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Carbon fibre, steel fibre and graphite were used as conductive fillers to prepare cementitious materials with excellent electrothermal properties. The electrically conductive cementitious materials with different volume dosages were analysed through compressive and flexural strength, electrochemical impedance spectroscopy and temperature rise tests. An equivalent circuit model was established to study the electrically conductive heat generation mechanism in the electrically conductive cementitious composites. The results indicate that the mechanical properties of cementitious composite materials with a ternary conductive phase are better than those of pristine cementitious materials because the fibrous filler improves their mechanical properties. However, the incorporation of graphite in the material reduces its strength. Introducing fibrous and point-like conductive phase materials into the cementitious material enhances the overall conductive pathway and considerably reduces the electrical resistance of the cementitious material, enhancing its conductive properties. The volume ratios of carbon fibre, steel fibre and graphite that achieve an optimal complex doping in the cementitious material were 0.35%, 0.6% and 6%, respectively. This was determined using the mutation point of each circuit element parameter as the percolation threshold. In addition, at a certain safety voltage, there is a uniform change between the internal and surface temperatures of the conductive cementitious material, and the heating effect in this materialis is considerably better than that in the pristine cementitious material. [ABSTRACT FROM AUTHOR]

In this study, carbon nanotube (CNT)/carbon nanofiber (CNF) composite electrothermal films were prepared by electrospinning, and the effects of the CNT content and carbonization temperature on the electrothermal properties of the CNT/CNF composite films were investigated. The experimental results demonstrated that the conductivity of the CNT/CNF composite electrothermal film (0.006–6.89 S/cm) was directly affected by the CNT content and carbonization temperature. The electrothermal properties of the CNT/CNF positively correlated with the CNT content, carbonization temperature, and applied voltage. The surface temperature of CNT/CNF can be controlled within 30–260 °C, and continuously heated and cooled 100 times without any loss. The convective heat transfer with air is controllable between 0.008 and 31.75. The radiation heat transfer is controllable between 0.29 and 1.92. The prepared CNT/CNF exhibited a heat transfer efficiency of up to 94.5%, and melted a 1 cm thick ice layer within 3 min by thermal convection and radiation alone. [ABSTRACT FROM AUTHOR]

Transparent conductive oxide (TCO) thin films are highly sought-after for their unique characteristics of conducting electricity and transmitting visible light, making them ideal conductive coating materials for electronic devices. We carried out a comprehensive analysis of the deposition, optical, electrical, and structural properties of ITO and Ag/ITO thin films on glass substrates in this study. The weight ratio of the deposited metals was 1:10, 2:10, and 4:10 wt.% (Sn:In) for ITO films and 1:1:10 wt.% (Ag:Sn:In) for Ag–ITO film. The films were annealed at 300°C using a program controller furnace. We employed infrared cameras to analyze the surface temperature profiles of these thin films under external voltage supply. We also investigated the resistivity behavior of both ITO and Ag–ITO films, analyzing them with regard to Mott's variable range hopping (VRH) model and the fluctuation-induced tunneling model. Scanning electron microscope images revealed that adding Ag increased the grain size of ITO thin films. The average grain size for ITO thin film was determined as 186 nm, while it was found to be 270 nm for Ag–ITO thin film. Furthermore, incorporating Ag into the ITO thin film resulted in a reduction of 21.5% in transmittance over the complete visible range of the electromagnetic spectrum when compared to the ITO thin film without Ag as measured by ultra-visible spectrophotometer. The figure of merit was obtained as 0. 3 4 4 × 1 0 − 3 Ω − 1 for ITO and 0. 0 5 2 4 × 1 0 − 3 Ω − 1 for Ag–ITO thin films. However, the resistance of the ITO thin film was calculated to be 9.58 k Ω , while that of the Ag–ITO film was found to be 6.99 k Ω. The ITO thin film that included Ag exhibited a lower electrical resistivity due to the larger grain size caused by doped Ag atoms in the structure, leading to less electron scattering at the grain boundaries and a resulting decrease in resistivity as determined by four-point probe system. Thermal imaging camera measurements revealed that the surface temperature of the ITO thin film decreased with the addition of Ag under high voltage application, but not under low voltage. When a voltage of 350 V and 250 V was applied to the thin films, the ITO film exhibited a surface temperature of 73.9°C and 50.4°C, whereas under identical conditions, the Ag–ITO film showed a surface temperature of 62°C and 44.1°C, respectively. Furthermore, both films exhibited exponentially increasing surface temperature behavior under a certain voltage, suggesting that they have potential for transparent heaters and high-voltage/low-current applications. [ABSTRACT FROM AUTHOR]

