Search

Superhydrophobic textiles have attracted great interest due to their special functions and wide applications. However, it is still a huge challenge to construct a durable superhydrophobic coating for large-scale applications due to the complicated process and high cost. In this work, a facile two-step method was developed to construct superhydrophobic cotton fabric with fluorine-free treatment. The cotton fabrics were treated with modified nano SiO2 to construct rough surfaces. Then, the silicone oil was introduced into the surface of the cotton fabric to form superhydrophobic cotton fabric. The results showed that the modified nano SiO2 and silicone oil were stably fixed on the fiber surface. The static water contact angle test showed that contact angle of the modified cotton fabric was 158°, indicating excellent superhydrophobic properties. Furthermore, the self-cleaning and anti-pollution test results showed that the superhydrophobic cotton fabric possessed good self-cleaning and antifouling performance. This superhydrophobic fabric avoids the use of fluoropolymers and reduces the harm to humans and environment, showing a wide range of applications.

Tissue engineering is an enabling technology that can be used to repair, replace, and regenerate different types of biological tissues and holds great potential in various biomedical applications. As the first line of defense for the human body, the skin has a complex structure. When skin is injured by trauma or disease, the skin tissues may regenerate under natural conditions, though often resulting in irreversible and aesthetically unpleasant scarring. The development of skin tissue engineering strategies was reviewed. Although the traditional approaches to skin tissue engineering have made good progress, they are still unable to effectively deal with large-area injuries or produce full-thickness grafts. In vitro three-dimensional (3D) skin constructs are good skin equivalent substitutes and they have promoted many major innovative discoveries in biology and medicine. 3D skin manufacturing technology can be divided into two categories: scaffold-free and scaffold-based. The representatives of traditional scaffold-free approaches are transwell/Boyden chamber approach and organotypic 3D skin culture. Because of its low cost and high repeatability, the scaffold-free 3D skin model is currently commonly used for cytotoxicity analysis, cell biochemical analysis, and high-throughput cell function. At present, many drug experiments use artificial skin developed by traditional approaches to replace animal models. 3D bioprinting technology is a scaffold-based approach. As a novel tissue manufacturing technology, it can quickly design and build a multi-functional human skin model. This technology offers new opportunities to build tissues and organs layer by layer, and it is now used in regenerative medicine to meet the increasing need for tissues and organs suitable for transplantation. 3D bioprinting can generate skin substitutes with improved quality and high complexity for wound healing and in vitro disease modeling. In this review, we analyze different types of conventional techniques to engineer skin and compare them with 3D bioprinting. We also summarized different types of equipment, bioinks, and scaffolds used in 3D skin engineering. In these skin culture techniques, we focus on 3D skin bioprinting technology. While 3D bioprinting technology is still maturing and improvements to the techniques and protocols are required, this technology holds great promise in skin-related applications.

The hydrophilicity and inherent flammability of cotton textiles severely limit their usage. To solve these drawbacks, a superhydrophobic and flame-retardant (SFR) coating made of chitosan (CH), ammonium polyphosphate (APP), and TiO2-SiO2-HMDS composite was applied to cotton fabric using simple layer-by-layer assembly and dip-coating procedures. First, the fabric was alternately immersed in CH and APP water dispersions, and then immersed in TiO2-SiO2-HMDS composite to form a CH/APP@TiO2-SiO2-HMDS coating on the cotton fabric surface. SEM, EDS, and FTIR were used to analyze the surface morphology, element composition, and functional groups of the cotton fabric, respectively. Vertical burning tests, microscale combustion calorimeter tests, and thermogravimetric analyses were used to evaluate the flammability, combustion behavior, thermal degradation characteristics, and flame-retardant mechanism of this system. When compared to the pristine cotton sample, the deposition of CH and APP enhanced the flame retardancy, residual char, heat release rate, and total heat release of the cotton textiles. The superhydrophobic test results showed that the maximal contact angle of SFR cotton fabric was 153.7°, and possessed excellent superhydrophobicity. Meanwhile, the superhydrophobicity is not lost after 10 laundering cycles or 50 friction cycles. In addition, the UPF value of CH/APP@TiO2-SiO2-HMDS cotton was 825.81, demonstrating excellent UV-shielding properties. Such a durable SFR fabric with a facile fabrication process exhibits potential applications for both oil/water separation and flame retardancy.

Yarn-based strain sensor is an emerging candidate for the fabrication of wearable electronic devices. The intrinsic properties of yarn, such as excellent lightweight, flexibility, stitchability, and especially its highly stretchable performance, stand out the yarn-based strain sensor from conventional rigid sensors in detection of human body motions. Recent advances in conductive materials and fabrication methods of yarn-based strain sensors are well reviewed and discussed in this work. Coating techniques including dip-coating, layer by layer assemble, and chemical deposition for deposition of conductive layer on elastic filament were first introduced, and fabrication technology to incorporate conductive components into elastic matrix via melt extrusion or wet spinning was reviewed afterwards. Especially, the recent advances of core–sheath/wrapping yarn strain sensor as-fabricated by traditional spinning technique were well summarized. Finally, promising perspectives and challenges together with key points in the development of yarn strain sensors were presented for future endeavor.

