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This study exhibits potential prospects in thermal management fields and promising alternatives for the thermal harvesting of renewable energy.

A self-lubrication composite incorporating activated carbon particles containing lubricating oil (AC-oil) was fabricated in an epoxy resin matrix. Pure EP and AC/EP composites were also fabricated for comparison. Thermogravimetric analysis (TGA) was conducted to examine the oil absorption rate of AC-oil. The fracture surfaces and the worn surfaces of the pure EP and its composites were studied using scanning electron microscopy (SEM). The results revealed that the content of AC-oil particles was of significance for the tribological and mechanical properties of the AC-oil/EP composites, and the oil absorption rate of the AC-oil was about 21%. The best tensile and tribological properties of the AC-oil/EP composites were obtained at an AC-oil content of 1 wt% and 10 wt%, respectively. Compared with pure EP, the wear resistance of the AC-oil (10 wt%)/EP composites increased 3.21 times and the friction coefficient decreased by 25.7%. The tensile strength of the AC-oil (1 wt%)/EP composites increased by 38.6% and 28.3%, respectively, when comparing with the pure EP and AC/EP composites. The solid–liquid two-phase self-lubrication mechanism was also discussed according to SEM and energy dispersive spectrometer (EDS) analysis of the worn surfaces and the counterpart surfaces.

A superhydrophobic coating with long-lived wear resistance was successfully prepared by integrating the hydrophobization of cotton fiber fabric and the curing of epoxy composites consisting of polyurethane (PU), polyfluoroalkoxy (PFA) and hydrophobic SiO2 nanoparticles. Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) were employed to investigate the chemical compositions and morphologies of the modified cotton fiber fabric and the prepared coating. When the epoxy solution containing 35 wt% PFA and 25 wt% PU, the obtained coating exhibited superhydrophobic behavior with a water contact angle (WCA) of 153.5 ± 1°. Tribological tests indicated that this fiber fabric/epoxy composites coating had stable friction coefficient and excellent wear-resistance under the harsh conditions with the applied load of 2.8 MPa and the sliding velocity of 0.51 m s−1. After 240000 cycles of abrasion, the coating just showed the decrease in thickness of 80 μm without apparent damage and could retain high hydrophobicity with the WCA of 142°. Simultaneously, the coating was resistant to the acid or alkali solution. This wear-resistant superhydrophobic fiber fabric/epoxy composites coating may be a good candidate for the practical industrial applications under harsh working conditions.

In this study, epoxy (EP) composites filled with different contents of polyvinylidene fluoride (PVDF) and carbon nanotubes (CNTs) were fabricated by the solvent evaporation and curing method. FT-IR and XRD analysis were performed to explore the discolorment mechanism of the PVDF/EP composites before and after curing. The effects of the PVDF and CNT content on the mechanical and tribological properties of the composites were investigated. Results revealed that 1.0% CNT/30% PVDF/EP composites exhibited a 36.2% and 10.1% increase in flexural strength and hardness, as compared to those of the 30% PVDF/EP composites. The wear rates of 1.0% CNT/30% PVDF/EP composites and 30% PVDF/EP composites were 92.1% and 86.8% lower than that of pristine EP under 1.0 MPa and 0.76 m s−1, respectively. Meanwhile, the fractured and worn surfaces of specimens were both analyzed by the observations of SEM. In addition, wear tests under various applied loads were conducted for pristine EP, 30% PVDF/EP and 1.0% CNT/30% PVDF/EP composites. The results showed that the wear properties of the two composites were both superior to those of pristine EP due to the formation of a transfer film as revealed by SEM-EDS analysis, which could effectively protect the worn surface from direct abrasion during the wear testing.

In this study, a superhydrophobic polysulfone (PSU) composite coating with a high water contact angle (WCA) of 159° and a low slide angle (SA) of only 3.5° has been fabricated through a simple thermal spraying method. The ductility and mechanical properties of the PSU composite coating were improved effectively through the combination of the cross-linking ability of PVDF and the special multilayer structure of MMT. The wear resistance of the prepared coating is approximately 14.3 times longer than that of commercial fluorocarbon coating. Simultaneously, the prepared superhydrophobic coating also possesses outstanding corrosion resistance; the corrosion current and corrosion potential decreased from 10−0.9 to 10−3.6 μA cm−2 and from −803 to −218 mV, respectively. Furthermore, the prepared coating demonstrated superb self-cleaning, anti-fouling and durability properties. It is believed that this robust superhydrophobic PSU/PVDF/MMT–PDMS composite coating may provide the possibility to realize large-scale fabrication and applications in industry.

