Transport Ability Research Articles

Preparation and characterization of unidirectional water-transported bilayer PLA/ZnO-PAN/SPA nanofibrous membrane for wound healing

Wound infection caused by excessive exudate leads to overhydration of wounds and prevents wound healing. Thus, there is a need for a wound dressing to be developed that can unidirectionally export excess biological fluid while inhibiting bacterial infection. Herein, a nanofibrous bilayer membrane with a unidirectional water transport function was fabricated by electrospinning as a novel wound dressing, which can export excess biological fluid efficiently and further inhibit bacterial infection. The inner layer of the bilayer nanofiber membrane is polylactic acid (PLA)-zinc oxide (ZnO) nanofibers, which are hydrophobic and antibacterial. The outer layer is polyacrylonitrile (PAN)-sodium polyacrylate (SPA) nanofibers, which are hydrophilic and liquid-absorbent. The bilayer nanofibrous membrane's morphology, mechanics, thermal stability, wettability, water absorption, gas permeability, and unidirectional water transport ability were characterized and evaluated. The study showed that the nanofibrous bilayer membrane exhibited excellent physicochemical properties and biological performance, and its mechanical properties can reach 4.6 MPa. In addition, when the thickness of the hydrophobic layer is 3 µm and the thickness of the hydrophilic layer is 44 µm, the double-layer fiber membrane can effectively export the excess biological fluid in 5.09 s and prevent the wound from wetting again. The nanofibrous bilayer membrane with excellent water absorption, air permeability, thermal stability, and mechanical strength provides a feasible solution for chronic wound healing.

Construction of robust one-dimensional nanowire-regulated graphene oxide membranes for efficient dye/salt separation

Loose nanofiltration (NF) for graphene oxide (GO) membranes is an emerging efficient strategy for separating dye/salt mixtures in textile wastewater to realize sustainable resource recovery. This study proposes a novel approach for constructing a laminated GO membrane with interlayer water-transporting nanochannels by intercalating tannic acid nanowires (TANs). The interlayer spacing of the GO membrane can be expanded by one-dimensional TANs while cross-linking between hydrophilic TANs and GO nanosheets enhance the mechanical stability of this sheet-wire structure and interlayer channels. The membrane is able to achieve excellent water permeability without sacrificing selectivity due to the dual driving force resulting from the ultrafast water transport ability of primitive graphene planes and interlayer hydrophilic nanowires. The modified GO membrane exhibits a high water permeability of 52.1 L m−2 h−1 bar−1, which is twice that of the pure GO membrane and excellent selectivity of 85.5 to the methyl blue/NaCl mixed solution. Overall, this work provides a feasible strategy for constructing a mixed-dimensional GO-based membrane with a robust structure and multi-pathways to achieve excellent perm-selectivity for dye/salt separation.

Construction of ZnFe2O4/g-C3N4 nanocomposite catalyst for degradation of organic compound through photodegradation and heterogeneous Fenton oxidation

ZnFe2O4/g-C3N4 heterojunction nanocomposite photocatalyst was prepared by one-step solvothermal method using graphite carbon nitride (g-C3N4) and zinc ferrate (ZnFe2O4), and characterized by SEM/EDX, XRD, FT-IR, Zeta potential, and VSM. The cationic-dye methylene blue (MB) was selected as the target pollutant for photocatalytic degradation and the degradation mechanism of the heterogeneous nanocomposite photocatalyst was analyzed. The photocatalyst can accelerate the separation of photogenerated electron-hole pairs, increase the number of photocatalytic reaction sites, and have strong REDOX ability and charge transport ability. The degradation efficiency of MB is 3 times and 2 times of that of pure g-C3N4 and ZnFe2O4, respectively. Visible light (Vis)/ZnFe2O4/g-C3N4/sodium percarbonate (SPC) photo-Fenton system established under the synergistic effect of ZnFe2O4/g-C3N4 and SPC can continuously produce ·OH, ·O2− and h+. In half an hour, 93% of MB was degraded by Vis/ZnFe2O4/g-C3N4/SPC, and the degradation rate of MB was above 90% for 5 consecutive cycles. Through characterization and water treatment experiments, ZnFe2O4/g-C3N4 heterostructure nanocomposite photocatalyst has the characteristics of high efficiency photocatalytic oxidation activity, stability, superparamagnetism, easy separability and reusability, and can be reused continuously. Therefore, it is a promising photocatalyst in the field of wastewater treatment and a potential candidate material for the treatment of refractory organic pollutants.

