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Human activity monitoring is a complex endeavor, which mainly depends on pressure or strain sensors.

This work reports the preparation and application of microwave thermally expanded graphene (G)/polyaniline (PANI) conductive paste. The results from XRD revealed that the polyaniline did not change its crystal structure after being combined with microwave thermally expanded graphene. FTIR and Raman spectra revealed that there was a strong π–π interaction between polyaniline and microwave thermally expanded graphene. The resultant conductive pastes possess obvious shear-thinning phenomenon, which are suitable for screen printing to produce conductive circuits. The printed polyester fabric showed significant conductivity which can be tuned by changing the printing time and line length. This study paves the way to large-scale fabrication of flexible conductive circuits for various applications.

Leuco dye-based thermochromic materials offer enormous potential for visible molecular logic due to the appealing reversible color-changing effect. The stable color state is uncontrollable as it depends only on the spontaneous protonation of the leuco dye and color developer. There is still a challenge to propose an effective approach to control bistable color function at required temperature. A family of azobenzenes with various alkyl chains (AZO(n)) is designed for protonation competition with leuco dye. The hydrogen bond and Van der Waals forces are formed between color developer and AZO(n). The color developer can be locked to provide the proton for the leuco dye by Z-AZO(n), while it can be released upon Z-to-E photoisomerization. The locked state can be lasted for more than 16 hours. This optically controlled leuco dye-based system demonstrates a visible sequential logic operation with four-input signals, and provides a new type of protonation-based optical control., The authors are grateful for the financial support of National Natural Science Foundation of China (21975107), Natural Science Foundation of Jiangsu Province (SBK2019020945), the European Research Council (ERC) through CoG “PHOTHERM” and the Swedish Research Council, VR., Postgraduate Research & Practice Innovation Program of Jiangsu Province (KYCX20_1783), and China Scholarship Council (202006790096). Additionally, the authors thank Monika Shamsabadi from Chalmers University of Technology for polishing the language., With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).

Piezoresistive pressure sensors based on conductive polyurethane (PU) sponge have attracted much attention due to their facile fabrication, convenient signal collection and good stability, yet it is a challenge to prepare a cost-effective PU composite for pressure sensing with good sensitivity and a wide strain range. Herein, a conductive poly(vinyl alcohol)/sulfuric gel electrolyte@PU (PVA/H2SO4@PU) composite is fabricated by impregnating commercial PU sponge into a PVA/H2SO4 gel electrolyte. The conductivity of the as-prepared composite is provided by the gel electrolyte and the carbonized PU sponge by sulfuric acid. Due to the typical porous structure of the elastic PU sponge and the high elasticity of the PVA/H2SO4 gel electrolyte, the composite shows excellent compression performance. The PVA/H2SO4@PU-based piezoresistive pressure sensor exhibits a good sensitivity of 0.080 kPa−1 in a tiny and low pressure range (0.51–3.01 kPa), a wide sensing range (0–80.0%) and a long durability over 1800 s (1325 cycles). Thereafter, the pressure sensor was used to monitor facial muscle movements, airflow, finger bending, grasping different amounts of weights, etc. This indicates that the pressure sensor obtained in this work has broad application prospects in human activity monitoring. Furthermore, the PVA/H2SO4 gel electrolyte is readily available and inexpensive, which reduces the cost of the composites for pressure sensing.

Considering the harm to human skin caused by excessive solar radiation, a simple method to indicate sunlight intensity and alert people instantly is needed. A solar-driven thermochromic fabric (SDTCF) with the function of light intensity monitoring is successfully constructed via printing a solar-driven thermochromic paste onto the surface of polyester fabric. With the enhancement of irradiation intensity from 100 W m−2 to 600 W m−2, the saturation temperature of the SDTCF increases sharply from 32.2 °C to 52.6 °C based on photothermal conversion. Under solar irradiation, the color of the SDTCF changes visibly from orange at ambient temperature (21.5 °C) to green (38.0 °C), which is attributed to the heat generated by photothermal conversion. The temperature decreases rapidly to ambient temperature once the light source is turned off, and the color of the SDTCF returns instantly to the initial orange. These results demonstrate that the SDTCF exhibits stable photothermal conversion and high-contrast reversible color change performance under sunlight irradiation. The SDTCF makes it possible to monitor the sunlight irradiation intensity in a timely fashion via color change for human body protection and health management. The SDTCF maintains stable solar-driven heating performance even throughout 100 heating/cooling cycles, and it shows outstanding durability against repeated bending, twisting, and stretching deformations.

A responsive function is significant to surfaces with special wettability, especially for breaking through their limitations in practical applications. We report a novel strategy, which is effectiv...

The durable superhydrophobic and oleophobic coating has been fabricated based on perfluorodecanethiol fluorosilicone polyurethane (PFDT-FSPU) and thiol-modified cellulose substrate. The PFDT-FSPU was prepared from a fluorosilicone polyurethane and perfluorodecyl mercaptan via thiol-ene click chemistry. The thiol-modified cellulose substrate was obtained by a condensation reaction of 3-mercaptopropyl triethoxysilane (MPTES) and hydroxyl of cellulose substrate. The crosslinked network structure was formed by radical polymerization of double bonds in the PFDT-FSPU when the polyurethane was irradiated with ultraviolet light, and it was anchored on the surface of the cotton fibers by click reaction between the thiol-modified cellulose substrate and the PFDT-FSPU. FTIR spectroscopy illustrates that the synthesis of PFDT-FSPU and Raman spectroscopy characterizes the structure of thiol modified cotton fabric. The water and hexadecane contact angle were 158.2° and 128.3° respectively, and oil-repellent grade reached to 8 and antifouling grade was 4, which indicated that the coated fabric exhibited good amphiphobic and antifouling properties. Most importantly, the coated fabric showed excellent durability and can still maintain the superhydrophobicity and oleophobicity even after 600 cycles of abrasion or 30 times of washing cycles or 168 h of accelerated aging test.

