Photothermal Polymer Nanocomposites of Tungsten Bronze Nanorods with Enhanced Tensile Elongation at Low Filler Contents

We present polymer nanocomposites of tungsten bronze nanorods (TBNRs) and ethylene propylene diene monomers (EPDM). The combination of these components allows the simultaneous enhancement in the mechanical and photothermal properties of the composites at low filler contents. The as-synthesized TBNRs had lengths and diameters of 14.0 +/- 2.4 nm and 2.5 +/- 0.5 nm, respectively, and were capped with oleylamine, which has a chemical structure similar to EPDM, making the TBNRs compatible with the bulk EPDM matrix. The TBNRs absorb a wide range of near-infrared light because of the sub-band transitions induced by alkali metal doping. Thus, the nanocomposites of TBNRs in EPDM showed enhanced photothermal properties owing to the light absorption and subsequent heat emission by the TBNRs. Noticeably, the nanocomposite with only 3 wt% TBNRs presented significantly enhanced tensile strain at break, in comparison with those of pristine EPDM, nanocomposites with 1 and 2 wt % TBNRs, and those with tungsten bronze nanoparticles, because of the alignment of the nanorods during tensile elongation. The photothermal and mechanical properties of these nanocomposites make them promising materials for various applications such as in fibers, foams, clothes with cold weather resistance, patches or mask-like films for efficient transdermal delivery upon heat generation, and photoresponsive surfaces for droplet transport by the thermocapillary effect in microfluidic devices and microengines

Experimental Study on the Fire Spreading between Vehicles Using a Real Scale Fire Test

Extended Abstract With increasing vehicle, the vehicle fire is considered one of the dangerous disaster. Because vehicles have the many inflammable materials as like gasoline engine oil, plastic and leather etc. Especially, when the vehicle fire is occurred in underground parking lot, the fire can easily spread around the vehicles due to the narrow parking space. [1] Thus, the vehicle fire can be developed to the large fire. In order to prevent the fire spreading, the fire extinguishing systems are installed in underground parking lot. However, these extinguishing systems are designed initial fire suppression, thus it is difficult to extinguish the large fire due to the fire spreading. [2] Therefore, fire spread between vehicles should be considered to improve extinguishing performance. In this study, experimental studies are performed to analyse the fire spread characteristics between vehicles using a real scale fire tests. The fire spread characteristics is analysed by using the temperature measured in various part of the vehicle. The fire is occurred at passenger seat by using the gasoline. Also, the vehicles used in the experiments are the fourwheel sedan. The vehicle is divided into four regions according to the characteristics of the inflammable materials (seat, engine room, fuel tank and bumper

Vertical distributions of organic matter components in sea ice near Cambridge Bay, Dease Strait, Canadian Archipelago

Ice algae thriving within sea ice play a crucial role in transferring energy to higher trophic levels and influencing biogeochemical processes in polar oceans; however, the distribution of organic matter within the ice interior is not well understood. This study aimed to investigate the vertical distribution of organic matter, including chlorophyll a (Chl-a), particulate organic carbon and nitrogen (POC and PON), carbohydrates (CHO), proteins (PRT), lipids (LIP), and food material (FM), within the sea ice. Samples were collected from the bottom, middle, and top sections of the sea ice column near Cambridge Bay during the spring of 2018. Based on the δ13C signature, biochemical composition, and POC contribution of biopolymeric carbon (BPC), the organic substances within the sea ice were predominantly attributed to marine autotrophs. While the highest concentrations of each parameter were observed at the sea ice bottom, notable concentrations were also found in the upper sections. The average sea ice column-integrated Chl-a concentration was 5.05 ± 2.26 mg m−2, with the bottom ice section contributing 59% (S.D. = ± 10%) to the total integration. The column-integrated concentrations of FM, BPC, POC, and PON were 2.05 ± 0.39, 1.10 ± 0.20, 1.47 ± 0.25, and 0.09 ± 0.03 g m−2, respectively. Contributions of the bottom ice section to these column-integrated concentrations varied for each parameter, with values of 20 ± 6, 21 ± 7, 19 ± 5, and 28 ± 7%, respectively. While the bottom ice section exhibited a substantial Chl-a contribution in line with previous studies, significantly higher contributions of the other parameters were observed in the upper sea ice sections. This suggests that the particulate matter within the interior of the sea ice could potentially serve as an additional food source for higher trophic grazers or act as a seeding material for a phytoplankton bloom during the ice melting season. Our findings highlight the importance of comprehensive field measurements encompassing the entire sea ice section to better understand the distribution of organic carbon pools within the sea ice in the Arctic Ocean