Double‐Carbon‐Layer Core–Shell Complex Sulfides Derived from Bimetallic Metal–Organic Frameworks for Li‐/Na‐Ion Battery Storage

Metal–organic frameworks (MOFs) have been extensively studied due to their porous structures and large specific surface areas. Its unique combination of central metal and organic ligand has become a common precursor for the synthesis of metal phosphides, selenides, oxides, and sulfides. However, the carbonaceous structure derived from some MOF materials is still not enough to perfectly alleviate the negative impact of the volume change of metal sulfides. Herein, bimetallic MOF (Zn‐Co‐ZIF) is used as a precursor, coated with dopamine hydrochloride, and then calcined and gas‐phase vulcanized to prepare ZnS/CoS2‐C@NC with a double‐carbon‐layer core–shell structure. The existence of the two carbonaceous structures can not only improve the electron transport ability, but also play an important role in alleviating the volume expansion caused by metal sulfides during repeated charging and discharging. Due to its stable carbon layer structure, ZnS/CoS2‐C@NC has a higher specific capacity (1175.4 mAh g−1 in lithium‐ion batteries (LIBs) and 430.9 mAh g−1 in sodium‐ion batteries after 100 cycles at a current density of 0.2 A g−1 respectively) and excellent rate capability (338.2 mAh g−1 specific capacity maintained after 2000 cycles at a current density of 5 A g−1 in LIBs).

Erchen Decoction improves iron homeostasis in mice with non-alcoholic fatty liver disease by regulating iron transport capacity in the spleen

To investigate the effect of Erchen Decoction on iron homeostasis in mice with nonalcoholic fatty liver disease (NAFLD) and its mechanism for regulating iron transport in spleen cells. Thirty male C57BL/6J mice were given a high-fat diet for 12 weeks and randomized (n=6) at the 7th week for gavage (3 times a week) of drinking water (NAFLD model group), Erchen Decoction at low, medium and high doses (7.5, 15, and 30g/kg, respectively), or polyene phosphatidyl choline (PPC; 9.12 mg/kg), with another 6 mice with low-fat and low-sugar feeding as the control group. The active components of Erchen Decoction were determined by HPLC-MS. Lipid accumulation in the liver was evaluated by HE staining and Nile red staining. Prussian blue staining was used to observe iron content in the spleen. The iron ion content in the liver tissue was detected using a detection kit. The expressions of ferroportin1 (Fpn1), transferrin receptor (TfR), Steap3, HO-1, Ter-119, CD163 and CD68 were detected using Western blotting, immunohistochemistry and immunofluorescence staining. Medium- and high-dose Erchen Decoction partially reversed the increase of lipid accumulation in the liver of NAFLD mice and showed better lipid-lowering effect than PPC. The NAFLD mice showed significantly decreased iron ion content in the spleen with increased hepatic and serum iron contents (P < 0.05), decreased TfR protein expression (P < 0.05), and increased Fpn1 and Steap3 protein expressions (P < 0.05), and these changes were significantly improved by the drug interventions. Erchen Decoction also improved the function of CD163 macrophages in the spleen of NAFLD mice by up-regulating the expression of HO-1 (P < 0.05). Erchen Decoction can alleviate high-fat diet-induced iron metabolism disorder by improving the iron ion transport ability of the spleen cells to delay the progression of NAFLD.

