Wet Test Research Articles

Electrophoretic deposition of tea tree oil containing chitosan/gelatin/whitlockite composite coatings for biofilm protection and bone tissue regeneration

This work presents a design of experiment (DoE) approach to optimize the electrophoretic deposition (EPD) parameters for chitosan (CS), gelatin (Gel), and whitlockite (WH) composite coatings on titanium substrate. The suspension for EPD was prepared by dissolving CS and Gel in acetic acid and WH nanoparticles (NPs) were dispersed in ethanol. Afterward, both (CS, Gel solution, and WH suspension) were mixed and the suspension stability was evaluated using zeta potential. Deposition parameters like voltage, concentration of WH, and time were optimized using Taguchi L16 orthogonal array with four control factors. The statistical data obtained confirmed that a higher time with average voltage and WH concentration is ideal to achieve deposits with maximum yield and minimum signal-to-noise ratio. Tea tree oil (TTO) in different concentrations was added to these optimized conditions. Different physiochemical characterization like x-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), in-vitro degradation, surface adhesion, and wettability tests were done to evaluate the coating stability, adhesion, surface and chemical properties. The obtained data confirmed that coatings were mechanically strong, chemically stable, and possessed good adhesion strength to the substrate. To further confirm the bone tissue regeneration potential of the coatings, in-vitro bioactivity, cell viability, and cell proliferation tests were done. The obtained data confirmed that CS/Gel/WH composite is highly bioactive and promotes osseointegration. TTO at lower concentrations facilitates cell proliferation but it is toxic at higher concentrations. TTO interacted with the coating matrix via non-covalent interactions that resulted in its slow and sustained release over 28 days. TTO showed antibacterial effect when tested with E. coli bacteria. Hence, in this work, experimental, statistical, physiochemical, and biological analyses are discussed in detail based on the current knowledge of WH coatings and the effect of TTO on cytocompatibility as well as biofilm prevention.

Enhancing Wear Resistance of UHMWPE Composites with Micro MoS2 and Nano Graphite: A Taguchi-DOE Approach.

This study presents an in-depth investigation into the wear characteristics of ultrahigh-molecular-weight polyethylene (UHMWPE) composites reinforced with microsized MoS2 and nanosized graphite particles. The objective is to enhance the wear resistance of the UHMWPE by examining the effects of various parameters and optimizing the wear performance. To achieve this goal, wet wear tests were conducted under controlled conditions, and the results were compared between composites with micro MoS2 and nano graphite reinforcements. The Taguchi method was employed to design the experiments (DOE) using an L9 orthogonal array. Four key parameters, namely, reinforcement percentage, load, speed, and track radius, were varied systematically to analyze their impact on wear characteristics, including wear rate, frictional forces, and the coefficient of friction (COF). The data obtained from the experiments were subjected to analysis of variance (ANOVA) to identify the significant factors affecting wear behavior. Subsequently, the optimal wear parameters were determined through regression analysis, allowing for the prediction of wear characteristics under the optimum conditions. This research not only provides insights into the comparative performance of micro MoS2 and nano graphite reinforcements in UHMWPE composites but also offers a comprehensive approach to optimizing wear resistance by employing advanced statistical and experimental techniques. The findings contribute to the development of more durable and wear-resistant materials with potential applications in various industries, such as those investigated in the study, which are commonly employed, such as automotive, aerospace, medical devices, or manufacturing.

Phytin recovered from grain distillation can serve as a phosphorus fertilizer for maize and soybean

