A series of polysulfonamide (PSA)/TiO 2 modifier nano-composite films were successfully prepared by in-situ polymerization at a low temperature based on 4, 4-diaminodiphenylsulfone and terephthaloyl chloride in the ...A series of polysulfonamide (PSA)/TiO 2 modifier nano-composite films were successfully prepared by in-situ polymerization at a low temperature based on 4, 4-diaminodiphenylsulfone and terephthaloyl chloride in the common solvent N, N-dimethylacetamide (DMAc). It was shown that the nano particles were well dispersed in the polymer substrate. Mean-while, PSA/TiO 2 /modifier composites exhibited good UV-resistant properties and mechanical properties. In addition, the composites’ heat stability improved. These prepared composites are promising in preparing spinning solution and might have potential application in heat-resistant fiber.展开更多
A kind of new nano composite with ultraviolet (UV) ray resistance and high temperature stability was prepared by in-situ polymerization in low temperature. Polysulfonamide (PSA) was synthesized with 4, 4'-diamin...A kind of new nano composite with ultraviolet (UV) ray resistance and high temperature stability was prepared by in-situ polymerization in low temperature. Polysulfonamide (PSA) was synthesized with 4, 4'-diaminodiphenyl sulfone (DDS) and terephthaloyl chloride (TPC) in the common solvent N, N-Dimethyl- -acetamide (DMAc). Nano filler is a certain nano titanium oxide modified by silicon oxide (TMS), which plays the role of UV resistance additives. Properties of the novel composite materials were characterized by Atomic Force microscopy (AFM), thermal gravimetric Analysis (TGA) and Ultraviolet Spectroscopy. AFM had showed the sizes and distributions of TMS particles in the nanocomposite. Ultraviolet Spectroscopy for the nanocomposites showed a large absorption in UV band. TGA showed the decomposition temperature was increased over ten degrees with 0.5% wt TMS for this nanocomposite compared with pure PSA.展开更多
The effect of domain switching on anisotropic fracture behavior of polycrystalline ferroelectric ceramics was revealed on the basis of the micromechanics method. Firstly, the electroelastic field inside and outside an...The effect of domain switching on anisotropic fracture behavior of polycrystalline ferroelectric ceramics was revealed on the basis of the micromechanics method. Firstly, the electroelastic field inside and outside an inclusion in an infinite ferroelectric ceramics is carried out by the way of Eshelby-Mori-Tanaka's theory and a statistical model, which accounts for the influence of domain switching. Further, the crack extension force (energy-release rate) G(ext) for a penny-shape crack inside an effective polycrystalline ferroelectric ceramics is derived to estimate the averaged effect of domain switching on the fracture behavior of polycrystalline ferroelectric ceramics. The simulations of the crack extension force for a crack in a BaTiO3 ceramics are shown that the effect of domain switching must be taken into consideration while analyzing the fracture behavior of polycrystalline ferroelectric ceramics. These results also demonstrate that the influence of the applied electric field on the crack propagation is more profound at smaller mechanical loading and the applied electric field may enhance the crack extension in a sense, which are consistent with the experimental results.展开更多
The colored poly(m-phenylene isophthalamide)(PMIA)spinning solution was prepared by wet spinning and the die-swell of the colored PMIA spinning solution was done when it was extruded from a die in this experiment.The ...The colored poly(m-phenylene isophthalamide)(PMIA)spinning solution was prepared by wet spinning and the die-swell of the colored PMIA spinning solution was done when it was extruded from a die in this experiment.The properties and structures of colored PMIA fibers were characterized by scanning electron microscopy(SEM).The colored PMIA spinning dopes were first commixed in a pressurizer and then spun into a coagulation bath.The effect of die swell on the colored PMIA solution was resulted from the viscoelastic properties of the colored PMIA solution in the spinning process.The results showed that the die-swell ratio of the colored PMIA solution increased linearly with increasing the pressure and die length/diameter ratio(L/D).At the same pressure and L/D,the die-swell ratio decreased with the increase of filter layers and temperature.Also,optimized spinning parameters of the dopedyed PMIA fiber were obtained.展开更多
