Surface Power Density Research Articles

Innovative Wearable Electronics: Next-Generation Nitrogen-Doped Lutetium-Carbon Microspheres Composites for Robust Energy Harvesting.

In the quest to advance wearable electronics, this study presents a novel method using nitrogen-doped lutetium-carbon microspheres (N, Lu-CMS) for high-performance piezoelectric energy harvesting. The synthesis of N, Lu-CMS begins with the polymerization of sucrose, followed by the preparation of N, Lu-CMS metal complexes through the incorporation of lutetium (III) nitrate hydrate and thiourea, yielding a black powder product. The wearable electronic device is designed with a silicon rubber (SR) matrix, reinforced with 0D fillers such as N, Lu-CMS, or molybdenum disulfide (MoS₂). Mechanical testing revealed a significant improvement in compressive modulus, reaching 3.7MPa (N, Lu-CMS) at a concentration of 3 parts per hundred rubber (phr). Electromechanical assessments demonstrated efficient energy conversion, while biomechanical analysis, including thumb pressing tests, showed a notable increase in output voltage, peaking at ≈285mV (N, Lu-CMS) at 3 phr. This research provides a foundation for future engineering applications, particularly in electronic packaging for wearable electronics and smart devices, underscoring the significant impact of N, Lu-CMS in this emerging field. The surface power density achieved is 0.026 nWcm- 2 (N, Lu-CMS) and 0.0056 nWcm- 2 (Hybrid). Lastly, the conversion efficiency is 6.26% for N, Lu-CMS, and 1.05% for the hybrid system.

An acoustic nanogenerator based on porous PDMS/ZnO/PVDF-TrFE structure for self-powered intermediated-frequency sound monitoring

Abstract Sound energy is widely present in natural environment, nowadays predominantly collected using voluminous and heavy rigid devices, limiting their portability. Till now, there are few reports about using flexible materials to collect sound energy, and it is usually susceptible to environmental humidity. This study combines flexible polymer polydimethylsiloxane (PDMS), piezoelectric material polyvinylidene difluoride trifluoroethylene (PVDF-TrFE), nano zinc oxide (ZnO), and conductive carbon nanotubes (CNTs) to fabricate a porous nano ZnO/PVDF-TrFE/CNTs PDMS sound-driven nanogenerator (PZPCP SNG). It amalgamates frictional and piezoelectric effects: its porous structure enables efficient collection of vibration and frictional energy generated by sound waves; the piezoelectric effect of PVDF-TrFE and nano ZnO facilitates the conversion of acoustic mechanical energy, collectively enhancing the generator's output. Experimental optimization yields the best production conditions, achieving optimal outputs of 481.1 mV (open-circuit voltage), 209.13 nA (short-circuit current) under 400 Hz/125 dB sound stimuli, with a surface power density of 9.1 µW/m² (volumetric power density of 2.28 mW/m³). And it can convert sound ranging from 63-3000 Hz. With hardware circuitry, up to 5 series-connected light-emitting diodes (LEDs) can be illuminated within the circuit, demonstrating a certain degree of sound recognition capability. The proposed PZPCP SNG design is simple, effective, and lightweight, enabling flexible and stable intermediated-frequency acoustic energy harvesting. Its hydrophobic structural characteristics render it adaptable to various humidity, presenting a new approach toward widespread low-power sound detection and self-powering applications.

Energy-harvesting tile incorporating an origami coupling mechanism.

We present the design and evaluation of a simple, compact and efficient electromagnetic energy harvesting tile that can be used to harness energy from footsteps. The proposed harvester incorporates a translational-rotational origami-inspired coupling mechanism to transform the axial loads exerted by human footsteps into a localized rotation of an electromagnetic generator. The coupling mechanism employs a non-rigid tunable Kresling spring, the restorative behaviour of which is tunable to maximize energy transduction from the applied load to the generator. A computational model is developed to optimize the design parameters of the mechanism, which are then utilized to fabricate a prototype of the energy harvester. The tile is tested under loading conditions that mimic a human step, where it is demonstrated that it is capable of generating 4.18 W of electrical power per step with a surface power density of 2609 μW cm-2.This article is part of the theme issue 'Origami/Kirigami-inspired structures: from fundamentals to applications'.