A novel polyurethane elastomer (PUE) that exhibited high tensile strength, large elongation at break, great color strength and supreme color fastness was successfully designed and synthesized. The PUEs were prepared with isophorone diisocyanate (IPDI) as hard segments, polycarbonate diol (PCDL)/polytetrahydrofuran glycol (PTHF) as mixed soft segments, and anthraquinone chromogen as the chain extender agent. The relationships between the mechanical properties/color performance and chromogen addition content were investigated. The chromogen actual access rate of the obtained BPUEs was evaluated by UV-Vis. The clear tortuous surface and entanglements were exhibited in PUEs micromorphology structure, indicating a significant reinforcement of mechanical properties. Elongation-at-break and tensile strength reached the maximum value 2394% at 1% (BPUE1) and 18.29 MPa at 5% (BPUE5), respectively, and then decreased as chromogen addition content increased. Mechanical testing results correlate well with XRD and SEM findings, which proved that anthraquinone chromogen induced an improvement in phase separation. Furthermore, BPUE films displayed high color strength and excellent color fastnesses. The rubbing fastness and washing fastness of BPUE1 and BPUE0.5 reached grade 5, respectively. These inspiring findings suggest that PUE films with superb performance have potential to be directly applied in the textile field.

This work reported the preparation and application of graphene oxide (GO)/waterborne polyurethane (WPU) composite paste. The rheological properties of GO/WPU composite paste which were strongly affecting the printing pattern definition of printed patterns were analyzed. The influences of reduced GO (RGO)/WPU composite paste printed fabrics with various GO contents on UV protection factor (UPF) values and UV transmittance were investigated. The color performance and fastness of RGO/WPU composite paste printed fabrics were evaluated. GO/WPU composite paste showed as shear thinning behavior or pseudo-plastic characterization. GO/WPU 0.9% composite paste possessed the lowest printing viscosity index (PVI) and excellent printing definition. In terms of UV protection, RGO/WPU composite paste printed fabrics with low GO loading still exhibited great UV protection ability, and super higher UPF value (7 5 7) was obtained at RGO/WPU 1.2% composite paste printed fabric. The K/S values of RGO/WPU composite paste printed fabrics were gradually increased with the increase of GO content. Although dry and wet rubbing fastness decreased with the increase of GO content, but they all exhibited excellent washing fastness.

Design and fabrication of smart surfaces for separation of oily water have been developed rapidly. Nevertheless, construction of these smart surface materials by using green and sustainable paths for intelligent separation of oily water still faces huge challenges. The aim of this study was to develop a facile, sustainable, and energy-efficient approach for the fabrication of smart coatings with pH-responsive switchable wettability. The coating was formed on the textiles from UV-cured fluoride-free pH-responsive polyurethane (pH-PU). The wettability of obtained textiles could switch reversibly between superhydrophobicity and underwater superoleophobicity due to the protonation and deprotonation of the pH-PU under different pH conditions, which was used to successfully separate either oil or water from oily water with high separation efficiencies. More importantly, oil-in-water and water-in-oil emulsions could all be selectively separated with high water flux and oil purity by as-fabricated textiles, and t...

Graphene conductive silk substrate is a preferred material because of its biocompatibility, flexibility and comfort. A flexible natural printed silk substrate circuit was fabricated by one step transfer of graphene oxide (GO) paste from transfer paper to the surface of silk fabric and reduction of the GO to reduced graphene oxide (RGO) using a simple hot press treatment. The GO paste was obtained through ultrasonic stirring exfoliation under low temperature, and presented excellent printing rheological properties at high concentration. The silk fabric was obtained a surface electric resistance as low as 12.15 KΩ cm−1, in the concentration of GO 50 g L−1 and hot press at 220 °C for 120 s. Though the whiteness and strength decreased with the increasing of hot press temperature and time slowly, the electric conductivity of RGO surface modification silk substrate improved obviously. The surface electric resistance of RGO/silk fabrics increased from 12.15 KΩ cm−1 to 18.05 KΩ cm−1, 28.54 KΩ cm−1 and 32.53 KΩ cm−1 after 10, 20 and 30 washing cycles, respectively. The results showed that the printed silk substrate circuit has excellent washability. This process requires no chemical reductant, and the reduction efficiency and reduction degree of GO is high. This time-effective and environmentally-friendly one step thermal transfer and reduction graphene oxide onto natural silk substrate method can be easily used to production of reduced graphene oxide (RGO) based flexible printed circuit.

In this paper, an electroconductive silk fabric is fabricated by electrostatic self assemble of reduced graphene oxide (RGO) and polyaniline (PANI) under acid aqueous solution lower the isoelectric point (pI) of silk. The RGO coated silk fabric (silk-RGO) is prepared by self assemble graphene oxide (GO) sheets on the surface of silk, then the GO reduced to RGO, and aniline (ANI) self-assembled on the surface of silk-RGO in situ polymerization of PANI. The results show that the electrical conductivity of silk is mainly influenced by the composition of outermost layer, the ANI and GO concentration, ANI dipping time also contribute to the electrical conductivity of silk. When PANI self-assembled on the outermost layer of silk-RGO, a blue-green, high conductive and flexible silk fabric with a lower electrical surface resistance of 0.330 K cm−1 was obtained. The SEM shows that RGO sheets formed a thin film on the surface of silk, and PANI deposited on the surface of silk with nanowires. The Raman and FTIR-ATR spectra of silk-PANI and silk-RGO-PANI are presented PANI characteristic peaks, and the thermostability of self-assembled samples enhanced.

