Film Surface Research Articles

Characterization and Ambient Temperature Hydrogen Sulfide Sensing of Annealed NiO-MnO₂ Thin Films Prepared via Jet Nebulizer Spray Pyrolysis

A jet nebulizer spray pyrolysis technique to synthesize NiO-MnO2 thin films was demonstrated. These nanosheets were annealed at 350, 450 and 550 °C for 2 hours. The thin films surface morphology and structure were characterized using scanning electron microscopy, XRD, and UV spectroscopy. Subsequently, utilized as gas sensors for the detection of hydrogen sulphide gas. The introduction of NiO into MnO2 nanosheets significantly improved the gas-sensing performance. Notably, the gas-sensing response of the NiO-MnO2 nanosheet sensor surpassed that of both NiO and MnO2 alone, reaching a notable value of 165 when detecting 100 ppm hydrogen sulfide gas with the NiO-MnO2 thin film sensor. A remarkable feature of the NiO-MnO2 thin film sensor is its accelerated response time, registering at 10 seconds when exposed to 100 ppm of hydrogen sulfide gas. The mechanism underlying gas sensing and the factors contributing to the enhanced gas response of NiO-MnO2 thin film is thoroughly discussed. From a broader perspective, these developed sensors present a novel platform for the identification and monitoring of hydrogen sulfide gas, showcasing significant advancements in gas-sensing technology.

Dipropyl sulfide optimized buried interface to improve the performance of inverted perovskite solar cells

Recently, [4–(3,6-dimethyl-9H-carbazol-9-yl)butyl] phosphonic acid (Me-4PACz) has garnered significant attention as a highly effective passivation layer for NiOx. However, the Me-4PACz passivation layer shows low wettability to perovskite precursors, hindering the crystallization of perovskite. Moreover, Me-4PACz does not uniformly and completely cover NiOx, failing to achieve an optimal passivation effect. The presence of high-valence-state Ni species and reactive hydroxyls on the NiOx film surface leads to perovskite degradation. To address this, dipropyl sulfide (DPS) was incorporated into a solution of Me-4PACz. This approach not only enhances the wettability of Me-4PACz, facilitating the growth of larger perovskite grains but also enables Me-4PACz to form a homogeneous passivation layer with strong coverage. This effectively prevents direct contact between NiOx and perovskite films. Additionally, DPS interacts with reactive hydroxyls, removing them from the NiOx surface and mitigating the deprotonation reaction of MA/FA in perovskite. Furthermore, DPS is reducible, which helps in reducing high-valent Ni (Ni4+), thereby decreasing redox reactions at the interface. As a result, the optimized perovskite solar cells with DPS achieved a power conversion efficiency (PCE) of 22.29%, higher than the control device of 20.52%. Moreover, the DPS-decorated device demonstrated excellent stability, retaining over 80% of its initial PCE value, compared to only 60% retention in the control device. This work modified the buried interface and offers valuable insights for subsequent similar studies.

Tetrapyrrolic macrocycles self-organization into floating layers and sensory properties of their Langmuir-Schaefer films