Multifunctional textiles were fabricated by one-step in-situ synthesis of zeolite imidazole skeleton-8 (ZIF-8) on polydopamine (pDA) templated cotton fabrics. A homogenous distribution of ZIF-8 nanoparticles on cotton fiber surface was achieved as per surface morphology study by SEM and TEM, and the heterogeneous nucleation mechanism of depositing the dense ZIF-8 film on pDA-templated cotton fabrics was proposed. FTIR spectra, XPS, and XRD have indicated the presence and confirmed the chemical composition of ZIF-8 on coated cotton fabrics. The fabricated ZIF-8/cotton fabrics showed excellent photocatalysis for Methylene blue decomposition under ultraviolet radiation, and the photocatalysis mechanism was discussed. In addition, the coated fabrics showed robust antimicrobial activity towards Escherichia coli. This facile and affordable fabrication method based on dopamine and ZIF-8 is promising for large-scale production of multifunctional textiles.

Yarn-shaped supercapacitors are favored due to their small size, high specific capacitance, and light weight. Herein, we reported a distinctive type of ply twist yarn supercapacitor by in situ polymerization of pyrrole on carbon nanotubes (CNTs)/cotton ring spun yarns. CNTs and polypyrrole (PPy) were successfully embedded into the cotton yarns with a ply twist structure. The as-developed electrode exhibited excellent electrical conductivity (20 Ω/cm), good mechanical properties (59.8 MPa, 24.6%), a high specific capacitance of 386.5 mF/cm2 with the current density of 1 mA/cm2, and ideal cycle stability with the retention of 87.8% after 5000 cycles. Meanwhile, the assembled supercapacitor showed a power density of 278.4 μW/cm2 and an energy density of 13.21 μWh/cm2. It also presented outstanding capacitive performance under different angles. This facile ply twist method provided new possibilities for one-dimensional (1D) supercapacitor and flexible wearable electronics applications.

Flexible fabrics with excellent photothermal conversion performance are highly demanded in developing smart textiles. This work reports the deposition of copper sulfide@polydopamine (CuS@PDA) nanocomposites on the surface of cotton fabrics. The morphology and structure of CuS@PDA coated cotton fabrics were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction (XRD) and thermogravimetric analysis. The mechanism of the deposition and bonding of CuS@PDA on the surface of cotton fabrics was discussed. It was found that PDA coating resulted in a uniform dispersion of CuS@PDA on cotton fabrics with enhanced bonding fastness between the nanocomposites and fibrous matrix. Due to the unique encapsulation structure of CuS@PDA nanocomposites, the coated cotton fabrics were used as efficient photocatalysts for photodegradation of methylene blue. In addition, the CuS@PDA coated cotton fabrics exhibited excellent photothermal conversion and thermal imaging properties. The photocatalysis and photothermal conversion performance of CuS@PDA coated cotton fabrics endows the potential in smart textile applications.

Flexible multiple functional textiles for oil/water separation and photodegradation are highly demanded in highly effective and environmentally friendly wastewater purification. In this work, β-FeOOH nanorods were in situ hydrothermally grown on polydopamine (PDA)-templated cotton fabric (CF) followed by decoration of 1-Dodecanethiol (DDT) on the surface for highly efficient oil/water separation and visible-light-driven photodegradation of dyes. The morphology, structure and wettability of the as-prepared fabrics were characterized and the oil/water separation together with photocatalysis of MB were investigated. The results showed that β-FeOOH nanorods were successfully grown on the PDA-templated cotton fabrics with durable hydrophobicity and lipophilicity. The as-prepared fabrics were demonstrated in oil/water separation of different oil with high separation rates, and the mechanism was proposed. The fabrics also showed excellent visible-light-driven photocatalytic performance in degrading methylene blue (MB) solution with stability and reliability, and the photocatalysis mechanism was contributed. This work provides insights on developing multiple functional textiles by combining photocatalysis with special wettability.

The applications of a variety of bioactive ceramics such as hydroxyapatite (HA) in orthopedics are limited by their insufficient mechanical properties, especially poor fracture toughness. Thus, further extending the clinical applications of these materials warrants the enhancement of their mechanical properties. Although the reinforcement of ceramics by 2D nanomaterials has been well recognized, integrated structural, mechanical, and functional considerations have been neglected in the design and synthesis of such composite materials. Herein, we report the first use of silica-coated reduced graphene oxide (S-rGO) hybrid nanosheets to create bioceramic-based composites with simultaneously enhanced mechanical and biological properties. In the representative HA-based bioceramic systems prepared by spark plasma sintering, S-rGO incorporation was found to be more effective for increasing the Young's modulus, hardness, and fracture toughness than the incorporation of uncoated reduced GO (rGO). Furthermore, when assessed with osteoblast-like MG-63 cells, such novel materials led to faster cell proliferation and higher cell viability and alkaline phosphatase activity than are generally observed with pure HA; additionally, cells demonstrate stronger affinity to S-rGO/HA than to rGO/HA composites. The S-rGO/bioceramic composites are therefore promising for applications in orthopedic tissue engineering, and this research provides valuable insights into the fabrication of silica-coated hybrid nanosheet-reinforced ceramics. Nanyang Technological University This study was supported by Nanyang Technological University (NTU,Grant No. M4080160).