AbstractPhosphorus (P) recovery from waste streams can increase food system P use efficiency while simultaneousl mitigating point source P losses. Phytin is a P‐rich waste product generated from maize grain biorefineries, largely located in the US Midwest. However, since the majority of P in phytin is organic, phytin‐P is likely to have limited crop availability in soil following application, as it must first be mineralized to orthophosphate‐P by soil phosphatases. To evaluate the fertilizer potential of phytin recovered from a maize wet milling plant and test hypothesized mechanisms of P mineralization, a five‐step gradient of phytin substitution for monoammonium phosphate (MAP) (0%, 25%, 50%, 75%, and 100% substitution) was evaluated for maize (Zea mays L.) and soybean (Glycine max L.) growth in a P‐deficient Aquic Argiudoll. Irrespective of crop species, aboveground biomass at end of vegetative growth (VT stage) was similar for up to 75% phytin substitution as MAP, but was 21% lower for maize and 49% for soybean when phytin was fully substituted for MAP. Soil microbial biomass carbon (C), nitrogen (N), and P, as well as activities of phosphomonoesterase and phosphodiesterase were invariant across the phytin substitution gradient, suggesting negligible mineralization of phytin P. Full substitution of MAP with phytin lowered soil microbial biomass C:N by 121% for maize and by 153% for soybean, and soil phosphatase activities per unit microbial biomass C were 24% higher under soybean. Our results indicate that phytin can be partially substituted for highly water‐soluble P fertilizers for the two major crop species of the US Midwest in which phytin waste generation is co‐located.

Relationship between chloride ingress and concrete cover quality of inland structures exposed to deicing salts

The apparent diffusion coefficient of chloride ions is used to evaluate the durability of existing concrete structures against chloride attack. The coefficient requires in situ measurements of chloride profiles, which use destructive sampling techniques, such as core drilling. In this study, the relationship between the apparent diffusion coefficient of chloride ions obtained from destructive tests and the air-permeability coefficient obtained from a non-nodestructive Torrent method in the existing road bridges exposed to deicing salts was analyzed. The obtained relationship was different from the common trends obtained from laboratory chloride-immersion tests and in situ measurements in marine/coastal concrete structures. Additional cyclic wetting and drying tests in a laboratory revealed the effects of environmental differences on the apparent diffusion coefficient of chloride ions. A higher ratio of the drying period, in the case of deicing salts, reduced the apparent diffusion coefficient.

Antifungal Susceptibility Assessment of Innovative and Non-Conventional Lime Mortars Incorporating Almond-Shell Powder Bio-Waste Subjected to Particle-Dispersion Technique.

A favorable environment for fungi colonization in building materials' surfaces can emerge when certain hygrothermal conditions occur. Thus, reducing fungal growth susceptibility is of major interest. Furthermore, if the integration of bio-wastes is performed in parallel with the development of innovative materials for this purpose, a more sustainable and environmentally friendly material can be obtained. In this study, the fungal susceptibility of lime mortars incorporating almond-shell powder (ASP) microparticles (2 and 4%, wt.-wt. in relation to the binder content) was evaluated. The particle-dispersion technique was employed to prepare the bio-waste introduced in the mixtures. The fungal susceptibility of ASP samples was compared with nanotitania (n-TiO2) with recognized antifungal properties. Mechanical strength, water absorption, and wettability tests were also performed for a better characterization of the composites. Although the addition of 2% ASP led to mechanical properties reduction, an increase in the compressive and flexural strength resulted for 4% of the ASP content. Difficulties in fungal growth were observed for the samples incorporating ASP. No fungal development was detected in the mortar with 2% of ASP, which may be correlated with an increase in the surface hydrophobic behavior. Furthermore, mortars with ASP revealed a reduction in water absorption by capillarity ability, especially with 4% content, suggesting changes in the microstructure and pore characteristics. The results also demonstrated that an improvement in the physical and mechanical properties of the lime mortars can be achieved when ASP microparticles are previously subjected to dispersion techniques.