The influence of the chemical structure of the 5,10,15,20-tetraphenylporphyrin (I) and 2-aza-21-carba-5,10,15,20-tetraphenylporphyrin (II) on their supramolecular organization in floating layers at the air/water interface and sensor properties in Langmuir-Schaefer films has been investigated. It was shown that a minor change in the macrocycle structure (namely, the replacement of a single nitrogen atom from the center to the periphery of macrocycle) has a considerable effect on the surface properties and hysteresis processes of the floating layers. Using the Bruster angle microscopy, it was established that both porphyrins aggregate even before the compression of their floating layers begins. The aggregation is more pronounced in porphyrin I. The analysis of hysteresis loops showed that the formation of a floating layer by the modified porphyrin II requires approximately 100 times more energy than for the unmodified porphyrin I. Using the Langmuir-Schaefer (LS) method, the floating layers were transferred onto solid substrates and the resulting thin films were analyzed by atomic force microscopy, scanning electron microscopy, polarization optical microscopy, and spectrophotometry. The combination of these methods revealed a general tendency of the porphyrins to form 3D structures on the surface of LS-films. The study of the basic properties of the porphyrin's LS-films showed that both porphyrins are diprotonated. The protonation process in porphyrin II occurs at a concentration of HClO4 that is 1000 times lower than that observed in porphyrin I. The greater tendency to protonation of porphyrin II is caused by the availability of both nitrogen atoms (the external nitrogen atom located at the macrocycle periphery and the internal nitrogen atom, which becomes more assesible to interactions due to the distortion of the macrocycle). As for the sensor properties of LS-films for iodide ion in aqueous solutions, it was observed that the diprotonated form of porphyrin I exhibited higher sensitivity due to a more developed film surface because of the presence of a greater number of 3D aggregates. The data obtained can be used in the development of efficient pH-controlled thin-film sensor materials for halide ions.

Filler processing and mixing effects of polyoxymethylene/graphene nanocomposite on tribo-mechanical performances

Binary nanocomposites based on polyoxymethylene (POM) and graphene nanoplatelet (GNP) were fabricated to improve the tribo-mechanical performances of high-precision sliding parts in linear drive system applications. Liquid-phase exfoliation technique and surface modification by 3-aminopropyltriethoxysilane (APTES) were used to process GNP filler for improved endowment of POM/e-GNP matrix-filler interfacial adhesion. Results show that processed e-GNP at optimal 0.5 wt% loading is distributed uniformly in the matrix and enables excellent stress-transfer during the mechanical loading, increasing flexural modulus, impact strength and elongation at break by 51.3 %, 41.9 % and 24.5 %, respectively, in contrast to neat POM. Simultaneously, coefficient of friction (COF) and specific wear rate (Ws) of POM in ambient temperature were also reduced substantially by e-GNP incorporation under both dry (COF by 19.5 %, Ws by 40.6 %) and grease lubricated (COF by 38.2 %, Ws by 76.4 %) sliding conditions. Smoothened wear surface and formation of homogeneous transfer film on the steel counterface were accounted for large specific surface coverage and low-shear strength of e-GNP at the contact interface, especially during the dry sliding. In addition, the accumulated energy dissipation by frictional work was calculated in the sliding interfaces based on friction force-displacement (F-D) hysteresis loop. However, pristine POM/GNP exhibited poor matrix-filler adhesion and deteriorated composite properties due to the aggregated structure which can cause subsurface defects and serve as a failure site. The proposed new material would extend the applications of precision parts by overcoming the tribo-mechanical related issues for quieter and accurate linear motion systems.

In Situ Functionalization of Polar Polythiophene-Based Organic Electrochemical Transistor to Interface In Vitro Models.

Organic mixed ionic-electronic conductors are promising materials for interfacing and monitoring biological systems, with the aim of overcoming current challenges based on the mismatch between biological materials and convectional inorganic conductors. The conjugated polymer/polyelectrolyte complex poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT/PSS) is, up to date, the most widely used polymer for in vitro or in vivo measurements in the field of organic bioelectronics. However, PEDOT/PSS organic electrochemical transistors (OECTs) are limited by depletion mode operation and lack chemical groups that enable synthetic modifications for biointerfacing. Recently introduced thiophene-based polymers with oligoether side chains can operate in accumulation mode, and their chemical structure can be tuned during synthesis, for example, by the introduction of hydroxylated side chains. Here, we introduce a new thiophene-based conjugated polymer, p(g42T-T)-8% OH, where 8% of the glycol side chains are functionalized with a hydroxyl group. We report for the first time the compatibility of conjugated polymers containing ethylene glycol side chains in direct contact with cells. The additional hydroxyl group allows covalent modification of the surface of polymer films, enabling fine-tuning of the surface interaction properties of p(g42T-T)-8% OH with biological materials, either hindering or promoting cell adhesion. We further use p(g42T-T)-8% OH to fabricate the OECTs and demonstrate for the first time the monitoring of epithelial barrier formation of Caco-2 cells in vitro using accumulation mode OECTs. The conjugated polymer p(g42T-T)-8% OH allows organic-electronic-based materials to be easily modified and optimized to interface and monitor biological systems.