With the intensification of global climate problems, electric heating has recently attracted much attention as a clean and low-carbon heating method. Carbon nanotubes (CNTs) are an ideal medium for electric heating applications due to their excellent mechanical, electrical, and thermal properties. The preparation of electrothermal films based on an aqueous CNT dispersion as a raw material is environmentally friendly. However, in the traditional one-step filtration method, the residual excess dispersant and the small aspect ratio of the CNTs in the preparation process limit the performance of electrothermal CNT films. In this paper, we report a two-step filtration method that removes the free dispersant and small CNTs in the first filtration step and obtains denser CNT films by controlling the pores of the filter membrane in the second filtration step. The results suggest that, compared to the CNT1 film obtained from one-step filtration, the CNT1-0.22 film, obtained from two-step filtration using 1 and 0.22 μm membranes, has a smoother and flatter surface, and the surface resistance is 80.0 Ω sq−1, which is 29.4% lower. The convective radiation conversion efficiency of the CNT1-0.22 film is 3.36 mW/°C, which is 36.1% lower. We anticipate that such CNT films could be widely applied in building thermal insulation and underfloor heating. [ABSTRACT FROM AUTHOR]

Copyright of Wool Textile Journal is the property of National Wool Textile Science & Technology Information Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Carbon fiber paper (CP) was prepared by wet forming technology, and liquid-phase polypyrrole/carbon fiber paper matrix composites (LPPY/CF) and gas-phase polypyrrole/carbon fiber paper matrix composites (GPPY/CF) were prepared by liquid-phase polymerization and gas-phase polymerization on CP, respectively. Then the effects of dopant, oxidant and solubility of pyrrole (PY) on the resistivity of LPPY/CF and the solubility of ferric trichloride (FeCl3) on the resistivity of GPPY/CF were discussed. Finally, the mechanical properties and thermal conductivity of CP, LPPY/CF and GPPY/CF were compared. The results show that: when ammonium persulfate (APS) and sodium anthraquinone-2-sulfonate (AQS) are used as oxidant and dopant, respectively, and pyrrole concentration is 0.75 mol/L, the resistivity of LPPY/CF is as low as 0.152Ω·cm; and when the solubility of FeCl3 is 1.2 mol/L, the resistivity of GPPY/CF is as low as 0.139Ω·cm. Compared with CP, not only the resistivity of LPPY/CF and GPPY/CF decreased significantly, but also the mechanical properties, hydrophobicity, electrical conductivity and heating properties increased significantly. Compared with LPPY/CF, GPPY/CF not only has lower resistivity, but also has better mechanical properties and heating uniformity. However, due to the easy corrosion of PPY, GPPY/CF has poor long-term energy storage capacity. [ABSTRACT FROM AUTHOR]