Efficient detection of nitrite in water based on an Au/NiO/Rh trimetallic composite modified laser-induced graphene electrode prepared by one-step electrodeposition

In this study, we employed a straightforward and rapid one-step electrodeposition method to enhance modify an Au/NiO/Rh composite on laser-induced graphene (LIG) for nitrite (NO2–) detection. We extensively characterized and tested the morphological composition and electrochemical properties of the electrode using scanning electron microscopy and other characterization techniques. To compare the electrochemical active surface areas of the electrode before and after modification, we conducted cyclic voltammetry experiments. Additionally, we confirmed the changes in electron transfer performance and adsorption energy of the modified electrode through by density functional theory calculations. The experimental results demonstrate that the combined modification of LIG with rhodium nanoparticles (RhNPs) and gold nanoparticles (AuNPs) improves electron transport ability at the electrode interface and enhances the electrode's electrocatalytic performance. The incorporation of nickel oxide (NiO) also provides a larger reaction area and more active sites for NO2– detection. The synergistic effects of these three modified components significantly enhance NO2– detection at the electrode, surpassing the performance of the bimetallic modified electrode. Under optimized experimental conditions, the sensor exhibits a linear range of 1 μmol/L to 1 mmol/L and a detection limit of 0.3 μmol/L. Furthermore, the sensor demonstrates excellent anti-interference and repeatability properties. We successfully applied the sensor for determination of NO2– in tap water, yielding satisfactory results. This research presents a promising strategy for the portable, sensitive, and in-situ detection of NO2– in water environments using metal-based electrochemical sensors.

Selective Si&lt;sub&gt;3&lt;/sub&gt;N&lt;sub&gt;4&lt;/sub&gt; Etching for 3D NAND Integration by Using Low Concentration of H&lt;sub&gt;3&lt;/sub&gt;PO&lt;sub&gt;4&lt;/sub&gt;

This study investigated the etching kinetics of Si3N4 in various concentration of H3PO4 solution and the effect of Si3N4 etching enhancers on the etching process, particularly for 3D NAND trench structures. 30 wt% H3PO4 was used to etch Si3N4, which can produce higher Si3N4/SiO2 etching selectivity and similar Si3N4 etching rate compared to a conventional 85 wt% H3PO4. 30 wt% H3PO4 showed significantly improved etching performance for the Si3N4/SiO2 3D NAND structure as compared to 85 wt% H3PO4. In particular, the transportation ability of H3PO4 into 3D NAND trench structures can be improved by reducing viscosity of etchant, which can be obtained by reducing the concentration of H3PO4. In addition, Si3N4 etching enhancers were introduced to accelerate the Si3N4 etching kinetics in 30 wt% H3PO4. Addition of such additives improved the Si3N4 etching rate and Si3N4/SiO2 etching selectivity while suppressing oxide regrowth. The results provide valuable insights for optimizing selective Si3N4 etching process in 3D NAND structures.

P-type conductive BaZrS3 thin film and its band gap tunning via Ruddlesden-Popper Ba3Zr2S7 and titanium alloying

BaZrS3 is an emerging chalcogenide perovskite that possesses excellent light absorption and carrier transport abilities comparable with the halide perovskites. Besides, it shows better stability and lower toxicity. However, BaZrS3 is only reported as n-type conductivity in previous studies. Lack of p-type conductivity limits its application into solar cells or other complex devices. In addition, strategies to tailor its band gap (∼1.8–2.2 eV) to optimal range (∼1.4–1.5 eV) for solar absorbers are not well established. In this work, for the first time, we demonstrate p-type conductive BaZrS3 thin film with the hole concentration and mobility as high as ∼1018 cm−3 and 30 cm2/Vs, respectively, and the Ba vacancy was the most probable defect contributing to the p-type conductivity. Ruddlesden-Popper Ba3Zr2S7 thin film and orthorhombic BaZr1-xTixS3 alloy thin film are also prepared by co-sputtering from BaZrS3 and BaS/BaTiS3 targets. Inspiringly, 4% Ti substitution for Zr can tune the band gap of BaZr1-xTixS3 from 2.2 to 1.5 eV, a near ideal value for photovoltaic absorbers according to Shockley − Queisser limit. Successful optoelectronic tuning strategies for chalcogenide perovskite in this work may pave the way for its application into complex optoelectronic devices like solar cells.