Impact of photobiomodulation therapy on pro-inflammation functionality of human peripheral blood mononuclear cells – a preliminary study

Research into the efficacy of photobiomodulation therapy (PBMT) in reducing inflammation has been ongoing for years, but standards for irradiation methodology still need to be developed. This study aimed to test whether PBMT stimulates in vitro human peripheral blood mononuclear cells (PBMCs) to synthesize pro-inflammatory cytokines, including chemokines. PBMCs were irradiated with laser radiation at two wavelengths simultaneously (λ = 808 nm in continuous emission and λ = 905 nm in pulsed emission). The laser radiation energy was dosed in one dose as a whole (5 J, 15 J, 20 J) or in a fractionated way (5 J + 15 J and 15 J + 5 J) with a frequency of 500, 1,500 and 2,000 Hz. The surface power densities were 177, 214 and 230 mW/cm2, respectively. A pro-inflammatory effect was observed at both the transcript and protein levels for IL-1β after PBMT at the energy doses 5 J and 20 J (ƒ=500 Hz) and only at the transcript level after application of PBMT at energy doses of 20 J (ƒ= 1,500; ƒ=2,000 Hz) and 5 + 15 J (ƒ=500 Hz). An increase in CCL2 and CCL3 mRNA expression was observed after PBMT at 5 + 15 J (ƒ=1,500 Hz) and 15 + 5 J (ƒ=2,000 Hz) and CCL3 concentration after application of an energy dose of 15 J (frequency of 500 Hz). Even though PBMT can induce mRNA synthesis and stimulate PBMCs to produce selected pro-inflammatory cytokines and chemokines, it is necessary to elucidate the impact of the simultaneous emission of two wavelengths on the inflammatory response mechanisms.

Tri-generation of sensible heat, hydrogen, and electricity in an aluminum-air flow battery (AAB) system

The performance of an aluminum-air flow battery (AAB) unit cell is experimentally studied for application to a tri-generation system as a district heating resource of sensible heat storage, hydrogen production, and electric power generation. A layer-type unit cell is designed to protect against leakage of hydrogen gas during operation and to ensure electrolyte circulation in the AAB system. The electrolyte is made with NaOH pellets dissolved in purified water. A direct current (DC) loader is used to measure the electric power of the AAB unit cell, while a resistance temperature detector (RTD) is used to measure the electrolyte temperature at the unit cell inlet and outlet. The objective of the present work is to study the effect of operation parameters [i.e., electrolyte temperature (Tin), mass flow rate (ṁNaOH), and molar concentration (XNaOH)] on the performance of the tri-generation AAB system. The electric power of the AAB unit cell increases in the electrolyte temperature from 20 ℃ to 50 ℃ with increases in the NaOH molar concentration from 1 M to 4 M. The performance measurement of the AAB unit cell shows that the total surface power density of sensible heat, hydrogen, and electric power increased with increases in electrolyte temperature from 35 ℃ to 55 ℃. The tri-generation system operates for 140 min under the condition of Tin = 40 ℃, ṁNaOH=14.48 g/s, and XNaOH=4 M.

Simultaneous Optimization and Integration of Multiple Process Heat Cascade and Site Utility Selection for the Design of a New Generation of Sugarcane Biorefinery.

Biorefinery plays a crucial role in the decarbonization of the current economic model, but its high investments and costs make its products less competitive. Identifying the best technological route to maximize operational synergies is crucial for its viability. This study presents a new superstructure model based on mixed integer linear programming to identify an ideal biorefinery configuration. The proposed formulation considers the selection and process scale adjustment, utility selection, and heat integration by heat cascade integration from different processes. The formulation is tested by a study where the impact of new technologies on energy efficiency and the total annualized cost of a sugarcane biorefinery is evaluated. As a result, the energy efficiency of biorefinery increased from 50.25% to 74.5% with methanol production through bagasse gasification, mainly due to its high heat availability that can be transferred to the distillery, which made it possible to shift the bagasse flow from the cogeneration to gasification process. Additionally, the production of DME yields outcomes comparable to methanol production. However, CO2 hydrogenation negatively impacts profitability and energy efficiency due to the significant consumption and electricity cost. Nonetheless, it is advantageous for surface power density as it increases biofuel production without expanding the biomass area.