The cotton textiles with superhydrophobic and flame-retardant properties used in this study were manufactured by combining nano APP@SiO2 with silicone oil. To generate nano APP@SiO2 particles, the APP is coated with nano SiO2. The nano APP@SiO2 improves the flame retardancy of cotton textiles while altering the surface roughness of cotton fabrics, making them superhydrophobic after being treated with silicone oil. Cotton fabrics’ surface topography, chemical components, crystalline structure, thermal stability, flame-retardant, and superhydrophobic properties were investigated. The modified cotton fabric demonstrated not only exceptional superhydrophobicity with a WCA of 151.28°, but also good flame-retardant property. This multifunctional cotton fabric offers a wide range of commercial applications.

The flexible strain sensor can transform the micro or macro deformation into the visual electrical signals for monitoring the physiological and motor characteristics of human body. However, the current commercial strain sensors generally have some shortcomings such as large stiffness and small strain range. In this work, a flexible compressive strain sensor with the 3D conductive network was fabricated by using biomacromolecule sericin protein dispersed carbon nanotubes (SSCNTs) as the conductive material and melamine foam (MF) as the elastic matrix. The results showed that the sensitivity of MF/SSCNTs elastic foam was 1.36 in the strain range of 0-70% with the CNTs content of 10 wt% and the cyclic compressive sensing performance was stable for at least 1600 cycles. This kind of flexible compressive strain sensor is environmentally friendly, low cost, simple process, and provides a new method for the preparation of green flexible sensor.

CuO/BiVO4 (BVO) nanocomposite photocatalyst was immobilized on cotton fabrics through polydopamine (PDA) templating for multiple application including highly efficient visible-light-driven photocatalysis, antimicrobial activity and UV protection. The morphology and structure of CuO/BVO nanocomposites and the coated fabrics were characterized by transmission electron microscopy (TEM), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), Ultraviolet-visible diffuse reflectance spectra (UV–vis DRS), photoluminescence (PL) spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and UV–Vis spectroscopy. The functionalized cotton fabrics were found to be highly effective in degradation of methylene blue (MB) under visible light irradiation with stability and recyclability, and about 97.7% of MB aqueous solution was degraded after 200 min exposure with 92.1% of the photocatalytic activity preserved even after five recycles. The mechanism of enhanced photocatalytic activity was proposed. The coated fabrics also demonstrated to be UV protective and antimicrobial. This work will benefit the development of durable and recyclable textile based photocatalysts with multiple function.

Highly efficient and reusable photocatalysts that enable photodegradation of pollutants under visible light is the key in waste water treatment with impacts on environment and sustainable development. In this article, we report the preparation and application of a novel core–shell photocatalyst of bismuth vanadate@polydopamine (BiVO4@PDA). The optical absorption property and microstructure of the BiVO4@PDA particles were measured by ultraviolet–visible spectrophotoscopy (UV–Vis), photoluminescence (PL) spectroscopy and transmission electron microscope. The BiVO4@PDA can be attached to cotton fabrics by electrostatic assembly and molecular bonding. The morphology and structure of the cotton fabric@BiVO4@PDA were characterized by SEM, X-ray photoelectron spectroscopy and X-ray diffraction. The photocatalytic activity results show that the methylene blue (MB) can be completely degraded by BiVO4@PDA under visible light irradiation within 250 min. Moreover, the mechanism for the MB photodegradation using the cotton fabric@BiVO4@PDA photocatalyst under visible light were investigated. With the novel core–shell structure, the as-developed BiVO4@PDA particles can be used as highly efficient photocatalysts for visible light driven photodegradation. The BiVO4@PDA particles can be attached to different substrates due to the excellent adhesive and bonding nature of PDA towards high-efficient photocatalysis.

Steel ring reinforcement technology is an effective method to eliminate the damage of tunnel structure caused by ground load, surrounding foundation pit and underground water source. The grouting material used to fill the gap between the tunnel segment and the steel ring should have the characteristics of low viscosity, high strength, rapid curing at room temperature and anti-subway vibration. In this work, a special polyurethane modified epoxy resin grouting was fabricated to overcome the inherent brittleness of epoxy resin, and was combined with the reactive diluent and the amine curing agent to suit the above applications. The results showed that both tensile and impact strength of epoxy resin grouting modified by polyurethane were improved obviously compared with those without modification, presenting an obvious toughening effect. Although the viscosity increased slightly, it can still meet the perfusion requirements of steel ring reinforcement of subway tunnels.

In this work, the superhydrophobic and UV-resistant cotton fabrics were fabricated via combining the nano titanium dioxide (TiO2) and silicone oil. The nano-TiO2 makes cotton fabrics possess outstanding ultraviolet (UV) resistance property, while increases the micro and nano size rough structure on the surface of cotton fabric. Then the cotton fabric was hydrophobically treated with silicone oil to make it superhydrophobic. The chemical constituents, structures, superhydrophobic and UV-resistant performance of cotton fabrics were analyzed. The cotton fabric treated with titanium dioxide and silicone oil not only showed excellent superhydrophobicity, but also displayed good UV-resistant ability. Water contact angle and UPF value can reach 161.32° and 55.17 respectively. Such multifunctional cotton fabric has broad commercial application prospects.