Although graphene-based polymer electrothermal films have received great attention, the graphene aggregation restricts the improvement in electrothermal performance. This study reports graphene (GN)/two-dimensional polyarylamide nanosheets (2DPA) filled poly (hexamethylene terephthalamide) (PA6T) composite film with outstanding electrothermal and mechanical performance. Owing to the addition of 2DPA, the as-prepared 2DPA-GN/PA6T composite film can attain a high heating-up rate of 25.5 °C/s, 1.8 times higher than that of GN/PA6T composite film (14.1 °C/s). Furthermore, the 2DPA-modified composite film showed a remarkable heating temperature rise to ∼230 °C, 80 °C higher than that of GN/PA6T composite film (∼150 °C). Additionally, the film had excellent mechanical performance with tensile strength and modulus of elasticity of 32.5 MPa and 4.6 GPa, which were 24.2 % and 52.3 % higher than that of GN/PA6T composite film, respectively. Such outstanding performance came from strong interfacial adhesion between GN and PA6T, induced by 2DPA nanosheets through hydrogen bonding and π-π interactions, which were confirmed by FTIR and UV–Vis measurements. Besides improving interfacial adhesion, 2DPA can also reduce the surface defect density of the GN through π-π conjugation. Both improved interfacial adhesion and reduced defects of GN contributed to the formation of electrically conductive and stress transfer pathways, which supported the excellent electrothermal and mechanical properties of 2DPA-GN/PA6T composite films. This study demonstrates an effective way to prepare high-performance graphene composites for electrothermal applications, with expected uses in aerospace, industry, and other technological fields. [Display omitted] • A graphene-nylon-based electrothermal composite film was designed and prepared. • Interfacial modifiers improved the electrothermal and mechanical performance of the graphene-nylon-based film. • Interfacial modifiers promoted interfacial adhesion as well as the densification and integrity of graphene structure. • The graphene-nylon-based films showed great promise as a heating element and wearable device. [ABSTRACT FROM AUTHOR]

Copyright of Advanced Textile Technology is the property of Zhejiang Sci-Tech University Magazines and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Electric heating gloves are essential for people working in severe cold environments which could protect their hands warm efficiently. Existing electric heating gloves, however, tend to restrict the movement of the fingers and have limited thermal protection, affecting the working efficiency of the wearers. Here, we report on the development and evaluation of carbon nanotube film (CNTF) and metal fiber based electric heating gloves. The electric heating elements were placed in the back of the gloves, and we tested the electric heating properties of the gloves. They showed great electrothermal performance and it had a certain repeatability and stability through multiple experiments. Then the electro-thermal and ergonomic performance of the gloves were evaluated under the severe cold outdoor environment of −20 ± 2°C. In comparison with conventional single layer polar fleece gloves and carbon fiber electric heating gloves that purchased from the market, CNTF based gloves and metal fiber-based gloves demonstrated outstanding advantages in terms of faster heating speed, great warmth retention, and enhanced finger agility, which is attributed to the electrothermal properties of CNTF and metal fiber as well as the structural design of the gloves. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Tiangong University is the property of Journal of Tianjin Polytechnic University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Electric heating gloves are essential for people working in severe cold environments which could protect their hands warm efficiently. Existing electric heating gloves, however, tend to restrict the movement of the fingers and have limited thermal protection, affecting the working efficiency of the wearers. Here, we report on the development and evaluation of carbon nanotube film (CNTF) and metal fiber based electric heating gloves. The electric heating elements were placed in the back of the gloves, and we tested the electric heating properties of the gloves. They showed great electrothermal performance and it had a certain repeatability and stability through multiple experiments. Then the electro-thermal and ergonomic performance of the gloves were evaluated under the severe cold outdoor environment of -20 ± 2°C. In comparison with conventional single layer polar fleece gloves and carbon fiber electric heating gloves that purchased from the market, CNTF based gloves and metal fiber-based gloves demonstrated outstanding advantages in terms of faster heating speed, great warmth retention, and enhanced finger agility, which is attributed to the electrothermal properties of CNTF and metal fiber as well as the structural design of the gloves. [ABSTRACT FROM AUTHOR]

Herein, the electromagnetic interference (EMI) shielding and electrothermal properties of MXene‐coated cellulose hybrid papers (MCPs) and fabrics (MCFs) with high flexibility and low density, which are manufactured by a dip‐dry coating approach, are reported. For this purpose, MCPs and MCFs are fabricated by dipping cellulose papers and fabrics repeatedly into an aqueous dispersion of MXene. The electron microscopic and X‐ray diffraction data reveal that MXene sheets are coated uniformly on the surfaces of cellulose fibrils and fibers and that their contents increase with the dip‐dry coating cycle. For MCP10 (5.68 wt% MXene) and MCF10 (11.77 wt% MXene), which are manufactured by ten‐time dip‐dry coating cycles, high electrical conductivity of 1.91 and 0.08 S cm−1 are attained, respectively. In addition, MCP10 and MCF10 possess excellent absolute EMI shielding effectiveness (SSEt) of 2198 and 1100 dB cm2 g−1 at 8 GHz, respectively, which is due to the multiple internal reflection and absorption of incident EM waves by conductive and interconnected MXene‐coated cellulose fibrils and fibers. It is also found that MCP1 (0.9 wt% MXene) and MCF1 (1.9 wt% MXene) at one‐time dip‐dry coating cycle show outstanding electrothermal performance in aspects of high saturated temperatures and energy conversion efficiency at low applied voltages. [ABSTRACT FROM AUTHOR]