INTERFACIAL TENSION AND CONTACT ANGLE TESTS OF RHAMNOLIPIDS AND SOPHOROLIPIDS IN SANDSTONE FOR ENHANCED OIL RECOVERY

In the context of the development of enhanced oil recovery technology, biotechnology can be used to develop new methods that are more environmentally friendly and sustainable, one of which is the use of biosurfactants. Rhamnolipids and sophorolipids are non-toxic biosurfactants, biodegradable, and environmentally favorable substances. This study compares the results of laboratory studies on fluid-to-fluid interactions, including the interfacial tension and rock wetness tests at various concentrations and salinities, which represent high salinity, medium salinity, and low salinity. The mechanism of these two biosurfactants is based on reducing the interfacial tension (IFT) between the fluids and changing the wettability of the rock to a more water-wet state. In the interfacial tension test, the reduction in the interfacial tension of rhamnolipids reached 10-2 mN/m, while that of sophorolipids only reached 10-1 mN/m. Then, the sandstone wettability test showed that the two biosurfactants were classified as water-wet (<75°). This happens because of its chemical structure, which has two parts: the hydrophobic part and the hydrophilic part. Within the salinity range of 8,000-32,000 ppm, the rhamnolipids work better in the higher salinity to reduce interfacial tension, and the salinity has a subtle effect on the contact angle. On the other hand, sophorolipids were not affected by salinity for both interfacial tension and contact angle. These two biosurfactants have the potential to increase oil recovery in sandstone so that they can contribute to environmentally friendly biotechnology.

Bioinformatic Analysis Strategy in Restriction Enzyme Selection for Indonesian Panulirus homarus Identification by PCR-RFLP

The spiny lobster (Panulirus homarus) is a valuable fishery commodity in Indonesia, particularly in its juvenile life form. However, identifying the early life forms of the spiny lobster can be challenging, as it exhibits similar morphological features compared to the juveniles of other Panilurid lobsters. Molecular-based identification, specifically DNA sequencing, is the best method for species identification, but it requires advanced instruments and is costly. An alternative method is proposed here, using the PCR-RFLP technique, which is low-cost, rapid, and has standard instrumentation requirements. The challenge with this method is selecting the appropriate restriction enzyme to determine the targeted species’ identity. This study proposes using the REfind (https://github.com/indriatmoko07/REfind), R package to select the best restriction enzyme for identifying P. homarus, applicable to other species. The bioinformatics workflow used in this study successfully identified BseSI or BmgI as the most suitable restriction enzymes among 739 restriction enzymes to differentiate P. homarus from other Panilurid species. This result was validated by employing a wet lab test using the BseSI enzyme and successfully validated the bioinformatics result. These findings may be useful for biologists in conducting various studies that require rapid, low-cost, and identification of specific species in the future.

Preparation and performance evaluation of a novel temperature-resistant anionic/nonionic surfactant

Aiming at oil extraction from a tight reservoir, the Jilin oil field was selected as the research object of this study. Based on the molecular structures of conventional long-chain alkyl anionic surfactants, a new temperature-resistant anionic/nonionic surfactant (C8P10E5C) was prepared by introducing polyoxyethylene and polyoxypropylene units into double-chain alcohols. The resulting structures were characterized by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (1H-NMR), and electrospray ionization mass spectrometry (ESI–MS). Then, based on surface tension, interfacial tension, adsorption resistance, wettability, and emulsification performance tests, the performance of C8P10E5C was evaluated. The FT-IR, ESI–MS, and NMR spectra confirmed that C8P10E5C was successfully prepared. The critical micelle concentration (CMC) of C8P10E5C in water was 2.9510 × 10−4 mol/L (the corresponding mass concentration is 0.26%), and the surface tension of the aqueous C8P10E5C solution at this concentration was 30.5728 mN/m. At 0.3% concentration, the contact angle of the C8P10E5C solution was 31.4°, which is 60.75% lower than the initial contact angle. Under high-temperature conditions, C8P10E5C can still reduce the oil–water interfacial tension to 10−2 mN/m, exhibiting good temperature resistance. At 110 °C, upon adsorption to oil sand, the C8P10E5C solution could reduce the oil–water interfacial tension to 0.0276 mN/m, and the interfacial tension can still reach the order of 10−2 mN/m, indicating that C8P10E5C has strong anti-adsorption capability. Additionally, it has good emulsifying performance; upon forming an emulsion with crude oil, the highest drainage rate was only 50%. The forced imbibition oil recovery of C8P10E5C is 65.8%, which is 38.54, 24.22, and 27.25% higher than those of sodium dodecyl benzene sulfonate, alkyl polyoxyethylene ether carboxylate, and alkyl ether carboxylate, respectively.

