Advanced Materials Research Vols. 1061-1062

Abstract: In-situ formation of nanometric TiC reinforcements based on Ti matrix composites were researched by a novel preparation method, which including glucose polymers coating and powder metallurgy. The results showed that TiC nanoparticles were homogeneously distributed in Ti matrix, and the as-sintered Ti-TiC composites displayed excellent compressive properties which ultimate compressive strength was 2500 MPa, yield strength was 1450 MPa and strain to fracture was 53 %.

Abstract: boron carbide–cerium boride porous composites are prepared by hot pressed sintering, and mechanical properties and microstructure of boron carbide–cerium boride porous composites were tested. The results show that Flexibility strength of B₄C-CeB₆ porous composites is greatly improved compared with that of monolithic porous boron carbide. B₄C react with CeO₂ to completely form CeB₆ in porous composites. CeB₆ particles in B₄C grain boundary are produced by in-situ reaction. The presence of CeB₆ reinforcing particles could also suppress growth of B₄C grains which normally leads to improved strength.

Abstract: Silicoaluminophosphate (SAPO) molecular sieves with CHA and AFI structures have been synthesized under hydrothermal conditions from similar reaction mixtures using 3-Aminopropyl-triethoxysilane as silicon source. The XRD analysis indicated that the phase selectivity could follow the sequence of SAPO-34→SAPO-34+ SAPO-5→SAPO-5 →amorphous phase with increasing the amount of the silicon source. The phase selectivity can be explained by the increasing alkalinity of the medium with the 3-Aminopropyltriethoxysilane concentration.

Abstract: Cu-doped carbon aerogels were prepared by the sol-gel polymerization of resorcinol with formaldehyde in aqueous solution to produce organic gels that are supercritically dried in n-hexane and subsequently pyrolyzed in an inert atmosphere, using sodium carbonate as catalyst and copper acetate as copper source. The addition amount of the copper acetate in the initial reaction mixture has a profound effect on the surface morphology and pore texture of the resulting aerogel. It is shown that the introduction of copper lead to generation of ultrafine micropores. The desulfurization performance of the as-obtained carbon aerogels was evaluated by selective adsorption of dibenzothiophene (DBT) as a model sulfur compound and benzene as a competitive aromatic compound. It is found that the adsorption capacity for DBT is related to the volume of micropores. And the selectivity is improved with the increase of copper content, indicating the presence of copper is favorable to DBT retention on the surface via its π-complexation effect.

Abstract: B₄C-CeB₆ porous composites are prepared by hot pressed sintering between 1900°C and 2000°C, and mechanical properties and phase composition of B₄C-CeB₆ porous composites were tested. The results show that the porous rate of B₄C-CeB₆ porous composites ranges between 30%-48% at sintering temperate 1900°C-2000°C. Porous rate of B₄C-CeB₆ porous composites is decreased with temperature be increased. Flexibility strength of B₄C-CeB₆ porous composites is greatly improved compared with that of monolithic porous boron carbide. B₄C react with CeO₂ to completely form CeB₆ in porous composites.

Abstract: This paper has studied heat shrinkable properties of COC/PETG blending film with microvoids inside. The shrink curve, shrink force, film structure and light barrier effect were studied by use of electron stretcher, SEM, shrink force tester, ultraviolet spectrophotometer and so on. The results indicated that COC/PETG blending film with many microvoids inside can receive more than 70% shrinkage and lower shrink force by comparing transparent PETG shrink film. At the same time, COC/PETG shrink film has excellent UV-light barrier effect from 310-400nm which also has good visual light barrier effect from 400-800nm because of it 85% opacity and 25% transparency.

Abstract: A new type of syntactic foam fabricated with four types of hollow microspheres (HGMs) were prepared and its compressive properties were tested following ASTM D 695-96 standard. The HGMs were designed to have specific size distribution and wall thickness. The compressive strength and modulus of the new syntactic foam were compared with those prepared with single type of HGMs. With same density, the new syntactic foam have better compressive properties.

Abstract: The carbon aerogels doped with nickel were produced by sol-gel, supercritical ethanol drying, and high-temperature carbonization, using resorcinol-furfural as carbon source, nickel nitrate as nickel source, absolute ethanol as dispersion medium, 1,2-epoxypropane as gel initiator, polyacrylic acid as the chelating agent. The carbon aerogels were characterized by nitrogen adsorption and XRD. The effects of the molar ratio of 1,2-epoxypropane to nickel on porosity of the Ni-doped carbon aerogels were investigated. It is found that the Ni-doped carbon aerogels have abundant mesopores and the doped nickel is dispersed in samples in metallic state and oxide or pure metal depending on the preparation conditions. The mesopore volume and average mesopore size all increase with the ratio of 1,2-epoxypropane to nickel.

Abstract: The corrosion inhibition effect of composite inhibitors of sodium silicate on carbon steel was studied in 200 mg/L chlorine dioxide solution by static weight-loss method at room temperature (25 °C) .Analyzed the possible corrosion mechanism and the optimal conditions. The results show that sodium silicate and HEDP had apparent synergistic effect in chlorine dioxide solution. When the mass concentration of sodium silicate was 200 mg/L and HEDP was 100 mg/L can make the corrosion inhibiting rate on carbon steel up to 86.58%.

Abstract: CMC/Eu complexes were synthesized in different pH values by reacting with Eu³⁺ and CMC, a kind of biodegradable polymer. FT-IR results confirmed that, on CMC chains, carboxyl groups and the oxygen atom of unsubstituted hydroxyl groups and ether bonds were all involved in the reaction with Eu³⁺. TG analysis showed that CMC/Eu complexes were thermally stable in a wide temperature range from 30 to 300°C. The emission intensity decreased when the pH value increased from 7.0 to 12.0. However, at pH=12, because that the extent of reaction of Eu³⁺ and CMC decreased and CMC degraded, the complexes had a weak fluorescence intensity.