Preparation of a pure ZIF-67 membrane by self-conversion of cobalt carbonate hydroxide nanowires for H2 separation

A self-conversion strategy was adopted for the first time to achieve a pure ZIF-67 membrane on a porous alumina tube for H2 separation.

Effect of Compaction Pressure and Sintering Time on the Properties of Sintered Cu-10Sn Bronze

Bronze-based composite materials are well known for use as friction materials. They are produced by powder metallurgy techniques from bronze powder, which acts as a matrix, and various friction modifying additives. The objective of this work was to study the effect of compaction pressure and sintering time on the properties of the unmodified bronze matrix. The bronze powder used was prealloyed with a composition of Cu-10Sn. The specimens were pressed by uniaxial die compaction with pressures of 282 to 339 MPa. The sintering experiments were conducted in an alumina tube furnace at 800 °C with sintering times of 30, 45, and 60 min under a vacuum pressure of 2.25x10-2 Torr. From the results, it was found that the density of the samples increased with increasing compaction pressure. A microstructural examination of the samples for the different sintering times showed them to look very similar. Finally, the highest sintered density of 7.30 g/cm3 was obtained at 800 °C for 60 min.

Evaluating High Temperature Modulus and Strength of Alumina Tube in Vacuum by a Modified Split Ring Method

Alumina is a typical ceramic material and possesses high strengthand stiffness at both room temperature and high temperature. The split ring methodhad been established to evaluate the elastic modulus and bending strength of aluminatube materials at ambient temperature. However, both equations for modulus andstrength became lightly inapplicable with the increased temperature. For theelastic modulus, it was lack of precise approaches and advices for deformationmeasurement in the heating furnace. For the bending strength, changes of sampledimensions due to thermal expansion would take an effect on the calculatingresults. In this work, several improvements have been taken into account tocalibrate the above deviations. Results revealed that the modulus and strengthregularly decreased from room temperature to 1300 °C and accorded well with other conventional testing methods.It proved the accuracy and reliability of this modified split ring method,which might be used to evaluate other ceramic tube materials at hightemperature.

Potential continuous removal of toluene by ZnO nanorods grown on permeable alumina tube filters

Vertical ZnO nanorods were successfully grown on the crystalline surface of an Al2O3 microfilter by the simple technique of evaporation of prepared solution at atmospheric pressure (ESAP) for photocatalytic degradation of toluene.

Porous NiO nanosheets self-grown on alumina tube using a novel flash synthesis and their gas sensing properties

Porous NiO nanosheets self-grown on alumina tube using a novel flash synthesis displayed wide dynamic range detection to VOC vapours.

Preparation and gas sensing property of Ag-supported vanadium oxide nanotubes

A facile microwave irradiation was used to synthesize Ag nanoparticle supported on vanadium oxide nanotubes (VONTs) in this paper. The VONTs on alumina tube installed with Pt electrodes were tested for gas sensing towards C 2 H 5 OH , NH 3 and C 6 H 5 CH 3 gases. Detailed studies showed that the sensing capabilities were greatly enhanced in comparison to those of pure nanotubes. It was found that the Ag nanoparticles supported on VONTs sensing films exhibited a high C 2 H 5 OH selectivity compared with NH 3 and C 6 H 5 CH 3 gases. When the sensor is exposed to C 2 H 5 OH , the ethanol molecules interact with the preadsorbed oxygen ions on the Ag nanoparticles surface. The ethanol oxidation on the Ag nanoparticles leads to the transfer of electrons into the semiconducting VONTs and this is reflected as the change in conductance of sensor. The presence of Ag nanoparticles on the surface of VONTs serves to enhance the C 2 H 5 OH oxidation due to a higher oxygen ion-chemisorption on the conductive Ag nanoparticle surfaces.