To fabricate thick-walled hollow glass microspheres （HGMs） for inertial confinement fusion （ICF） targets by sol-gel technology, we investigated the effects of glass composition, blowing agent, refining temperature...To fabricate thick-walled hollow glass microspheres （HGMs） for inertial confinement fusion （ICF） targets by sol-gel technology, we investigated the effects of glass composition, blowing agent, refining temperature, pressure and composition of furnace atmosphere on the wall thickness of HGMs by numerical simulation and experiments. The results showed that the residence times of the thick-walled HGMs in the encapsulating and refining phases decreased with the increase of wall thickness of HGMs. As a response to this challenge, glass composition must be optimized with the object of high surface tension and low viscosity at refining temperature, and the blowing agents with high decomposition temperature should be used, furthermore the concentration of blowing agents in gel particles must also be precisely controlled. The higher volume fraction of argon gas in the furnace atmosphere, the thicker the wall of HGMs. Due to the limited operating range of furnace atmosphere pressure, changing furnace atmosphere pressure could not significantly increase the wall thickness of HGMs. Although increasing refin- ing temperature can improve the yield of high quality HGMs, a higher furnace atmosphere temperature may lead to a decrease in the wall thickness of HGMs. When the volume fraction of argon gas in the furnace atmosphere ranged from 80% to 95%, the furnace atmosphere pressure ranged from 1.0×l0^5 Pa to 1.25×105 Pa, and the refining temperature ranged from 1600℃ to 1800℃, we produced thick-walled （5-10 ktrn） HGMs with good sphericity, wall thickness uniformity and surface finish. However, the yield of high quality HGMs needs to be further improved. The compressive strength, tensile strength and permeation coefficient to deuterium gas of thick-walled HGMs at ambient temperature decreased with increase of the wall thickness.展开更多
SAPO-34 is one of the main catalysts used in the petrochemical industry. Various effective methods have been developed to synthesize SAPO-34 with optimal size and characteristics for such application, In the present s...SAPO-34 is one of the main catalysts used in the petrochemical industry. Various effective methods have been developed to synthesize SAPO-34 with optimal size and characteristics for such application, In the present study, SAPO-34 was synthesized using a dry gel method at high temperatures. Morpholine was used as an organic template. The products were characterized by X-ray diffraction, field-emission scan- ning electron microscopy, energy-dispersive X-ray spectroscopy, and gas sorption analysis, The results showed that application of the dry gel method at high temperatures successfully afforded a pure catalyst with high crystallinity, Small particles of less than 500 nm could be obtained within a short reaction time of 30 min.展开更多
基金supported by the Chinese Key Laboratory of Science and Technology for Defense(Grant No.91400C680603090C68)
文摘To fabricate thick-walled hollow glass microspheres （HGMs） for inertial confinement fusion （ICF） targets by sol-gel technology, we investigated the effects of glass composition, blowing agent, refining temperature, pressure and composition of furnace atmosphere on the wall thickness of HGMs by numerical simulation and experiments. The results showed that the residence times of the thick-walled HGMs in the encapsulating and refining phases decreased with the increase of wall thickness of HGMs. As a response to this challenge, glass composition must be optimized with the object of high surface tension and low viscosity at refining temperature, and the blowing agents with high decomposition temperature should be used, furthermore the concentration of blowing agents in gel particles must also be precisely controlled. The higher volume fraction of argon gas in the furnace atmosphere, the thicker the wall of HGMs. Due to the limited operating range of furnace atmosphere pressure, changing furnace atmosphere pressure could not significantly increase the wall thickness of HGMs. Although increasing refin- ing temperature can improve the yield of high quality HGMs, a higher furnace atmosphere temperature may lead to a decrease in the wall thickness of HGMs. When the volume fraction of argon gas in the furnace atmosphere ranged from 80% to 95%, the furnace atmosphere pressure ranged from 1.0×l0^5 Pa to 1.25×105 Pa, and the refining temperature ranged from 1600℃ to 1800℃, we produced thick-walled （5-10 ktrn） HGMs with good sphericity, wall thickness uniformity and surface finish. However, the yield of high quality HGMs needs to be further improved. The compressive strength, tensile strength and permeation coefficient to deuterium gas of thick-walled HGMs at ambient temperature decreased with increase of the wall thickness.
文摘SAPO-34 is one of the main catalysts used in the petrochemical industry. Various effective methods have been developed to synthesize SAPO-34 with optimal size and characteristics for such application, In the present study, SAPO-34 was synthesized using a dry gel method at high temperatures. Morpholine was used as an organic template. The products were characterized by X-ray diffraction, field-emission scan- ning electron microscopy, energy-dispersive X-ray spectroscopy, and gas sorption analysis, The results showed that application of the dry gel method at high temperatures successfully afforded a pure catalyst with high crystallinity, Small particles of less than 500 nm could be obtained within a short reaction time of 30 min.
