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In order to enhance the interfacial adhesion of carbon fiber (CF) and polymer matrix, a multiscale gradient modulus intermediate layer with rigid-flexible (GO-PA) hierarchical structure was designed and fabricated between CFs and matrix by a facile and businesslike strategy. The polarity, roughness and wettability of CFs surface as well as the thickness of intermediate layer in composite have been significantly increased after rigid-flexible hierarchical structure was constructed. The IFSS, ILSS, compression and impact toughness manifested that the hierarchical structure could bring about a fantastic improvement (76.8%, 46.4%, 40.7% and 37.8%) for the interfacial and mechanical properties than other previous reports. Consequently, the establishment of CF surface with gradient modulus rigid-flexible hierarchical structure via regulation of nanoparticles and polymer array would open a new, viable and promising route to obtaining high-performance composites.

Using a facile strategy to fabricate multifunctional cotton fabrics with superhydrophobicity, conductivity and antibacterial activity is an important and urgent issue in the development of natural fabrics. Herein, a new type of cotton fabric, denoted as Cot@PDA/Ag/NDM, has been fabricated utilizing mussel-inspired polydopamine (PDA) chemistry, followed by electroless Ag plating and n-dodecyl mercaptan (NDM) self-assembly. The influence of dopamine (DA) and AgNO3 concentration on the surface morphology and conductivity, as well as NDM treatment time on the surface wettability of the fabric is systematically investigated. Cot@PDA/Ag/NDM not only exhibits superhydrophobicity with water contact angle of 155.9 ± 1°, but also possesses excellent self-cleaning and antifouling properties. In addition, the fabric has a highly conductive surface with sheet resistance as low as 10.2 Ω cm, and shows outstanding mechanical properties and antibacterial activity against Escherichia coli and Staphylococcus aureus.

Metallic foams with a high fraction of porosity, low density and high-energy absorption capacity are a rapidly emerging class of novel ultralight weight materials for various engineering applications. In this study, Y-Cr and Ce-Cr-coated Ni-Cr-Fe alloy foams were prepared via the pack cementation method, and the effects of Y and Ce addition on the coating microstructure and oxidation performance were analyzed in order to improve the oxidation resistance of open-cell nickel-based alloy foams. The results show that the Ce-Cr coating is relatively more uniform and has a denser distribution on the surface of the nickel-based alloy foam. The surface grains of the Ce-Cr-coated alloy foam are finer compared to those of the Y-Cr-coated alloy foam. An obvious Ce peak appears on the interface between the coating and the alloy foam strut, which gives rise to a “site-blocking” effect for the short-circuit transport of the cation in the substrate. X-ray diffraction analysis shows that the Y-Cr-coated alloy foam mainly consists of Cr, (Fe, Ni) and (Ni, Cr) phases in the surface layer. The Ce-Cr-coated alloy foam is mainly composed of Cr and (Ni, Cr) phases. Furthermore, the addition of Y and Ce clearly lead to an improvement in the oxidation resistance of the coated alloy foams in the temperature range of 900-1000 °C. The addition of Ce is especially effective in enhancing the diffusion of chromium to the oxidation front, thus, accelerating the formation of a Cr2O3 layer.

The interface between carbon fibers (CFs) and matrix resin makes a critical contribution to bulk performance of composites. In order to enhance interfacial properties and anti-hydrothermal aging behaviors of methyl phenyl silicone resin (MPSR) composites, octamaleamic acid-polyhedral oligomeric silsesquioxanes (POSS-acid) were directly grafted onto CFs surface by chemical bonding for the first time. Surface chemical groups and morphologies of CFs before and after POSS-acid grafting were systematically characterized. Scanning electron microscopy and atomic force microscopy images showed a uniform distribution of POSS-acid on the fiber surface and the improved surface roughness. POSS-acid cages grafting could improve obviously the fiber polarity, wettability, and free energy by dynamic contact angle analysis testing. The interlaminar shear strength (ILSS) of MPSR composites reinforced with the POSS-acid-modified CFs (CF-POSS) was 45.01 ± 1.69 MPa, which increased by 52.73 % compared to that of MPSR composites reinforced with untreated CFs (29.47 ± 0.94 MPa). And, impact strength of CF-POSS composites (77.69 ± 2.83 kJ m−2) was increased by 32.89 % compared to that of untreated CF composites (58.46 ± 1.91 kJ m−2). Moreover, ILSS of CF-POSS composites after hydrothermal aging treatment was 40.89 ± 1.51 MPa with a decrease of just 9.15 % compared to that of untreated CF composites (20.52 ± 0.65 MPa) with an obvious decrease of 30.37 %. Meanwhile, POSS-acid functionalization did not decrease fiber tensile strength. Based on our design starting from simple chemistry and inexpensive materials, such hierarchical reinforcements with improved interfacial strength and anti-hydrothermal aging behaviors have great potential in advance polymer matrix composites.

Wf/Cu82Al10Fe4Ni4(30) composites and Wf/Cu82Al10Fe4Ni4(60) composites were prepared by penetrating casting method. Three-point bending test and dynamic compression test showed that Wf/Cu82Al10Fe4Ni4(30) composites possessed higher mechanical properties than Wf/Cu82Al10Fe4Ni4(60) composites. Microstructure observation of Wf/Cu82Al10Fe4Ni4(30) composites revealed that a small amount of tungsten diffused into the Fe–Ni solid solution precipitated on the surface of tungsten fibers. The damage occurred mainly within the tungsten fibers after three-point bending test and dynamic compression test in Wf/Cu82Al10Fe4Ni4(30) composites, indicating that the composites possessed high interface strength. Dislocation density was high and stacking faults emerged in Wf/Cu82Al10Fe4Ni4(30) composites after dynamic compression. Microstructure observation of Wf/Cu82Al10Fe4Ni4(60) composites revealed that long strip of tungsten grains occurred at the edge of tungsten fibers, within which damage mainly emerged after three-point bending test, indicating that strength of the edge of tungsten fibers was low in Wf/Cu82Al10Fe4Ni4(60) composites. The fibrous structure of tungsten fiber was coarse or even disappeared in some areas, and dislocation density was low in Wf/Cu82Al10Fe4Ni4(60) composites after dynamic compression.