Eliminating performance loss from perovskite films to solar cells.

Preoptimizing perovskite films may generally improve the performance of the final perovskite solar cells (PSCs). However, the research on whether the film optimization fully contributes to the enhancement of the final PSCs has been long neglected. We demonstrated that the preparation of metal electrodes by high-vacuum thermal evaporation, an unavoidable step in almost all device fabrication processes, will damage the surface of perovskite films, resulting in component escape, defect density rebound, carrier extraction barrier, and film stability deterioration. Therefore, the prepared perovskite film and the final film actually working in devices are not exactly the same, and the contribution of film optimization to the device improvement was weakened. We designed a bilayer structure composed of graphene oxide and graphite flakes to eliminate the unwanted film inconsistencies and thus save the film optimization loss. Therefore, the efficient PSCs with power conversion efficiency of 25.55% were obtained, which demonstrated negligible photovoltaic performance loss after operating for 2000 hours.

Does the palpebral morphology influence the tear meniscus height between Caucasian and Asian eyes?

The central lower TMH is used as a clinical measure of tear volume in the assessment of contact lens candidates and patients with dry eyes. Ethnic differences in eyelid morphology may influence the measurement of the TMH. Furthermore, with the advent of larger contact lenses, such as scleral lenses, it would be of clinical value to assess the TMH centrally and peripherally. The purpose of this study was to evaluate and compare the TMH at different positions along the palpebral margin between Caucasian and Asian eyes. This prospective study evaluated the lower TMH in five positions (central, temporal and nasal limbus and temporal and nasal periphery) of the right eye using the Keratograph 5M (Oculus) instrument in Caucasian and Asian participants between 10 am and 12 pm. The TMH at each position was taken three times and averaged and analyzed using a 5 × 2 repeated-measures analysis of variance. Central TMH did not differ significantly (F = 0.02, p=0.88) in Caucasians (n = 20, aged 24.45 [2.30] years, TMH 0.320 [0.052] mm) and Asians (n = 20, aged 22.25 [3.43] years, TMH 0.325 [0.048] mm). A difference was noted with respect to TMH positions along the lid margin (F = 64.17, p<0.001), independent of ethnicity (F = 2.15, p=0.15). A post hoc analysis revealed a significantly higher TMH temporally when compared with centrally or nasally (p<0.001). This study demonstrated the similarity of the central TMH and the differences in the peripheral TMH within Caucasian and Asian eyes. This may be clinically relevant when using the Tear Film & Ocular Surface Society Dry Eye Workshop II diagnostic algorithm for dry eyes and when fitting scleral contact lenses. Future studies need to consider that ethnic differences may exist for certain tests in order to personalize the care and management of each patient.

Defects passivation in chloride-iodide perovskite solar cell with chlorobenzylammonium halides

Despite promising optoelectronic properties, it is a matter of fact that ion migration is unavoidable in chloride-iodide-based perovskite solar cells due to a radius mismatch between chlorine and iodine. Local defects like atomic vacancies or accumulation of atoms might occur due to ion migration in chloride-iodide-based perovskite thin film. Again, atomic vacancies are prevalent in solution-processed perovskite thin film. Here we have investigated the passivation of these defects with two organic halide passivators named 4-chlorobenzylammonium chloride and 4-chlorobenzylammonium bromide. They passivate both the surface and bulk of the perovskite thin film. The surface of the perovskite thin film is passivated with the bulky organic benzylammonium cations. The bulk of the perovskite thin film is passivated with the diffusion of chlorine or bromine. With different combinations of the two passivators, we vary the chlorine range from 50% to 100% and the bromine range from 25% to 50%. We have found the champion cell performance for 75% chlorine and 25% bromine combination. The enhancement of device efficiency was around 15% compared to the control device and the device stability was also considerably enhanced.

