Adsorption of Escherichia coli (E. coli) cells on red mud (RM) is important in the interactions between RM and bacteria. The objective of this work is to study adsorption of E. coli onto RM and to determine its influence in relation to the surface properties of RM. The effects of different calcination temperatures on the surface properties of red mud were investigated by thermogravimetric analysis, x-ray diffraction, scanning electron microscopy, Brunauer, Emmett, Teller (surface measurement)/N2 adsorption method, and zeta potential analysis. A higher adsorption capacity was observed from RM calcinated at 700 °C (RM700) due to larger pores formed on the surface of RM. The correlation between the adsorption efficacy and surface properties of RM is discussed and the extended Derjaguin-Landau-Verwey-Overbeek theory suggests that when the adsorption reaches equilibrium, the increased adsorption of E. coli onto RM is due to the smaller energy barrier between E. coli and RM700 as compared with that between E. coli and raw RM (RM0).

The crushing strength or compression strength is a fundamental mechanical property for reticulated ceramic foams. There are essential influencing variables such as the rate of the applied load, the size of the applied load area, the sample size, and the strut homogeneity of the samples. In this work, the impact of the variation of the testing parameters on the crushing strength measurement was evaluated with the help of industrially produced ceramic foams made of Al2O3, ZrO2, SiC, and fused silica. The results indicate that the rate of the applied load has no significant influence on the crushing strength of the ceramic foams. Whereas the size of the applied load area and the sample size have an evident influence. The experimental results were compared with the minimum principal stress distribution calculated with FEM.

Retention of a nanostructure in thermoelectric materials through rapid sintering (e.g., field-assisted sintering) is generally associated with leaving certain amounts of porosity due to short sintering times. In this study, the influence of porosity on the thermoelectric transport properties in Bi2Te3-based alloys was studied by changing the sintering pressure during spark plasma sintering. N-type Bi2Te3 and p-type (Bi0.2Sb0.8)2Te3 were sintered at 673 K using pressures from 50 to 300 MPa to obtain different levels of porosity. Electrical resistivity, thermal conductivity, Seebeck coefficient, carrier concentrations, and Hall mobility were measured and characterized. The results show that increasing sintering pressure is effective in reducing porosity, which lowers electrical resistivity and increases the carrier concentrations. The transport properties were fitted to general effective medium equations and demonstrate that in p-type (Bi0.2Sb0.8)2Te3 sintered at high pressures, decreases in electrical resistivity and lattice thermal conductivity exceeded the Seebeck coefficient reduction, improving the thermoelectric figure of merit.

Carbon nanotubes (CNTs) supported Pd nanoparticle (NP) catalysts (Pd/CNTs) were prepared by a green and facile synthesis method based on hydrogen-bonding self-assembly. The size and loading of Pd NPs on catalysts were easily controlled by tuning both the relative amount of citrate to Pd salt in the solution and the relative amount of Pd NPs to CNTs. The size of Pd NPs on as-prepared catalysts can be tuned in the range of 3–6 nm, and Pd loading can be controlled in the range of 0–19 wt%. The catalysts were characterized by Brunauer–Emmett–Teller measurement, x-ray diffraction spectroscopy, and x-ray photoelectron spectroscopy. The performance of Pd/CNTs catalysts was evaluated in the hydrogenation of nitrobenzene. Compared with the catalysts prepared by the impregnation method or supported on conventional supports, Pd/CNTs catalysts show relatively higher activity and selectivity. The recyclability tests indicate that the Pd/CNTs catalysts can be used at least five times without significant loss in activity and selectivity.

A new type of cross-linked poly(vinyl alcohol) (PVA)-sulfosuccinic acid (SSA) polymers were synthesized by varying the amount of SSA and then blending with 3-amino-1,2,4-triazole (ATri) and 1H-1,2,4-triazole (Tri) at different stoichiometric ratios to obtain proton conductive membranes in anhydrous state. The proton conductivities of membranes were investigated as a function of azole composition, SSA composition, and operating temperature. The final structures of the copolymers were confirmed by Fourier transform infrared spectra. The resultant hybrid membranes are transparent, flexible, and showed good thermal stability up to approximately 200 °C. Differential scanning calorimetry results illustrated the homogeneity of the materials. The cross-linking of the structure was confirmed by the alteration of solubility of the membranes. Methanol permeability measurements showed that the composite membranes have lower methanol permeability compared to Nafion 112. The proton conductivity of the membranes continuously increased with increasing SO3H content and 3-amino-1,2,4-triazole (ATri) content. A maximum proton conductivity of 7.26 × 10−3 S/cm was achieved for ATri-3 at 140 °C under anhydrous conditions. Incorporation of ATri unit (according to Tri unit) significantly increased the proton conductivity of the membranes, probably due to the ion transport channel or network structures formed in the membranes.