger than 4.3 M, is an important parameter influencing the synthesis ofkalsilite.展开更多
基金financially supported by the National Key Research&Development Program of China(Nos.2020YFB2008300,2020YFB2008303)。
文摘Titanium matrix composites reinforced with ceramic particles are considered a promising engineering material due to their combination of high specific strength,low density,and high modulus.In this study,the TA15-based composites reinforced with a volume fraction of 10% to 25%(TiB+TiC)were prepared using powder metallurgy and casting technique.Microstructural characterization and phase constitution were examined using optical microscopy(OM),scanning electron microscopy(SEM),and X-ray diffraction(XRD).In addition,the microhardness,room temperature(RT)and high temperature(HT)tensile properties of the composites were evaluated.Results revealed that the reinforcements are distributed uniformly even in the composites with a high volume of TiB and TiC.However,as the volume fraction exceeds 15%,TiB and TiC particles become coarsening and exhibit rod-like and dendritic-like morphology.Microhardness increases gradually from 321.2 HV for the base alloy to a maximum of 473.3 HV as the reinforcement increases to 25vol.%.Tensile test results indicate that a reinforcement volume fraction above 20% is beneficial for enhancing tensile strength and yield strength at high temperatures,but it has an adverse effect on room temperature elongation.Conversely,if the reinforcement volume fraction is below 20%,it can improve high-temperature elongation when the temperature exceeds 600℃.
文摘The addition of 2,5-pyridinedicarboxylic acid(2,5-PDCA)to the Mg-Al LDH coating,which was prepared by one-step hydrothermal synthesis,had extremely enhanced the corrosion protection of AZ31 Mg alloy,although the 2,5-PDCA could not be intercalated into the interlayer spacing.The corrosion current density of 0.05 mol L^(−1)2,5-PDCA LDH containing LDH coating is 3.18 nA cm^(−2),reduced by two orders of magnitude compared to the LDH coating without inhibitor,and the corrosion inhibition efficiency of the coating is 98.05%.The coating formed on the surface of AZ31 was peeled off from the substrate by using a mechanical method and SEM observation of the cross-section showed that the coating consisted of three different layers.The innermost layer is a thick layer that consists of Mg(OH)_(2)and the intermediate layer is LDH,which is vertical to the substrate and the outmost layer is a thin but very dense deposit layer of LDH agglomerates with complexes of 2,5-PDCA and Mg.This kind of sediment/LDH/Mg(OH)_(2)three-layer composite structure was accountable for the increase in the corrosion resistance of AZ31 Mg alloy.
基金supported by Chongqing Newcent New Materials Co.,Ltd.,China (No.2021GKF-0708).
文摘Tetragonal barium titanate was synthesized from barium hydroxide octahydrate and titanium tetrachloride through a simple one-step hydrothermal method.The effect of different solvents on the crystal structure and morphology of barium titanate nanoparticles during the hy-drothermal process was investigated.Except for ethylene glycol/water solvent,impurity-free barium titanate was synthesized in pure water,methanol/water,ethanol/water,and isopropyl alcohol/water mixed solvents.Compared with other alcohols,ethanol promotes the formation of a tetragonal structure.In addition,characterization studies confirm that particles synthesized in methanol/water,ethanol/water,and isopropyl al-cohol/water mixed solvents are smaller in size than those synthesized in pure water.In the case of alcohol-containing solvents,the particle size decreases in the order of isopropanol,ethanol,and methanol.Among all the media used in this study,ethanol/water is considered the optimum reaction media for barium titanate with high tetragonality(defined as the ratio of two lattice parameters c and a,c/a=1.0088)and small aver-age particle size(82 nm),which indicates its great application potential in multilayer ceramic capacitors.
基金funded by“Natural Science Foundation of Anhui Province,Grant No.2008085QC130”.