A three-dimensional (3D) hierarchical microfiber bundle-based scaffold integrated with silver nanowires (AgNWs) and porous polyurethane (PU) was designed for the Joule heater via a facile dip-coating method. The interconnected micrometer-sized voids and unique hierarchical structure benefit uniform AgNWs anchored and the formation of a high-efficiency 3D conductive network. As expected, this composite exhibits a superior electrical conductivity of 1586.4 S/m and the best electrothermal conversion performance of 118.6 °C at 2.0 V compared to reported wearable Joule heaters to date. Moreover, the durable microfiber bundle-PU network provides strong mechanical properties, allowing for the stable and durable electrothermal performance of such a composite to resist twisting, bending, abrasion, and washing. Application studies show that this kind of Joule heater is suitable for a wide range of applications, such as seat heating, a heating jacket, personal thermal management, etc.

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, cotton fabrics were reported to be typically functionalized by loading silver nanowires (AgNW) on the surface of the polydopamine modified cotton fabric. Firstly, AgNW were prepared by a polyol method and then a polydopamine-modified cotton fabric was prepared by being immersed in AgNW dispersion by the dip-coating method. The resulting silver nanowire/polydopamine/cotton-based nanocomposites (APCN) has a surface specific resistance as low as 2.4 Ω and has good durability and flexibility. In addition, the electrothermal properties of APCN were investigated by applied voltage. The result showed that the composite material can reach 80 °C in a short time under the voltage of 1.8 V, and conform to the power balance model. The steady-state temperature of the composite material is closely related to the voltage, and has a quadratic relationship with the voltage and expresses linear relation with the electric power. [ABSTRACT FROM AUTHOR]

With the development of communication facilities, electromagnetic pollution has become more problematic in modern society. Outdoor electromagnetic devices such as signal stations and radar units are the main source of electromagnetic pollution. Therefore, it is urgent to develop electromagnetic interference (EMI) shielding composites for outdoor applications. Meanwhile, the accumulation of ice on the surfaces of these facilities often has serious effects, especially in winter and cold areas. To this end, the Polydimethylsiloxane/Graphite/Carbon black-Polydimethylsiloxane/Fe 3 O 4 @Multi-walled carbon nanotube-Aramid paper@Ag (PDMS/GP/CB-PDMS/Fe 3 O 4 @MWCNTs-AgP) laminated composite was prepared by combining spraying, scraping and electroless plating techniques to enable the coordination of EMI shielding and de-icing. Through the rational design of the absorbing and conducting layers, the PDMS/GP/CB-PDMS/Fe 3 O 4 @MWCNTs-AgP composite has a shielding effectiveness of 31.35 dB in the X-band and an ultra-high absorption coefficient (A) of 0.9. It is worth noting that, due to the rough structure and the low surface energy of the surface layer, the composite exhibits excellent superhydrophobicity (158° ± 1°). Importantly, the PDMS/GP/CB-PDMS/Fe 3 O 4 @MWCNTs-AgP composite exhibits stable electrothermal properties, with a fast response and high-speed de-icing capability. At 0.1 W/cm2 input electrical power, ice completely melts in 210 s. And the composite shows excellent photothermal properties, with the ice completely melts within 180 s at 1 sun. The composite also shows excellent self-cleaning properties and acid-alkali resistance. This multifunctional EMI shielding composite provides a new strategy for the safe and long-term use of all-weather outdoor devices. [Display omitted] • A superhydrophobic electromagnetic interference shielding composite was prepared by layer-by-layer method. • The composite in the X-band has a shielding effectiveness of 31.35 dB and an absorption coefficient of 0.9. • The dual-sized particles endow the composite excellent electro/photo-thermal and superhydrophobic properties. • The composite possesses good acid-alkali resistant and self-cleaning ability. [ABSTRACT FROM AUTHOR]