In this paper, we succeed in fabricating high-temperature fiber of polysulfonamide/ZnO. Polysulfonamide/ZnO nanocomposite was prepared by in-situ polymerization. Some studies and characterization of Polysulfonamide/ Z...In this paper, we succeed in fabricating high-temperature fiber of polysulfonamide/ZnO. Polysulfonamide/ZnO nanocomposite was prepared by in-situ polymerization. Some studies and characterization of Polysulfonamide/ Zinc oxide nanocomposite with ZnO 0.5% have been done. It includes ηr,, Crystal degree and thermal property. Experiment's results showed that, ZnO as filler can improve crystal degree of polysulfonamide fiber. The crystal degree has been bnproved, from lower than 20% up to 27%. ηr of polysulfonamide/ Zinc oxide nanocomposite solution with ZnO 0.5% is 2.03. The maxinum weight loss of the nanocomposite occurred at 453.5 ℃.展开更多
This paper proposes a method to model hydrocarbon reforming by coupling detailed chemical kinetics with complex computational fluid dynamics. The entire chemistry of catalyzed reactions was confined within the geometr...This paper proposes a method to model hydrocarbon reforming by coupling detailed chemical kinetics with complex computational fluid dynamics. The entire chemistry of catalyzed reactions was confined within the geometrically simple channels and modeled using the low-dimensional plug model, into which the interactive thermal control of the multi-channel reforming reactor has been implemented with a tail-gas combustor around the external surface of these catalytic channels. The geomet- rically complex flow in the tail gas combustor was simu- lated using FLUENT without involving any chemical reactions. The influences of the conditions at the reactor inlet such as the inlet gas velocity, the inlet gas composi- tion and the variety of hydrocarbons of each channel on gas conversions were investigated numerically. The impact of the tail gas combustor setup on the efficiency of the reforming reactor was also analyzed. Methane catalytic partial oxidation (CPOx) and propane steam reforming (SR) were used to illustrate the approach reported in the present work.展开更多
Mechanisms of selective hydrolysis of alginates under hydrothermal conditions were investigated by comparing reactivities of sodium alginate(Na-ALG,960 ku)solutions and calcium alginate(Ca-ALG)gels as substrates.Under...Mechanisms of selective hydrolysis of alginates under hydrothermal conditions were investigated by comparing reactivities of sodium alginate(Na-ALG,960 ku)solutions and calcium alginate(Ca-ALG)gels as substrates.Under hydrothermal conditions(150°C),hydrolysis of Na-ALG gave product molecular weights of 223,66,26 and 17 ku while those of Ca-ALG gave product molecular weights of 340,102,45 and 31 ku for reaction times of 10,20,30 and 60 min,respectively.The ratios of mannuronic acid(M)to guluronic acid(G)varied only slightly(from 1.3 to 1.2)for Na-ALG over the range of reaction times at 150°C,while ratios(M/G)for Ca-ALG exhibited a remarkable decrease(from 1.1 to 0.8).Diad sequence of alginate products obtained for Na-ALG were 17%,23%,27%and 31%(GG);30%,32%,36%and 38%(MM);and 53%,46%,37%and 32%(GM+MG);while for Ca-ALG they were 18%,22%,24%and 33%(GG);26%,23%,26%and 18%(MM);and 56%,54%,50%and 48%(GM+MG).Reaction mechanisms are proposed for hydrolysis of alginate solutions and alginate gels under hydrothermal conditions;de-polymerization of alginates into monomers and monomeric sequences can be controlled not only by hydrothermal conditions,but also by varying the physical state(solution,gel)of the starting materials.展开更多
基金Project supported by the Shanghai Leading Academic Discipline Project (Grant No.s30107)the Science and Technology Commission of Shanghai Municipality (Grant No.0852nm00600)
文摘A series of polysulfonamide (PSA)/TiO 2 modifier nano-composite films were successfully prepared by in-situ polymerization at a low temperature based on 4, 4-diaminodiphenylsulfone and terephthaloyl chloride in the common solvent N, N-dimethylacetamide (DMAc). It was shown that the nano particles were well dispersed in the polymer substrate. Mean-while, PSA/TiO 2 /modifier composites exhibited good UV-resistant properties and mechanical properties. In addition, the composites’ heat stability improved. These prepared composites are promising in preparing spinning solution and might have potential application in heat-resistant fiber.
文摘A kind of new nano composite with ultraviolet (UV) ray resistance and high temperature stability was prepared by in-situ polymerization in low temperature. Polysulfonamide (PSA) was synthesized with 4, 4'-diaminodiphenyl sulfone (DDS) and terephthaloyl chloride (TPC) in the common solvent N, N-Dimethyl- -acetamide (DMAc). Nano filler is a certain nano titanium oxide modified by silicon oxide (TMS), which plays the role of UV resistance additives. Properties of the novel composite materials were characterized by Atomic Force microscopy (AFM), thermal gravimetric Analysis (TGA) and Ultraviolet Spectroscopy. AFM had showed the sizes and distributions of TMS particles in the nanocomposite. Ultraviolet Spectroscopy for the nanocomposites showed a large absorption in UV band. TGA showed the decomposition temperature was increased over ten degrees with 0.5% wt TMS for this nanocomposite compared with pure PSA.
