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Currently used humidity sensors have a large size which seriously hinders their applications in many special fields. Therefore, a facile way for fabricating miniaturized humidity sensors is desired. In this work a high-performance, nanofiber bundle sensor (NfBS) was fabricated through immersing nylon66 (PA66)/multiwall carbon nanotubes (MWCNTs) nanofiber bundles into a polyvinyl alcohol solution. In the PA66/MWCNTs nanofiber bundles the MWCNTs were absorbed on the surfaces of the PA66 nanofibers. The NfBS exhibited a wide range of 11–85% relative humidity (RH) sensitivity with a fast response-recovery time as well as small hysteresis and good repeatability, but had an extremely small size (about 0.1 mm in diameter and 2 mm in length) due to the unique advantages of nanofiber bundles. In addition, the NfBS showed good performance in monitoring human breath. The results in this study provide a promising opportunity and a good method for manufacturing mini-humidity sensors with smaller sizes for electronic products. [ABSTRACT FROM AUTHOR]

ABSTRACT Up to now, research on the dynamic process of conductive network formation has tended to focus on composite particles with one-dimensional geometry, such as carbon black and carbon nanotubes. However, studies on this subject based on fillers with two-dimensional structure, such as graphite, are rare in the literature. In this work, the dynamic percolation and rheological properties of poly(methyl methacrylate) (PMMA)-graphite composites under an electric field were investigated. The activation energies of conductive network formation and polymer matrix mobility were calculated from the temperature dependence of the percolation time and the zero-shear viscosity. It was found that the activation energy calculated from the zero-shear viscosity was not influenced by the electric field in the concentration range investigated, but the electric field had an effect on the activation energy calculated from the percolation time. This finding emphasizes that the electrical and rheological properties have different physical origins. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43810. [ABSTRACT FROM AUTHOR]

The strain-sensing behaviors of carbon black (CB)/polypropylene (PP) and carbon nanotubes (CNTs)/PP conductive composites prepared by the vacuum-assisted hot compression were studied and compared. When ten extension-retraction cycles were applied, it was found for CB/PP, the value of the maximum responsivity (Δ R/ R, Δ R-the instantaneous variation of the resistance during the test, R-the original resistance) decreased gradually with increasing the cycle number, but it began to rise from the seventh cycle. The value of the min Δ R/ R increased during the whole test. While for CNTs/PP, both the values of the max and min Δ R/ R decreased rapidly. It is suggested that the different behaviors mainly depend on the distinction in the dimension of the conductive fillers and the preparation technique. [ABSTRACT FROM AUTHOR]

Resistivity variations of carbon black (CB)/polypropylene (PP) and carbon nanotubes (CNTs)/PP conductive polymer composites subjected to different tensile speeds were studied with the same maximum strain 3%. With increasing tensile speed, the responsivity (ΔR/R0, R0is the original resistance, ΔR is instantaneous change in resistance) shows an obvious increase for both CPCs, although the increase degree is different. CB/PP has a higher responsivity than that of CNTs/PP during the tension and unloading process. It is proposed that the difference depends mainly on the distinction in the microstructure of conductive fillers and the interaction between the fillers and the matrix. [ABSTRACT FROM AUTHOR]

A conductive carbon nanotube (CNT) based polymer composite was constructed in which the conductive network utilized the selective distribution of CNTs in a co-continuous phase polymer blend. CNTs were first uniformly coated on the surface of polyethylene (PE) fine particles through alcohol assisted dispersion under ultrasonication, and then the CNTs coated PE particles were melt compounded with polycarbonate (PC). The theoretical prediction from both thermodynamics and kinetics indicated the CNTs mainly stayed at the interface between PC and PE. Rheological measurements and scanning electron microscopy (SEM) and optical microscopy (OM) observations provided the evidences for the selective distribution of CNTs and revealed the transition from the dispersed/matrix phase structure to the co-continuous phase structure at 50 wt% of PC. As PE and PC formed co-continuous phases, the CNTs formed a perfect conductive network on the phase interfaces, which resulted in a percolation threshold between 0.3 and 0.5 vol%, a relatively low value for CNTs filled thermoplastic composites reported in the literature. [ABSTRACT FROM AUTHOR]

The article reports on a study of the carbon nanotubes/ultrahigh molecular weight polyethylene (CNTs/UHMWPE) conductive composite with a low percolation threshold. It was shown that the resistivity decreased during isothermal treatment above the melting point of UHMWPE. This relaxation was proven as a function of time, temperature, filler concentration, and heating rate.

