Binder-free and free-standing electrodes have been regarded as an attractive and promising structure in lithium–sulfur batteries. In this work we describe how a free-standing sulfur/reduced graphene oxide with embedded carbon nanotubes electrode has been synthesized by a novel, facile and eco-friendly method taking advantage of the solubility difference of polar and nonpolar materials. First, the nonpolar elemental sulfur is dissolved in a weak polar solvent (ethanol) by intensive ultrasonication. During a subsequent heavy polar solvent (deionized water) drop-wise procedure, nano-sized sulfur particles are precipitated from the ethanol and deposited on the dispersed carbon nanotubes and graphene oxide. Noticeably, since ascorbic acid is taken as the reducing agent for graphene oxide at 75 °C, the process produces no toxic byproducts. Besides, the ‘as-designed’ sulfur/reduced graphene oxide with embedded carbon nanotubes graphene oxide displays a unique structure with both the sulfur and carbon nanotubes embedded in the basal plane of reduced graphene oxide. The manufactured electrode is found to exhibit excellent rate capability and cyclability, with the maximum capacity of 1025 mA h g−1 observed in the third cycle and a stable capacity of 704 mA h g−1 after 100 cycles.

Using commercial polyurethane foams as templates, PU/RGO foams were prepared by a simple dip-coating method, which is economical and suitable for industrialized production. The formation of RGO was studied using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and scanning electron microscopy (SEM). The microwave absorption properties of the PU/RGO foams were investigated and the results show that for composites with a RGO loading of 31.3 wt%, the minimum reflection loss of the PU/RGO foam can reach −50.8 dB at 12.9 GHz, and the frequency bandwidth at less than −10 dB is from 10.75 to 15.95 GHz at a thickness of 2.5 mm. In addition, the results of cyclic compression tests and twisting experiments indicated that the PU/RGO composite was highly resilient. Moreover, the measured density of the foam material is just approximately 0.027 g cm−3 which is considerably smaller compared with most commercial wave-absorbing materials. The fabricated PU/RGO foams can be used as good microwave absorbing commercial cladding materials, with particularly lightweight and highly elastic properties.

In this paper, a novel (ZnSnO3/PVDF)@PPy nanofiber (ZPPs)/EP composite (ZPPE) was prepared and its damping and mechanical properties were investigated. The morphology and structure of the composites were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The damping performance was investigated by dynamic mechanical analysis (DMA), and the results showed that for composite ZPPE-60 (i.e., 60% wt ZnSnO3), the storage modulus (E′), loss modulus (E′′) and loss factor (tan δ) values at 20 °C and 1 Hz increased respectively by about 195%, 655% and 330% compared with the epoxy matrix due to the piezo-damping effect (external mechanical energy–electrical energy–heat energy) and internal friction effect (from fiber–fiber and fiber-matrix friction). The flexural strength and Shore D hardness were also measured to test the composites' mechanical and wear resistance properties. The results suggested that the fabricated ZPPE composites can be used as good structural damping materials.

Shape memory polymers (SMPs) have attracted the attention of both the industry and academia due to the fact that they can deform and fix into a temporary shape, and recover their permanent, original shape upon exposure to an external stimulus. In this work we propose a novel, shape memory three-dimensional (3D) polyurethane-based (PU) graphene foam (PGF)/epoxy/carbon nanotubes (PGEC) composite. The composite uses epoxy resin (EP) as matrix, a low-density (about 0.030 g/cm3), highly porous, commercially available PU sponges as the scaffold, and graphene and carbon nanotubes (CNTs) as conductive network. The proposed PGEC composites demonstrate excellent conductivity and could be triggered within 150 s by applying an electric field of approximately 1.43 V mm−1. The proposed SMP composite material is simple and fast to manufacture, operational, and low cost.

Thermally reduced graphene networks (TRGN) with low densities, less than 10 mg cm−3, were synthesized by thermal reduction of graphene oxide/poly(vinyl alcohol) networks. To evaluate the electromagnetic wave absorption properties of TRGN, TRGN were nondestructively backfilled with wax via a vacuum-assisted method. The as-prepared TRGN/wax composites, using integrated TRGN as fillers rather than directly dispersing graphene sheets in wax, exhibit better electromagnetic wave absorption capabilities because of the 3D conductive frameworks, which could generate more effective electrical loss in terms of dissipating the induced current in the TRGN/wax composites. Specifically, for the TRGN/wax composite with ∼1 wt% TRGN, the minimum reflection loss reaches −43.5 dB at 12.19 GHz with a thickness of 3.5 mm, and the bandwidth of reflection loss less than −10 dB (90% absorption) can reach up to 7.47 GHz. More importantly, our work provides a promising approach for constructing graphene-based composites with strong electromagnetic wave absorption ability at very low filler loadings.

In this manuscript we present a novel, shape memory aerogel/epoxy composite structure composed of a reduced carbon nanotube and graphene compound aerogel as a scaffold and epoxy resin as a matrix. The composite was prepared via a vacuum infusion method and to the best of our knowledge it represents the first instance of a shape memory effect directly driven by an electrical field observable in polymer-infused conductive carbon scaffolds. Furthermore, the composite material obtained displays a high conductivity (i.e., up to 5.2 S m−1). In the manuscript it is shown that the composite's high conductivity can be attributed to the built-in 3D network of the thermally reduced graphene and carbon nanotube compound aerogel which displays high conductivity (16 S m−1) coupled with low density (6 mg mL−1). The composite material presented in this work is likely a suitable candidate for applications requiring polymer-infused conductive aerogels such as electromagnetic shielding, actuators and thermal sensors.