A Contact‐Separation Mode Hybrid Generator Based on Magnetic Springs

The emergence of the intelligent society presents a significant challenge with regard to distributed energy. One potential solution is to harvest energy from the environment to power micro/nano systems. Herein, an electric‐triboelectric hybrid generator (ETMHG) supported by magnetic springs is presented that operates in the contact‐separation mode. The traditional mechanical springs in the triboelectric nanogenerators are replaced by magnetic springs, and solenoid coils are added. This structure can achieve electromagnet‐triboelectric hybrid generation without significantly increasing the volume of the generator, and the use of magnetic springs offers a solution to the issues of difficult installation and mechanical wear and tear that are inherent in mechanical spring‐based triboelectric nanogenerators. The proposed hybrid generation ETMHG is shown to increase the output capacity of the generator, improve the efficiency of environmental energy harvesting, and achieve an instantaneous maximum power of 4.75 mW and instantaneous maximum power density of 95 W m−3. The ETMHG can charge a 10 μF capacitor that improves efficiency by 52.6% compared to an electromagnetic generator. The output surface power density of TENG in ETMHG can reach 1.12 W m−2.

High-Performance Coaxial Counter-Rotating Triboelectric Nanogenerator with Lift-Drag Hybrid Blades for Wind Energy Harvesting.

Wind energy holds potential for in-situ powering large-scale distributed wireless sensor nodes (WSNs) in the Internet of Things (IoT) era. To achieve high performance in wind energy harvesting, a coaxial counter-rotating triboelectric nanogenerator with lift-drag hybrid blades, termed CCR-TENG, has been proposed. The CCR-TENG, which can work in non-contact and soft-contact modes, realizes low-speed wind energy harvesting through a combination of counter-clockwise rotating lift-type blades and clockwise rotating drag-type blades. Non-contact CCR-TENG realizes low-speed wind energy harvesting at wind speeds as low as 1 m/s. The output of a CCR-TENG, working in soft-contact mode, achieves 41% promotion with a maximum short-circuit current of 0.11 mA and a peak surface power density of 6.2 W/m2 with two TENGs connected in parallel. Furthermore, the power density per unit of wind speed achieves 746 mW/m3·s/m. Consequently, two fluorescent lamps were successfully illuminated and six temperature sensors were continuously lit by the CCR-TENG. The reported CCR-TENG significantly improves low-speed environmental wind energy utilization and demonstrates broad application prospects for in-situ power supply of distributed wireless transmission devices and sensors in the era of the IoT.

Mechanical and Chemical Resistance of UV Coating Systems Prepared under Industrial Conditions Using LED Radiation.

The furniture industry constantly strives to search for ecological and cost-effective solutions in the production of wood-based composites. It is anticipated that furniture with a honeycomb core and HDF-facing will gain market share. Understanding how specific technical and procedural factors on the finishing line affect the resistance of coatings on furniture elements made of honeycomb boards was the main goal of the study. With the use of a digital microscope, the roughness of two different types of HDF was tested. On the industrial UV LED+Hg finishing line, 198 different surface coating variations were produced by applying five or six layers of varnish applied, ranging from 3 to 30 g/m2 and hardening them with various surface power densities. On the basis of statistical tests, the influence of individual factors on abrasion, impact, and scratch resistance was determined. The nanointendence test of the coatings was used to measure the hardness and elasticity modulus. The coloring caused by coffee traces was checked using a colorimeter. The findings confirm the conception that LED+Hg lamp modules can replace mercury and gallium-doped mercury lamps.