Multifunctional cotton fabrics were fabricated by coating of anionic waterborne polyurethane (WPU)/Cu2-XSe. The surface morphology of WPU/Cu2-XSe coated cotton fabric was characterized by scanning electron microscopy equipped with energy dispersive X-ray spectroscopy. The microstructural structure was further investigated through Fourier transform infrared (FT-IR) spectra, X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD), and the thermal stability was evaluated by thermogravimetric analysis (TG). The results indicated that WPU/Cu2-XSe nanocomposites coating was successfully deposited on cotton fabric surface. The WPU/Cu2-XSe coated cotton fabrics exhibited high photothermal conversion efficiency, and the coated fabrics were demonstrated for thermal imaging in wearable electronic devices. The coated fabrics also exhibited high photochromic efficiency. The development of multifunctional WPU/Cu2-XSe coated cotton fabrics provides novel strategies for developing smart textiles.

Flexible electronic devices with strain sensing and energy storage functions integrated simultaneously are urgently desirable to detect human motions for potential wearable applications. This paper reports the fabrication of a cotton/carbon nanotube sheath-core yarn deposited with polypyrrole (PPy) for highly multifunctional stretchable wearable electronics. The microscopic structure and morphology of the prepared sheath-core yarn were characterized by scanning electron microscopy and Fourier transform infrared spectrometry. A mechanical experiment demonstrated its excellent stretchable capacity because of its unique spring-like structure. We demonstrate that the sheath-core yarn can be used as wearable strain sensors, exhibiting an ultrahigh strain sensing range (0-350%) and excellent stability. The sheath-core yarn can be used in highly sensitive real time monitoring toward both subtle and large human motions under different conditions. Furthermore, the electrochemical performance of the sheath-core yarn was characterized by cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The measured areal capacitance was 761.2 mF/cm2 at the scanning rate of 1 mV/s. The method of spinning technology may lead to new exploitation of CNTs and PPy in future wearable electronic device applications.

It has been paid much attention to improve the helical twisting power (β) of dopants in chiral nematic liquid crystals (CLCs); however, the correlations between the β value and the molecular structures as well as the interaction with nematic LCs are far from clear. In this work, a series of reversibly photo-switchable axially chiral dopants with different lengths of alkyl or alkoxyl substituent groups have been successfully synthesized through nucleophilic substitution and the thiol-ene click reaction. Then, the effect of miscibility between these dopants and nematic LCs on the β values, as well as the time-dependent decay/growth of the β values upon irradiations, has been investigated. The theoretical Teas solubility parameter shows that the miscibility between dopants and nematic LCs decreases with increasing of the length of substituent groups from dopant 1 to dopant 4. The β value of chiral dopants in nematic LCs decreases from dopant 1 to dopant 4 both at the visible light photostationary state (PSS) and at the UV PSS after UV irradiation. With increasing of the length of substituent groups, the photoisomerization rate constant of dopants increases for trans-cis transformation upon UV irradiation and decreases for the reverse process upon visible light irradiation either in isotropic ethyl acetate or in anisotropic LCs, although the constant in ethyl acetate is several times larger than the corresponding value in LCs. Also, the color of the CLCs could be tuned upon light irradiations. These results enable the precise tuning of the pitch and selective reflection wavelength/color of CLCs, which paves the way to the applications in electro-optic devices, information storage, high-tech anticounterfeit, and so forth.

There is an increasing demand for safe, environmentally benign energy storage devices in portable electronic appliances, wearable gadgets, flexible displays, and other personal multimedia devices. In this study, we have fabricated an all-solid-state flexible asymmetric supercapacitor using a novel 3D porous reduced graphene oxide/manganese dioxide@polyaniline (RGO/MnO2@PANI) hybrid film as the positive electrode and a self-assembled 3D pillared graphene aerogel as the negative electrode material with a polyvinyl alcohol/potassium hydroxide (PVA/KOH) gel electrolyte. The flexible composite film was synthesized by vacuum filtration of GO and a MnO2@PANI mixture followed by chemical reduction of the resulting film in a hydrothermal autoclave. The 3D graphene aerogel was synthesized by a hydrothermal route using a solution of the nonionic triblock copolymer Pluronic F-68 as a soft template and vitamin C as a reducing agent. Herein, the Pluronic copolymer played dual roles: first, it enabled the effective dispersion of graphene oxide in water, and second, it assisted the formation of a stable 3D pillared hydrogel assembly. The RGO/MnO2@PANI-based symmetric supercapacitor shows a high energy density of 18.33 W h kg−1 at a power density of 0.388 kW kg−1. An asymmetric supercapacitor (graphene aerogel//RGO/MnO2@PANI), which was fabricated by optimizing the individual electrode materials, exhibited a very high energy density of 38.12 W h kg−1 at a power density of 1.191 kW kg−1 utilizing a large potential window of 1.5 V. Moreover, 3 cells connected in series successfully lit up a red LED for 45 s and displayed similar performance under bending conditions.