Chemical Interaction between the Sr4Al6O12SO4 Ceramic Substrate and Al–Si Alloys

Samples of Sr4Al6O12SO4 are obtained through a solid-state reaction of Al2O3, SrSO4, and SrCO3. The samples are then made into 1 and 4 cm pellets by compacting them at 100MPa and sintering them at 1400 °C for 4 h. The compound is analyzed using X-ray diffraction. Static immersion and wettability tests are carried out to evaluate corrosion resistance in contact with Al–Si. Corrosion tests are conducted by immersing the samples at 800, 900, and 1000 °C for 24, 50, and 100 h, while wettability is studied at 900, 1000, and 1100 °C for 2 h. Afterwards, the samples are subject to metallographic preparation. The samples are then analyzed using optical microscopy, scanning electron microscopy, and image analysis. In general, reaction products consisting of alumina, spinel, oxides, and sulfates are found. The contact angles obtained are between 124° and 135°. It is concluded that the Sr4Al6O12SO4 ceramic substrate is resistant to corrosion by the Al–Si alloy because of the slight thickness of the reaction products found in the samples (73 μm), considering the severe conditions of the experiment: 1000 °C and 100 h of isothermal temperature. Furthermore, Sr4Al6O12SO4 is not wettable by Al–Si alloys. These results suggest that the ceramic substrate could be used in the refractory industry, possibly as an additive to commercial refractory ceramics. For future work, it is recommended to carry out the same study with the aluminum–magnesium alloy and as an additive in commercial refractory ceramics.

Analysis of the Mechanical Properties of Cured Sludge by Alkaline Excitation of Phosphogypsum

Engineering slag is a green building material that meets the requirements of contemporary sustainable development, and the solidification technology of residue is particularly important in the practical engineering of resource utilization and environmental protection. In order to reuse the waste soil and industrial waste and reduce the construction cost, the stabilization effect of adding different contents of calcium oxide, blast furnace slag and phosphogypsum to the waste soil of a township road reconstruction project was studied. The unconfined compressive strength test of calcium oxide further clarified the solidification mechanism of residual soil and helped us to obtain the optimal curing ratio. The dry and wet cycle test simulated the influence of temperature and humidity changes on the appearance, quality, strength and water resistance in actual engineering. The experimental results show that the unconfined compressive strength of the sample reaches 1.273 MPa after 7 days of curing when the mixture of 4% calcium oxide (ratio to 100% plain soil) and 16% blast furnace slag (ratio to 100% plain soil) is mixed. When the three materials were mixed, the unconfined compressive strength of 4% calcium oxide (the ratio of 35% phosphogypsum and 65% plain soil) and 16% blast furnace slag (the ratio of 35% phosphogypsum and 65% plain soil) reached 1.670 MPa and 3.107 MPa at 7 and 28 days, respectively. The curing age has a significant promoting effect on the stability of loess. The dry and wet cycle test results conclude that the specimens have good durability and stability. The results of microstructure analysis shows that a large number of ettringite and C-S-H gel were formed in the gelling system, which not only makes the original soil more stable, but also acts as a part of filling pores, and the two work together to support the soil and improve the strength.

Assessment of the Arc Resistance of 3D-Printed Insulation Materials for Outdoor High-Voltage Applications

High-voltage electrical equipment insulation often uses composite materials like epoxy resin, cross-linked polyethylene, polyurethane, and silicone rubber as encapsulation. 3D printing technology offers a more efficient and cost-effective solution, producing intricate elements without cutting and casting. Research shows that 3D printed materials have comparable properties to polymer-based insulation, but further testing is needed to evaluate their resistance to harsh environmental conditions. This research investigates the arc resistance properties of 3D printed insulation materials for outdoor high-voltage applications, assessing their suitability for outdoor applications. The wet and dry arc resistance tests were performed in accordance with ASTM D495-99 and IEC-60587. The present work investigated three varieties of samples: polylactic acid, epoxy resin, and silicone rubber. The results of the tests reveal that polylactic acid test samples have average wet and dry arc resistance times of 2.5 hours and 1.4 seconds, which is less than silicone rubber and epoxy resin. Additional research is required to comprehend the behavior of arc formation in polylactic acid insulation materials for high-voltage 3D printing applications.