The variations of electrical property of an ultralight conductive carbon nanotube/polymer composite foam upon compression were investigated. It was found the sharp increase of volume resistivity and strain was generated by the same microstructural change, i.e., the damage of foam struts. Even the strain was increased to as high as 50%, the ultimate resistivity remained stable. Volume resistivity of the foam kept almost changeless under an invariant external mechanical field. The stable microstructure of the conductive network formed by contact of CNTs and the high endurance of samples' core regions endow the ultralight conductive foam with much stable electrical properties. [ABSTRACT FROM AUTHOR]

As a crucial element for wearable devices, high‐performance strain sensors have been spotlighted as an ideal strategy to develop machine‐human interfaces and healthcare systems. It still remains a huge challenge to construct flexible strain sensors with equational response in a broad range. Herein, highly stretchable multi‐walled carbon nanotubes (MWCNTs)–decorated thermoplastic polyurethane (TPU) fibers with a porous microstructure are produced through a scalable and facile strategy by wet‐spinning and ultra‐sonication. The fiber is composed of pure TPU fibers with MWCNTs decorated on the surface. The porous fiber is then assembled as a strain sensor. Interestingly, the effective MWCNTs distribution on the TPU fiber enables exponential sensing over the whole strain range. The sensor possesses a high gauge factor (GF, 102 at 300% strain), very large workable sensing range (300% strain), excellent durability (10 000 cycles), light weight (0.85 g cm−3), and fast response (200 ms). The as‐prepared strain sensor exhibits excellent insensitive properties toward buckling, torsion, temperature, and humidity stimuli. Based on the high sensing performance, the fiber‐shaped strain sensor detects human movements precisely by directly attaching to skin or embedding in garments, demonstrating huge potential in human–machine interfaces, health monitoring application, etc. [ABSTRACT FROM AUTHOR]

High-performance electronic films with multifunctional properties for personal therapy and health management are highly desirable for integrated smart wearable electronic devices. By utilizing a double-layer coating strategy and the synergistic effect of heterostructures, a carboxylated carbon nanotubes@MXene/cellulose film (CNTs@MXene/CFs) with interconnected conductive network was prepared via a facile dip-coating and spray-coating approach. The Joule heating, photothermal conversion and electromagnetic interference (EMI) shielding performance were realized due to the synergetic effect of MXene and CNTs, delivering an intriguing Joule heating performance (154 °C at an applied voltage of 4 V), an outstanding photothermal conversion efficiency (105 °C at 4 suns) and a remarkable EMI shielding effectiveness of 32.62 dB. This work provides a feasible pathway to fabricate high-performance versatile films and offers insights into the design of highly integrated multifunctional devices for personal medical therapy application in future therapy electronic fields. [Display omitted] [ABSTRACT FROM AUTHOR]

Conductive polymer composites (CPCs) have found applications as eco-friendly vapor sensor. In this study, ramie fiber (RF) was incorporated into poly (lactic acid) (PLA), an eco-friendly polymer, through a premixing process of conductive fillers (carbon black (CB) and carbon nanotubes (CNTs)) and RF. The introduction of RF increases the crystallinity of composites without sacrificing electrical properties. The influence of RF on the vapor sensing behaviors of the CPC was investigated in detail. Compared with those systems with only conductive fillers, i.e. , CB/PLA and CNT/PLA, the RF embedded CPCs show higher electrical conductivity with lower percolation threshold, better shape stability toward ‘good solvent’ such as dichloromethane, and excellent reversibility upon ‘poor’ solvent. The increased crystallinity and the interaction between conductive fillers and RF are responsible for the phenomenon. To illustrate the conductive network evolution during tests, a schematic was proposed. The results suggest that conductive polymer composites containing RF can be applied as a promising eco-friendly vapor sensor. [ABSTRACT FROM AUTHOR]