Epoxy structural adhesive has good mechanical properties, especially high adhesion, low shrinkage rate, and high stability, widely used in steel plate reinforcement, crack repair, bridge splicing, and concrete bonding, etc. However, due to the high cross-linking density and high internal stress after curing, its shortcomings, such as brittleness, the poor performance of fatigue resistance and heat resistance, limit its application in special track engineering. In this work, two kinds of epoxy structural adhesives (EPA-1, EPA-2) with low viscosity and room temperature curing were synthesized by selecting different bisphenol A epoxy resin and active diluent as component A and modified amine curing agent as component B. The results showed that EPA-1 and EPA-2 presented significant toughness compared with the classic construction adhesive (AralditeXH160). The yield strengths of EPA-1 and EPA-2 were 4.88 MPa and 13.13 MPa, and the shear strengths were 11.93 MPa and 13.08 MPa, respectively, showing good adhesive properties. In addition, the viscosities of EPA-1 and EPA-2 were 127 mPa·s and 308 mPa·s, respectively, and their decomposition temperatures were all above ∼280 °C, which indicated that the self-made epoxy structural adhesives could be used for the repair of cracks in the vibration subway tunnel.

Carbon nanotube (CNT) possesses eminent mechanical properties and has been widely utilized to toughen bioceramics. Major challenges associated with CNT-reinforced bioceramics include the inhomogeneous dispersion of CNTs and the insufficient interfacial strength between the two phases. To address such issues, this research describes the first use of silica-coated CNT (S-CNT) core-shell structures to reinforce bioceramics using hydroxyapatite (HA) as a representative matrix. HA-based composites with 0.1–2 wt% S-CNT are sintered by spark plasma sintering to investigate their mechanical and biological properties. It is found that when 1 wt% raw CNT (R-CNT) is added, very limited increases in fracture toughness ( K IC ) is observed. By contrast, the incorporation of 1 wt% S-CNT increased the K IC of HA by 101.7%. This is attributed to more homogeneously dispersed fillers and stronger interfacial strengths. MG63 cells cultured on the 1 wt% S-CNT/HA pellets are found to proliferate faster and possess significantly higher alkaline phosphatase activities than those grown on the HA compacts reinforced with 1 wt% R-CNT, probably by virtue of the released Si ions from the SiO2 shell. Therefore, the S-CNT core-shell structures can improve both mechanical and biological properties of HA more effectively than the conventionally used R-CNTs. The current study also presents a novel and effective approach to the enhancement of many other biomedical and structural materials through S-CNT incorporation.

Graphene was recently demonstrated to exhibit excellent electromagnetic interference (EMI) shielding performance. In this work, ultralight (∼5.5 mg/cm 3 ) graphene aerogels (GAs) were fabricated through assembling graphene oxide (GO) using freeze-drying followed by a chemical reduction method. The EMI shielding properties and mechanisms of GAs were systematically studied with respect to the intrinsic properties of the reduced graphene oxide (rGO) sheets and the unique porous network. The EMI shielding effectiveness (SE) of GAs was increased from 20.4 to 27.6 dB when the GO was reduced by high concentration of hydrazine vapor. The presence of more sp 2 graphitic lattice and free electrons from nitrogen atoms resulted in the enhanced EMI SE. Absorption was the dominant shielding mechanism of GAs. Compressing the highly porous GAs into compact thin films did not change the EMI SE, but shifted the dominant shielding mechanism from absorption to reflection.

3D graphene foam was recently demonstrated to exhibit excellent electromagnetic interference (EMI) shielding performance. In this work, we prepared 3D graphene foams by incorporating a surface modification process of graphene via self-polymerization of dopamine with a subsequent foaming process. The multiple roles played by polydopamine (PDA), including as nitrogen doping source and as an enhancement tool to achieve higher extent of reduction of the graphene through providing wider pathways and larger accessible surface areas were discussed in detail. Despite the presence of the PDA which acted as barriers among the graphene layers that hindered the electrons movement, the enhanced reduction of graphene sheets and the polarization effects introduced by PDA decoration compensated the negative effect of the barrier on EMI shielding effectiveness (SE). As a result, the PDA decorated 3D graphene foams showed improved EMI shielding effectiveness (SE) compared to PDA-free graphene foam (from 23.1 to 26.5dB). More significantly, the EMI shielding performance of the PDA decorated graphene foam was much superior to all existing carbon-based porous materials when the thickness of the specimen was considered.

Electromagnetic interference (EMI) shielding performance of chemically and thermally reduced graphene aerogels (GAs) was systematically studied. The EMI shielding mechanisms were extensively analyzed in terms of the distinct surface characteristics resulted from the different reduction methods for the first time. EMI shielding effectiveness (SE) of chemically and thermally reduced GAs reached 27.6 (GAC) and 40.2 dB (GAT) at the thickness of 2.5 mm, respectively. It was found that the introduction of nitrogen atoms through chemical reduction induced localized charges on the carbon backbone leading to strong polarization effects of GAC. The relatively incomplete reduction caused a large number of side polar groups which prevented the graphene sheets from π-π stacking. In contrast, the higher extent of reduction of graphene sheets in GAT left a smaller amount of side polar groups and formed more sp2 graphitic lattice, both factors favored π-π stacking between the adjacent graphene sheets, resulting in higher electrical conductivity and enhanced EMI SE. The EMI shielding performance of the GAs prepared outperformed the recent reported porous carbon materials with respect to the absolute SE value at the similar thickness and/or density.