Organic Electrochemical Transistor Based on Hydrophobic Polymer Tuned by Ionic Gels

AbstractHydrophobic conjugated polymers have poor ionic transport property, so hydrophilic side chains are often grafted for their application as organic electrochemical transistors (OECTs). However, this modification lowers their charge transport ability. Here, an ionic gel interfacial layer is applied to improve the ionic transport while retaining the charge transport ability of the polymers. By using the ionic gels comprising gel matrix and ionic liquids as the interfacial layers, the hydrophobic polymer achieves the OECT feature with high transconductance, low threshold voltage, high current on/off ratio, short switching time, and high operational stability. The working mechanism is also revealed. Moreover, the OECT performance can be tuned by varying the types and ratios of ionic gels. With the proposed ionic gel strategy, OECTs can be effectively realized with hydrophobic conjugated polymers.

Organic Electrochemical Transistor Based on Hydrophobic Polymer Tuned by Ionic Gels.

Hydrophobic conjugated polymers have poor ionic transport property, so hydrophilic side chains are often grafted for their application as organic electrochemical transistors (OECTs). However, this modification lowers their charge transport ability. Here, an ionic gel interfacial layer is applied to improve the ionic transport while retaining the charge transport ability of the polymers. By using the ionic gels comprising gel matrix and ionic liquids as the interfacial layers, the hydrophobic polymer achieves the OECT feature with high transconductance, low threshold voltage, high current on/off ratio, short switching time, and high operational stability. The working mechanism is also revealed. Moreover, the OECT performance can be tuned by varying the types and ratios of ionic gels. With the proposed ionic gel strategy, OECTs can be effectively realized with hydrophobic conjugated polymers.

Construction of the Stable Lubricant Film on One-Dimensional Cone-Structured Surfaces for Directional Liquid Transport.

Directional liquid transport along one-dimensional structures finds vast applications in fog harvest, liquid separation, sensing, chemical synthesis, and numerous other scenarios. Dynamically, the liquid transport speed is boosted by the driving force and retarded by the hysteresis from the liquid/substrate interface. A capillary force-relied lubricant film or a covalently attached polymer brush on the surface could increase liquid mobility temporarily by reducing the interfacial hysteresis. However, the easy depletion of the lubricant film and the stringent restriction of the substrate severely hamper droplet's directional transport in a long run. Herein, we report a feasible and durable hysteresis reduction design with the polymer-brush stabilized lubricating surface (PBSLS). The PBSLS is achieved through incorporating liquid-like polydimethylsiloxane brushes (b-PDMS) and the liquid PDMS oligomer (o-PDMS). The covalent attached b-PDMS "locks" the lubricant oil o-PDMS to the cone surface via strong intermolecular van der Waals force in between. The PBSLS on the cone surface can be sustained under constant shearing force from liquid transport for at least 6 h. A cone with such PBSLS shows increased ability of droplet transport and enhanced fog collection performance in the long run. This design supplies an effective way toward regulating macro-level interfacial performance through surface design on the molecular level.

Construction of high-rate performance sulfurized Poly(acrylonitrile) nanofibers cathodes for practical lithium–sulfur batteries via tellurium catalytic regulation

The rapid charge-discharge and wide operating temperature range are of great significance to the research of lithium-sulfur batteries. However, the poor electronic and ionic conductivity of sulfurized polyacrylonitrile limits the high-rate and low-temperature performance of lithium-sulfur batteries. In this work, a tellurium-doped sulfurized polyacrylonitrile nanofibers-based cathode material (Te0.02S0.98FPAN) is successfully fabricated by air-blow spinning for lithium-sulfur batteries. It is found that Te0.02S0.98FPAN maintained a high reversible specific capacity of 742 mAh·g−1composites after 200 cycles at a current density of 0.2 C (0.014% decay per cycle), whereas it provides a reversible specific capacity of 641 mAh·g−1composites after 500 cycles even at a large current density of 1.0 C (0.021% decay per cycle), manifesting its excellent high-rate performance. Moreover, Te0.02S0.98FPAN still maintained a high reversible specific discharge capacity of 586 mAh·g−1composites after 100 cycles at 0.2 C at a low temperature of 5.0 °C, confirming its wide operating temperature range. Both the eutectic accelerator (tellurium) and the one-dimensional nanofibrous structure greatly improve the migration rate and electron transport ability of Li+ ions, enhancing reaction kinetics and providing fast and stable migration channels for ions and electrons. Therefore, Te0.02S0.98FPAN has a higher oxidation-reduction reaction rate and less polarization. This study not only provides new ideas for the cathode design of lithium-sulfur batteries with high rate and wide temperature range, but also paves the way for the development of practical lithium-sulfur batteries. In particular, when tested in practical conditions of high areal loading (Te0.02S0.98: 5.0 mg cm−2) and lean electrolyte (E/Te0.02S0.98: 10 μL mg−1), this cathode delivers high reversible capacities of 725 mAh g−1 composite (0.1 C) and 663 mAh g−1 composite (0.2 C), demonstrating its great potential for future application.