Benefitting from the wearability, ductility and portability, flexible and stretchable strain sensors display a more extensive field of applications than traditional sensors in terms of medical diagnosis, smart home, environmental monitoring and so on. However, the critical sensing performances, such as sensitivity, sensing range, stability and detection limit of flexible strain sensors still need to be improved. Microstructural optimization has been considered as an efficient strategy for tuning the performances. In this work, a carbon nanotubes (CNTs)/carbon black (CB)/thermoplastic polyurethane (TPU) fibrous film (CCTF) is prepared through electrospinning, spraying and ultrasonic anchoring technique. Synergetic conductive layers by combining CNTs/CB and CB are constructed on both sides of CCTF. In virtue of the optimization of microstructures and the synergetic conductive network, the obtained CCTF possesses an ultrawide response range (up to 500 % strain), high sensitivity (gauge factor, GF up to 1516), short response/recovery time (80/80 ms), low detection limit (0.05 % strain), favorable sensing stability and long-term durability. CCTF with excellent strain sensing performances is assembled as a strain sensor, which accounts for full range human biological signal acquisition, including joint movements, muscle tension, and facial micro-expressions. This paper provides a certain reference significance for the preparation and fabrication of next-generation flexible strain sensors with high performances. A flexible strain sensor based on carbon nanotubes (CNTs)/carbon black (CB)/thermoplastic polyurethane (TPU) film (CCTF) is fabricated through electrospinning, spraying and ultrasonic anchoring technologies. CCTF possesses excellent sensing performance due to the optimization of the microstructure, achieving a wide sensing range (up to 500 % strain), high sensitivity (GF up to 1516), low detection limit (0.05 % strain), and short response/recovery time (80/80 ms). [Display omitted] • A fibrous strain sensor with synergetic conductive networks of CNTs/CB and CB is fabricated. • The sensor possesses both a wide sensing range (500 % strain) and high sensitivity (GF up to 1516). • Low detection limit (0.05 % strain) and short response/recovery time have also been achieved. • The sensor is demonstrated to precise full range human biological signal acquisition. [ABSTRACT FROM AUTHOR]

Solar steam generation (SSG) has been considered as a promising method to produce fresh water from seawater. Due to high light absorption and excellent chemical stability, carbon nanotube (CNT) has been widely used for SSG. However, it is still challenge to simultaneously realize high water evaporation rate and energy efficiency for CNT based solar steam generator. Herein, ultralight anisotropic Ti 3 C 2 T x MXene/carbon nanotube (A-Ti 3 C 2 T x /CNT) aerogels are designed and fabricated for highly efficient SSG. The combination of CNT and Ti 3 C 2 T x MXene endows the hybrid aerogel with high light absorption and effective localized surface plasmon resonance (LSPR), resuting in enhanced light-to-heat conversion efficiency. The porous structure of aerogel leads to multiple scattering and absorption, further contributing to the photothermal conversion process. Moreover, the low thermal conductivity of aerogel structure effectively reduces the heat loss to environment. Through tailoring the anisotropic channel, the A-Ti 3 C 2 T x /CNT hybrid aerogel with average channel size of 80 μm possesses most efficient water transport due to the capillary effect and formation of intermediate water. Therefore, the A-Ti 3 C 2 T x /CNT hybrid aerogel exhibits high average light absorption of 95.68% in the wavelength range of 200–2500 nm, excellent water evaporation rate of 2.10 kg m−2 h−1 under 1 sun irradiation (1 kW m−2) with a high energy efficiency of 93.4%, and remarkable durability with 7 days continuous water evaporation. The A-Ti 3 C 2 T x /CNT hybrid aerogel also shows high resistance to salt crystallization due to its high salt transport flux of 1.90 kg m−2 h−1. This work offers a prospective strategy for constructing highly efficient solar steam generator with stable performance for practical application in seawater desalination. A Short Summary: Through combining carbon nanotube (CNT) with high light absorption and Ti 3 C 2 T x MXene with excellent light-to-heat conversion efficiency, ultralight anisotropic Ti 3 C 2 T x MXene/carbon nanotube hybrid aerogels are fabricated for highly efficient solar steam generation. The obtained aerogel with suitable pore structure exhibits a high light absorption ability of up to 95.68% in the wavelength range of 200–2500 nm, an excellent water evaporation rate of up to ∼2.10 kg m−2 h−1 under 1 sun irradiation (1 kW m−2)) with a high energy efficiency of 93.4%, and a remarkable durability of up to 7 days. [Display omitted] [ABSTRACT FROM AUTHOR]