In this study, nickel tailings were utilized to prepare electrothermal coatings composited with nano-graphite/multilayer graphene, and the effects of heat treatment temperature and time of nickel tailings on the performance of electrothermal coatings were investigated. The experimental results show that the addition of nickel tailings can significantly enhance the performance of the composite electrothermal coatings. Using nickel tailings treated at 60 °C for 2 h caused the temperature response time of the coatings to decrease by 57%, and the maximum temperature was 55.4 °C. However, as the treatment temperature was increased to 100 °C, a large amount of oxygen was introduced into the system, which led to a weakening of the ferric ion conduction in the ferromagnesian olivine, resulting in only a 28.6% reduction in the temperature response time at the maximum temperature of 45.4 °C. Meanwhile, it was established that the multidimensional stabilized conductive network formed by nickel tailings and nano-graphite/multilayer graphene enhanced the comprehensive performance of the coating. In addition, the study on the coating work stability revealed that the electrothermal coating prepared by adding nickel tailings treated at 60 °C for 2 h can maintain the maximum stable temperature above 55 °C for a long period of time, which is significantly better than the samples without nickel tailings and with nickel tailings heat-treated at 100 °C. This electrothermal composite coating is particularly suitable for low-pressure and low-power high-efficiency heating equipment, energy saving and environmental protection. Compared with the existing work, this experiment uses nickel tailings solid waste as auxiliary filler, which has the advantages of low cost, simple fabrication process, energy saving, environmental protection, low energy consumption, etc. It provides a more sustainable and eco-friendly solution for heating needs in a variety of fields. The material will be developed in the direction of higher conversion efficiency and higher temperature threshold in the future. It can be widely used in the fields of intelligent heating of houses, intelligent electric heating of clothes, and de-icing of wings of aircrafts. • Incorporation of waste nickel tailings into nano-graphite/multilayer graphene composite powders to improve the performance of composite electrothermal coatings. • Temperature response time of the electrothermal coating by 57%. • The fluctuation of each performance in the cycling stability test lasting 10 days was less than 1%. [ABSTRACT FROM AUTHOR]

Due to the significance of electron and heat transfer in designing the nanoscale semiconductor devices, the transient analysis of electrothermal properties has attracted extensive attention. In this paper, the density-gradient and dual-phase-lag (DPL) equations are first combined to predict the electron and heat transport in nanoscale transistors. The DPL equation is solved with the consideration of the temperature jump boundary condition that dealing with phonon–wall collisions. We have shown that the temporal and spatial distributions of related physical variables can be obtained by self-consistently solving these equations. Furthermore, the spectral element time-domain method is used to discretize these equations. Numerical results of electrothermal properties for both 2-D and 3-D field-effect transistors have been demonstrated to show the robustness and universality of the proposed model. Therefore, the model we proposed can be used with the temporal and spatial distributions, which could be helpful for evaluating the electrothermal performance and computational designing of nanoscale transistors. [ABSTRACT FROM AUTHOR]

• The use of graphene and carbon fiber as conductive phase materials for the preparation of graphene-conductive asphalt-recycled permeable concrete. • Determined the optimal conductive filler ratio and achieved a resistivity of only 3.2 Ω·m. • The effect of the required snow melting thickness and snow melting time on the efficiency of pervious asphalt slabs for snow melting are studied. Conductive-asphalt-recycled pervious concrete alleviates the urban "heat island effect" and "rain island effect" to realize the resourceful and efficient use of waste concrete and also reduces the probability of urban snow and ice disasters to ensure the safety of winter operation of asphalt pavements in cold areas. This study presents a theoretical and technical basis for ensuring the winter operational safety of asphalt pavements in cold regions. First, we compound graphene and carbon fiber as conductive phase materials and prepare graphene-conductive asphalt-recycled permeable concrete using recycled coarse aggregates with straight top and bottom holes. Then, we analyzed the electrical conductivity, road performance, and electrothermal performance of the specimens prepared using different recycled coarse aggregate substitution rates under different snowfall levels to determine their snow melting efficiency and verify their application in cold regions. The results indicate that the quality of the recycled aggregates is high, the optimal conductive filler ratio is 0.3% polyacrylonitrile-based carbon fiber and 1.5% graphene by mass of asphalt, and the resistivity of the specimens is only 3.2 Ω·m. Moreover, the conductivity and road performance of the graphene-conductive asphalt-recycled concrete decreases with an increase in the replacement rate of the recycled coarse aggregate, and the artificially prefabricated upper and lower through holes affect the conductivity of the specimens to a certain extent. Further, the graphene-conductive asphalt-recycled pervious concrete shows excellent snow melting potential, and as the required snow melting thickness and snow melting time increase, the effect of pervious asphalt slabs for snow melting efficiency becomes more significant. Moreover, when the replacement rate of the recycled concrete aggregate is within the range of 0–50%, it can be completed in 2–3 h under different snowfall levels of snow melting requirements. [ABSTRACT FROM AUTHOR]