Quantitative characterization of the temporal-spatial evolution of RONS in air surface micro-discharge using UV–VIS optical absorption spectroscopic diagnosis and modeling approach

The research of the chemically active species of cold atmospheric pressure plasmas is a essential step for a more in-depth comprehension of the effects of its interaction with the target. In this paper, the temporal and spatial evolution of key species O3, NO2 and NO3 produced by surface micro-discharge in air were investigated. UV–VIS optical absorption spectroscopy at 254 nm, 400 nm and 662 nm were used to measure the concentrations of O3, NO2 and NO3, respectively. The results show that the temporal evolution of O3, NO2 and NO3 are revealed a significant correlation with the surface power density (SPD). The phenomenon of O3 and NO3 quenching occur once the SPD overcomes a critical value of 0.15 W cm−2. An O3-enriched atmosphere (peak concentration around 3000 ppm) is formed when the SPD is below the critical value, and a NO2-enriched atmosphere (maximum NO2 density around 600 ppm) is formed at higher SPD. In addition, the concentration distribution of O3, NO2 and NO3 in the chamber ranging from 10–100 mm of the downstream of the mesh electrode tends to be uniform. Finally, a zero-dimensional model of the afterglow chemistry, validated using the experimental measurements, is developed to determined important reactions affecting O3, NO2 and NO3 respectively, and obtain insight into the evolutionary behavior of the considered reactive species.

Tolerance Increase in Escherichia coli O157:H7 and Methicillin-Resistant Staphylococcus Aureus USA300 Exposed to Low-Power Continuous Ultraviolet Radiation from Narrow-Wavelength Sources

Escherichia coli O157:H7 is a major cause of foodborne disease outbreaks throughout the world, while methicillin-resistant Staphylococcus aureus (MRSA) is responsible for many difficult-to-treat infections in humans. Ultraviolet (UV) irradiation is commonly used for disinfection in food processing, medical facilities, and water treatment to prevent the transmission of these pathogen. With increased use of UV disinfection technologies over the last few years because of COVID-19 and concerns about other communicable disease, it has become a concern that microbial species could develop tolerance to UV irradiation, especially when it is applied continuously. To elucidate the effect of continuous UV exposure at different wavelengths and power levels on the tolerance development of bacteria, Escherichia coli O157:H7 and MRSA)USA300 growths were investigated by continuously exposing inoculated agar plates to six different commercially available UV sources at wavelengths of 222 nm, 254 nm, 275 nm, and 405 nm. The agar plates in these experiments were partially covered by a thin acrylic sheet, which provided either complete protection from the UV to the cells directly under the sheet, no protection if significantly away from the sheet, or partial protection near the edges of the sheet due to shading or small amounts of UV reflection under the sheet at the edges. In these experiments, tolerant cells of E. coli and S. aureus were found from the 222 nm, the 405 nm, and one of the 254 nm sources. Upon examination of the power of each UV source, it was shown that the 275 nm and 254 nm sources that resulted in no tolerant cells had surface power densities [at 25 cm (10 in.)] that were more than 10–200 times greater than those that had tolerant cells. These results suggests that bacterial cells have a higher chance to develop UV tolerance under lower power UV sources (under the experimental conditions in our laboratory). Genome investigation of the tolerant colonies revealed that there are no significant differences between the cells that developed tolerance and the original organism, hinting at the need to explore the role of epigenetics mechanisms in the development of UV tolerance in these bacteria.

Energy-efficient anti-icing performance of a hybrid superhydrophobic and electrothermal coating on metallic substrates

This paper reports the development of a hybrid anti-icing coating consisting of a thin-film electric heater and a superhydrophobic top coating. The coating was applied to a stainless steel substrate by a simple multi-layered spray coating process. The heating film consists of a layer of copper-based epoxy, insulated between layers of a polydimethylsiloxane (PDMS) elastomer. The heating film had a fast thermal response and showed excellent thermal stability at temperatures up to 100 °C. The SiO2-PDMS superhydrophobic top coating demonstrated an average static contact angle of 164° and hysteresis of 3° for water. The icephobic properties of the hybrid coating were investigated by a series of experiments conducted in a cold chamber. The hybrid coating reduced the ice adhesion strength by 83% and delayed the onset of droplet freezing when compared to the untreated substrate. Under continuous spray of 5 °C water at −20 °C chamber temperature, complete anti-icing of the hybrid coating was achieved with a minimum surface power density of 0.34 W/cm2. Water droplets rolled off the 45° inclined superhydrophobic surface before freezing, resulting in 37% less energy consumption for anti-icing. The superhydrophobic heating film has potential for industrial applications due to its simple fabrication process and energy-efficient anti-icing performance.