Characterization and In Vitro Evaluation of Porous Polymer-Blended Scaffolds Functionalized with Tricalcium Phosphate.

Bone tissue is one of the most transplanted tissues. The ageing population and bone diseases are the main causes of the growing need for novel treatments offered by bone tissue engineering. Three-dimensional (3D) scaffolds, as artificial structures that fulfil certain characteristics, can be used as a temporary matrix for bone regeneration. In this study, we aimed to fabricate 3D porous polymer scaffolds functionalized with tricalcium phosphate (TCP) particles for applications in bone tissue regeneration. Different combinations of poly(lactic acid) (PLA), poly(ethylene glycol) (PEG with molecular weight of 600 or 2000 Da) and poly(ε-caprolactone) (PCL) with TCP were blended by a gel-casting method combined with rapid heating. Porous composite scaffolds with pore sizes from 100 to 1500 µm were obtained. ATR-FTIR, DSC, and wettability tests were performed to study scaffold composition, thermal properties, and hydrophilicity, respectively. The samples were observed with the use of optical and scanning electron microscopes. The addition of PCL to PLA increased the hydrophobicity of the composite scaffolds and reduced their susceptibility to degradation, whereas the addition of PEG increased the hydrophilicity and degradation rates but concomitantly resulted in enhanced creation of rounded mineral deposits. The scaffolds were not cytotoxic according to an indirect test in L929 fibroblasts, and they supported adhesion and growth of MG-63 cells when cultured in direct contact.

Fe-doped NaV3O8 thin films as an efficient electrode with enhanced performance for asymmetric supercapacitor device

Pure and Fe-doped NaV3O8 films on SS substrates were prepared using the cost-effective spray pyrolysis technique. Fe has been doped into the NaV3O8 at different weight percentages of 1, 3 and 5. Preliminary characterizations like XRD and SEM analysis have been carried out for the deposited films to study the changes that occur in the structural and morphological properties of the films caused by doping. The EDAX analysis determines the elements present in the film, whereas the oxidation states of the elements present were determined by XPS analysis. The surface wettability test reveals the hydrophilic nature of the films. A three-electrode system with 1 M NaNO3 aqueous electrolyte was used to study the electrochemical characteristics of the prepared films. The results have shown that the 3 wt% Fe-doped NaV3O8 film achieved a specific capacitance of 131 F/g at a current density of 0.5 A/g surpassing the performance of pure NaV3O8 film. Subsequently, a 3 wt% Fe-doped NaV3O8 // AC configured asymmetric supercapacitor device was fabricated and it displayed a specific capacitance of 13.4 F/g with a specific energy and power density of 1.86 Wh/kg and 999 W/kg, respectively at a current density of 0.5 A/g. The device obtained a capacitance retention of 70.1 % even after 5000 cycles. Therefore, the present study probes into the impact of incorporating Fe into NaV3O8, by exploring its structural, morphological, and electrochemical characteristics.

Study on Adhesive and Microstructure Properties of Rice Husk Ash-Based Geopolymer Hybrid Alkyd Coating

ABSTRACT Ensuring strong adhesion, especially under varying environmental conditions, is a significant challenge in the field of coating technology. This research aims to enhance alkyd paint adhesive strength by incorporating rice husk ash-based geopolymer (GP-RHA) as a filler. Response Surface Methodology (RSM) technique was employed to systematically study the impact of GP-RHA levels on the adhesive strength of alkyd coatings under dry and wet conditions. The morphology of the coatings was analyzed using SEM-EDX. In dry pull-off test, the incorporation of GP-RHA in alkyd coatings led to an improvement in adhesive strength with the highest recorded adhesive strength of 3.9 MPa at a ratio of 41.67% wt. GP-RHA and 58.33% wt. alkyd paint. However, this higher proportion of GP-RHA resulted in the formation of a larger pore sizes hybrid coating, further causing water infiltration into the coating’s pore structure in wet pull-off test. Outcomes of this research showed the promising potential of GP-RHA filler in alkyd paint formulations to enhance adhesion. These findings offer valuable insights into the development of coatings utilizing agro-waste as a filler to improve its adhesive properties.