Impurity-healing interface engineering for efficient perovskite submodules.

One issue that always strands the scaling-up development of perovskite photovoltaics is the significant efficiency drop when enlarging the device area, which is caused by the inhomogeneous distribution of defected sites1-3. In the narrow band gap formamidinium lead iodide (FAPbI3), the native impurities of PbI2 and δ-FAPbI3 non-perovskite could induce unfavored non-radiative recombination, as well as inferior charge transport and extraction 4,5.Here, we develop an impurity-healing interface engineering strategy to well address the issue both in small-area solar cell and large-scale submodule. With the introduction of a functional cation, 2-(1-cyclohexenyl)ethyl ammonium, two-dimensional (2D) perovskite with high mobility is rationally constructed on FAPbI3 to horizontally cover the film surface and vertically penetrate to the grain boundaries of 3D perovskites. Such unique configuration not only comprehensively transforms the PbI2 and δ-FAPbI3 impurities into stable 2D perovskite and realize a uniform defect passivation, but also provides interconnecting channels for efficient carrier transport. As a result, the FAPbI3-based small-area (0.085 cm2) solar cells achieve a champion efficiency over 25.86% with a notably high fill factor (FF) of 86.16%. More encouragingly, the fabricated submodules with the aperture area of 715.1 cm2 obtain a certified record efficiency of 22.46% with a good FF of 81.21%, showcasing the feasibility and effectualness of the impurity-healing interface engineering for scaling-up promotion with well-preserved photovoltaic performance.

Solar driven photocatalytic colored co–TixOyNz amorphous film prepared through air plasma treatment of sputtered titanium film

Colored co–titanium oxides and oxynitride amorphous thin film were fabricated through air plasma treatment of sputtered titanium films. Air plasma treatment led to the removal of the passive film that developed on the titanium film surface, and changes in the structural and optical properties of the films. The amorphous nature, grain size, and thickness of the films remained invariant after the treatment process. The surface roughness of the films increased upon plasma treatment. UV-vis spectroscopy study showed the reduction of the bandgap energy of the films after the air plasma treatment and the maximum reduction was found for the thinner film. The 60min air plasma treatment of the thinner film (AD5: film with 5 min deposition time) leads to the changes in bandgap from 4.11 eV to 3.26 eV, and significant Urbach energy values pointed to the formation of defect states. XPS analysis highlighted that the plasma treatment process led to the formation of titanium oxides (TiO2, Ti2O3) and oxynitrides (TiON), accompanied with Ti2+ defect states in the bandgap. The degradation of methylene blue dye solution with plasma-treated film (PT5) as the photocatalyst resulted in 88% degradation efficiency under 240min irradiation of solar simulator. The degradation has also been checked with natural solar illumination and is found to have a 90% degradation efficiency in 480min.

Waterborne polyurethane with curcumin moieties for rapid responsive warnings and emergency antimicrobial action: Application in crab freshness preservation

The ideal smart food-packaging film exhibits responsive color warnings and antimicrobial properties when food metamorphism starts. However, in practical applications, these film responses are slow, usually taking several days, which is not conducive to effective antimicrobial effects. In this study, natural plant-derived curcumin was introduced into waterborne polyurethane (WPU) dispersions through two modes: free-state and end-capping. During the film-forming process, under the influence of surface tension, the capped-end curcumin migrated to the surface and further immobilized free curcumin through π-π interactions. Consequently, curcumin accumulated on the film surface, preventing flipping in moist or hydrophobic environments, in addition to acting as a color indicator for the rapid detection of crab spoilage, thus generating ammonia for a real-time response (of approximately 60 s). Simultaneously, the curcumin degraded, producing water-soluble antimicrobial curcumin-degradation products. This study significantly advances the practical application of curcumin in smart food packaging.