Novel hollow nano/microspheres of polyaniline (PANI) with mesoporous brain-like convex-fold shell structures were prepared via a new micelle-mediated phase transfer method, using perfluorooctanoic acid (PFOA)/aniline as a soft template. These self-assembled hollow spheres possess high specific surface areas (835.7 m2 g−1), and uniform particle morphology with narrowly distributed particle size can be controlled by adjusting the PFOA/aniline molar ratio and polymerization time. The conductive emeraldine state of PANI is also confirmed by FT-IR spectroscopy, UV-vis spectroscopy, X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry. In particular, these PANI spheres exhibit superhydrophobicity and high oleophobicity simultaneously, with contact angles of 165 ± 0.9°, 134 ± 0.8°, 131 ± 0.9° and 125 ± 0.7° towards water, glycerin, ethylene glycol and corn oil, respectively. Furthermore, the mechanisms of PANI structural evolution are proposed involving the formation, phase transfer and self-reassembly process of PFOA/aniline spherical micelles.

Polydopamine-modified Ag/TiO2 porous nanofibers (PDA-Ag/TiO2 porous NFs) were successfully prepared as a composite catalyst via a simple electrospinning process combined with an impregnation method. It was found that the PDA-Ag/TiO2 porous NFs present a corn-like, coarse, porous structure where the TiO2 NFs look like corn cobs and the Ag nanoparticles (NPs) act as corn kernels. In our research, carbon nanotubes (CNTs) were embedded during the original spinning as pores were formed using electrospinning. After calcination, the loss of the CNTs left a lot of holes in the internal structure of the TiO2 NFs that made the specific surface area increase by about 30 percent compared to the pure TiO2 NFs. Ag NPs embedded in the TiO2 NFs could prevent the recombination of electron–hole pairs generated from photocatalysis and could transfer the captured electrons to participate in the photocatalysis reaction process. The PDA which wrapped the TiO2 NFs homogeneously could adsorb organic matter and promote the spatial separation of photogenerated charges. The higher photocatalytic efficiency demonstrated a synergy between the Ag NPs and PDA with PDA playing the role of the gripper to capture organic molecules, and the Ag NPs doped in the TiO2 NFs acting as the electron conveyer which could restrain the recombination of electron–hole pairs. The new composite catalyst has potential application in cleaning up organic pollutants.

Oil spillage and industrial oily wastewater have caused severe environmental concerns. A super absorbent material capable of separating oil–water mixtures, especially with a high absorption capacity and mechanical strength, is urgently desired. Here, a common and feasible approach to fabricate carbon nanotubes (CNTs) reinforced polyurethane (PU) sponge is presented that shows superhydrophobic and superoleophilic properties. The method involves the oxidative self-polymerization of dopamine and the reaction of hydrophilic polydopamine (PDA) with hydrophobic octadecylamine (ODA). The superhydrophobic stability of the as-prepared sponge with temperatures and in corrosive solutions of different pH is investigated. The as-prepared sponge could quickly and selectively absorb various kinds of oils up to 34.9 times of its own weight, and the absorbed oils can be collected by a simple squeezing process. More interestingly, the mechanical strength of the as-prepared sponge is improved due to the structural reinforcement of CNTs anchored on the sponge skeleton. Furthermore, the recovered sponge could be reused to separate oil–water mixture 150 times while maintaining its high absorption capacity. This promising multifunctional sponge exhibits significant potential as an efficient absorbent in large-scale oil–water separation applications.

In this paper, three kinds of noble metal nanoparticles (NMNs) were successfully loaded on hierarchical TiO2 nanotube arrays (TiO2 NTs) to improve photocatalytic (PC) activity of gas phase pollutants. The hierarchical TiO2 NTs, with unique top-nanoporous and bottom-nanotubular structure, were prepared through a facile two-step anodization method, and then the noble metal nanoparticles were loaded on the TiO2 NTs by means of a photo-reduction method. The gas phase photocatalytic activity of TiO2 NTs and NMNs/TiO2 NTs were estimated by decomposition of gaseous methanol. The formation of Schottky junctions between TiO2 NTs and NMNs significantly improved the PC due to they could significantly accelerate the electron transfer and thus reduction of the recombination of photogenerated electrons and holes.

This study presents the first demonstration of STEP for organic synthesis. The synthesis of benzoic acid was fully driven by solar energy without the input of any other forms of energy. STEP (the Solar Thermal Electrochemical Process) was established to drive chemical reactions by using solar heat to minimize the energy and maximize the rate of a growing portfolio of electrolysis reactions. The use of solar energy can minimize or eliminate the carbon footprint associated with the production of societal staples. To date this has included STEP chemistries for the high solar efficiency generation of hydrogen fuels, carbon dioxide splitting to generate fuels and graphite, hematite (iron ore) splitting for iron metal, of lime from limestone, and the production of bleach, magnesium and other useful chemistries. Benzoic acid is produced by the electrolysis of toluene. Solar thermal and solar electrical energy synergistically drive the electrolysis; solar thermal decreases the requisite electrolysis voltage, and improves the kinetics, selectivity and yield of the reaction, while solar electrical current drives the electrolysis. The low electrolysis potential inhibits over-oxidation of the product. In this STEP organic synthesis of benzoic acid at an applied photopotential of 3 V the reaction conversion of benzoic acid is 3.9% at a temperature of 30 °C, 12.4% at 60 °C, and 32.0% at 90 °C. The results demonstrate that the STEP is suitable for an efficient synthesis of benzoic acid from toluene.