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Personalized rehabilitation training provides maximum help to stroke patients to alleviate the after-effects and restore the body to normal function. However, available monitoring devices have the disadvantages of being large, requiring professional guidance, and lacking intuitive signal display capabilities. Herein, a bio-inspired wearable high-performance strain sensor with a simple structure can simultaneous electrical signals and optical visualization in response to external stimuli. The sensor comprises a conductive layer with significant electromechanical behaviors of cellulose nanocrystals (CNC)/carbon nanotubes (CNTs)/MXene nanohybrid network, and a stretchable elastomer layer consisting of thermoplastic polyurethane and fluorescent agent. Benefiting from the designed microcracks and fluorescent material, the strain sensor exhibits ultra-high sensitivity (476800), ultra-low detection limit (0.005%), low response time (60 ms), wide working range (0–100%), and enables strain visualization for applications in visually rehabilitation training monitoring. Based on these sensing characteristics, the sensor shows great advantages in human motion and sound monitoring, with the integration of digital signals and visual images makes it show great potential in visually personalized rehabilitation training monitoring. [Display omitted] • Cellulose nanocrystals are introduced to modulate the sensitivity of the strain sensor. • CCMTPF has ultrahigh sensitivity of 476800 and ultralow detection limit of 0.005%. • CCMTPF achieves electric signals and visualization of optical images responses under strain. • CCMTPF has been demonstrated for visual rehabilitation training monitoring in real time. [ABSTRACT FROM AUTHOR]

Graphical abstract This study reports an aligned wave-like carbon nanotubes (CNTs)/thermoplastic polyurethane (TPU) fibrous network based strain sensor with ultra-wide sensing range, low detection limit, fast response rate and excellent stability, which provides a good candidate for wearable devices and artificial intelligence (AI). Highlights • An aligned conductive fibrous mat based strain sensor with wave-like structure was fabricated. • The sensor possesses an ultrahigh stretchability of 900%, combining with an excellent stability. • An ultralow detection limit (0.5%) and a fast response time of 70 ms have both been achieved. • The sensing behaviors of the CNTs/TPU fibrous sensor agree well with the tunneling theory. • The designed wave-like structure and the joints structure caused the fine sensing performances. Abstract Recently, flexible strain sensors with large stretchability, high sensitivity and excellent stability have been widely concerned owing to their potential applications in wearable electronic devices. However, the challenge of narrow sensing range still remains for strain sensors with high performance. In this paper, we proposed a facile, cost-effective and scalable technology to manufacture the carbon nanotubes (CNTs)/thermoplastic polyurethane (TPU) fibrous strain sensor with aligned wave-like structure. Through electrospinning technique, we prepared an aligned TPU fibrous mat, then used a simple and effective assembly approach to induce CNTs to wrap TPU fibrous mat through ultrasonication. The sensing properties of CNTs/TPU mats in vertical and parallel directions were investigated, respectively. The sensing behaviors of the two sensors both agreed well with the tunneling theory. Compared with the random CNTs/TPU mats and parallel direction sample, the aligned CNTs/TPU fibrous mats in vertical direction possessed an ultra-high stretchability (900%) and excellent durability (10,000 cycles at the strain of 200%). An ultra-low detection limit (0.5%) and fast response time of 70 ms were also achieved, exhibiting a favorable sensitivity. The generation of the wave-like structure and the joints structure in the designed conductive network, which could affect the evolution of the conductive paths subsequently, led to these excellent sensing performances. The CNTs/TPU mats strain sensor was then assembled to monitor both subtle human motions, like cheek bulging and phonation; and vigorous human motions, like leg squatting and elbow bending, both showing excellent sensing performances. The present paper provides a good candidate for potential applications as artificial skins, human-activity monitoring and personal healthcare. [ABSTRACT FROM AUTHOR]