Cold Atmospheric plasma treatments trigger changes in sun-dried tomatoes mycobiota by modifying the spore surface structure and hydrophobicity

The contamination of sun-dried tomatoes during processing can have a decisive impact on the quality of the finished product. In this study we investigated how Cold Atmospheric Plasma (CAP) under high surface power density (SPD) values can reduce fungal contamination in sun-dried tomatoes. In the application of this innovative processing method, the established “regime” for air plasma chemistry was the transition regime or NOx regime. First, we isolated and identified the mycobiota present on the tomatoes surfaces by mean of the analysis of the ITS region. The analysis revealed 32 different species, with A. niger , A. tubingensis, A. chevalieri , A. flavus, and A. alternata being the most abundant. Then, to reduce the fungal population, CAP-NOx was applied for 5, 10, 20 and 30 min on the surface of dried tomatoes. After incubation for 10 days, we observed that the antifungal effect was species and dose-dependent. In vitro investigation on the most abundant species revealed that A. chevalieri PSJ144 was the most sensitive species (almost 90%) immediately after 5 min of CAP treatment. With the increase of the exposure time up to 30 min, a strong reduction (p ≤ 0.05) of spore germination of A. alternata PSJ77 and A. tubingensis PSJ100 was observed (98 and 92%, respectively). However, spores of A. niger PSJ38 and A. flavus PSJ30 showed the highest resistance to the treatment. Moreover, the reparameterized Weibull function allowed to obtain useful information about germination kinetics as a function of time of CAP-NOx treatment, revealing that the resistance of the spores was: A. chevalieri < A. alternata < A. tubingensis < A . flavus < A. niger . In situ analyses confirmed a significant effect on natural fungal contamination by CAP-NOx treatment (76.5% of reduction), likely due to cell membrane rupture and cell death caused by plasma radicals. In addition, Pearson correlation analysis showed that spore resistance was highly correlated (p = 0.98) with their hydrophobicity. In a nutshell, our results clearly indicate that CAP-NOx treatment is an effective technique to reduce fungal contamination in sun-dried tomatoes. Among non-thermal processing methods, CAP shows promising perspectives of application in the tomato industry, to mitigate the effects of energy price rises. • A. niger , A. tubingensis, were most abundant species in dried tomatoes. • CAP reduced the fungal contamination on the dried tomatoes by 76.5%. • A. niger and A. flavus spores were more resistant ones to CAP. • A. chevalieri spores were inactivated after 0.1 min of CAP-NOx. • Spore hydrophobicity was correlated with the spore resistant to CAP.

Synthesis of TiO2 nanoparticles and the performance of dye-sensitized solar cells

TiO2 electrodes were effectively produced through the hydrothermal technique and used to build photosensitizer photovoltaic energy. Its impacts of Mn2 + and Co2 + particles on TiO2 anode characteristics were also investigated. XRD, TEM/HRTEM, UV–Vis Spectroscopy, and I–V characterization were used to characterize the materials, and their photo-conversion efficiencies were assessed using IPCE and EIS. TiO2 has no contaminant layer, according to X-ray diffraction measurements. The X-ray micrographs of TiO2 loaded with (Mn and Co) particles are essentially identical to those of Nano composite, indicating that no one has any impact on synthesis of crystalline Titanium dioxide. The impact of depletion region on the group kinetics and photo electrochemical characteristics of nanomaterial Titanium surfaces was studied. The results of the experiments revealed that the amount of TiO2 in the sample has a significant impact on the photo electrochemical capabilities. The power density of (Mn and Co) Tio2 surface was lowered with illumination of 100 m W/cm2 white radiation due to the substantial shift in smooth branching point and process. The system that occurred due to whole frequency of Titanium surfaces with particles loading.

Scanning electron microscopy, biochemical and enzymatic studies to evaluate hydro-priming and cold plasma treatment effects on the germination of Salvia leriifolia Benth. seeds.