The flexible piezoresistive sensor (FPS) with typical three-dimensional (3D) structure is a key component for many wearable products because of its excellent performance. We report a high-performance FPS based on micro-nano 3D networked conductive electrospun membrane. This membrane is framed by thermoplastic polyurethane electrospun membrane (TPUEM) coated with reduced graphene oxide(rGO) bridged conductive poly (styrene-co-methacrylic acid)@polypyrrole (P(St-MAA)@PPy) microspheres. Interestingly, P(St-MAA)@PPy microsphere is adsorbed on the surface of rGO/TPU fiber, leading to the formation of a hierarchical conductive surface that enhances the sensitivity to external pressure. The obtained P(St-MAA)@PPy/rGO/TPUEM pressure sensor can effectively detect small pressure (0.94 Pa). The pressure sensor shows a low operating voltage (1.0 V), high sensitivity (13.65 kPa−1), short response time (37 ms), and excellent cycle stability (over 1650 cycles). As a result, this pressure sensor is used to monitor the body's physiological signals and motions, such as the human pulse, facial muscles and joint movements, etc. This novel P(St-MAA)@PPy/rGO/TPUEM pressure sensor can meet the performance requirements of wearable electronic products, demonstrating great potential in human health monitoring and human-computer interaction.

Common graphene fibers are dark black and naked, which limits their application in smart textiles and other electronic devices because of their poor expressive force in colorful clothing. Bare graphene fibers are directly exposed to human skin or other materials during their use, causing a short circuit. Here, we propose a coaxial approach to prepare novel flexible and red reduced graphene oxide (rGO) fibers with a color cover agent – TiO2 slurry and a coloring agent – a pigment/polyurethane paste (rGO–TiO2–pigment/PU) shell, via a dip-coating method. The unique coaxial design of the fiber can not only effectively avoid the risk of a short circuit, but also cover the black color of the inner graphene fibers and give the fibers a red appearance. The core of the coaxial rGO fiber had a high electrical conductivity of 156.6 S cm−1, and the red shell was insulative. The tensile strength of the rGO fiber was 453.39 MPa, while the tensile strength of the red rGO fiber reached 531.31 MPa. According to the CIE 1931 chromaticity diagram, the chromaticity coordinates of the red rGO fibers were x = 0.403 and y = 0.341, which indicated that the color of the red rGO fibers was bright and acceptable in the textile field. The colorful shell has the properties of acid resistance and alkali resistance. The excellent performance of the colorful rGO fibers provides the possibility of creating wearable electronics and conductive textiles and more.

Materials possessing simultaneous thermochromism and thermofluorescence are promising in various applications. In order to address the challenges associated with performance, versatility, and feasibility, a direct blending approach is developed to synthesize thermoresponsive polymer composites from indenoquinacridone dye solution and various polymer matrices. This feasible and scalable method affords polymer materials exhibiting simultaneous color-change and turned-on emission upon heating, high reversibility, programmable response temperature, high-contrast signal output, feasible preparation, and mechanical adaptability. Printed patterns of the composite on cotton fabric show clear optical responses to temperature changes. The integration of high-performance optical thermoresponses and advantages of the polymer matrices lays the foundation for large-scale employment of these composite materials in a wide range of applications.

Multifunctional silk fabrics with electrical conductive, anti-ultraviolet and water repellent were successfully prepared by surface modification with graphene oxide (GO). The yellow-brown GO deposited on the surface of silk fabric was converted into graphitic black reduced graphene (RGO) by sodium hydrosulfite. The surface properties of silk fabrics were changed by repeatedly RGO coating process, which have been proved by SEM and XPS. The SEM results showed that the RGO sheets were successive form a continuously thin film on the surface of silk fabrics, and the deposition of GO or RGO also can be proved by XPS. The electrical conductivity was tested by electrical surface resistance value of the silk fabric, the surface resistance decreased with increasing of RGO surface modification times, and a low surface resistance value reached to 3.24 KΩ cm−1 after 9 times of modification, indicating the silk obtained excellent conductivity. The UPF value of one time GO modification silk fabric (silk-1RGO) was enhanced significantly to 24.45 in comparison to 10.40 of original silk. The contact angle of RGO coating silk samples was all above of 120°. The durability of RGO coated silk fabrics was tested by laundering. The electrical surface resistance of silk-4RGO (65.74 KΩ cm−1), silk-6RGO (15.54 KΩ cm−1) and silk-8RGO (3.86 KΩ cm−1) fabrics was up to 86.82, 22.30 and 6.57 KΩ cm−1 after 10 times of standard washing, respectively. The UPF value, contact angle and color differences of RGO modified silk fabric slightly changed before and after 10 times of standard washing. Therefore, the washing fastness of electric conduction, anti-ultraviolet and water repellent multifunctional silk fabrics was excellent.

Cotton fabric was modified with β-cyclodextrin (β-CD) forming inclusion complex to yield color strength, pattern sharpness, and color fastness for ink-jet printing. The modified cotton fabric was confirmed with the presence of new strong absorption peaks around 1713 cm-1 and 1243 cm-1 in FT-IR. β-CD had been covalently grafted on cotton fabric via the esterification reaction of citric acid (CTR) with cellulose and β-CD. The results indicated that printing performances of the ink-jet printed fabric were enhanced through β-CD modification. The K/S value was enhanced from 4.21 to 6.72, the width of printed line was decreased from 1.48 mm to 1.25 mm, and the color fastness was improved to 3-4 level. These improvements were due to the truncated cone structure of β-CD, which can form inclusions with water-based pigment. Meanwhile, the crease recovery performance was also improved with the aid of CTR. A comparison between the unmodified and modified cotton fabric suggested that the crease recovery angle of β-CD modified cotton fabric was increased by 25.0 % in the warp direction. Therefore, printing performance and crease recovery performance of β-CD modified and water-based pigment printed cotton fabric were enhanced remarkably.