Abstract Highly flexible and stretchable strain sensors play an important role in the wearable electronic systems. Up to now, it is still an enormous challenge to achieve a good balance between the wide response range and high sensitivity for a resistive-type flexible strain sensor. In this work, we prepared a fiber-shaped strain sensor based on thermoplastic polyurethane (TPU) and multi-walled carbon nanotubes (MWCNTs) via a simple and cost-efficient wet-spun method. The production process can satisfy continuous and large-scale preparation. The generation of the interesting porous structure is related to the solvent exchange in solidification process and beneficial to the improvement of the sensing range. In the uniaxial stretching test, the MWCNTs/TPU fiber-shaped sensor showed an ultra-wide workable strain range (320%), a high sensitivity (gage factor of 22.2 within 160% strain and 97.1 for strain of 160–320%) and a fast response time (<200 ms). The MWCNTs/TPU composite fiber sensor exhibited good reproducibility and excellent durability in multi-cycle test (9700 cycles at 100% strain). The mechanism of the response behavior was studied through the tunneling theory. The strain sensor shows potential applications in human motion detections including bending of the fingers, elbows and knee, squatting and squat-jumping. The present paper provides an effective strategy for the design of high performance fiber-shaped wearable electronic systems. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

The advantages of segregated conductive polymer composites are greatly hampered owing to its limited preparation technology, which seriously relies on hot compression with low efficiency. The plunger type injection molding (PTIM) is employed to fabricate segregated carbon nanotubes (CNTs)/high density polyethylene (HDPE)/ultra-high molecular weight polyethylene (UHMWPE) composites in this paper, which lowers the production cycle by 45%, compared with the conventional hot compression. The morphology and conductive properties are investigated in detail. Graceful segregated conductive network and a very low percolation threshold (0.45 vol%) of the polymer composites have both been achieved. The present processing technique with short production cycle provides a fancy idea to realize segregated conductive polymer composite in mass production. [ABSTRACT FROM AUTHOR]

In this paper, we used epoxy (EP) as a third component to tune the electromechanical performances of the conductive porous foam. A directional ice-template freezing method was utilized to fabricate a carbon nanotubes (CNTs)/EP/thermoplastic polyurethane (TPU) porous foam with a herringbone-like structure. CNTs were homogeneously distributed in the skeleton of the foam. The microstructure of the herringbone-like foam was studied in detail from both the directions perpendicular and parallel to the freezing front movement direction. An ultralow percolation threshold (0.088 vol%) of the conductive foam was achieved. The strength of the CNTs/TPU/EP foam was significantly enhanced with the increase of the CNTs and EP contents. When the foams were exposed to a compression strain from 0 to 70%, the resistance of the porous material decreased in a good linear manner. The foams showed a good differenciation capability towards different compression strain amplitude. Upon multiple cyclic compressive process, the change of the resistance tended to be stable after several compression loading-unloading cycles' measurement. After a pre-compression treatment, the resistance response also became much stable on the basis of the re-arrangement of the conductive network and the stabilized cells structure of the foam. The porous foam possesses a rapid response speed (about 160 ms). Our flexible porous foam with a good chemical resistance can be used in ethanol to sense the finger pressing, and it showed excellent sensing performances when applied to monitor human body motions. [ABSTRACT FROM AUTHOR]

A novel approach, i.e. manipulating the size of incorporated polymer matrix particles, was proposed to tune the positive temperature coefficient (PTC) characteristics of carbon nanotubes (CNTs)/polypropylene (PP) composites with a segregated microstructure. For the conductive properties of CNTs/PP composites, the percolation threshold decreased from 1.32 vol% to 0.44 vol% when the matrix particle size enlarged from 20 to 1200 µm, showing an inverse correlation effect. The controllable PTC characteristics in resistivity are attributed to the microstructure development of conductive pathways and the heat-induced volume expansion of polymer matrix particles. An extremely high PTC material has also been achieved through this method. The present work provides an effective route to acquire a tunable temperature-resistivity sensor. [ABSTRACT FROM AUTHOR]

Resistivity–temperature characteristics of conductive multi-walled carbon nanotubes (MWCNT)/epoxy (EP) composite were studied during a heating-cooling run (HCR) with different top test temperatures. The values of R e (room-temperature resistance at the end of a HCR) decrease with increasing the top test temperature. The fluctuation-induced tunneling conduction (FITC) and the hysteresis effect developing in MWCNT/EP composite are responsible for this fascinating phenomenon. In order to understand this result further, resistivity–temperature characteristic at different cooling rates was studied. The values of R e also decrease with rising the cooling rate. This paper provides an effective approach to acquire a tunable temperature sensor. [ABSTRACT FROM AUTHOR]