Fabrication of PEDOT:PSS/Ag2Se Nanowires for Polymer-Based Thermoelectric Applications

Flexible Ag2Se NW/PEDOT:PSS thermoelectric composite films with different Ag2Se contents (10, 20, 30, 50, 70, and 80 wt.%) are fabricated. The Ag2Se nanowires are first fabricated with solution mixing. After that, Ag2Se NW/PEDOT:PSS composite film was fabricated using a simple drop-casting method. To evaluate the potential applications of the Ag2Se NW/PEDOT:PSS composite, their thermoelectric properties are analyzed according to their Ag2Se contents, and strategies for maximizing the thermoelectric power factor are discussed. The maximum room-temperature power factor of composite film (178.59 μW/m·K2) is obtained with 80 wt.% Ag2Se nanowires. In addition, the composite film shows outstanding durability after 1000 repeat bending cycles. This work provides an important strategy for the fabrication of high-performance flexible thermoelectric composite films, which can be extended to other inorganic/organic composites and will certainly promote their development and thermoelectric applications

Effect of SrTiO3 Nanoparticles in Conductive Polymer on the Thermoelectric Performance for Efficient Thermoelectrics

We present hybrid organic inorganic materials, namely, SrTiO3/polyaniline (PANI) composites, with high thermoelectric performance; samples with various SrTiO3 contents (10, 20, 30, and 50 wt.%) were prepared. The PANI component was obtained through the polymerization of aniline monomers, followed by camphosulfonic acid-doping to enhance its electrical conductivity. SrTiO3, with a high Seebeck coefficient, was used as the N-type inorganic componenet; it was synthesized via a one-pot solvothermal methods and, then, dispersed into the conductive PANI matrix. The SrTiO3 content influenced the Seebeck coefficient and electrical conductivity of the resulting composites. The variations in the thermoelectric properties of the SrTiO3/PANI composites consequently changed their power factor; at room temperature, the highest value was ~49.6 μW·m/K2, which is 17 times larger than that of pure PANI

Conductive PEDOT:PSS-Based Organic/Inorganic Flexible Thermoelectric Films and Power Generators

We present a simple thermoelectric device that consists of a conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)-based inorganic/organic thermoelectric film with high thermoelectric performance. The PEDOT:PSS-coated Se NWs were first chemically synthesized in situ, and then mixed with an Ag precursor solution to produce the PEDOT:PSS-coated Ag2Se NWs. The PEDOT:PSS matrix was then treated with dimethyl sulfoxide (DMSO) prior to the production of flexible PEDOT:PSS-coated Ag2Se NW/PEDOT:PSS composite films with various weight fractions of Ag2Se via a simple drop-casting method. The thermoelectric properties (Seebeck coefficient, electrical conductivity, and power factor) of the composite films were then analyzed. The composite film with 50 wt.% NWs exhibited the highest power factor of 327.15 μW/m·K2 at room temperature. The excellent flexibility of this composite film was verified by bending tests, in which the thermoelectric properties were reduced by only ~5.9% after 1000 bending cycles. Finally, a simple thermoelectric device consisting of five strips of the proposed composite film was constructed and was shown to generate a voltage of 7.6 mV when the temperature difference was 20 K. Thus, the present study demonstrates that that the combination of a chalcogenide and a conductive composite film can produce a high-performance flexible thermoelectric composite film

Carvone Decreases Melanin Content by Inhibiting Melanoma Cell Proliferation via the Cyclic Adenosine Monophosphate (cAMP) Pathway