To improve foam stability in pigment foaming dispersions, a series of fatty alcohol polyoxyethylene ether (CmEOn) with different alkyl chain and ethylene oxide (EO) chain length (m = 12, 14, 16 and n = 5, 7, 9) were used as foam stabilizer to select the most superior structure for stabilizing foam. The effects of CmEOn on surface tension were investigated which revealed that the CMC of CmEOn in the pigment foaming dispersion decreased with the increase of surfactant hydrophobicity or the decrease of hydrophilicity. Compared to the alkyl chain, EO chain length influenced foam more significantly. C14EO5 in the pigment foaming dispersion showed lowest CMC and equilibrium surface tension. The presence of wormlike micelles and lamellar liquid crystal of SDS and C14EO5 endowed the C14EO5 pigment foaming dispersion with highest viscosity which was distinctly different with other CmEOn. C14EO5 showed the most superior stabilization effects with foam half-life of 172.9 min at 9 wt%. To further analyze the stabilization mechanism of C14EO5, the foam volume and bubble diameter change were observed with a digital microscope. The results demonstrated that the superior stabilization effects of C14EO5 were closely related to its high viscosity, which mainly resulted in the decrease of foam drainage and gas permeability. C14EO5, the optimal CmEOn structure for stabilizing foam, shows excellent foam stabilization capability in pigment foaming dispersions, which is a promising tool to realize pigment foam coloring.

The controllability of foam stability is a vital feature that allows for practical applications of foam systems. Light, as an external stimulus, offers unique opportunities to tune the foam stability in a non-invasive manner with high spatiotemporal precision. However, most of the reported photoresposive foams were generated from ionic type surfactants, limiting their applications in industrial complex systems with multiple components. Herein, we design and synthesize a series of nonionic azobenzene surfactants with different polyoxyethylene glycol (EO) chain lengths (BEO-n-Azo, n, referring to the EO chain length, is 14, 19 and 23, respectively) to prepare photoresponsive foams. Detailed insights into the effects of EO chain length on photoisomerization properties, surface tension, as well as foamability and controllable stability of photoresponsive foams are presented. The results demonstrate that photoresposive foams are generated not only from single-component solutions of BEO-n-Azo, but also from multiple-component complex systems doped with BEO-n-Azo, providing a promising strategy to broaden applications of photoresponsive foams in industrial processes.

A novel raspberry-shaped thermochromic energy storage nanocapsule (RTESN) is successfully designed and fabricated with switchable sunlight absorption capacity based on color change for temperature regulation. The RTESN is developed by grafting amino-modified silica shell thermochromic nanoparticles (amino-TLD@SiO2 ) on the surface of epoxy-functionalized energy storage nanocapsules (paraffin@PSG), with a total particle size about 450 nm. RTESN exhibits a deep color under low temperatures, which can absorb sunlight for heating. During the continuous thermal energy supply, paraffin@PSG is capable of storing thermal energy owing to its large latent heat capacity of 118.7 J g-1 , thereby maintaining the slow temperature increase. When the temperature is higher than the phase change temperature of paraffin@PSG, the color of amino-TLD@SiO2 turns to white with more reflection of sunlight so that it reduces the absorption of thermal energy and prevents the further increase of temperature. The thermal regulation behavior is confirmed by setting up a wooden house with the surface covered with RTESN. Compared with the blank wooden house, the RTESN covered wooden house (RTESN-H) displays thermal insulation performances during heating and cooling with a maximum temperature difference of 7 °C.

Three novel UV curable polymeric dyes (UVPDs) based on multifunctional waterborne polyurethanes have been successfully developed to overcome the drawbacks of thermo-curing. The functionality of the UVPDs is tailored by end-capping with 2-hydroxyethyl acrylate (HEA), pentaerythritol triacrylate (PETA) and dipentaerythritol pentaacrylate (DPEPA). The chemical structure, molecular weight and carbon–carbon double bond (CC) content of the UVPDs were investigated. The thermal properties, curing behavior and color properties of the UVPDs are also discussed. It is found that the thermal stability of the UVPDs is improved upon increasing the functionality. The incorporation of chromophores into the polyurethane chain reduces the curing efficiency. The curing behavior observations demonstrate that the UVPDs can cure rapidly upon UV irradiation, especially the ones with higher functionality. A higher degree of cross-linking and better water resistance are obtained when UVPD films are cured with 5% photoinitiator. Furthermore, the UVPDs show outstanding UV light stability. The maximum absorption wavelength and curve trend of the cotton fabrics coated with the UVPDs remain unchanged while the color of the coated cotton fabrics slightly lightens when prolonging the UV curing time. The color fastness to rubbing and washing of the coated cotton fabrics with UVPD10 can be enhanced up to 4–5 grade after curing for 60 s.

Durable, reversible color changing polyester fabrics were successfully fabricated via a new approach of dyeing with thermochromic leuco dye-loaded silica nanocapsules (TLD@SiO2). TLD@SiO2 was prepared via tetraethyl orthosilicate hydrolyzation and condensation on the surfaces of emulsified thermochromic leuco dye (TLD) nano-droplets by a sol–gel method. The TLD@SiO2 was about 20 nm in size, and its shell could provide protection for TLD. The color of TLD@SiO2 changed from dark blue (25 °C) to light blue (45 °C) and white (80 °C), reversibly. The thermochromic mechanism originated from the conjugation structure conversion of the crystal violet lactone which was confirmed by density functional theory calculations. The shell materials (Si–O–Si) of TLD@SiO2 could be hydrated in water with temperature increase and produced hydrophilic hydroxyl groups for further treating polyester fabrics. These resulting polyester fabrics exhibited excellent thermochromic performance with a color transition temperature of 45 °C. Their color reversibly changed from dark blue (K/S = 12) to light blue (K/S = 2) at 610 nm for more than 50 times. Meanwhile, thermochromic polyester fabrics dyed at 130 °C displayed good color fastness. The washing, dry rubbing and wet rubbing fastness of the thermochromic polyester fabrics all reached above 4 grades, and the thermochromic polyester fabrics showed good solvent resistance.