文摘This study aims to improve the value of fast-growing wood and extend the heat-treated wood utilization using inorganic calcium carbonate(CaCO_(3))crystals via an in-situ synthesis method.CaCl_(2)and Na 2CO_(3)solutions with a concentration ratio of 1:1 were successively introduced into the thermally modified poplar wood obtained by steam heat treatment(HT)at 200℃for 1.5 and 3 h,resulting in the in-situ synthesis of CaCO_(3)crystals inside the heat-treated wood.The filling effect was best at the concentration of 1.2 mol/L.CaCO_(3)was uniformly distributed in the cell cavities of the heat-treated wood,and some of the crystals were embedded in the fissures of the wood cell walls.The morphology of CaCO_(3)crystals was mainly spherical and rhombic polyhedral.Three main types of CaCO_(3)crystals were calcite,vaterite,and aragonite.The HT of poplar wood at 200℃resulted in degrading the chemical components of the wood cell wall.This degradation led to reduced wood mechanical properties,including the surface hardness(HD),modulus of rupture(MOR),and modulus of elasticity(MOE).After CaCO_(3)was in-situ synthesized in the heat-treated wood,the HD increased by 18.36%and 16.35%,and MOR increased by 14.64%and 8.89%,respectively.Because of the CaCO_(3)synthesization,the char residue of the 200℃heat-treated wood samples increased by 9.31%and the maximum weight loss rate decreased by 19.80%,indicating that the filling with CaCO_(3)cannot only improve the mechanical properties of the heat-treated wood but also effectively enhance its thermal stability.
基金The project was supported by the Education Office of Jilin Province (No. 0047)
文摘A metal-organic coordination polymer [ZnE.s(phen)(BDC)2(OH)]2 (phen = 1,10- phenanthroline, BDC = benzene-1,4-dicarboxylic acid) 1 has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analyses and IR spectroscopy. The complex crystallizes in the triclinic system, space group PI with a = 11.199(2), b = 11.593(2), c = 11.865(3)/A, α= 99.330(1), β = 111.506(1), γ = 104.804(1)^o, V= 1328.4(5)A^3, Dc= 1.722 g/cm^3, Z = 1, Mr = 1377.82, F(000) = 692,μ(MoKa) = 2.306 mm^-1, S = 1.093, R= 0.0281 and wR = 0.0756 for 4179 observed reflections (I 〉 2σ(/)). The coordination polyhedron around Zn(II) can be described as a tetrahedron, trigonal bipyramid and octahedron. It is worth noting that the crystal structure of 1 is composed of tetranuclear zinc clusters linked by {ZnO6} units.
基金the Foundation of Education Committee of Hunan Province (06C195)the Research Award Fund for Outstanding Young Teachers of Hengyang Normal University (2006)the Construct Program of the.Key Discipline in Hunan Province.
文摘The title complex (C26H18CuN206, Mr= 517.96) has been synthesized by the reaction of α-furanacrylic acid with 1,10-phenanthroline (phen) in the solvent mixture of water and methanol. Crystal data: monoclinic, space group C2/c with a = 2.2927(4), b = 1.01248(18), c = 1.05061(18) nm, β = 111.188(3)°, V= 2.274(7) nm^3, Dc = 1.513 g/cm^3, Z = 4, F(000) = 1060,μ = 1.007mm^-1, R = 0.0320 and ωR = 0.0781. The crystal structural analysis shows that the copper atom is coordinated with four oxygen atoms from two α-furacrylic acids and two nitrogen atoms from 1,10-phenanthroline, giving a distorted octahedral coordination geometry. The result of electrochemical analysis shows that the electron transfer in the electrode reaction is quasi-reversible.
基金The project was supported by the Education Office of Jilin Province (No. 0047)
文摘A metal-organic coordination polymer {[Zn(Pht)(4,4'-bipy)(H2O)2]·2H2O}n (Pht = phthalate, 4,4'-bipy = 4,4'-bipyridine) 1 has been hydrothermally synthesized and characterized by elemental analysis, IR, TG, fluorescence spectrum and single-crystal X-ray diffraction. Yellow crystals crystallize in the monoclinic system, space group P2/n, a = 7.6346(14), b = 11.316(2), c = 10.8133(19) ,A, β = 92.A.A,A.(3)°, V = 933.3(3) A^3, C18H20N2O8Zn, Mr = 457.73, Dc = 1.629 g/cm^3, F(000) = 472, Z = 2,μ(MoKa) = 1.367 mm^-1, the final R = 0.0323 and wR = 0.0821 for 1859 observed reflections (Ⅰ〉 2σ(Ⅰ)). The structure of 1 exhibits a two-dimensional bilayer framework formed by hydrogen bonding interactions. Furthermore, 1 shows yellow photoluminescent property at room temperature.