Ba0.9Co0.7Fe0.2Nb0.1O3-δ perovskite as promising cathode material for proton ceramic fuel cell

The protonic ceramic fuel cell (PCFC) is limited in performance by the delayed oxygen reaction on the cathode caused by low temperature. Herein, we investigate Ba0.9Co0.7Fe0.2Nb0.1O3-δ (BCFN), a cathode material with excellent electrocatalytic activity and structural stability. The electrical conductivity relaxation method was explored for the proton transport ability of BCFN material, which revealed a proton diffusion coefficient of 0.515 × 10−3 cm s−1 at 600 °C. To further enhance the proton conductivity of material and increase the reaction sites, a BCFN-BaCe0.7Zr0.1Y0.1Yb0.1O3−δ (BCZYYb) composite cathode was developed and its average thermal expansion coefficient value was lowered to 15.7 × 10−6 K−1 from 30 to 800 °C. At 700 °C, a single cell with a BCFN-BCZYYb cathode achieves a peak power density of 859 mW cm−2, and the Rp value is 0.05 Ω cm2. Furthermore, good durability of stable operation at 150 mA cm−2 for 100 h is obtained at 600 °C. These results imply that BCFN-BCZYYb could be an effective PCFC cathode.

Study on the influence of chain extension and substituent position on charge transport properties and optoelectronic properties based on 2,5-di(pyrazine-2-yl)furan derivatives

In this paper, the basic structure of 2,5-di(pyrazine-2-yl)furan (DPF) was initially designed to tune the charge transport properties and photoelectric properties of organic materials by chain extension. Through the calculation of recombination energy, the structure with the introduction of anthracene group (DPF-A) is a stable P-type material with the smallest recombination energy in terms of adiabatic ionization potential, so the chain extended molecule DPF-A was selected as the base for the study of substituent positions. While thiophene, trifluorinated acyl, and methoxy groups were introduced to design DPF-A series derivatives. Density functional theory with high computational accuracy was applied to investigate geometric structure, orbital energy levels, ionization energy, electron affinity energy, and recombination energy. The results show that the increase (decrease) of the HOMO (LUMO) energy level leads to the red (blue)-shift of absorption wavelength and fluorescence emission wavelength; the vertical ionization potential decreases and the vertical electron affinity potential increases, thus the hole and electron injection barrier decreases; the decrease of the hole/electron recombination energy improves the charge transport ability of the molecule. Moreover, the adjustment of thiophene orientation and the position of the introduced group has the potential to transform the p-type material into an n-type material, resulting in the enhanced electron injection ability.

High‐Performance Photoabsorber Based on 2D Perovskites with Alternating Cations in the Interlayer Space: GA(MA)3M3I10

2D perovskites stabilized by alternating cations in the interlayer space (ACI) GA(MA)3Pb3I10 perovskite have achieved a power conversion efficiency (PCE) of exceeding 18%. However, the potential leakage of broken cells with the usage of lead is still an environment problem. Thus, developing recycling end‐of‐life products via cost‐effective and environmentally friendly strategies is the current mainstream trend for perovskite solar cells. In this study, potential lead‐free alternatives to ACI 2D GA(MA)3M3I10 perovskites with high optoelectronic and photovoltaic performance by replacing lead with metals such as Cd, Cu, Ge, Ni, Sn, Zn, Ca, Si, Fe, Mg, Sr, Ba, and Pd using first‐principles calculations are explored. The findings reveal that Cu, Zn, and Mg can finely tune the bandgap of GA(MA)3M3I10 within the optimum range (0.9–2.3 eV) required for photovoltaic applications. GA(MA)3Cu3I10 exhibits the strongest carrier transport ability, with the highest carrier mobility of 479.7 cm2 V−1 s−1. GA(MA)3Mg3I10 demonstrates the highest PCE of 23.6%, positioning itself as a promising photoabsorber candidate for photovoltaic applications. Findings not only contribute to the design of environmentally friendly, high‐efficiency ACI 2D perovskites, but also unveil a mechanism that is not experimentally detected.

