The synthesis and characterization of amphiphilic copolymers of poly（dimethyl siloxane）(PDMS),poly（ethylene oxide）(PEO), and heparin（Hep） were investigated. These multiblock copolymers wereidentified using;H-NMR...The synthesis and characterization of amphiphilic copolymers of poly（dimethyl siloxane）(PDMS),poly（ethylene oxide）(PEO), and heparin（Hep） were investigated. These multiblock copolymers wereidentified using;H-NMR, FTIR, end group analysis, and sulfur elemental analysis. The multiblockcopolymers were characterized by using DSC and X-ray diffractometry. The glass transition temperature,crystalline melting characteristics, annealing effect, and cold crystallization of the block copolymers weredetermined by DSC. The crystallinity of the block copolymers was also determined by X-ray diffractionmethod.展开更多
The Lotshi block with an area of 506 Km<sup>2</sup>, is located in the coastal basin in central Congo. It is between 12°31' and 12°53' east longitude and 05°33' and 05°44...The Lotshi block with an area of 506 Km<sup>2</sup>, is located in the coastal basin in central Congo. It is between 12°31' and 12°53' east longitude and 05°33' and 05°44' south latitude. As part of this research, we carried out geological observations in the field, and sampled rocky materials in sites of petroleum interest in the Lotshi Block and surroundings in order to contribute to the understanding of the petroleum geology of this block, more particularly of its petroleum system. The samples brought back from the field were subjected to microscopic, mineralogical, (DRX), chemical (XRF) analyses and to the extraction of the hydrocarbon binder contained therein at the laboratories of ULG (Belgium), CRGM and OR in Kinshasa. The results obtained are summarized as follows: 1) Mineralogically: quartz, k-feldspar, plagioclase, calcite and dolomite are the dominant minerals in the samples analyzed;2) Lithologically: two lithofacies (quartz sandstone and carbonate sandstone);3) On the petroleum level: the sandstone rock of Lotshi and its surroundings are impregnated with hydrocarbons. It contains between 12% and 25% of hydrocarbon binder.展开更多
A new series of chiral shish-kebab type liquid crystal block copolymers that form the smectic C(Sc*) phase was synthesized by solution polycondensation. The copolymers were characterized by GPC, DSC, TG, POM, X-ray di...A new series of chiral shish-kebab type liquid crystal block copolymers that form the smectic C(Sc*) phase was synthesized by solution polycondensation. The copolymers were characterized by GPC, DSC, TG, POM, X-ray diffraction and polarimeter. The copolymers 7 entered into liquid crystal phase whin they were heated to their melting temperatures (T-m) and the copolymers 8 were in liquid crystal phase at room temperature with low viscosities. The smectic sanded texture or focal-conic texture were observed on POM. All the chiral block copolymers showed high optical activity. No racemization has happened. Temperature-variable X-ray diffraction study together with POM and polarimetric analysis realized that they are chiral smectic C(Sc*) phase. Thus we offer in this report the first example of shish-kebab type liquid crystal block copolymers that form a chiral smectic C(Sc*) phase. The variation of melting and isotropization temperatures with molecular structure was also discussed.展开更多
The quantitative description of the sequence structure of emulsion-processed SBR and solution-processed SBR (by lithium catalyst)was carried out based on their spectral data Of ^(13)C-NMR.The calculating formulae whic...The quantitative description of the sequence structure of emulsion-processed SBR and solution-processed SBR (by lithium catalyst)was carried out based on their spectral data Of ^(13)C-NMR.The calculating formulae which could be used to obtain diad concentration from the peak intensifies of carbon spectra, average block length, average number of block, and the microstructure composition of the molecular chain were derived. The quantitative result showed that on the molecular chain styrene unit had the tendency to attach to trans-1,4 butadiene unit. The calculated result of the microstructure was in good agreement with that obtained through IR measurement.展开更多
A SBA-16-type mesoporous silica material was synthesized under a moderately acidic condition of 0.5 mol·L -1 HCl solution.These mesoporous materials were characterized with X-ray diffraction(XRD)pattern,scanning ...A SBA-16-type mesoporous silica material was synthesized under a moderately acidic condition of 0.5 mol·L -1 HCl solution.These mesoporous materials were characterized with X-ray diffraction(XRD)pattern,scanning electron microscopy(SEM),transmission electron microscopy(TEM),and nitrogen adsorption-desorption measurements.The three-dimensional microporosity of the prepared mesoporous silica having ordered hexagonal mesoporous structure was evidenced by the well-defined XRD patterns combined with TEM photographs.SEM observation showed a highly ordered cubic crystal structure for the prepared mesoporous silica.The size of these crystallites was maintained within the range of 4—6 μm,which is fairly important for the application to the stationary phase for separation.The nitrogen adsorption-desorption analysis revealed that the prepared mesoporous silica possessed a small pore diameter of 3.68 nm,a total surface area of 363.65 m2·g -1 ,a total pore volume of 0.38 cm3·g -1 ,and a pore-wall thickness of 6.63 nm.These features may lead to higher thermal and hydrothermal stability,excellent microporosity,and good connectivity.The mesoporous silica prepared in this study exhibited potential applications to catalysis,sensoring,and separation.展开更多
文摘The synthesis and characterization of amphiphilic copolymers of poly（dimethyl siloxane）(PDMS),poly（ethylene oxide）(PEO), and heparin（Hep） were investigated. These multiblock copolymers wereidentified using;H-NMR, FTIR, end group analysis, and sulfur elemental analysis. The multiblockcopolymers were characterized by using DSC and X-ray diffractometry. The glass transition temperature,crystalline melting characteristics, annealing effect, and cold crystallization of the block copolymers weredetermined by DSC. The crystallinity of the block copolymers was also determined by X-ray diffractionmethod.