Nanocomposites consisting of well-defined anatase TiO2 nanoparticles with an average diameter of 8 nm and multi-walled carbon nanotubes (MWCNTs) were fabricated by a facile two-step hydrothermal method using water as the main solvent, which is friendly to the environment and totally different from previous methods. The TiO2 nanoparticles were uniformly grafted on the surface of MWCNTs via intimate chemical bonds, which was beneficial for the enhancement of photocatalytic activity. The photocatalytic activities of as-prepared TiO2/MWCNT nanocomposites for degradation of rhodamine B under solar simulator illumination were investigated systemically. It was found that the photocatalytic activity of as-prepared TiO2/MWCNT nanocomposites was 7 times higher than that of pure TiO2 prepared via the same hydrothermal procedure. The enhancement was mainly due to the existence of MWCNTs, which could not only greatly improve the adsorption of rhodamine B, but also retard the recombination of photogenerated electron–hole pairs and absorb more light. The photocatalytic performance was further enhanced after being annealed at 400 °C and 500 °C for 1 h because of the improved crystallinity of anatase TiO2. Interestingly, the photocatalytic activities of samples annealed at 400 °C and 500 °C showed no difference, which was different from previous reports.

•We develop uniform nanotube arrays on Ti–35Nb–2Ta–3Zr alloy with 0%, 20%, 40% and 80% deformations by anodization method.•The composition of electrolyte also contributes to the arrangement of nanotube arrays.•Increasing deformation of Ti–35Nb–2Ta–3Zr alloy results in nanotubes with smaller diameter and bigger wall thickness.•The TiO2 grain size of nanotubes grown on undeformed Ti–35Nb–2Ta–3Zr alloy is bigger than that of deformed alloy.•Once Ti–35Nb–2Ta–3Zr alloy is deformed, the TiO2 grain size becomes larger with the increase of deformation.Nanotubes on Ti–35Nb–2Ta–3Zr alloy with different degrees of deformations in thickness were fabricated by anodization method. The effect of deformations on the morphology, crystal phase and grain size of nanotubes was investigated. Nanotube arrays with uniform diameter were achieved by using ethylene glycol (EG)/NH4F organic electrolyte, indicating the electrolyte composition will influence the arrangement of TiO2 nanotube arrays. With the increasing degree of deformation, the corrosion potential Ecorr of the alloys had a positive displacement, which suggested an enhanced anticorrosion ability and resulted in nanotubes with smaller diameter. After heat treatment, anatase TiO2 was obtained. Due to the existence of lattice distortion, the grain size of TiO2 nanotubes prepared by Ti–35Nb–2Ta–3Zr alloy with deformations was smaller than that of with no deformation. However, when the reductions of alloy increased, there was a tendency to make the grain size larger, which was probably caused by the restriction of the wall thickness of nanotubes. The study about the nanotubes formed on Ti–35Nb–2Ta–3Zr alloy with different deformations provides a basis for its application on the drug-loading by Ti alloy prosthesis artificial joint.

Polyethylene (PE) separator was modified by UV grafting methyl acrylate (MA) and nano-SiO2 composite layer. The structure of functional group and morphology of the separator were analyzed by Fourier transform infrared spectrum (FT-IR) and scanning electron microscope (SEM). The wetting behavior and the heat resistance of the separator were also investigated by contact angle test and thermal shrinkage test respectively. The results show that MA/nano-SiO2 composite layer is successfully grafted onto the PE separator, and the addition of the DI water and butanol can make the nano-SiO2 dispersed better and lead to a microporous structure of the grafting layer. The grafted separator has a better wettability and heat resistance than the pristine one.

Thermally reduced graphene networks (TRGN) with low densities, less than 10 mg cm−3, were synthesized by thermal reduction of graphene oxide/poly(vinyl alcohol) networks. To evaluate the electromagnetic wave absorption properties of TRGN, TRGN were nondestructively backfilled with wax via a vacuum-assisted method. The as-prepared TRGN/wax composites, using integrated TRGN as fillers rather than directly dispersing graphene sheets in wax, exhibit better electromagnetic wave absorption capabilities because of the 3D conductive frameworks, which could generate more effective electrical loss in terms of dissipating the induced current in the TRGN/wax composites. Specifically, for the TRGN/wax composite with ∼1 wt% TRGN, the minimum reflection loss reaches −43.5 dB at 12.19 GHz with a thickness of 3.5 mm, and the bandwidth of reflection loss less than −10 dB (90% absorption) can reach up to 7.47 GHz. More importantly, our work provides a promising approach for constructing graphene-based composites with strong electromagnetic wave absorption ability at very low filler loadings.

In this manuscript we present a novel, shape memory aerogel/epoxy composite structure composed of a reduced carbon nanotube and graphene compound aerogel as a scaffold and epoxy resin as a matrix. The composite was prepared via a vacuum infusion method and to the best of our knowledge it represents the first instance of a shape memory effect directly driven by an electrical field observable in polymer-infused conductive carbon scaffolds. Furthermore, the composite material obtained displays a high conductivity (i.e., up to 5.2 S m−1). In the manuscript it is shown that the composite's high conductivity can be attributed to the built-in 3D network of the thermally reduced graphene and carbon nanotube compound aerogel which displays high conductivity (16 S m−1) coupled with low density (6 mg mL−1). The composite material presented in this work is likely a suitable candidate for applications requiring polymer-infused conductive aerogels such as electromagnetic shielding, actuators and thermal sensors.