Effects of wind speed on performance of a novel forced-air ice slurry wet precooling system

Aiming at the problems of low humidity and high dry consumption in the present forced-air precooling room, the combination of the ice slurry wet cooling system with the forced-air precooling was proposed, and a novel forced-air ice slurry wet precooling test platform was designed and built. The purpose of this paper is to experimentally study the effects of wind speeds on the performance of ice slurry wet precooling system by taking tomatoes as precooling objects, including precooling rate, precooling uniformity, precooling energy consumption and weight loss ratio of tomatoes. Also, the results are compared with those of other similar studies such as traditional forced-air precooling system. The results show that with the increase of wind speed, the precooling rate increases, the required precooling time is shortened, and the temperature variation coefficient of tomatoes decreases first and then increased, that is, the precooling uniformity becomes better and then worse. When the wind speed is 2.5 m/s, the overall precooling uniformity is the best. The precooling energy consumption decreases first and then increases, and is relatively low when the wind speed is between 1.5 m/s and 2.5 m/s (lowest at 2.5 m/s), which is lower than that of traditional forced-air system. With the increase of wind speed, the weight loss of tomatoes decreases first and then fluctuates slightly, and the weight loss ratio is about 0.1 %, which is much lower than that of tomatoes in the traditional forced-air precooling system. Overall, the maximum wind speed is not recommended to exceed 2.5 m/s for the precooling system studied in this work. The results can provide references for the further research and development of forced-air precooling technology.

Analysis of wetability properties for kraft paper and corrugated cardboard

Corrugated cardboard and kraft paper are widely used in the packaging industry, providing versatility of use and protection for products. The analysis of the wettability properties of these materials is extremely important, as it allows us to understand how they react to humidity. This research aimed to study the wettability properties of corrugated paper (PO) and kraft paper in order to expand knowledge about the quality of packaging produced with them. The study was conducted in the laboratory using corrugated cardboard (PO) with waves of type "A", "B", "C" "E" and kraft paper obtained from coils with and without coating. The wettability tests performed were total immersion, absorption time and drop penetration method. The collected data was interpreted using descriptive and graphical analysis generated by the R program. The research concluded that for the total immersion test, both materials absorbed more water in the vertical position. In the droplet absorption and penetration time tests, cardboards with type “E” waves showed the highest results when compared to other materials, providing a superior barrier for products that will be transported in boxes of this type. Furthermore, the coated Kraft paper also demonstrated good performance for drop penetration testing, confirming the coating's effectiveness as a moisture barrier.

Chemical Species Formed on FeB-Fe2B Layers during Wet Sliding Wear Test

In the present work, X-ray photoelectron spectroscopy (XPS) survey spectra of borided AISI 316L for two different times (1 and 6 h) of exposure to simulated body fluid (SBF) were obtained after wet sliding wear. A borided layer of ~39 microns was obtained on the surface of the AISI 316L stainless steel using the thermochemical treatment of boriding. As part of the mechanical and chemical characterization of sliding wear, Berkovich nanoindentation and X-ray spectroscopy tests were used to determine the main properties of the borided layer. The results of the specific wear rate values were higher at 5 mm/s sliding speed than those recorded at 30 mm/s due to the influence of the exposure time of the sample and the complex combinations of chemical reactions with boron (e.g., B2S3, Cr2O3, and Fe2O3) on the surface during the sliding during 6 h of exposure in Hank’s solution due to the formation of the passive film. The knowledge of chemical species formed during wet sliding wear tests on borided AISI 316L is essential for understanding wear mechanisms and materials’ performance and optimizing material properties and materials’ and components’ reliability in the biomedical industry for screws and fastening plates.

Effect of Mo on wear resistance of Stellite31 cladding layer

Stellite alloys are a kind of cobalt-based alloys, which have excellent properties and are widely used in numerous areas. However, the wear resistance of Stellite alloys is poor at room temperature. In this study, Stellite31 cladding layers added with 0%, 1%, 2% and 3% of Mo(wt-%) were prepared by laser cladding. The grain sizes were measured by scanning electron microscope images, the distributions of Mo were analysed by energy dispersive X-ray spectrometry, the physical phase compositions were analysed by X-ray diffractometer, and the wear resistance was evaluated by reciprocating friction wear tester and wet sand wear testing machine. The results showed that the grain sizes of the cladding layers decreased with the increase of Mo content, the wear loss of the cladding layers became lower and the friction coefficient decreased under the same test conditions. It was concluded that increasing the Mo content could improve the wear resistance of the Stellite31 cladding layer at room temperature.