Graphene/metal-organic framework nano-sandwiches derived N, P-codoped porous carbon nanosheets as robust material for electrochemical analysis

Construction of novel two-dimensional porous carbon nanosheets with superior electrochemical activity is of great challenge. Here, graphene/ZIF-8 nano-sandwiches derived N, P-codoped porous carbon nanosheets (N, P-codoped PCN) was easily obtained by sequential room temperature self-assembly and high-temperature carbonization method. Relative to the widely used physically exfoliated graphene nanosheets (GN) and graphene/ZIF-8 derived N-doped porous carbon nanosheets (N-doped PCN), N, P-codoped PCN displayed larger active surface, faster electron transport ability and stronger physical adsorption ability, which can be ascribed to the dual doping effect of heteroatoms N and P. As a result, N, P-codoped PCN exhibited remarkable oxidation signal enhancement for tumor marker (8-hydroxy-2′-deoxyguanosine), analgesic and antipyretic drug (acetaminophen) and organic pesticide (benomyl). Besides, the limits of detection were measured as low as 1.58 nM, 7.50 nM and 2.10 nM with sensitivity of 270.00 μA μM−1 cm−2, 757.14 μA μM−1 cm−2 and 272.86 μA μM−1 cm−2 for 8-hydroxy-2′-deoxyguanosine, acetaminophen and benomyl, respectively. Basing on this, a novel and highly sensitive electrochemical sensing platform was developed. It is believed that the reported two-dimensional N, P-codoped PCN with unique structure and composition is highly valuable for the development of carbon-based electrochemical sensors.

Pulsed electric field enhanced Bacillus sp. DL4 biodegradation of triclosan: focusing on operational performance and metabolomic analysis

ABSTRACT Electrochemical-assisted microbial degradation technology was considered a crucial strategy to reduce micropollutants, but the mechanism of the pulsed electric field (PEF) in affecting biodegradation had not been systematically studied. This study aimed to construct a bio-electrochemical system (BES) using PEF to investigate its effect on the degradation of triclosan (TCS) by the aerobic bacterium Bacillus sp. DL4. The operating optimal parameters for the BES (i.e. 0.01 A of the pulsed current, 1000 Hz of the pulse frequency, Fe (+)–C (−) of the plate materials, 4 cm of the plate spacing) were obtained by batch experiments. The maximum biomass (OD600 = 1.0 ± 0.05) was achieved and the removal efficiency of TCS reached above 95% in 24 h under the obtained operating conditions. Meanwhile, a thorough and methodical investigation of the metabolites in strain DL4 stimulated by PEF using untargeted Liquid Chromatography – Mass Spectrometry (LC-MS). In multivariate analysis, the experimental groups showed a notable separation in Principal Components Analysis (PCA) and Orthogonal Partial Least Squares Analysis discriminant analysis (OPLS-DA) score plots. A total of 3181 differential metabolites were obtained, and the up-regulated metabolites were mainly related to ‘Aminoacyl-tRNA biosynthesis’, ‘Arginine and proline metabolism’, ‘Lysine degradation’, ‘ABC transporters’, and ‘TCA cycle’, implying that PEF enhanced the degradation efficiency of TCS by enriching functional genes with transport ability and ion migration ability in cells. This study illuminated how PEF can affect TCS biodegradation and gives insights into the application prospect of electrochemical-assisted biodegradation technology in water environment treatment.