Superhydrophobic coatings have received great attention over the past decades because of their specific performances, but most of them may lose their superhydrophobicity under harsh conditions especially in outdoor applications. In this paper, UV and pH dual stimuli-responsive self-repairing waterbased superhydrophobic coatings were prepared based on TiO2 with photocatalysis and pH-responsive microcapsules, which were durable against UV irradiation and chemically stable in contact with alkaline or acidic aqueous solutions. These coatings are an environment-friendly waterborne system and could be easily coated on various substrates. What is more, they can restore their superhydrophobicity and self-cleaning ability under UV light even after mechanically damaged or contaminated with organics. Moreover, this superhydrophobic coating was immersed into 5 wt% NaCl aqueous solutions for 24 h or underwent ten icing/melting cycles, their surfaces could also recover the superhydrophobicity under pH or UV stimuli.

An integrated approach to preparing a hybrid electrochemical sol using precursor tetrabutyl titanate and siliane coupling agents methyltriethoxysilane (MTES), γ-chloropropyltriethoxysilane (CPTS), N-octyltriethoxysilane (OTEOS) or dodecyltriethoxysilane (DTEOS) was investigated. The functional TiO 2 and hydrophobic chain in hybrid electrochemical sol were deposited on cellulose substrate via sol–gel electrochemical deposition to present sensitive superhydrophobic–superhydrophilic smart converting performance. By doping 2% silane coupling agent in hybrid electrochemical sol and depositing at applied voltage 13 V for 8.0 min, the cellulose substrate showed excellent superhydrophobicity. The contact angle reached to 166.1° with OTEOS/TiO 2 hybrid sol. During washing process, the contact angle of coated cellulose substrate declined to 161.3°, and decreased to about 119.1° after washing 10 times, which showed excellent washing durability for sol–gel electrochemical deposition. The contact angle was decreased to 0° during 10 5 μW/cm 2 ultraviolet (UV) for 11.0 min, which was caused by the photoinduced TiO 2 component, and the contact angle of the irradiated cellulose substrate recovered gradually in dark environment. When stored in the dark for 40 h, the contact angle could increase to 150.6°, and the fabric recovered to superhydrophobicity.

Conductive polymer composites (CPCs) are popular materials for strain sensors that can detect joint movements and monitor human health. However, it is still a challenge to balance the mechanical strength, resistance, wide function range and durability of CPCs. Herein, a textile-based CPCs, PFNS (polypyrrole/β-FeOOH modified nylon (containing 30% polyurethane)), has been prepared via in-situ hydrolysis of Fe3+ and in-situ polymerization of pyrrole. The stacked acicular β-FeOOH constructs more space for polypyrrole growth, rendering PFNS lower resistance (5 cm, 0.308 kΩ) and higher electrothermal temperature (50.4 °C at 12 V) than PNS (without β-FeOOH, 5 cm, 0.493 kΩ, 41.3 °C at 12 V). The rough polypyrrole layer endows PFNS with good hydrophobicity that can be still maintained under 100% strain and after electrothermal heating. The PFNS possesses outstanding one-dimensional stretchability (100% strain), fast response time (0.39–0.61 s) and recovery time (0.55–0.92 s) for the strains of 2.5%-10%, good sensitivity (3.24 MPa−1 in a high stress of 0.123 MPa and gauge factor of 3.06 in a 20% strain), and long-term sensing function (>1500 cycles). Furthermore, PFNS presents excellent detection capability for subtle, middle and large joint movements (e.g., pronouncing, back bending, push-up exercise, walking and jumping), indicating its flourishing prospect in wearable strain sensors.

Electrothermal heater (ETH) is very promising in wearable electronic area for its potential thermotherapy and electrical-warming garment applications. To fabricate a suitable conductive material for wearable ETH, knitted cotton is used as substrate for in-situ polymerization of pyrrole monomers, producing conductive polypyrrole/knitted cotton fabric (PKCF) with good flexibility and stretchability. A parallel strategy for current collectors is taken to enhance the temperatures of prepared PKCF from 37.0 to 51.0 °C at 8 V. This PKCF provides a service time about 13.5 h in a continuous electrothermal process, keeping a temperature above 35 °C. Besides, the PKCF still shows good electrothermal performances after bent or stretched several thousand times, and can be sewn on fabric to realize its electrothermal function in garments, which indicates a promising wearable market.

Superhydrophobic surfaces have attracted tremendous attraction because of their novel aspects of surface physics and important applications ranging from self-cleaning materials to microfluidic devices. However, most artificial superhydrophobic surfaces easily lose their superhydrophobicity under natural sunlight irradiation, physical rubbing or organic contamination. Here, fluoroalkyl silane (FAS)-loaded microcapsules, photocatalytic TiO2 nanoparticles and FAS modified SiO2 nanoparticles were mixed with waterborne polysiloxane resins to obtain waterborne self-healing superhydrophobic coatings. Superhydrophobic surfaces were formed by casting the coatings on the substrates after UV-irradiation and could sustain their superhydrophobicity even after 360 h accelerated weathering test. Meanwhile, the coating was durable enough to withstand water blasting and the attacks of strong acid or basic solutions without apparently changing its superhydrophobicity. More importantly, after being mechanically damaged or contaminated with organics, these coatings could restore their superhydrophobicity under UV light. All these characteristics ensure that the coatings have excellent long-term superhydrophobicity for outdoor service.