Silver nanowires (AgNWs) show promise for fabricating flexible transparent conductors owing to their excellent conductivity, high transparency, and good mechanical properties. Here, we present the fabrication of transparent films composed of AgNWs with diameters of 20−30 nm and lengths of 25−30 μm on polyethylene terephthalate substrates and glass slides substrates using the Meyer rod method. We systematically investigated the films’ optoelectronic and electrothermal properties. The morphology remained intact when heated at 25−150 °C and the AgNWs film showed high conductivity (17.6−14.3 Ω∙sq−1), excellent transmittance (93.9−91.8%) and low surface roughness values (11.2−14.7 nm). When used as a heater, the transparent AgNW conductive film showed rapid heating at low input voltages owing to a uniform heat distribution across the whole substrate surface. Additionally, the conductivity of the film decreased with increasing bending cycle numbers; however, the film still exhibited a good conductivity and heating performances after repeated bending.

Polysulfonamide/poly(3,4-ethylenedioxythiophene) (PSA/PEDOT) conductive composite yarns were prepared by the vapor phase polymerization technique. Ferric chloride (FeCl3) was used as the oxidant initiator with five different concentration settings (20, 40, 60, 80, and 100 g/L). The effects of oxidant concentration on the chemical composition, mechanical properties, and electrical conductivity of PSA/PEDOT composite yarns were analyzed. The surface resistance and mass-specific resistance of conductive yarns were measured to investigate its conductive behavior in terms of oxidant concentration, reaction time, impregnating time, and heating temperature. The effects of the applied voltage and the yarn’s combination structures (knotted, bundled, series, and parallel) on the electrothermal properties were determined using a direct current regulated power. It was concluded that the molecular structure and chemical composition of PSA is not changed significantly with the deposition of PEDOT. The optimized deposition settings for the preparation of the PSA/PEDOT conductive composite yarns were found to be 10 min (reaction time), 60 min (impregnating time), 80℃ (heating temperature), and 80 g/L (FeCl3 concentration). Correspondingly, the mass-specific resistance of PSA/PEDOT composite yarns could be up to 0.94 Ω g cm−2. The maximum heating temperature of PSA/PEDOT conductive composite yarns during the electrical heating procedure could be increased rapidly with an increase of applied voltage and then tended to be stable. The electrothermal properties of PSA/PEDOT conductive composite yarns with different combination structures (knotted, bundled, series, and parallel) have been investigated systematically. This study presents a new way to develop conductive polymer based yarns, which can be used as fibrous sensors, connection devices in smart clothing, and for electromagnetic shielding applications. [ABSTRACT FROM AUTHOR]

This paper discusses the electrothermal characteristics of microelectrical contacts for arcless switching. The 3-D microelectrical contact suitable for dc power-switching application is considered. The important parameters for the design of an arcless microelectrical contact are identified. The ON-state contact resistance and the temperature are calculated and simulated using an Finite Element Method (FEM) tool. In order to design an arcless switching contact, the simulation-based steady-state and transient temperature distributions are estimated. The OFF-state capacitance and the electric field distribution are calculated and simulated for the arcless microelectrical contact. The analysis is carried out for the materials Al, Cu, Au, and Pt. The power ratings of the arcless microelectrical contact are identified. These results can be considered while designing an arcless electrical contact for microswitches, relays, and circuit breakers. [ABSTRACT FROM AUTHOR]