文摘The Lotshi block with an area of 506 Km<sup>2</sup>, is located in the coastal basin in central Congo. It is between 12°31' and 12°53' east longitude and 05°33' and 05°44' south latitude. As part of this research, we carried out geological observations in the field, and sampled rocky materials in sites of petroleum interest in the Lotshi Block and surroundings in order to contribute to the understanding of the petroleum geology of this block, more particularly of its petroleum system. The samples brought back from the field were subjected to microscopic, mineralogical, (DRX), chemical (XRF) analyses and to the extraction of the hydrocarbon binder contained therein at the laboratories of ULG (Belgium), CRGM and OR in Kinshasa. The results obtained are summarized as follows: 1) Mineralogically: quartz, k-feldspar, plagioclase, calcite and dolomite are the dominant minerals in the samples analyzed;2) Lithologically: two lithofacies (quartz sandstone and carbonate sandstone);3) On the petroleum level: the sandstone rock of Lotshi and its surroundings are impregnated with hydrocarbons. It contains between 12% and 25% of hydrocarbon binder.
基金This work was supported by the National Natural Science Foundation of China (No. 29674025) and the Natural Science Foundation of Henan Province.
文摘A new series of chiral shish-kebab type liquid crystal block copolymers that form the smectic C(Sc*) phase was synthesized by solution polycondensation. The copolymers were characterized by GPC, DSC, TG, POM, X-ray diffraction and polarimeter. The copolymers 7 entered into liquid crystal phase whin they were heated to their melting temperatures (T-m) and the copolymers 8 were in liquid crystal phase at room temperature with low viscosities. The smectic sanded texture or focal-conic texture were observed on POM. All the chiral block copolymers showed high optical activity. No racemization has happened. Temperature-variable X-ray diffraction study together with POM and polarimetric analysis realized that they are chiral smectic C(Sc*) phase. Thus we offer in this report the first example of shish-kebab type liquid crystal block copolymers that form a chiral smectic C(Sc*) phase. The variation of melting and isotropization temperatures with molecular structure was also discussed.
文摘The quantitative description of the sequence structure of emulsion-processed SBR and solution-processed SBR (by lithium catalyst)was carried out based on their spectral data Of ^(13)C-NMR.The calculating formulae which could be used to obtain diad concentration from the peak intensifies of carbon spectra, average block length, average number of block, and the microstructure composition of the molecular chain were derived. The quantitative result showed that on the molecular chain styrene unit had the tendency to attach to trans-1,4 butadiene unit. The calculated result of the microstructure was in good agreement with that obtained through IR measurement.
文摘A SBA-16-type mesoporous silica material was synthesized under a moderately acidic condition of 0.5 mol·L -1 HCl solution.These mesoporous materials were characterized with X-ray diffraction(XRD)pattern,scanning electron microscopy(SEM),transmission electron microscopy(TEM),and nitrogen adsorption-desorption measurements.The three-dimensional microporosity of the prepared mesoporous silica having ordered hexagonal mesoporous structure was evidenced by the well-defined XRD patterns combined with TEM photographs.SEM observation showed a highly ordered cubic crystal structure for the prepared mesoporous silica.The size of these crystallites was maintained within the range of 4—6 μm,which is fairly important for the application to the stationary phase for separation.The nitrogen adsorption-desorption analysis revealed that the prepared mesoporous silica possessed a small pore diameter of 3.68 nm,a total surface area of 363.65 m2·g -1 ,a total pore volume of 0.38 cm3·g -1 ,and a pore-wall thickness of 6.63 nm.These features may lead to higher thermal and hydrothermal stability,excellent microporosity,and good connectivity.The mesoporous silica prepared in this study exhibited potential applications to catalysis,sensoring,and separation.