Improving Microbial Fuel Cell Performance Using Porous Capacitive Composite Bioanode Materials with Energy Storage Function

Microbial fuel cells (MFCs) have shown promise in solving energy and environmental problems, but their practical application is limited by their low power output. In this study, carbon nanotubes/polypyrrole composite anode materials were prepared on a porous sponge matrix. By combining the porous characteristics of sponge, the good conductive properties of carbon nanotubes, and the energy storage ability of polypyrrole capacitive materials, the prepared anode exhibited a large specific capacity, high porosity, large specific surface area, good electron transport ability, and good biocompatibility. The results showed that the maximum power density of the modified anode MFC reached 7.46 W m−3, which was 2.53 times higher than that of the control anode. The stored energy Qs released by the modified anode was 235.6 C m−2, 6.5 times higher than that of the control electrode. In addition, the transfer impedance Rct of the S/CNT/PPy electrode (5.5 Ω) was much lower than that of the control anode (16.8 Ω). The research presented in this paper demonstrates a new approach to improving the power generation ability and energy storage performance of MFCs.

Thermal performance of a radial-rotating oscillating heat pipe and its application in grinding processes with enhanced heat transfer

Grinding difficult-to-machining materials can generate massive heat. The heat generated by grinding easily accumulates in the grinding zone (the contact area between workpiece and wheel), leading to high temperatures, which harms the grinding quality and efficiency. Radial-rotating oscillating heat pipe (RR-OHP) can achieve high thermal performance and can potentially to apply in grinding with enhanced heat transfer. The RR-OHP is supposed to be designed in the grinding wheel to improve the heat transport ability, in this case, grinding heat can transfer out directly via the grinding wheel. RR-OHP needs to obtain high thermal performance under radial rotations, while the related research is still insufficient. In this paper, the influence of centrifugal acceleration (0 – 1620 m/s2), working fluid properties (methanol, DI water), and heat flux (1.5 × 104 – 4 × 104 W/m2) on the heat transport capacity are studied. A prototype of a grinding wheel combined with RR-OHPs is developed. A grinding simulation by the wheel is built to demonstrate the enhanced heat transfer of RR-OHPs in grinding process. Results show that the increment of heat flux and centrifugal acceleration can improve the thermal performance of RR-OHPs. The thermal resistance of RR-OHP filled with methanol is smaller than that of RR-OHP filled with DI water. In addition, under the condition that grinding speed of 12 m/s, infeed speed of 360 mm/min, and 1 mm depth of cut, the grinding wheel embedded with 16 RR-OHPs can transfer out 79% of total heat and control the temperature under 262 °C, based on the grinding simulation. On the contrary, the grinding wheel without RR-OHPs transfers only 34% of the total grinding heat, and the temperature reaches up to 766 °C.

Role of cations in the photovoltaic performance optimization of ternary stannates, MSnO3 (M = Ca, Sr, and Ba) and N2SnO4 (N = Ca, Sr, Ba, and Zn)

Given the tremendous interest in next-generation photoelectric conversion devices, such as tandem solar cells, indoor photoelectric conversion devices, and image sensors, the development of device-specific electron transport materials is essential for achieving high performance. Sn-based semiconductors are one of the edge materials with the potential to satisfy these requirements. In particular, ternary stannate compounds have shown high potential as electron transport electrodes in several impressive studies. However, systematic research on the electronic band structure and chemical bonding characteristics of these materials remains insufficient. In this study, we present the effect of cations on the crystal structure and electronic band structure of ternary stannate compounds, MSnO3 (MSO, M = Ca, Sr, and Ba) and N2SnO4 (N2SO, N = Ca, Sr, Ba, and Zn). Additionally, their potential as electron transport electrodes is verified by application in dye-sensitized solar cells (DSCs). Notably, although BaSnO3 (BSO) and Zn2SnO4 (Z2SO) had inferior dye adsorption properties, they exhibited higher overall performance in DSCs than the other stannate compounds. The origin of the excellent performances of BSO and Z2SO is attributed to their supportive electronic band features, including the lower flat-band potential and conduction band than that of the lowest unoccupied molecular orbital level of N719 dye and excellent charge transport property. This study highlights the decisive impact of the electronic band structure and charge transport ability of stannate compounds on the photoelectric conversion performance and provides design guidelines for developing new charge transport materials.