A series of polymeric dyes based on blocked waterborne polyurethanes (BWPUs) with varied molecular weights have been synthesized successfully. The influence of molecular weight on the thermal, rheological, and printing properties of the BWPUs are mainly investigated. The molecular weight of the BWPUs are tailored in the range of 2860–24 600 by selecting different chain lengths of polyethylene glycol (PEG0/400/600/1000/2000) as soft segments. The glass transition temperature (Tg) of the BWPUs decreased from 5.1 °C to −52.6 °C with increasing molecular weight of the soft segment, which implied a better film-forming property. Additionally, BWPUs with higher molecular weight offered better thermal stability. It is also found that BWPUs with a higher molecular weight show a more distinct shear thinning behavior and viscous behavior. The synthesized BWPUs were further applied in textile printing as both a colorant and adhesive to investigate their application performances. The printing viscosity index (PVI) values of all BWPUs pastes are below 0.3, suggesting that they are preferred for printing fine patterns on hydrophilic fibers. The color fastness of the printed cotton fabrics was found to be improved to 4–5 grade as the molecular weight of the BWPUs and baking temperature were increased. Consequently, the polymeric dyes could provide a novel route for obtaining high-quality printing products and shortening the textile coloring process.

To obtain an aqueous foam photo-switch, azobenzene molecules [4-hydroxy-4′-oxoalkyl azobenzene (HCnAzo) n = 4, 8, and 12] were synthesized. The hydrophobic chain length affected both photo-responsive properties and foam stability controllability. trans → cis isomerization of HCnAzo occurred by exposing to UV light for 1 s and the cis → trans process for HC4Azo, HC8Azo and HC12Azo was carried out by visible light irradiation for 12 min, 13 min and 14 min, respectively. The reversible isomerization was repeatable, maintaining high sensitivity. Due to the small steric effect and isomerization barrier, photo-isomerization of HC4Azo was more rapid than HC8Azo and HC12Azo. With the increase of the hydrophobic chain length, the decrease of thermal isomerization barrier resulted in less cis isomer and more trans isomer in photo-stationary state via UV and visible light irradiation, respectively. The combination of visible light and heat can accelerate the cis → trans isomerization speed. trans HC4Azo, HC8Azo and HC12Azo increased foam life from 6.67 min to 10.38, 9.91 and 7.74 min, respectively, resulting from the absorption on the air–water interface and a high affinity. cis HC4Azo, HC8Azo and HC12Azo decreased foam life from 6.67 min to 5.12, 5.49 and 6.02 min, respectively, attributed to the interfacial desorption and increase of surface tension. HC4Azo with sensitive photo-isomerization and effective foam stability controllability was the best choice for an aqueous foam photo-switch.

Camphor oil/latex dispersions were prepared by miniemulsion polymerization with a reactive emulsifier for the purpose of controlling camphor oil release. The prepared dispersions were characterized by dynamic light scattering method, transmission electron microscope and thermogravimetric analyses. The result indicates that camphor oil/latex dispersions had high stability and excellent ability for the control release of camphor oil. The volatility of camphor oil was averted after entrapping into the latexes. The particle size of the camphor oil/latex dispersion was approximately 89.4 nm and uniformly distributed when the dispersion was prepared at the conditions of that mass content of monomer (molar ratio of MMA to BA 2:3) to the dispersion 7.5 %, mass ratio of camphor oil to monomer 6 %, mass ratio of DNS-86 to monomer 20 %, molar ratio of AIBN to monomer 1.5 %, and mass ratio of HD to monomer was 2.5 %.

Chitosan (CS) was grafted on the wool after being wetted at different relative humidity (5 %, 65 % and 95 % RH) and induced by O2 plasma to investigate the influence of wetting pretreatment on the structure and properties of plasma induced chitosan (PICS)-grafted wool fabric. The effects of the RH of wetting pretreatment, CS concentration and grafting time on weight gain ratio and PICS-grafted wool fabric properties including wettability, dyeability and shrink resistance were studied. Scanning electron microscopy (SEM) observation showed that the scales on the wool fiber wetted at 95 % RH and then treated by O2 plasma were more severely damaged. The surface roughness and polar group content of PICS-grafted wool fabrics increased with the RH of wetting pretreatment. The analysis results of surface morphology by SEM and chemical composition by X-ray photoelectron spectroscopy (XPS) revealed much more CS on the surface of PICS-grafted wool fabric wetted at 95 % RH. The analysis results of weight gain ratio, contact angle, K/S value and area felting shrinkage manifested the optimum parameters of PICS grafting on the wool fabric wetted at 95 % RH could be set as the chitosan concentration of 2 g/l and the grafting time of 2 h. The machine washable wool fabric with the area felting shrinkage of 4.5 % and the better wettability and dyeability could be obtained by a new ecologically acceptable process of PICS grafting on the wool wetted at 95 % RH.

Recently, nanocomposites based on graphene and layered double hydroxides (LDH) have been developed and used in many fields. However, to the best of our knowledge, there is no report on the luminescence sensor applications of graphene/LDH composites. Herein, a hybrid graphene–ZnAl-LDH nanocomposite has been developed using a facile one-step process and the presence of LDH in the composite can effectively prevent the restacking of graphene and improve both its luminescence properties and thermal stability. Furthermore, the composite can be used as a portable shelf of the Ru(phen)3Cl2 (tris(1,10-phenanthroline)ruthenium(II) dichloride) sensor to selectively discriminate DNA. It was found that the graphene–ZnAl-LDH composite can effectively quench the emission of the Ru(phen)3Cl2 sensor. After the addition of a certain amount of DNA into the system, Ru(phen)3Cl2 was released from the graphene–ZnAl-LDH composite and it interacted with DNA immediately, leading to the luminescence recovery of the sensor. The results indicate that the RGO–ZnAl-LDH composite displayed an excellent luminescence response and good linear correlation to DNA. Therefore, the composite can be employed as a portable shelf of Ru(phen)3Cl2 to discriminate DNA. Moreover, both the shelf and the sensor can be easily collected and made ready for the next sample if there is no DNA in the solution. The proposed method was further applied to detect the immunodeficiency virus gene (HIV), thus providing a new field of application for hybrid graphene/LDH composites.