In this work, a novel fully autonomous photothermotropic material made by hybridization of the poly(N-isopropylacrylamide) (PNIPAM) hydrogel and antimony-tin oxide (ATO) is presented. In this photothermotropic system, the near-infrared (NIR)-absorbing ATO acts as nanoheater to induce the optical switching of the hydrogel. Such a new passive smart window is characterized by excellent NIR shielding, a photothermally activated switching mechanism, enhanced response speed, and solar modulation ability. Systems with 0, 5, 10, and 15 atom % Sb-doped ATO in PNIPAM were investigated, and it was found that a PNIPAM/ATO nanocomposite is able to be photothermally activated. The 10 atom % Sb-doped PNIPAM/ATO exhibits the best response speed and solar modulation ability. Different film thicknesses and ATO contents will affect the response rate and solar modulation ability. Structural stability tests at 15 cycles under continuous exposure to solar irradiation at 1 sun intensity demonstrated the performance stability of such a photothermotropic system. We conclude that such a novel photothermotropic hybrid can be used as a new generation of autonomous passive smart windows for climate-adaptable solar modulation.

Strain sensing is one of the core parts of smart fabric which can be expressed by electrical signals affected by external forces. In this paper, the strain sensing functional fabric was prepared by using the acidified carbon nanotubes (a-CNTs) as the conductive layer and the waterborne polyurethane (WPU) as the adhesive based on foam finishing method. The results showed that many hydroxyl and carboxyl groups were introduced into the surface of CNTs through acidification, which improved their dispersibility in aqueous solution. The blended film of a-CNTs and anionic WPU had excellent conductive properties. When the ratio of a-CNT to WPU was 9:1, the fabric had the smallest resistivity, about 0.13 Ω⋅m, and the corresponding tensile sensing sensitivity up to 55.2.

Dispersion systems such as solutions, suspensions and composites are frequently studied in the field of graphene and two-dimensional materials. The rapid development of these materials demands comprehensive insight into their dispersion systems. Here we present an innovative and systematic investigation on the dispersion systems of graphene-like two-dimensional materials. It is found that different dispersion systems exhibit similar fundamental laws which can be described based on a Most Probable Percolation Threshold (MPPT) theory. Two-dimensional sheets contact with their neighboring ones at around their MPPT concentrations and thus lead to sudden changes in various properties of dispersion systems, such as liquid crystal behavior, viscosity, mechanical strength, electrical conductivity and thermal properties. Starting from the MPPT theory, six new strategic guidelines for the engineering of dispersion systems are established. Based on these studies, we find that, appropriate size, appropriate thickness, and appropriate concentration, are the keys to the success of 2dMs dispersion systems in practical applications, and the MPPT theory could tell where it is appropriate. These investigations provide new theories, methodologies and guidelines for the science, engineering and developments of graphene and two-dimensional materials.

Soft micro-environment is one of the most important requirements for fast responses of liquid crystals (LCs) to external stimuli; however, the drawback of poor mechanical properties for LCs limits their further applications. In this work, the storage modulus ( G ′) of the LC physical gels, nematic 4-pentyl-4′-cyanobiphenyl (5CB) and 1,3:2,4-di- O -benzylidene- D-sorbitol (DBS), has been greatly enhanced by the addition of nano-silica into physical gels. The composite gels are formed through the synergistic effects of the nanoparticle and the gelator. The phase transition behaviors, morphologies, dynamic rheological behaviors and electro-optical properties of the composite gels were investigated using differential scanning calorimeter, polarized optical microscope and field emission scanning electron microscope, rheometer and LCD parameter tester, respectively. Compared with the LC physical gel without nano-silica, with the increase of nano-silica content from 0.1wt% to 4.0wt% at a fixed DBS content of 2.0wt%, the network texture of composite gels was changed from nano-fibrillar to spherulite-like. The G ′ increased firstly and then decreased with a maximum value of 1.5×105 Pa at the nano-silica content of 2.0wt%. The threshold voltage ( V th) and the off time ( τ off) increased within 1 time and 2 times, respectively. When the amount of nano-silica was only 0.5wt%, the G ′ of the composite gel was improved to 105 Pa, an order of magnitude higher than the gel without nanoparticles. Meanwhile, its V th and τ off only increased 46% and 63%, respectively. This work opens a new window to the applications of LCs with excellent self-supporting ability and fast switch responses.

Spills or leakages of hazardous chemicals involve high safety, health and environmental risks. Absorption of hazardous chemicals using absorbent materials is an advanced and efficient strategy for cleaning up hazardous chemical spills. Here, we report a new form of carbon-based macrostructure, graphene oxide beads with core/shell structures, for fast clean-up of hazardous chemicals. Graphene oxide beads are produced by one-step self-assembly of graphene oxide in a coagulation bath. The core of the beads is graphene oxide foam, while the shell is a graphene oxide membrane. The amphipathic and porous core provides a large absorption capacity for a broad range of hazardous chemicals. By incorporating layered silicates, graphene oxide beads become highly fire retardant, hence are especially suitable for cleaning up chemicals with accompanying fire risks. The millimeter-level size and spherical morphology of the beads offer high convenience in practical usage. Moreover, the beads can also be used in many other applications, such as heat energy storage and sustained release.