基金supported by the National Natural Science Foundation of China (No. 50472089)
文摘Olivine LiFePO 4 , as a cathode material for lithium ion batteries, was prepared by a novel optimized hydrothermal method; afterwards, the product mixed with glucose was two-step (350℃ and 700℃) calcinated under high-purity N 2 atmosphere to obtain the LiFePO 4 /C composite. The study on the hydrothermal preparation method, which focused on the influences of molar ratios, initial pH value, reaction temperature, and duration, was made to promote the resultant performances and to investigate the relations between the performances and the reaction conditions. The resultant samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical tests, which include charge-discharge, electrochemical impedance spectroscopy, and cyclic voltammetry. The result shows that the optimal hydrothermal condition is to set the Li:Fe:P molar ratio at 3:1:1 and the reaction temperature at 180℃ for 5 h duration with an initial pH value of 7. The optimized sample, with an average particle size of 100 to 300 nm and a discharge capacity of 118.2 mAh·g-1 at 0.1C, exhibits a stable and narrow-gapped charge-discharge platform and small capacity losses after cycles.
基金supported by the National Natural Science Foundation of China(No.20607015)Program for Young Excellent Talents in Tongji University(No.2006KJ057).
文摘High quality Sb-doped SnO2 electrode, with high oxygen evolution potential of 3.0 V, was successfully synthesized on the Ti substrates by in situ hydrothermal synthesis method.
基金The project was supported by the Education Office of Jilin Province (No. 0047)
文摘A new metal-organic coordination polymer [Zn(ipt)(im)2]2n·3nH2O 1 has been obtained by using hydrothermal synthesis and characterized by elemental analysis, IR, TG, fluorescence spectrum and single-crystal X-ray diffraction. The complex crystallizes in monoclinic, space group P2(1/n) with a = 10.653(3), b = 17.891(6), c = 10.743(4)A^°,β= 117.093(5)°, V= 1822.9(10) A^°3, Mr= 413.65, Dc = 1.507 g/cm^3,/t(MoKa) = 1.390 mm^-1, F(000) = 840, Z = 4, the final R = 0.0444 and wR = 0.1066 for 2434 observed reflections (I〉 2σ(I)). Furthermore, compound 1 shows blue photoluminescent property at room temperature.
基金Supported by the National Natural Science Foundation of China( No.2 973 3 0 90 ),the Research Funds for the DoctoralProgram of Higher Education,the State Key L aboratory of Coordination ChemistryNanjing U niversity and the Funds ofInner Mongolia Edu
文摘A novel supramolecular compound, [Co(IN)_2(H_2O)_4](1), was synthesized by means of the hydrothermal method and its structure was characterized with elemental analysis, FT-IR spectrum, TGA and X-ray diffraction. Though the unit cell structure of the title compound is only monomeric, all these units as building blocks are assembled into a novel three-dimensional supramolecular network via the widely hydrogen-bonding and π-π stacking interactions.
基金Program for Changjiang Scholars and Innovative Research Team in University (IRT0730)Chinese Ministry of Education Foundation for Core Young Teacher at University (GG-430-10403-1970)+1 种基金the Key Project of Department of Science and Technology of Jiangxi ProvinceProject of Education Department of Jiangxi
文摘The phase and morphology transformation during the hydrothermal treating process of Y2O3 was evaluated with X-ray difference (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), particle size and specific surface area determination. The results showed that the cubic Y2O3 did not transfer into hexagonal Y(OH)3 in pure water. Therefore, pure hexagonal Y(OH)3 with nanotube and microrod morphologies were obtained by hydrothermal treating Y2O3 at 150 oC for 12 h in 15 ml of 2 mol/L NaOH solution with and without PVA or PEG. It was suggested that the characteristic preferential growth of Y(OH)3 was attributed to the structure anisotropy of hexahedron Y(OH)3. The addition of PVA or PEG could promote the forming process of nanotubes by selective adsorption on different crystal planes, which altered the growth rate along different directions and resulted in the diffusion limit of constructing ions in the center top of rods. Finally, Y(OH)3:Eu and Y2O3:Eu nanotubes were also synthesized by using this method, and their photoluminescence properties were evaluated.