A waterborne polyurethane covalently bonded anthraquinone dye chromophore was successfully synthesized via incorporating micromolecule Disperse Red 91 into the polyurethane skeleton. The number- and weight-average molecular weights of the waterborne polyurethane based polymeric dye were about 6.57k and 10.3k, respectively. The maximum absorption wavelengths are 260 nm, 520 nm and 555 nm, which show a hypsochromic effect compared with the corresponding micromolecule dye. Thermal stability and centrifugal stability can be distinctly enhanced after the micromolecule dyes are covalently bonded to the polyurethane skeleton. The solubility of waterborne polyurethane based polymeric dye also offers reversibility and good color stability at different pH values. Thermal migration properties of this polymeric dye are improved by 82.4%, compared to that of a simple mixture of dye and polyurethane. The polymeric dye with enhanced color stability under centrifugation, acid, alkaline and thermal conditions can upgrade the product quality as it is employed in dyeing, coating or printing ink.

The cationic superfine pigment is prepared using octadecyl dimethyl benzyl ammonium chloride as dispersing agent in order to enable the pigment to dye wool through an exhaust process. Pigment uptake, color strength (K/S value), fastness properties, and penetration were measured. The results show that cationic superfine pigment can be adsorbed on wool under different pHs. Not only dyebath pH but also dyeing time and pigment dosage are found to be closely related to K/S value. The increase of pH results in high pigment uptake and K/S value which increases rapidly beyond or at isoelectric point (PI) of wool. Dry and wet rubbing fastness are improved with the increase of binder dosage, achieving 3 and 3–4 grade respectively as binder amount increases up to 40 % o.w.f. Wool yarns dyed by cationic superfine pigment present better light fastness over 5 grade than those treated with acid dyes. According to micrographs of cross-sections, the distribution of pigment particles on wool fibers shows loop dyeing. It has been demonstrated that it is feasible for cationic superfine pigment to dye wool by pH adjustment.

Dye-bonded blocked waterborne polyurethanes were developed to synchronously realize coloring and finishing of textiles and improve colorfastness using an anthraquinone chromophore and a methyl ethyl ketoxime blocking agent. The number-average molecular weight of the dye-bonded blocked polyurethane is 2303 g mol−1 and the polydispersity is 1.06, indicating a narrow molecular weight distribution. The maximum absorption wavelengths do not shift after the monomolecular chromophores are bonded to the polyurethane. The self-colored polyurethanes provide better centrifugal stability and water solubility than the dye-mixed blocked polyurethanes. The dye-bonded blocked polyurethane offers good thermal stability below 100 °C and undertakes de-blocking at about 150 °C. The covalent bonding of the anthraquinone moiety with the polyurethane chain and temporary blocking of the terminal isocyanate groups are conducive to enhancing the tinting strength and colorfastness of the treated cotton fabrics. The self-colored blocked polyurethanes with good elasticity and toughness can improve the recovery angle of the treated cotton up to 120°, which can also endow the fabric with wrinkle resistance.

To prepare a functional fiber surface with alterable superhydrophobic–superhydrophilic wettability on fabrics, a TiO2 hybrid sol was synthesized with tetrabutyl titanate and a fluoride silane coupling agent, 1H,1H,2H,2H-perfluorooctyltrimethoxysilane, via sol–gel technology. Within irradiation under UV light, the decay of the contact angle from superhydrophobicity to superhydrophilicity on the irradiated front fabric treated with the F–TiO2 hybrid sol was the fastest, and the contact angle on the irradiated reverse cotton fabric hardly changed. During this process, the contact angles of cotton, polyester, and wool fabrics kept within a tiny change (4°) with different doping ratios, and the UV irradiation had no effect on the reverse contact angles. During the storage process in the dark, the loss ratio of the front contact angle was decreased to 20% from 40% as the storage temperature increased to 60 °C from 30 °C.

An attempt has been made in this paper to investigate antimicrobial property of glycyrrhiza extract on cotton fabric. Uniform glycyrrhiza powders were obtained by superfine grinding. The particle size distribution of powders was mostly around 1 μm. Effects of ultrasonic on dispersion capability of glycyrrhiza powders were investigated. With the extension of ultrasonic time the value of zeta potential decreased significantly from −22 to −31 mV. Flavanone compounds which exhibit inhibitory effects against multiple viruses were extracted by ethanol from superfine glycyrrhiza powders. Qualitative and quantitative methods were used to test the antibacterial properties of the fabrics treated by glycyrrhiza extract. The results showed that the inhibition rates against S. aureus and E. coli were 81.75 and 73.81 % respectively indicating that the finished fabrics exhibited good antibacterial property. It retained about 30 % of its inhibition to S. aureus after 10 cycles of laundering. However, the fabrics treated with sol of glycyrrhiza exhibited more resistance to washing with 71.43 % inhibition rate after 5 times washing. The whiteness index of glycyrrhiza exact treated fabrics decreased from 93.28 to 90.22 % indicating that glycyrrhiza exact had little influence on the whiteness of fabrics.

To prepare a functional surface with dynamically modifiable wettability on cotton and polyester fabrics by hybrid coating, the F/TiO 2 hybrid sol were synthetized with tetrabutyl titanate and fluoride silane coupling agent via sol–gel technology. The anatase component in F/TiO 2 hybrid powder was mixed with rutile component from XRD, and the crystal component was unchanged in UV light and dark store condition. The switchable wettability of the fabric was assessed by contact angle in different conditions and time. The maximum contact angles of cotton and polyester fabrics coated with F/TiO 2 hybrid sol were 141.8° and 136.1°, respectively, and through UV irradiation, the minimum contact angles of cotton and polyester fabrics coated with F/TiO 2 hybrid sol were both 0°, respectively. Within storing in dark, the contact angles nearly completely reverted. The switchable cycle of the cotton was 84 h, while the switchable cycle of the polyester was 168 h. From AFM and fabric constructions (porosity, permeability and roughness) analysis, the fiber morphology had more effect on the contact angle than the fabric constructions. The F/TiO 2 hybrid powder and the coated fabric floated on water for their excellent hydrophobicity, and the samples deposited at the bottom of water as the wettability of coated fabric increased via UV irradiation. The irradiated samples were placed in dark, and the samples floated on water again. The water diffusion and permeable capacities further confirmed the dynamically modifiable wettability. The water diffusivity and permeable capacity further confirmed the excellent switchable wettability of coated fabrics by F/TiO 2 hybrid sol through UV irradiation or storage in dark.