Influence of Environmental Conditions on the Electrical Parameters of Side Connectors in Glass–Glass Photovoltaic Modules

This work focused on the verification of the electrical parameters and the durability of side connectors installed in glass–glass photovoltaic modules. Ensuring the safe use of photovoltaic modules is achieved, among others, by using electrical connectors connecting the PV cell circuit inside the laminate with an external electric cable. In most of the cases for standard PV modules, the electrical connector in the form of a junction box is attached from the back side of the PV module. The junction box is glued to the module surface with silicone where the busbars were previously brought out of the laminate through specially prepared holes. An alternative method is to place connectors on the edge of the module, laminating part of it. In such a case, the specially prepared “wings” of the connector are tightly and permanently connected using laminating foil, between two glass panes protecting against an electrical breakdown. Additionally, this approach eliminates the process of preparing holes on the back side of the module, which is especially complicated and time-consuming in the case of glass–glass modules. Moreover, side connectors are desirable in BIPV applications because they allow for a more flexible design of installations on façades and walls of buildings. A series of samples were prepared in the form of PV G-G modules with side connectors, which were then subjected to testing the connectors for the influence of environmental conditions. All samples were characterized before and after the effect of environmental conditions according to PN-EN-61215-2 standards. Insulation resistance tests were performed in dry and wet conditions, ensuring full contact of the tested sample with water. For all modules, before being placed in the climatic chamber, the resistance values were far above the minimum value required by the standards, allowing the module to be safely used. For the dry tests, the resistance values were in the range of GΩ, while for the wet tests, the obtained values were in the range of MΩ. In further work, the modules were subjected to environmental influences in accordance with MQT-11, MQT-12, and MQT-13 and then subjected to electrical measurements again. A simulation of the impact of changing climatic conditions on the module test showed that the insulation resistance value is reduced by an order of magnitude for both the dry and wet tests. Additionally, one can observe visual changes where the lamination foil is in contact with the connector. The measurements carried out in this work show the potential of side connectors and their advantage over rear junction boxes, but also the technological challenges that need to be overcome.

A rapid two-step process to prepare a high-throughput, efficient, reusable superhydrophobic–superoleophilic stainless steel mesh for oil/water separation

Currently, due to the industrial development, the direct discharge of large amounts of oil-containing wastewater has led to serious water pollution. It is necessary to develop an efficient, durable, and high-throughput material for oil–water separation. To achieve this, we prepared a nickel (Ni) coating with a loose leaf-like micro/nanostructure on the surface of stainless steel mesh (SSM), imparting it with superhydrophobic and superoleophilic properties. The deposition of ions onto the substrate was carefully controlled by adjusting the deposition parameters. Subsequently, the as-prepared Ni coating was further modified using a solution of perfluorooctyltriethoxysilane (PFOTS) in ethanol to obtain a PFOTS/Ni mesh (PNM) with excellent superhydrophobic–superoleophilic properties. Wettability tests revealed that the water contact angle (WCA) and oil contact angle (OCA) of the PNM, prepared under the optimized deposition conditions, were 161 ± 1° and 0°, respectively, with a water sliding angle (WSA) of less than 10°. Importantly, the PNM demonstrated remarkable mechanical stability in blade scratch and tape peel tests, as well as excellent chemical stability in acid-alkali resistance and electrochemical corrosion tests. And, the PNM exhibited remarkable self-cleaning capability. Additionally, PNMit filters displayed outstanding efficiency in separating oil and water (reaching 91.5%) and remarkable durability. The results indicate that the well-designed superhydrophobic–superoleophilic SSM exhibits advantages such as simple fabrication, low cost, high reusability, and strong robustness. It holds great potential for practical applications in the treatment of oily wastewater and oil spill remediation.