Preparation and Photodegradation of TiO2 Thin Films on the Inner Wall of Quartz Tubes.

Titanium dioxide thin films on the inner wall of quartz tubes were prepared in situ by the sol-gel method. Meanwhile, copper and cerium were loaded onto the surface of the titanium dioxide thin films to enhance photocatalytic activity and broaden the range of light absorption. X-ray diffractometer, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray spectrum, N2 gas adsorption, UV diffuse reflectance spectroscopy, electron paramagnetic resonance, photoluminescene spectroscopy, and so on were used to characterize the structure, morphology, chemical composition, and optical properties of the prepared photocatalyst. Methylene blue (MB) was used as a simulated organic pollutant to study the photocatalytic performance of the photocatalyst, which was a translucent, structurally stable, and reusable high-efficiency photocatalytic catalyst. Under UV lamp irradiation, the MB photodegradation efficiency was 94.5%, which reached 91.2% after multiple cycles.

Direct Imaging of Charge/Dopant Distribution in PANI/PSS Thin Films Using Advanced Frequency Modulation Electrostatic Force Microscopy.

This paper presents a detailed study that maps the surface charges and dopant distribution on the electropolymerized thin film of polyaniline-poly(styrenesulfonate) (PANI/PSS). The focus is on two distinct states of PANI/PSS: the fully doped emeraldine salt (ES/PSS) and the dedoped emeraldine base (EB/PSS). This investigation utilizes advanced frequency modulation electrostatic force microscopy (FM-EFM) and atomic force microscopy (AFM). The polymer film comprises polymer grains, and FM-EFM data suggest a non-uniform distribution of dopants on the grain surface, with a higher doped periphery than the core. Quantifying the charge at the periphery and core of ES/PSS and EB/PSS grains provides unique insight into the charge distribution within the polymer film. The charge density is estimated to be 10 times higher in the periphery region (∼120 μC/cm2) than in the core region (∼11 μC/cm2) and 100 times higher than EB/PSS (∼0.8 μC/cm2). We have directly observed the morphological changes of PANI/PSS from the ES/PSS state to the EB/PSS state using the AFM topographic profile. These findings provide a better understanding of the behavior of the charge/dopant distribution on the surface of the polymer films and pave the way for further research and development of PANI/PSS-based electronic devices.

Selective Chemical Etching to Remove 0D Cs4Pb(IBr)6 from Mixed‐Dimensional Perovskite Surface Achieving High Efficiency Flexible All‐Inorganic Perovskite Solar Cells with Superior Mechanical Durability

AbstractAll‐inorganic cesium lead halide flexible perovskite solar cells (f‐PSCs) exhibit superior thermal stability compared to their organic‐inorganic hybrid counterparts. However, their flexibility and efficiency are still below‐par for practical viability. This study presents an approach involving the introduction of multifunctional molecule ammonium benzenesulfonate (ABS) to selectively etch 0D‐Cs4Pb(IBr)6 from the mixed‐dimensional perovskite film surface, to attain more contact area between the perovskite and hole transport layer for improved hole extraction and transport. It is found that the ABS molecules bind to the perovskite lattice surface via O atoms and NH4+, effectively passivating surface defects and enhancing phase stability. The hydrophobic nature of the benzene ring in ABS further contributes to operational stability, leading to high cell efficiency of 15.00%, accompanied by enhanced operational stability. Even after undergoing 60 000 flexing cycles at a curvature radius of 5 mm, the ABS‐treated f‐PSC still retains over 98.5% of its initial efficiency. This multifunctional strategy for modifying typical mixed‐dimensional perovskite compositions significantly enhances the photovoltaic performance and stability of flexible all‐inorganic f‐PSCs.