The ultrafine paste used in electrophoretic paint was prepared via ultrasonic method with pigment yellow 83 (P.Y.83), octadecyl dimethyl benzyl ammonium chloride, and deionized water. The average particle size of the ultrafine paste was only 196 nm and zeta potential was 30 mV with ultrasound for 30 min and 2 wt.% cationic dispersant. The conductivity of the paint was improved as the cationic dispersant increased. Centrifugal stability of the paint with ultrafine paste reached the maximum at 2 wt.% cationic dispersant. Compared with the performances of cathodic electrophoretic paint with the ultrafine yellow paste, the anodic film was smooth, uniform, and neat with 0.5 wt.% cationic dispersant in the ultrafine yellow paste. Deposited amount of the anodic film was 27 g/m2, which was higher than the cathodic film. The curing property, adhesion, and chemical resistance of the cathodic film were better than the anodic film. Properties of five color cathodic paints (blue, yellow, red, black, and green) were di...

The effect of atmospheric pressure plasma treatment on wettability and dyeability of polysulfonamide (PSA) yarns and aging behavior were investigated. The helium and helium/oxygen plasma-treated PSA yarns were stored for different time varying from 10 to 60 days at the condition of 25 °C and 65 % relative humidity. The water absorption time and K/S value were used to determine the wettability and dyeability of polysulfonamide yarns before and after plasma treatment. The changes in surface morphology and chemical composition were analyzed by Scanning Electron Microscope (SEM) and X-ray Photoelectron Spectroscopy (XPS). The plasma treatments resulted in the decrease in water absorption time and the increase in K/S value, especially for the helium/oxygen plasma-treated PSA yarns dyed with cationic dyestuff. SEM observation confirmed that the PSA fiber surface was roughed and XPS analysis showed that the polar groups on PSA fiber surface increased after the plasma treatments. As plasma treatment time increased and oxygen gas was added, a greater degree of etching was achieved and more polar groups such as hydroxyl and carboxyl groups produced on PSA fiber surface, contributing to a better wettability and thus a better dyeability of the yarns. Almost no apparent aging effect was observed within 10 days. And then with the increasing storage time, the water absorption time and K/S value firstly quickly and then slowly increased and decreased. However, after 30 days, almost no aging effect was observed. The atmospheric pressure plasma treatment had no obviously influence on tensile strength of PSA yarns.

A novel cationic SiO2/TiO2 hybrid sol (CSTHS) is synthesized and coated onto the surface of a cellulose substrate to rebuild a characteristic surface, which is beneficial to transfer printing from ...

In order to enhance the adhesions of the UV-curable inks onto glass substrate, the silane coupling agents were added into the mixture of monomer and oligomer. The monomer, containing high functionality or surface tension could lead to a high cross-link density of the polymeric network and low adhesions of UV-curable inks. With the amount of ethyoxyls of ethoxylated trimethylolpropane triacrylate increasing, adhesions of the oligomers were improved. As the monomer concentration increased, the adhesion ability of UV-curable ink onto glass was decreased. The adhesion ability of UV-curable inks onto glass was increased via adding silane coupling agents. When the concentration of the silane coupling agents was more than 12%, the adhesion ability of UV-curable inks onto glass was decreased. Silane coupling agents (3-methacryloxypropyl) trimethoxy silane (KH570) and (3-aminopropyl) triethoxy silane (KH550) were more effective than (3-glycidoxypropyl) trimethoxy silane (KH560) in the inks under the same concentra...

The cotton fabrics were dyed by exhaust method using the pigment dispersions as colorant, and meanwhile the effects of particle character on dyeing performance were further investigated. The results showed that the larger zeta potentials, the higher K/S value, pigment uptakes, rubbing and washing fastness of the dyed cotton fabrics were. Adsorption isotherms were belonging to Langmuir type when zeta potentials were about 0.46 mV and 31.39 mV respectively. The cotton fabrics that dyed by the pigment dispersions with small particles had high K/S value, rubbing and washing fastness. The chemical structure of pigment had little influence on pigment uptakes, and all kind of pigment dispersions reach to 98 % uptakes after 30 min but exhibit various uptake rates at initial stage.

Fully printed wearable electronics based on two-dimensional (2D) material heterojunction structures also known as heterostructures, such as field-effect transistors, require robust and reproducible printed multi-layer stacks consisting of active channel, dielectric and conductive contact layers. Solution processing of graphite and other layered materials provides low-cost inks enabling printed electronic devices, for example by inkjet printing. However, the limited quality of the 2D-material inks, the complexity of the layered arrangement, and the lack of a dielectric 2D-material ink able to operate at room temperature, under strain and after several washing cycles has impeded the fabrication of electronic devices on textile with fully printed 2D heterostructures. Here we demonstrate fully inkjet-printed 2D-material active heterostructures with graphene and hexagonal-boron nitride (h-BN) inks, and use them to fabricate all inkjet-printed flexible and washable field-effect transistors on textile, reaching a field-effect mobility of ~91 cm2 V−1 s−1, at low voltage (, Heterojunction structures based on 2D materials show promise for wearable and textile electronics. Here, the authors demonstrate fully inkjet-printed hetero junctions of graphene and h-BN as a platform for FET-based smart electronics on wearable and washable textile substrates.