Finding a suitable method to increase seed germination rates of medicinal plants is critical to saving them from extinction. The effects of cold plasma (CP) treatments (using surface power densities of 80 and 100 W, with exposure times of 0, 120, 180, and 240 s) and incorporating hydropriming (carried out for 24 and 2h on normal and uncovered seeds, respectively) to enhance the seed germination of Salvia leriifolia Benth a native endangered Iranian medicinal plant, were evaluated in this study. Scanning electron microscopy (SEM) images identified more destroyed mesh-like structures in hydro-primed and uncovered seeds than in normal and dry seeds. In comparison to the control, and other treatments, employing 100 W of CP for 240 s produced the maximum germination percentage and rate, as well as a seedling vigor of I and II in hydro-primed and uncovered seeds. The levels of α-amylase activity increased when the power and exposure times of CP were increased. The uncovering and hydropriming of S. leriifolia seeds resulted in increased enzyme activity. Malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents were enhanced by increasing the power and exposure time of CP, especially in uncovered and hydro-primed seeds. The activity of antioxidant enzymes, including catalase (CAT) and superoxide dismutase (SOD), was correlated to changes in MDA and H2O2 levels. Finally, direct contact of CP with uncovered seeds in a short exposure time can improve the germination of S. leriifolia seeds via microscopic etching and activation of enzymes.

Standardized Volume Power Density Boost in Frequency-Up Converted Contact-Separation Mode Triboelectric Nanogenerators.

The influence of a mechanical structure's volume increment on the volume power density (VPD) of triboelectric nanogenerators (TENGs) is often neglected when considering surface charge density and surface power density. This paper aims to address this gap by introducing a standardized VPD metric for a more comprehensive evaluation of TENG performance. The study specifically focuses on 2 frequency-up mechanisms, namely, the integration of planetary gears (PG-TENG) and the implementation of a double-cantilever structure (DC-TENG), to investigate their impact on VPD. The study reveals that the PG-TENG achieves the highest volume average power density, measuring at 0.92 W/m3. This value surpasses the DC-TENG by 1.26 times and the counterpart TENG by a magnitude of 69.9 times. Additionally, the PG-TENG demonstrates superior average power output. These findings introduce a new approach for enhancing TENGs by incorporating frequency-up mechanisms, and highlight the importance of VPD as a key performance metric for evaluating TENGs.

MISTRAL campaign in support of W7-X long pulse operation

Following two initial campaigns [1], Stellarator Wendelstein 7-X (W7-X) has now completed the construction phase by installation of active cooling of all plasma facing components. The machine is presently commissioned for the next campaign (OP2) aiming at 1 GJ per pulse, e.g. 100 s at 10 MW, eventually aiming at 18 GJ, e.g. 1800 s at 10 MW. The key heating system is the Electron Cyclotron Resonance Heating (ECRH) system, consisting of 10 gyrotrons with power per gyrotron ranging from 0.6 MW up to 1.0 MW at 140 GHz. A phased upgrade of the installation is in progress with the addition of 2 gyrotrons and the development of 1.5 MW and 2.0 MW gyrotrons, such that at the end of the upgrade 4 gyrotrons will be available in each power class of 1.0, 1.5 and 2.0 MW [2]. The increased ECRH power, combined with O2 and X3 heating schemes at high densities, will lead to increased microwave stray radiation. This is non-absorbed microwave power that diffuses inside the vessel and is incident on all in-vessel components including vacuum windows and attached diagnostic systems. A fraction of the stray radiation is absorbed by resistive or dielectric losses of these components, leading to thermal loads that scale with stray radiation levels and pulse length. At W7-X a high power microwave stray radiation launch facility ’MISTRAL’ is available that is used to qualify invessel components for use at specified microwave surface power densities [Wm−2]. This paper reports on MISTRAL campaigns in 2020 2021 for testing of stray radiation loads during OP2 in W7-X, as well as on an EUROfusion program assessing stray radiation loads on ITER components. A dedicated, absolutely calibrated, caloric load was developed for the campaign to obtain measurement of stray radiation power levels as well as to conveniently expose samples. Amongst other we report on shielding concepts using metal enclosures combined with microwave absorbing coatings and dielectric heating of vacuum windows.