Study on the wear characteristics of cylindrical needle bearings on the crankshaft of RV decelerator

PurposeThe purpose of this study is to systematically analyze the wear of cylindrical needle bearings in rotary vector reducers under temperature rise and identify the influencing factors.Design/methodology/approachBased on the dynamic characteristics of the RV-20E reducer, the time-varying contact force of the cylindrical needle bearing and the entrainment speed of the inner and outer raceways were calculated. A mixed elastohydrodynamic lubrication model of the needle bearing, considering friction and temperature rise, was established using a dynamic rough tooth surface model. The model solved for the oil film thickness, contact stress and wear conditions of the bearing raceway contact area. The effects of the number of rolling needles, the diameter of rolling needles and surface strength on the wear characteristics were analyzed.FindingsThe results of this study show that the oil film thickness, oil film pressure and surface scratches of cylindrical needle bearings exhibit an uneven, patchy distribution under the combined effects of friction and temperature rise. When the radius of the rolling needle is less than 1.44 mm, inner ring wear is less than outer ring wear. Conversely, when the radius exceeds 1.44 mm, inner ring wear is greater. The optimal rolling needle radius is 1.6 mm. Increasing the number of rolling needles and enhancing the yield strength of the contact surface significantly extend bearing life.Originality/valueThis study provides valuable recommendations for optimizing bearing structural parameters and material characteristics in the design of rotary vector reducers.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2024-0242/

Evaluation of Scuffing Load Capacity of Helical Gear Based on the Tribo‐Dynamic Model

ABSTRACTThe scuffing load capacity of gear is closely related to the meshing temperature rise of tooth surface. The key to predict the temperature rise is to establish an accurate meshing temperature rise model. In the paper, a tribo‐dynamic model of helical gear is established through coupling of tooth surface lubrication parameters, and the influence of temperature rise on ambient temperature during meshing process is considered. Then, the effects of oil supply temperature, input speed and torque on tooth surface temperature rise, film thickness, friction excitation and gear dynamic characteristics are discussed. The results show that the temperature rise of the gear is higher during the engaging‐in and engaging‐out regions. Meanwhile, there is local high temperature at the end of the contact line due to the end effect. The vibration of gear along the off‐line‐of‐action direction is mainly determined by friction excitation. With the increase of oil supply temperature, input speed and torque, the risk of scuffing failure increases and the influence of oil supply temperature and input load is more significant. The conclusions of this paper may provide some valuable suggestions for the anti‐gluing failure design of gear in engineering.

Enhanced Oxidation‐Resistant and Conductivity in MXene Films with Seamless Heterostructure

AbstractMXene‐based films have garnered significant attention for their remarkable electrical and mechanical properties. Nevertheless, the practical application of MXene is impeded by its intrinsic instability caused by spontaneous oxidation. The traditional anti‐oxidative strategies frequently lead to a compromise in stability, electrical conductivity, and mechanical properties. In this study, a novel approach is proposed involving metal nano‐armoring, wherein a copper layer with nano thickness is deposited onto MXene film surfaces to establish a uniform and seamless heterogeneous interface (MXene@Cu). The precise tunability and uniformity of this heterostructure are consistently demonstrated through both theoretical calculations and experimental results. The MXene@Cu films exhibit exceptional electrical conductivity of 1.17 × 106 S m−1, electromagnetic interference shielding effectiveness of 77.1 dB, and tensile strength of 43.4 MPa. More importantly, this heterostructure significantly improves MXene's stability against oxidation. After exposure to air for 30 days, the resultant MXene@Cu films exhibit a remarkable conductivity retention of 72.0%, significantly exceeding that of pristine MXene films (44.3%). This scalable synthesis approach holds significant promise for electronic device applications, particularly in electromagnetic shielding and thermal management.

Engineering Thermoresponsive Poly(N-isopropylacrylamide)-Based Films with Enhanced Stability and Reusability for Efficient Bone Marrow Mesenchymal Stem Cell Culture and Harvesting.