基金supported by the Liaoning Provincial Education Department(No.L2015299)Innovative training program for College Students(Nos.201710148000118,201710148000147)
文摘One novel metal-organic framework(MOF), [Ba(L)(HO)](1, HL =aniline-2,5-disulfonic acid), has been synthesized by hydrothermal method. Each barium atom is eleven-coordinated into a distorted monocapped pentagonal antiprismatic arrangement. Compound 1 shows an interesting 3 D pillar-layered structure constructed from 2 D inorganic layers[Ba(SO)(HO)]and organic pillars of phenyl moieties of L2-linkages. The inorganic layers are supported by the organic pillars, generating a novel 3 D open framework structure with {3, 4~6, 5~5, 6~5,7~4}2{3}{5} topology. The result of fluorescence measurement can reveal that the decayed emission band centered at 492 nm may be caused by the interactions of the ligands and the metal ions.Compound 1 exhibits selective toward the adsorption of COover Nat 273 K.
基金Supported by the Hunan Provincial Department of Science and Technology Project (2009FJ3101)
文摘One novel binuclear copper(Ⅱ) complex [Cu 2 (Hpt) 2 (CO 3) 2 (H 2 O) 2 ]·H 2 O with copper carbonate and 3-(pyridin-2-yl)-1,2,4-triazole (Hpt) was hydrothermally synthesized and characterized by IR and X-ray diffraction analysis.The complex crystallizes in triclinic,space group P2 1 /n with a=0.6862(1),b=0.7805(1),c=1.1983(2) nm,α=72.03(2),β=107.72(3),γ=75.28(2)o,V=0.5884 nm 3,D c=2.105 g/cm 3,Z=1,F(000)=357,GOOF=1.041,the final R=0.01859 and wR=0.04348.The whole molecule is composed of two cooper ions,two Hpt molecules,two carbonate and three water molecules,forming a binuclear structure.The crystal structure shows that the cooper ion is coordinated with three nitrogen atoms from two Hpt molecules,two oxygen atoms from one carbonic acid and one water molecule,forming a distorted square pyramidal geometry.The TG analysis result shows that the title complex is stable under 131.0 ℃.
文摘It was focused on the applications and developments of microwave hydrothermal synthesis piezoelectric ceramic powder. The microwave hydrothermal vessel was designed and manufactured. The microwave hydrothermal synthesis system was established and the PZT piezoelectric ceramic powder was synthesized. XRD and TEM have been used to characterize the products in detail. The diameter of the PZT powder particle is from 40 to 60 nm.
基金Project supported by the Foundation of Education Committee of Hunan Province (05C001)Foundation of Hengyang Sci & Tech Bureau (2005Cg10-23) Fund for Distinguished Young Scholars of Hengyang Normal University (No. 2006)
文摘The title complex (C26H24CuN2O5, Mr = 508.01) has been synthesized by o-methylbenzoic acid, 2,2'-bipyridine (bipy) and copper perchlorate in the mixed solvent of water and methanol. It crystallizes in orthorhombic, space group P212121 with a = 0.70814(10), b = 1.6953(3), c = 1.9539(3) nm, V= 2.3457(6) nm^3, De= 1.439 g/cm^3, Z = 4,μ = 0.971 mm^-1, F(000) = 1052, R = 0.0432 and wR = 0.0860. The structural determination shows that the copper atom is coordinated by three oxygen atoms from two o-methylbenzoic acids and one water molecule together with two nitrogen atoms from 2,2'-bipyridine, giving a distorted square-pyramidal coordination geometry. The cyclic voltammetric behavior of the complex is also discussed.
