The oligo phenylene vinylene(oligo PV)/SiO 2 composite film was prepared by the sol gel process. The surface photovoltage spectroscopy(SPS) and electric field induced surface photovoltage spectroscopy(EFISPS) had been...The oligo phenylene vinylene(oligo PV)/SiO 2 composite film was prepared by the sol gel process. The surface photovoltage spectroscopy(SPS) and electric field induced surface photovoltage spectroscopy(EFISPS) had been used to investigate the charge transport process in olige PV/SiO 2 heterostructured composite. The results show that the oligo PV / SiO 2 composite film not only can improve the stability of oligo PV, but also have some photoelectric activity.展开更多
This paper reports on a new microporous composite silica membrane prepared via acid-catalyzed polymeric route of sol-gel method with tetraethylorthosilicate(TEOS)and a bridged silsesquioxane[1,2-bis(triethoxysilyl)eth...This paper reports on a new microporous composite silica membrane prepared via acid-catalyzed polymeric route of sol-gel method with tetraethylorthosilicate(TEOS)and a bridged silsesquioxane[1,2-bis(triethoxysilyl)ethane, BTESE]as precursors.A stable nano-sized composite silica sol with a mean volume size of^5 nm was synthesized. A 150 nm-thick defect-free composite silica membrane was deposited on disk support consisting of macroporous α-Al2O3 and mesoporousγ-Al2O3 intermediate layer by using dip-coating approach,followed by calcination under pure nitrogen atmosphere.The composite silica membranes exhibit molecular sieve properties for small gases like H2,CO2,O2,N2,CH4 and SF6 with hydrogen permeances in the range of(1-4)×10 -7mol·m -2·s -1·Pa -1(measured at 200°C,3.0×105 Pa).With respect to the membrane calcined at 500°C,it is found that the permselectivities of H 2 (0.289 nm)with respect to N2(0.365 nm),CH4(0.384 nm)and SF6(0.55 nm)are 22.9,42 and>1000,respectively, which are all much higher than the corresponding Knudsen values(H2/N2=3.7,H2/CH4=2.8,and H2/SF6=8.5).展开更多
Phenolic resin(PF) and nano-SiO2 were used to improve the curing property and high humidity resistance of epoxy resin (EP) and methyl nadic anhydride (MNA) resistor paint, respectively. Hydrogen bonds, formed between ...Phenolic resin(PF) and nano-SiO2 were used to improve the curing property and high humidity resistance of epoxy resin (EP) and methyl nadic anhydride (MNA) resistor paint, respectively. Hydrogen bonds, formed between phenolic resin and nano-SiO2 in alcohol, made nano-SiO2 disperse easily in EP/MNA paint through phenolic resin without being treated by supersonic vibration. When the mass ratio of PF to EP in paint is 3:7, the formed composite paint film can be cured in 2 min at 170 ℃ . When the mass ratio of nano-SiO2 to PF in paint is 3:100, the property of high humidity resistance of the composite paint is the best, meeting the requirement of varying ratio of resistance less than 0.1% after experiment on high humidity resistance. SEM analysis shows the surface of the composite paint film is smooth, glassy, tight and homogeneous, without acicular air holes.展开更多
SiC composite membrane was fabricated by mixing with SiC and ZnO powder. This mixture was pressed and sintered at 1,300 ℃ under air condition. This sintered ZnO-SiC membrane was dip-coated by silica sol and followed ...SiC composite membrane was fabricated by mixing with SiC and ZnO powder. This mixture was pressed and sintered at 1,300 ℃ under air condition. This sintered ZnO-SiC membrane was dip-coated by silica sol and followed by heat-treatment. This membrane was characterized by XRD （X-ray diffraction）, FE-SEM （field emission scanning electron microscopy） and BET （Brunauer-Emmett-Teller） instruments. Hydrogen permeation test was conducted at 0.1 MPa pressure and also variation of temperatures. The obtained value of heat-treated membrane after dip-coating at 298 K was obtained as 1.61 × 10-6 mol/（m2·s·Pa）.展开更多
文摘The oligo phenylene vinylene(oligo PV)/SiO 2 composite film was prepared by the sol gel process. The surface photovoltage spectroscopy(SPS) and electric field induced surface photovoltage spectroscopy(EFISPS) had been used to investigate the charge transport process in olige PV/SiO 2 heterostructured composite. The results show that the oligo PV / SiO 2 composite film not only can improve the stability of oligo PV, but also have some photoelectric activity.
基金Supported by the National Natural Science Foundation of China(20906047)the State Key Laboratory of Chemical Engineering(SKL-ChE-09A01)the State Key Laboratory of Materials-Oriented Chemical Engineering(ZK201002)
文摘This paper reports on a new microporous composite silica membrane prepared via acid-catalyzed polymeric route of sol-gel method with tetraethylorthosilicate(TEOS)and a bridged silsesquioxane[1,2-bis(triethoxysilyl)ethane, BTESE]as precursors.A stable nano-sized composite silica sol with a mean volume size of^5 nm was synthesized. A 150 nm-thick defect-free composite silica membrane was deposited on disk support consisting of macroporous α-Al2O3 and mesoporousγ-Al2O3 intermediate layer by using dip-coating approach,followed by calcination under pure nitrogen atmosphere.The composite silica membranes exhibit molecular sieve properties for small gases like H2,CO2,O2,N2,CH4 and SF6 with hydrogen permeances in the range of(1-4)×10 -7mol·m -2·s -1·Pa -1(measured at 200°C,3.0×105 Pa).With respect to the membrane calcined at 500°C,it is found that the permselectivities of H 2 (0.289 nm)with respect to N2(0.365 nm),CH4(0.384 nm)and SF6(0.55 nm)are 22.9,42 and>1000,respectively, which are all much higher than the corresponding Knudsen values(H2/N2=3.7,H2/CH4=2.8,and H2/SF6=8.5).
基金Supported by Science and Technology Committee of Tianjin(No06YFGPGX08400)
文摘Phenolic resin(PF) and nano-SiO2 were used to improve the curing property and high humidity resistance of epoxy resin (EP) and methyl nadic anhydride (MNA) resistor paint, respectively. Hydrogen bonds, formed between phenolic resin and nano-SiO2 in alcohol, made nano-SiO2 disperse easily in EP/MNA paint through phenolic resin without being treated by supersonic vibration. When the mass ratio of PF to EP in paint is 3:7, the formed composite paint film can be cured in 2 min at 170 ℃ . When the mass ratio of nano-SiO2 to PF in paint is 3:100, the property of high humidity resistance of the composite paint is the best, meeting the requirement of varying ratio of resistance less than 0.1% after experiment on high humidity resistance. SEM analysis shows the surface of the composite paint film is smooth, glassy, tight and homogeneous, without acicular air holes.
文摘SiC composite membrane was fabricated by mixing with SiC and ZnO powder. This mixture was pressed and sintered at 1,300 ℃ under air condition. This sintered ZnO-SiC membrane was dip-coated by silica sol and followed by heat-treatment. This membrane was characterized by XRD （X-ray diffraction）, FE-SEM （field emission scanning electron microscopy） and BET （Brunauer-Emmett-Teller） instruments. Hydrogen permeation test was conducted at 0.1 MPa pressure and also variation of temperatures. The obtained value of heat-treated membrane after dip-coating at 298 K was obtained as 1.61 × 10-6 mol/（m2·s·Pa）.