Poly(N-isopropylacrylamide) (PNIPAM) offers a promising platform for non-invasive and gentle cell detachment. However, conventional PNIPAM-based substrates often suffer from limitations including limited stability and reduced reusability, which hinder their widespread adoption in biomedical applications. In this study, PNIPAM copolymer films were formed on the surfaces of glass slides or silicon wafers using a two-step film-forming method involving coating and grafting. Subsequently, a comprehensive analysis of the films' surface wettability, topography, and thickness was conducted using a variety of techniques, including contact angle analysis, atomic force microscopy (AFM), and ellipsometric measurements. Bone marrow mesenchymal stem cells (BMMSCs) were then seeded onto PNIPAM copolymer films prepared from different copolymer solution concentrations, ranging from 0.2 to 10 mg·mL-1, to select the optimal culture substrate that allowed for good cell growth at 37 °C and effective cell detachment through temperature reduction. Furthermore, the stability and reusability of the optimal copolymer films were assessed. Finally, AFM and X-ray photoelectron spectroscopy (XPS) were employed to examine the surface morphology and elemental composition of the copolymer films after two rounds of BMMSC adhesion and detachment. The findings revealed that the surface properties and overall characteristics of PNIPAM copolymer films varied significantly with the solution concentration. Based on the selection criteria, the copolymer films derived from 1 mg·mL-1 solution were identified as the optimal culture substrates for BMMSCs. After two rounds of cellular adhesion and detachment, some proteins remained on the film surfaces, acting as a foundation for subsequent cellular re-adhesion and growth, thereby implicitly corroborating the practicability and reusability of the copolymer films. This study not only introduces a stable and efficient platform for stem cell culture and harvesting but also represents a significant advance in the fabrication of smart materials tailored for biomedical applications.

Fabrication and characterization of novel biodegradable films based on tomato seed mucilage and gelatin plasticized with polyol mixtures

This research evaluates the potential of tomato seed mucilage (TSM) –gelatin (Ge) in producing edible films. Edible films were made using various ratios of TSM to Ge (1:0, 0.33:0.66, 0.66:0.33, and 0:1). Moreover, the effects of including three types of plasticizers, namely, glycerol (Gly), sorbitol (Sor), and polyethylene glycol (PEG) were investigated. The findings indicated that adding Ge did not affect the thickness of the films (p>0.05). However, it significantly increased the tensile strength (TS) and Young's modulus while reducing the elongation at break (EB) (p˂0.05). A higher TSM ratio significantly increased total color difference (ΔE) and yellowness index while decreasing film lightness and whiteness index (WI) (p˂0.05). The contact angle significantly decreased with the TSM ratio increases and Ge decreases (p˂0.05). Moreover, this led to higher opacity, solubility, moisture content, oxygen permeability, water vapor permeability (WVP), swelling, and moisture absorption (p˂0.05). Adding a plasticizer had no effect on the films' opacity, contact angle, and thickness. The Gly-containing film featured the highest EB, solubility, moisture content, swelling, WVP, oxygen permeability, and moisture absorption. The Sor-containing film had the highest TS. TSM concentration was directly correlated with increased film heterogeneity and surface roughness. X-ray diffraction peaks became sharper by increasing TSM concentration and including PEG, while Gly inclusion produced ordered broad peaks.

Investigation of the high temperature molten salt corrosion properties of Inconel625 alloy with Al

The Inconel625 (In625) alloy is one of the main materials in heat receivers of concentrated solar power (CSP). To further improve the corrosion resistance of heat receivers in molten salt, Al element that can form an oxide film was added into In625 alloy. In this study, In625 alloy with 3 wt% Al was prepared, and its corrosion resistance in carbonate (Li2CO3-Na2CO3-K2CO3) at 650 °C was studied. Results showed that a continuous dense oxide protective film (Al2O3 + LiAlO2) in surface of sample was formed by adding Al element during high temperature molten salt corrosion, which reduced the corrosion rate of In625 alloy. The corrosion rate of In625 alloy with 3 wt% Al corroded for 48 h and 120 h were 44 μm/year and 89 μm/year, respectively.