文摘The effect of domain switching on anisotropic fracture behavior of polycrystalline ferroelectric ceramics was revealed on the basis of the micromechanics method. Firstly, the electroelastic field inside and outside an inclusion in an infinite ferroelectric ceramics is carried out by the way of Eshelby-Mori-Tanaka's theory and a statistical model, which accounts for the influence of domain switching. Further, the crack extension force (energy-release rate) G(ext) for a penny-shape crack inside an effective polycrystalline ferroelectric ceramics is derived to estimate the averaged effect of domain switching on the fracture behavior of polycrystalline ferroelectric ceramics. The simulations of the crack extension force for a crack in a BaTiO3 ceramics are shown that the effect of domain switching must be taken into consideration while analyzing the fracture behavior of polycrystalline ferroelectric ceramics. These results also demonstrate that the influence of the applied electric field on the crack propagation is more profound at smaller mechanical loading and the applied electric field may enhance the crack extension in a sense, which are consistent with the experimental results.
文摘The colored poly(m-phenylene isophthalamide)(PMIA)spinning solution was prepared by wet spinning and the die-swell of the colored PMIA spinning solution was done when it was extruded from a die in this experiment.The properties and structures of colored PMIA fibers were characterized by scanning electron microscopy(SEM).The colored PMIA spinning dopes were first commixed in a pressurizer and then spun into a coagulation bath.The effect of die swell on the colored PMIA solution was resulted from the viscoelastic properties of the colored PMIA solution in the spinning process.The results showed that the die-swell ratio of the colored PMIA solution increased linearly with increasing the pressure and die length/diameter ratio(L/D).At the same pressure and L/D,the die-swell ratio decreased with the increase of filter layers and temperature.Also,optimized spinning parameters of the dopedyed PMIA fiber were obtained.
文摘In this paper, we succeed in fabricating high-temperature fiber of polysulfonamide/ZnO. Polysulfonamide/ZnO nanocomposite was prepared by in-situ polymerization. Some studies and characterization of Polysulfonamide/ Zinc oxide nanocomposite with ZnO 0.5% have been done. It includes ηr,, Crystal degree and thermal property. Experiment's results showed that, ZnO as filler can improve crystal degree of polysulfonamide fiber. The crystal degree has been bnproved, from lower than 20% up to 27%. ηr of polysulfonamide/ Zinc oxide nanocomposite solution with ZnO 0.5% is 2.03. The maxinum weight loss of the nanocomposite occurred at 453.5 ℃.
文摘This paper proposes a method to model hydrocarbon reforming by coupling detailed chemical kinetics with complex computational fluid dynamics. The entire chemistry of catalyzed reactions was confined within the geometrically simple channels and modeled using the low-dimensional plug model, into which the interactive thermal control of the multi-channel reforming reactor has been implemented with a tail-gas combustor around the external surface of these catalytic channels. The geomet- rically complex flow in the tail gas combustor was simu- lated using FLUENT without involving any chemical reactions. The influences of the conditions at the reactor inlet such as the inlet gas velocity, the inlet gas composi- tion and the variety of hydrocarbons of each channel on gas conversions were investigated numerically. The impact of the tail gas combustor setup on the efficiency of the reforming reactor was also analyzed. Methane catalytic partial oxidation (CPOx) and propane steam reforming (SR) were used to illustrate the approach reported in the present work.
文摘Mechanisms of selective hydrolysis of alginates under hydrothermal conditions were investigated by comparing reactivities of sodium alginate(Na-ALG,960 ku)solutions and calcium alginate(Ca-ALG)gels as substrates.Under hydrothermal conditions(150°C),hydrolysis of Na-ALG gave product molecular weights of 223,66,26 and 17 ku while those of Ca-ALG gave product molecular weights of 340,102,45 and 31 ku for reaction times of 10,20,30 and 60 min,respectively.The ratios of mannuronic acid(M)to guluronic acid(G)varied only slightly(from 1.3 to 1.2)for Na-ALG over the range of reaction times at 150°C,while ratios(M/G)for Ca-ALG exhibited a remarkable decrease(from 1.1 to 0.8).Diad sequence of alginate products obtained for Na-ALG were 17%,23%,27%and 31%(GG);30%,32%,36%and 38%(MM);and 53%,46%,37%and 32%(GM+MG);while for Ca-ALG they were 18%,22%,24%and 33%(GG);26%,23%,26%and 18%(MM);and 56%,54%,50%and 48%(GM+MG).Reaction mechanisms are proposed for hydrolysis of alginate solutions and alginate gels under hydrothermal conditions;de-polymerization of alginates into monomers and monomeric sequences can be controlled not only by hydrothermal conditions,but also by varying the physical state(solution,gel)of the starting materials.