Carbon aerogels derived from biomass have been considered as potential microwave absorption (MA) materials because of the intrinsic hierarchical porous structure, low density, and excellent heat resistance. However, high carbonation temperature or long carbonation time is always required to achieve optimized MA performance. Herein, the low-temperature carbonization of carbon nanotube (CNT)/cellulose aerogel was realized to develop a carbon aerogel for efficient MA. Compared with the carbon aerogel derived from pristine cellulose, the incorporation of CNT endowed the CNT/cellulose-derived carbon aerogel with improved dielectric loss, and thus improved MA performance at reduced carbonation temperature. The carbon aerogel carbonized at only 550 °C for 2 h exhibited a minimum reflection loss value of −43.6 dB and a broad effective absorption bandwidth (reflection loss below −10 dB) of 7.42 GHz. The low carbonation temperature and outstanding MA performance make this new carbon aerogel be promising candidate for MA applications. [Display omitted] • With the aid of CNT, desirable dielectric loss of resultant carbon aerogel was achieved at reduced carbonation temperature and time without destroying the intrinsic hierarchical porous structure. • CNT was uniformly introduced into cellulose aerogel without damaging the structure. • The carbon aerogel exhibited a minimum reflection loss value of -43.6 dB and a broad effective absorption bandwidth (reflection loss below -10 dB) of 7.42 GHz. [ABSTRACT FROM AUTHOR]

The present work proposes a facile method to fabricate elastic micropatterned array, which can be further assembled into multifunctional interlocked e-skin. The as-prepared e-skin can simultaneously recognize pressure–temperature stimuli, monitor multiple arterial pulses waveform. Moreover, human physiological signals can be real-time wirelessly monitored by a remote mobile phone. • Elastic micropatterened array is fabricated via a cost-effective method. • Interlocked e-skin exhibits superior sensing stability in a wide working range. • Such interlocked e-skin can simultaneously recognize pressure–temperature stimuli. • Such interlocked e-skin can discriminate multiple arterial pulses waveform. • Human physiological signals can be wirelessly monitored by a remote mobile phone. Electronic skin (e-skin) based on elastic piezoresistive sensor is considered to be one of the most important components for future wearable electronic devices, whose performances can be substantially improved by shaping patterned surface. However, most patterned surfaces are generally fabricated via some tedious methods. Obviously, it is still a huge challenge to realize high sensing performance via facile fabrication process. Here, an efficient but facile method named hot-air-gun assisted preparation is proposed, which enable quasi-hemispherical micropatterned array to be directly fabricated on the single-walled carbon nanotubes (SWCNTs)/thermoplastic polyurethane (TPU) film. The interlocked micropatterns can significantly improve the sensing performance of the as-prepared e-skin based on such micropatterned film, endowing it with very fast response time (<46 ms), wide working range (0.055–254.8 kPa) and excellent durability (>20000 cycles). Interestingly, the interlocked e-skin exhibits multifunction to simultaneously discriminate pressure–temperature stimuli. Moreover, it can monitor a variety of human physiological signals (e.g., arterial pulse waveform, voice recognition and human breathing behavior), indicating a promising application in human–machine interaction. Furthermore, the as-prepared interlocked e-skin could be connected to a wireless transmitter for wireless monitoring respiratory rates. Considering the facile preparation process and the low-cost raw materials, this approach can be easily scaled up for practical production. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) are potential electromagnetic (EM) wave absorption (MA) material due to the strong dielectric loss, nevertheless, sole CNTs suffer from limited MA ability because of the interface impedance mismatch of CNTs and the skin effect, which leads to high reflection of EM wave. The impedance mismatch characteristics of CNTs can be effectively improved by incorporation of polyaniline (PANI) with an intermediate conductivity. However, to optimize the dispersion of CNTs and incorporate PANI into CNTs uniformly, chemical modifications were generally utilized. These methods involve strong acid and thus suffers from long-term and high risk. In particular, these methods would destroy the conjugate structure of CNTs and thus deteriorate the dielectric loss. Herein, the introducing of polyvinyl pyrrolidone (PVP) not only improves the dispersion of CNTs, but also helps to produce the monomer micelle and uniformly self-assemble on the surface of CNTs as steric stabilizer. The uniform PANI shell can solve the contradiction between strong dielectric loss of CNTs and the poor property of impedance match between CNTs and air, resulting in excellent MA ability. The minimum reflection loss (RL min) of obtained CNT/PANI hybrid reaches −41.5 dB at 9.5 GHz when the absorber mass ratio was only 10% due to the good dispersion of CNT/PANI hybrids. The effective absorption bandwidth (EB) with RL ≤ −10 dB reaches 5.1 GHz at the thicknesses of 2 mm. This work provides a facile, eco-friendly and defect-free way to fabricate CNT/PANI hybrid with excellent and tunable performance of MA. [ABSTRACT FROM AUTHOR]