Melanin, which determines the color of the skin and hair, is initially synthesized to protect the skin from ultraviolet light; however, excessive melanin pigmentation caused by abnormal cell proliferation can result in various melanocytic lesions. Cyclic adenosine monophosphate (cAMP) is known to regulate cell cycle progression and consequently to inhibit the division of abnormally proliferating cells. In this work, we aimed to test whether carvone, a scent compound from plants, inhibits proliferation and subsequently reduces melanin content of melanoma cells and to determine whether its beneficial effects are mediated by the cAMP pathway. We found that carvone decreases melanin content and inhibits melanoma cell proliferation in a concentration-dependent manner. Meanwhile, it inhibited the activation of cell cycle-associated proteins such as cyclin-dependent kinase 1 (CDK1). Of note, the beneficial effects of carvone were abrogated by cAMP inhibition. Our findings indicate potential benefits of carvone for the treatment of melanomas and presumably other hyperpigmentation-related dermatological disorders such as melasmas, lentigines, and excessive freckles

A comprehensive exploration of PPS/MgO@MoS2 core–shell composites for enhanced thermal and mechanical performance

The growing worldwide energy crisis and environmental issues have prompted the exploration of sustainable alternatives across different sectors, such as the automotive realm. Electric vehicles (EVs) have surfaced as a practical substitute for traditional fossil fuel-driven vehicles, with their efficacy being contingent upon the weight of the vehicle. In this investigation, we present polyphenylene sulfide (PPS) as an advanced engineering plastic, boasting exceptional resistance to high temperatures and chemical stability. Its versatility makes it suitable for a range of applications within the automotive industry. However, the thermal conductivity of PPS is lower than those of other engineering plastics. Therefore, a novel core–shell structure comprising magnesium oxide (MgO) and molybdenum sulfide (MoS2) was fabricated to enhance the thermal and mechanical properties. The core–shell structure was elucidated via a comprehensive analysis using various techniques. Furthermore, the PPS/MgO@MoS2/PA composites were synthesized to address the challenges associated with high filler ratios. Tensile strength evaluations and thermal conductivity assessments confirmed the effectiveness of the proposed materials for diverse engineering applications, particularly in EVs. Additionally, surface treatments with polyformaldehyde and (3-aminopropyl)triethoxysilane (PA) improved the adhesion with the PPS matrix, which enhanced the mechanical tensile strength to 90 MPa. As the filler ratio increased, the MgO@MoS2 core–shell achieved a high through-plane heat conductivity of 4.07 W/m·K, which is 22 times compared to pristine PPS. Hence, this study provides valuable insights into the ongoing pursuit of sustainable automotive solutions by addressing the critical issues of energy efficiency, environmental impact, and materials science

Thermoelectric Generator Using Polyaniline-Coated Sb2Se3/β-Cu2Se Flexible Thermoelectric Films

Herein, Sb2Se3 and β-Cu2Se nanowires are synthesized via hydrothermal reaction and water evaporation-induced self-assembly methods, respectively. The successful syntheses and morphologies of the Sb2Se3 and β-Cu2Se nanowires are confirmed via X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), and field emission transmission electron microscopy (FE-TEM). Sb2Se3 materials have low electrical conductivity which limits application to the thermoelectric generator. To improve the electrical conductivity of the Sb2Se3 and β-Cu2Se nanowires, polyaniline (PANI) is coated onto the surface and confirmed via Fourier-transform infrared spectroscopy (FT-IR), FE-TEM, and XPS analysis. After coating PANI, the electrical conductivities of Sb2Se3/β-Cu2Se/PANI composites were increased. The thermoelectric performance of the flexible Sb2Se3/β-Cu2Se/PANI films is then measured, and the 70%-Sb2Se3/30%-β-Cu2Se/PANI film is shown to provide the highest power factor of 181.61 μW/m·K2 at 473 K. In addition, a thermoelectric generator consisting of five legs of the 70%-Sb2Se3/30%-β-Cu2Se/PANI film is constructed and shown to provide an open-circuit voltage of 7.9 mV and an output power of 80.1 nW at ΔT = 30 K. This study demonstrates that the combination of inorganic thermoelectric materials and flexible polymers can generate power in wearable or portable devices