In this work, we have reported a facile method to fabricate multifunctional three-dimensional filter cotton (3D FC). Silver nanoparticles (AgNPs) was in situ hydrothermally grown on polydopamine (pDA)-templated filter cotton followed by decoration of 1-Dodecanethiol on the surface for highly efficient oil/water separation, antibacterial and catalytic activity. The morphologies and structural characteristics of functionalized filter cotton were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction analysis (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. It has exhibited good superhydrophobic property with a water contact angle (WCA) of 152.5°, and high oil/water separation efficiency. In addition, the 3D filter cotton also be provided with efficient antibacterial properties against E. coli. The catalytic activity of the functionalized filter cotton was evaluated by the reduction of 4-nitrophenol (4-NP), and it has also performed robust reusability. The multifunctional 3D filter cotton can effectively remove oil and dyes in wastewater, which has promising application prospects in many fields.

The smart fabric is a new material that began to develop in the 1990s, and on the basis of the nature and function of original material, it joined the features of intelligent perception. On the performance, intelligent fiber can sense the changes of heat, light, chemistry, mechanical, temperature, and electromagnetic, then react accordingly. For smart textiles, the sensor is the core part, now most commonly used micro/nano strain sensor are using silicon and zinc oxide and others inorganic as main material. But inorganic materials have limited deformation ability, once deformation occurs, the sensor will be strictly damaged. So, the development of flexible, high sensitivity, wide range of strain of the flexible intelligent fiber strain sensor has a very important application prospect. For the stretch-able sensor, the prepared conductive material must be placed on the substrate of the flexible polymer. In this paper, graphene is used as conductive material to construct an orderly conductive layer. Waterborne polyurethane was used as dispersant and adhesive, then strengthen the interface between the layer of conductive material and elastic fabric binding force, and finally prepare a kind of high sensitivity, wide strain range, stable performance and high elastic intelligent fibers.

Despite the strong application potential of graphene in various areas, incorporation of graphene into fibrous system for durable, flexible and reliable wearable applications is still of challenge. We hereby propose the fabrication of reduced graphene oxide (rGO) on PET fabrics through polydopamine (PDA) templating. Dopamine was self-polymerized on PET fabrics to for a PDA layer as a secondary platform for loading graphene oxide (GO) via vacuum filtration, and the as-prepared PET/PDA/GO was immediately reduced to PET/PDA/rGO by hot-pressing. The surface morphology, structure and properties were investigated with the mechanism proposed. The UV protective property and electrical conductivity of the prepared PET/PDA/rGO together with the durability against washing and bending and twisting were studied, and the application of the coated fabrics as wearable sensor was demonstrated.

Structural analysis showed that cyclosiloxane hybrid polymer (CHP) is a collection of nano-sized nacre-like structures in random orientations. Inspired by the reinforcement of nacre-like materials, basal-functionalized graphene (GO-AA) was inserted between CHP layers, acting as ‘double-sided tape’ to improve the mechanical properties. The resulting GO-AA/CHP nanocomposites showed a 156% improvement in toughness with only a 0.08 wt% loading of GO-AA, and a 25% improvement in thermal conductivity with a 0.10 wt% loading of GO-AA. The proposed ‘double-sided tape’ effect was also used to explain the highly efficient enhancement in thermal conductivity. This research promotes the application of CHP in harsher environments, demonstrates its prospects in thermal management areas, and contributes to nature-inspired materials design.

An effective chemical strategy for the synthesis of polymer–ionic liquid (IL) electrolytes with ion-conducting channels, physically modulated by variously dimensioned IL-functionalized carbon materials (IL-FCMs) including carbon black (CB), multi-walled carbon nanotubes (MWCNT) and reduced graphene oxide sheets (RGO) is reported, enabling a fundamental understanding of the relationship between carbon structures and ion transport behavior. The risk of electrical shorts is eliminated by the presence of IL groups on the surfaces of CMs and only minimal amounts of the IL-FCMs (⩽1.0 wt.%) in the polymer/IL composite electrolytes (e.g., polymer matrix filled with 1.0 wt.% IL-FCMs has a conductivity of ∼10−7 S cm−1 at 100 °C). Increase in ion transport within the reorganized ion channels of the composite polymer electrolytes (CPEs) is confirmed by the enhanced ionic conductivity and low activation energy for through-plane and in-plane ionic conduction at different temperature (40–160 °C). Maximum improvement in the ionic conductivity (150–300% at 100 °C) can be achieved by optimizing the carbon structure and the loading ratio, which leads to highly ionic conductive polymer/IL composite electrolytes for practical applications.