Hydrothermally etching commercial carbon cloth to form a porous structure for flexible zinc-ion hybrid supercapacitors

A novel modification method of hydrothermal treatment in acidic potassium chlorate solution is proposed here to etch directly the commercial carbon cloth (CC) surface to produce a porous structure with oxygen-rich functional groups and a large specific surface area (OCC). Following that, an in-situ polypyrrole coating is deposited on OCC (PPy@OCC) to improve conductivity and electrochemical stability. The assembled zinc-ion hybrid supercapacitors (Zn-HSCs) used the PPy@OCC sample as the cathode and Zn foil as the anode, and they demonstrated excellent electrochemical properties. The device has a capacity retention of 92 % after 10,000 cycles at a current density of 20 mA cm−2 and an area capacity of up to 4.74 mAh cm−2 at a current density of 0.5 mA cm−2. It also has a high surface energy density of 4740 Wh cm−2 and a high peak surface power density of 20.23 mW cm−2. When the Zn foil is replaced as the anode to flexible Zn-HSCs by electrodeposited Zn on CC (Zn@CC), the remarkable volume energy density (27.22 mWh cm−3) and flexibility are demonstrated, implying that the prepared PPy@OCC is an ideal electrode for high-performance flexible Zn-HSCs.

Development of a hybrid anti-icing coating with superhydrophobic and electrothermal properties

<h2>Abstract</h2> This talk presents the simple fabrication and experimental characterization of an energy-efficient hybrid anti-icing coating. The multi-layered coating consists of an electric heating film with a SiO₂ / polydimethylsiloxane (PDMS) superhydrophobic top coating. The heating film is composed of a thin layer of copper-based epoxy, insulated in a PDMS film. The hybrid coating was applied to a 17-4PH stainless steel substrate by a simple sequential spray-coating process. The superhydrophobic coating possessed a static contact angle of 164° and a sliding angle of 3°. Characterization of the heating film demonstrated its fast thermal response, producing a 60 °C temperature rise in 52 s. Icing experiments conducted at −10 °C showed that, when compared to the untreated substrate, the hybrid coating increased the droplet freezing time from 13 s to 63 s and reduced the ice adhesion strength from 284 kPa to 50 kPa. In a simulated spray-icing environment, anti-icing was achieved with a minimum surface power density of 0.26 W/cm². The superhydrophobic coating reduced the energy consumption for anti-icing by 40%. The results show that the hybrid coating has potential for use in industrial applications due to its simple fabrication, high energy-efficiency, and robust anti-icing performance.

Multifunctional composite polyvinyl alcohol films prepared with economic conductive carbon black and MXene microcapsuled APP

Multifunctional flexible electrothermal film has the advantages of high heating efficiency, good heat dissipation conditions, high surface power density, flame retardant and so on, which is widely used in construction, medical, agriculture, military, household products and other fields. In this work, a new type of economical, environmentally friendly, fire-safe electrothermal and electromagnetic (EMI) shielding composite film with PVA as the binder was prepared by introducing MXene-microcapsuled ammonium polyphosphate (MAPP) and conductive carbon black (CCB). After the addition of MAPP as a synergist, the conductivity of the PVA/CCB/MAPP films was increased by 66.5%. In addition, it shows excellent EMI shielding effectiveness (47.1 dB, 0.4 mm thickness). Furthermore, the PVA/CCB/MAPP thin film can reach 100 °C at an applied voltage of 12 V. These results also show good cycling and long-term electrothermal performance. In the combustion performance test, compared with PVA-0, the PVA/CCB/MAPP film had an 86.6% lower pHRR, and the THR was decreased by 59.9%. The surface temperatures of the wood sticks and FPUF reached 79.9 °C and 62.1 °C, respectively, showing excellent electrothermal effects. The PVA/CCB/MAPP film can also completely inhibit the combustion of FPUF. In short, the study offers a novel method to gain eco-friendly, fire safety and EMI shielding electrothermal films that can be coated on different substrates.