Electromagnetic interference (EMI) shielding composites are inevitably damaged in the long-term usage which would affect the regular operation of the devices. Hence, the demand for materials with healable and reliable EMI shielding performance has increased. Here, a flexible conductive composite owning both self–healing and EMI shielding functions is facilely developed, with carbon nanotubes (CNTs) as conductive filler and dynamically crosslinked polyurethane bearing Diels–Alder bonds (PUDA) as polymer matrix. The PUDA/CNT composite shows a high EMI shielding effectiveness (EMI SE) of 30.7 dB at 5.0 wt% CNT loading in the range of X-band (8.2–12.4 GHz). And the EMI SE can recover from 16.8 dB for damaged state to 29.8 dB after three times cut/healing cycles, revealing excellent EMI SE retention of 97.1%. The PUDA/CNT composite also exhibits healable tensile properties with an elongation at break up to 571% ± 31% at 2.0 wt% CNT content and self-healing efficiency of 89.2% after the repeatable healing. This work demonstrates a healable EMI shielding composite, which ensures the reliability and long-time use under harsh conditions. Image 1 • The flexible self–healing EMI shielding composite is facilely developed. • The composite exhibits excellent mechanical and EMI shielding properties. • The composite shows highly efficient self-healing performance based on the Diels-Alder bonds. [ABSTRACT FROM AUTHOR]

Effective heat dissipation capacity and electromagnetic interference (EMI) shielding performance are urgently required for modern electronic equipment. Herein, pristine carbon nanotubes (CNTs) were first nondestructively functionalized by eco-friendly dopamine chemistry, which maintained the integrity of inherent graphitic lattice structure of CNTs. In the meanwhile, introduction of polydopamine (PDA) improved interfacial interaction between PDA-coated CNTs (CNT@PDA) and the ethylene-vinyl acetate copolymer (EVA) matrix. Favorable pathways for rapid thermal conduction and electron transmission were paved by oriented arrangement of CNT@PDA. As a result, dual-functional CNT@PDA/EVA composite films were fabricated, which exhibited remarkable in-plane thermal conductivity (TC) and prominent EMI shielding effectiveness (EMI SE). The TC and EMI SE of the 70 wt% CNT@PDA/EVA composite film climbed up to 17.9 W/mK and 32.4 dB, respectively. Furthermore, the CNT@PDA/EVA composite films revealed outstanding flexibility and mechanical fatigue durability. After repeated bending test, the retention ratio of the in-plane TC and EMI SE was 98% and 97%, respectively. The in-plane TC and EMI SE presented excellent retention ratio of 94% and 95% after repeated tensile test, respectively. Our work provides a valuable reference to design and fabricate dual-functional or multifunctional composites applied in modern electrical systems and electronic devices. [ABSTRACT FROM AUTHOR]

Ultrathin flexible transparent film heaters (TFHs) with fast response time are fabricated by embedding single-wall carbon nanotubes (CNTs) into transparent poly(vinyl alcohol) (PVA) film using a green all-water based solution process. Typically, CNTs network was firstly constructed on the surface of commercial polycarbonate film by a continuous hot roll pressing and spraying technique. The obtained CNTs network was then transferred to the surface of ultrathin PVA film using a transfer spinning technique coupled with hot pressing approach. The resulting film not only shows well optical and electrical properties of 475 Ω/aq with a transmittance of 77.3%, but also exhibits strong interfacial adhesion (standing 100 repeated scratches with 3 M sticky tape) and good flexibility (allowing more than 1000 bending cycles). Very interestingly, the fabricated PVA/CNT TFHs presents a quick Joule heating effect with a very fast heating time and rate of 8 s and 11.4 °C/s, respectively, under low impressed voltage (<15 V). These results demonstrate that our TFH is therefore considered suitable for providing anti-fogging or de-icing in optics and optoelectronic devices, as well as for wearable heating systems. [ABSTRACT FROM AUTHOR]