A new structural design and tailored morphology of polymer-functionalized graphene (polymer-FG) are employed to optimize composite polymer electrolytes (CPEs). The ionic transfer conditions including Li salt dissociation, amorphous content and segmental mobility are significantly improved by incorporating polymer-FG, especially that having a polymeric ionic liquid (PIL) and a polymer brush structure [PIL(TFSI)-FGbrush]. Electrical shorts are eliminated due to the presence of the functionalized polymer on reduced graphene oxide (RGO) and a minimal amount of polymer-FG in the PEO/Li+ polymer electrolytes (PEs). Polymer-FG with PIL brushes increases significantly the Li ion conductivity of PEO/Li+ PE by >2 orders of magnitude and ∼20-fold at 30 °C and 60 °C with high Li salt loading (O/Li = 8/1), respectively. Furthermore, significant improvements in mechanical properties are observed where only 0.6 wt% addition of the PIL(TFSI)-FGbrush led to more than 300% increase in the tensile strength of the PEO/Li+ at an O/Li ratio of 16/1. Li-ion battery performance was evaluated with the CPE containing 0.6 wt% of PIL(TFSI)-FGbrush, resulting in superior capacity and cycle performance compared to those of the PEO/Li+ PE. Thus, we believe, embedding minimal amounts of structurally and morphologically optimized polymer-FG nano-fillers can lead to the development of a new class of SPEs with high ionic conductivity for high performance all-solid-state Li-ion batteries.

Monitoring and assessment of the health of a civil structural material are the critical requirements to ensure its safety and durability. In this work, a coating strategy on carbon nanotubes (CNTs) was employed for the dispersion of CNTs in geopolymer matrix. The geopolymer nanocomposites prepared exhibited ultrahigh self-sensing performance based on the unique behaviors of SiO2 coating on CNTs in the geopolymer matrix. The SiO2 layer on CNTs was partially or fully removed during the fabrication process to restore the conductive nature of CNTs, facilitating the dispersion of CNTs and forming well-connected 3D electrical conductive networks. The gauge factor (GF) of geopolymer nanocomposites reached up to 663.3 and 724.6, under compressive and flexural loading, respectively, with the addition of only 0.25 vol % of SiO2-coated CNTs (SiO2–CNTs). The values were at least twice higher than those recently reported self-sensing structural materials containing different types of carbon-based fillers. The underlyi...

Versatile and reversibly rapid responsive one-dimensional photonic crystals with a diffraction efficiency of 97%, which consisted of uniformly 273 ± 48 nm wide liquid crystal belts within transmission holographic polymer dispersed liquid crystal (HPDLC) gratings, were formulated by a facile single step holography based on a hyperbranched monomer. The effect of the monomer average functionality on the photopolymerization kinetics and the electro-optical performances as well as the grating morphologies was investigated. The results show that the low intrinsic viscosity of the hyperbranched monomer accounts for a well-structured morphology in terms of providing a prolonged gelation time for the liquid crystals to diffuse from the light illumination region during the holographic polymerization induced phase separation. Another intriguing observation is that with an increase in the hyperbranched monomer loading, the diffraction efficiency of the HPDLC gratings gradually increases from zero to an average of 94% and then levels off. This is quite different from previous results that gave less than a 50% diffraction efficiency when the monomer average functionality was larger than 4.

Interaction of cell surface glycoproteins with endogenous lectins on the cell surface regulates formation and maintenance of plasma membrane domains, clusters signaling complexes, and controls the residency time of glycoproteins on the plasma membrane. Galectin-9 is a soluble, secreted lectin that binds to glycoprotein receptors to form galectin–glycoprotein lattices on the cell surface. Whereas galectin-9 binding to specific glycoprotein receptors induces death of CD4 Th1 cells, CD4 Th2 cells are resistant to galectin-9 death due to alternative glycosylation. On Th2 cells, galectin-9 binds cell surface protein disulfide isomerase (PDI), increasing retention of PDI on the cell surface and altering the redox status at the plasma membrane. Cell surface PDI regulates integrin function on platelets and also enhances susceptibility of T cells to infection with HIV. We find that galectin-9 binding to PDI on Th2 cells results in increased cell migration through extracellular matrix via β3 integrins, identifying a unique mechanism to regulate T-cell migration. In addition, galectin-9 binding to PDI on T cells potentiates infection with HIV. We identify a mechanism for regulating cell surface redox status via a galectin–glycoprotein lattice, to regulate distinct T-cell functions.

β-Galactoside-binding lectin 9 (galectin-9) is a tandem repeat-type member of the galectin family. It was initially characterized as an eosinophil chemoattractant and an inducer of apoptosis in thymocytes. Subsequently, galectin-9 was identified as a ligand for transmembrane immunoglobulin mucin domain 3 (Tim-3), a type I glycoprotein induced on T cells during chronic inflammation. Work in autoimmune diseases and chronic viral infections have led to the current hypothesis that the function of Tim-3 is to limit immune responses. However, it is still not known to what degree these effects are due to the galectin-9/Tim-3 interaction. In this study, we show that galectin-9 is not limited to the role of a pro-apoptotic agent, but that it can also induce the production of pro-inflammatory cytokines from T helper cells. This effect is dose-dependent and does not require Tim-3. These findings suggest that the effects of galectin-9 on T cells are more complex than previously thought and are mediated by additional receptors apart from Tim-3.