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1 | INTRODUCTION In recent years, membranes have been extensively used in commercial processes for gas separation. The membrane separation process (MSP) has been very promising, and due to its [...], The membrane separation process represents an advance in this area, and the use of nanocomposites enables their improvement. Polyamide 6 (PA6) membranes were produced with attapulgite (ATP) and montmorillonite (MMT) clays by melting through the hot pressing of thin films. Subsequently, the membranes were characterized by thermogravimetry (TGA), showing a significant mass loss at 330[degrees]C. Differential scanning calorimetry (DSC) revealed that the clay increased thermal stability. X-ray diffraction (XRD) was performed, confirming the presence of characteristic peaks of polyamide 6, and with the introduction of clay, there were changes in the shapes. Contact angle measurements showed that the clays increased the hydrophilicity of the membranes. Atomic force microscopy (AFM) revealed that the presence of clays modified the surface roughness. The tensile test showed that the clays decreased the strength of the nanocomposites. Oxygen permeation confirmed a decrease in the permeability of compositions containing clay compared with pure PA6 membranes. Studies aimed at understanding the interaction of gases with the membrane material represent a small part of research on the selective barrier. This work aimed to obtain flat membranes from polyamide 6/clay nanocomposites to separate gaseous mixtures using the thin film hot-press fusion method. Highlights * PA6 membranes were produced with ATP and MMT clays via hot pressing of thin films. * Introduction of clay enhances thermal stability in PA6 membranes and reduce gas permeability. * ATP clay increases membrane stiffness; MMT decreases strength. * Membranes with PA6 and clays exhibit good water vapor selectivity. KEYWORDS clay, membrane, nanocomposites, polyamide 6 more...

For magnesium (Mg) matrix composites (MMCs), trade-off between strength and plasticity has long been an issue of puzzle. In this work, hot-press sintering and hot extrusion are used to prepare Ti particles (Tip) reinforced AZ31 (Tip/AZ31) composites. The strength, plasticity, and wear resistance of Tip/AZ31 composites are improved simultaneously. Ti particles refine the grains of composites and accelerate the precipitation of Mg17Al12 particles in Mg matrix. The best tensile properties and wear resistance are achieved in 6 wt%Tip/AZ31 composite, with ultimate tensile strength of 290 MPa, elongation of 15.5 %, and wear rate of 4.343 × 10−3 mm3/m, respectively. Especially, the wear rate of 6 wt%Tip/AZ31 is reduced by 54.6 % compared to the matrix alloy. The underlying strengthening mechanisms, toughness mechanisms, and wear mechanisms of Tip/AZ31 composites were discussed in detail. more...

Abstract To develop a material with strong impact resistance, bending direction and in‐plane direction, the tensile and bending properties of sandwich films obtained by placing and re‐pressing a compression‐molded polypropylene sheet between two sheets of carbon‐fiber‐reinforced thermoplastics (CFRTPs) were evaluated. Three types of CFRTP were investigated, and thermoplastic nylon 66, polyurethane, and polyphenylene sulfite were used as the resin base materials to wrap the carbon fiber. Regarding the tensile properties of the sandwich films, the Young's modulus and maximum stress values were lower compared with those of the CFRTP sheets, regardless of the resin base material. However, improvements in elongation properties of 97%, 109%, and 156%, respectively were found, transforming the film into a softer and stronger film. Regarding the bending properties of the sandwich films, the Young's modulus and maximum stress values were higher compared with those of the CFRTP sheet. To examine the influence of the number of layers, the five‐layer sheet, in which the sandwich film was placed in two CFRTP sheets, exhibited inferior elongation properties to the three‐layer sheet during the tensile test. However, the results of the bending test found a significant improvement in Young's modulus of approximately 2.5 times and final strength of approximately three times. We anticipate that this material could be applicable to components requiring specific mechanical properties in both bending and in‐plane directions in future applications. Highlights CFRTP sandwich sheets were fabricated using a simple hot‐press method. The sandwich sheet showed improved mechanical properties in the in‐plane directions. Both the tensile modulus and the bending modulus have reached the GPa‐order. The sandwich film in question had particularly excellent bending properties. The sandwich film showed dependence on the number of layers. In‐plane elasticity of the films was evaluated using a falling ball test. more...

In this study, electrical steel laminated composites with positive Si gradient (PO-G), counter Si gradient (CO-G), and cross Si gradient (CR-G) were fabricated by hot-press sintering, cold rolling and annealing. The microstructure evolution during processing, as well as the magnetic and mechanical properties were investigated. The results indicate that the microstructure of the high-silicon layer and medium-silicon layer in the hot-pressed composites featured columnar grains throughout the thickness. The microstructure of the low-silicon layer in the hot-pressed CO-G sample consisted of equiaxed grains. However, a mixed structure dominated by columnar grains with some equiaxed grains was observed in the inner low-silicon layer of the PO-G and CR-G samples. Following cold rolling, the thickness ratio of each layer remained largely unchanged. After annealing, the microstructure of each layer transformed into columnar grains. The average grain size of the high-silicon layer, medium-silicon layer, and low-silicon layers in the three composites were approximately 20–23 μm, 33–38 μm, and 42–49 μm, respectively. Compared with the CO-G and CR-G samples, the annealed PO-G composite exhibited lower core loss at 400–1000 Hz and superior tensile strength. Furthermore, the core loss of the three composites was greater than that of the initial medium-silicon and high-silicon materials. This can be attributed to the increased hysteresis loss due to the existence of multi-layer interface. more...