基金supported by the Science and Technology Development Project of Jilin Provincial Science & Technology Department(201205080)
文摘A metal-organic coordination polymer [Ni(PDB)(bix)(H20)]n (H2PDB = 3,4-pyri- dinedicarboxylic acid, bix = 1,4-bis(imidazol-l-ylmethyl)-benzene) 1 has been hydrothermally synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. Blue crystals crystallize in the triclinic system, space group PI with a = 9.1849(8), b = 9.2065(9), c = 12.9308(12) °, a = 103.3070(10), β = 104.7160(10), y = 90.5900(10)°, V = 1026.42(16)/k3, C21H19NsNiOs, Mr = 480.12, Dc = 1.553 g/cm3, F(000) = 496, Z = 2,/l(MoKa) = 0.991 mm-1, the final R = 0.0325 and wR = 0.0799 for 3561 observed reflections (I 〉 2σ(I)). The structure of 1 exhibits a two-dimensional network structure.
基金supported by the Science and Technology Development Project of Jilin Provincial Science & Technology Department(201205080)the Science and Technology Research Projects of the Education Office of Jilin Province (No. 2012. 358)
文摘A new two-dimensional cobalt coordination polymer has been prepared and fully characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. The compound [Co(C2O4)(bix)]n 1 crystallizes in the monoclinic system, space group C2/c, with a = 11.549(3), b = 15.700(3), c = 9.260(2) A, β = 102.984(3)°, V = 1636.0(6) A^3, C16HIaCON4O4, Mr= 383.23, Dc = 1.556 g/cm^3, μ(MoKa) = 1.078 mm^-1, F(000) = 780, Z = 4, the final R = 0.0455 and wR = 0.1286 for 1483 observed reflections (I 〉 2σ(I)). Of the compound, the Co center is octahedrally coordinated with oxalate acting as a tetra-dentate ligand coordinated to the cobalt atom and each bix serving as a bridging ligand by employing two N-donors to coordinate with the Co center. An infinite {Co2(C2O4)2}∞ chain is formed along the α axis. Furthermore, the 1D chains are held together via bix ligands to generate a two-dimensional network structure with 1D coronal-like channels (ca. 5.691A × 15.700A).
基金supported by the Youth Foundation of Luoyang Normal University(No.10000875)the Foundation of Education Department of Henan Province(No.2011A150021)
文摘A new 3d-4fheterometallic polymer {[Sm2Cu(PDC)2(SO4)2(H20)6]·2H2O}n 1 has been synthesized by Sm2O3, Cu(SO4)2·5H2O and pyridine-3,5-dicarboxylic acid under hydrothermal conditions. The compound crystallizes in triclinic system, space group Pi, with a = 6.352(7), b = 10.040(10), c = 10.315(11) A, α = 94.958(14), β = 95.556(7), γ = 99.747(14)°, V = 641.7(12)A3, Z = 1, M, = 1030.63, Dc= 2.651 Mg/m3,μ = 5.615 mm-1, F(000) = 491, the final R = 0.0491 and wR = 0.1345 for 2098 observed reflections with I 〉 2σ(I). The compound is a three-dimensional network structure in which infinite lanthanide-carboxylate chains are linked by [Cu($04)2]2- metalloligands to form a mixed-metal coordination network.
基金financially supported by the Key Projects in the National Science & Technology Pillar Program during the Eleventh Five-year Plan Period (No. 2006BAD10B04)
文摘The properties of aluminosilicate kalsilite have attracted the interest of researchers in chemical synthesis, ceramic industry, biofuels, etc. In this study, kalsilite was hydrothermally synthesized from microcline powder in a KOH solution. The microcline powder, rich in potassium, aluminum, and silicon, was collected from Mountain Changling in Northwestem China. The effects of temperature, time, and KOH concentration on the decomposition of microcline were investigated. The kalsilite and intermediate products were characterized by means of wet chemistry analysis, X-ray Diffraction (XRD), infi'ared spectrometry (IR), 29Si magic angle spinning nuclear magnetic resonance (29Si MAS NMR), 27A1 MAS NMR, and scanning electron microscope (SEM). With increasing temperature, the microcline powder transforms into a metastable KAlSiO4 polymorph before transforming further into pure kalsilite. A mixture of both kalsilite and metastable KAlSiO4 polymorph is obtained when the hydrothermal reaction is carried out within 2 h; but after 2 h, kalsilite is the predominant product. The concentration of KOH, which needs to be larger than 4.3 M, is an important parameter influencing the synthesis ofkalsilite.