Carbon/glass fiber hybrid textile reinforced concrete is a relatively new composite material with good mechanical capacity and excellent electrical conductivity. Both small-scale slab heating experiments and numerical simulation are presented in this paper. Temperature variation curves obtained during heating indicate the effects of environmental temperature, heat-conducting layer thickness and electric heating power. Comparison of temperature rising between the situations with and without thermal isolation layer is given as well. The results indicate that the textile can form a good conductive heating network and generate enough heat to raise the temperature in the concrete when connected to a power supply, while the resistance of the slab remains stable during the heating. Numerical results are in good accordance with the experiments. Real time snow-melting experiment was conducted to verify the feasibility of deicing. The electrothermal properties of textile can be utilized for deicing and snow melting in a safe, environmentally friendly and efficient way. [ABSTRACT FROM AUTHOR]

To reduce the impact of road ice and snow disaster, it is necessary to adopt low energy consumption and efficient active deicing and snow melting methods. In this article, three functional components are combined into a conductive ethylene propylene diene monomer (EPDM) rubber composite material with good interface bonding. Among them, the mechanical and electrical properties of the composite material are enhanced by using carbon fiber cloth as a heating layer. EPDM rubber plays a mainly protective role. Further, aluminum silicate fiber cloth is used as a thermal insulation layer. The mechanical properties of EPDM rubber composites reinforced by carbon fiber cloth and the thermal behaviors of the composite material in high and low temperature environments were studied. The heat generation and heat transfer effect of the composite were analyzed by electrothermal tests. The results show that the conductive EPDM rubber composite material has good temperature durability, outstanding mechanical stability, and excellent heat production capacity. The feasibility of the material for road active deicing and snow melting is verified. It is a kind of electric heating deicing material with broad application prospects. [ABSTRACT FROM AUTHOR]

Recently, more and more researchers have focused on electrical textiles that can provide or convert energy to facilitate people's lives. Knitting conductive yarns into ordinary fabrics is a common way for electrical textiles to transmit heat or electrical signals to humans. This paper is aimed at studying the resistance values and temperatures of electrothermal knitted conductive fabric (EKCF) subjected to certain voltages over time. Six types of EKCFs with structural differences were fabricated using a computerized flat knitting machine with intarsia technology. Uniform samples 10 × 10 cm in size were made from wool, as were two different specifications of silver-coated conductive yarns. The wool yarn and one silver-coated yarn were mixed to knit a resistance area 2 × 2 cm in size in the center of the EKCF to observe heating behaviors. The experiment results showed that when the EKCFs were subjected to certain voltages over time, the resistance values of the resistance area increased over a short time and then gradually decreased, and the temperature gradually increased in the first 1000 s and tended toward stability after a certain period of time. The structural coefficient κ between different knitted structures (which predicted the thermal properties of different EKCFs subjected to different voltages) was analyzed. These results are of great significance for predicting the electrothermal performance of EKCFs with different knitted structures. On the basis of these results, an optimized knitted structure was selected as the best EKCF for wearable textiles, and the findings contribute to the field of technological and intelligent electrothermal garments and related products. [ABSTRACT FROM AUTHOR]

Silver nanowires (AgNWs) show promise for fabricating flexible transparent conductors owing to their excellent conductivity, high transparency, and good mechanical properties. Here, we present the fabrication of transparent films composed of AgNWs with diameters of 20–30 nm and lengths of 25–30 μm on polyethylene terephthalate substrates and glass slides substrates using the Meyer rod method. We systematically investigated the films' optoelectronic and electrothermal properties. The morphology remained intact when heated at 25–150 °C and the AgNWs film showed high conductivity (17.6–14.3 Ω∙sq−1), excellent transmittance (93.9–91.8%) and low surface roughness values (11.2–14.7 nm). When used as a heater, the transparent AgNW conductive film showed rapid heating at low input voltages owing to a uniform heat distribution across the whole substrate surface. Additionally, the conductivity of the film decreased with increasing bending cycle numbers; however, the film still exhibited a good conductivity and heating performances after repeated bending. [ABSTRACT FROM AUTHOR]