Low Viscosity Research Articles

Synergetic effect of hybrid surface treatment on the mechanical properties of adhesively bonded AA2024-T3 joints

ABSTRACT Improving the surface properties of AA2024-T3 aluminium alloys is crucial for achieving durable and sustainable joints. For this purpose, AA2024-T3 alloys were first sandblasted at 4, 5 and 6 bar pressures using aluminium oxide and glass sphere abrasives. Then, the sandblasted samples were subjected to the chemical surface treatment resulting in a hybrid surface process. The surface properties of sandblasted and hybrid surface-treated AA2024-T3 alloys were characterised by 3D image analysis, contact angle and roughness measurement. Additionally, single-lap joints were fabricated using adhesives with low and high viscosity. The effect of changes in the viscosity of adhesives and the surface properties of the AA2024-T3 on the mechanical properties of the joints has been analysed in detail. It was found that both sandblasting and hybrid surface treatments applied to AA2024-T3 alloys caused significant improvement in the mechanical properties of the joints. AA2024-T3 alloys, which were chemically surface treated after being sandblasted with glass spheres at 6 bar pressure, were joined using low and high viscosity adhesives, and the failure load of these joints increased by approximately 110% and 68%, respectively, compared to untreated samples. In the case of aluminium oxide usage, the increase rates were determined to be 93% and 43%.

MASTER OT J030227.28+191754.5: An unprecedentedly energetic dwarf nova outburst

Abstract We present a detailed study of the MASTER OT J030227.28$+$191754.5 outburst in 2021–2022, which reached an amplitude of $10.2\:$mag and a duration of $60\:$d. The detections of (1) the double-peaked optical emission lines, and (2) the early and ordinary superhumps, established that MASTER OT J030227.28$+$191754.5 is an extremely energetic WZ Sge-type dwarf nova (DN). Based on the superhump observations, we obtained its orbital period and mass ratio as $0.05986(1)\:$d and 0.063(1), respectively. These values are within a typical range for low-mass-ratio DNe. According to the binary parameters derived based on the thermal–tidal instability model, our analyses showed that (1) the standard disk model requires an accretion rate $\simeq\!\! 10^{20}\:$g$\:$s$^{-1}$ to explain its peak optical luminosity, and (2) large mass was stored in the disk at the outburst onset. These factors cannot be explained solely by the impact of its massive ($\gtrsim\!\! 1.15\, M_{\odot }$) primary white dwarf implied by Kimura et al. (2023, ApJ, 951, 124). Instead, we propose that the probable origin of this enormously energetic DN outburst is the even lower quiescence viscosity than other WZ Sge-type DNe. This discussion is qualitatively valid for most possible binary parameter spaces unless the inclination is low enough ($\lesssim\!\! 40^\circ$) for the disk to be bright, explaining the outburst amplitude. Such low inclinations, however, would not allow detectable amplitude of early superhumps in the current thermal–tidal instability model. The optical spectra at outburst maximum showed strong emission lines of the Balmer, He i, and He ii series, the core of which is narrower than $\sim \! 800\:$km$\:$s$^{-1}$. Considering its binary parameters, a Keplerian disk cannot explain this narrow component, but the presumable origin is disk winds.

Thermo-controlled microfluidic generation of monodisperse alginate microspheres based on external gelation.

Droplet-based microfluidic systems have received much attention as promising tools for fabricating monodisperse microspheres of alginate solutions with high accuracy and reproducibility. The immediate and simple ionotropic gelation of alginate, its biocompatibility, and its tunability of mechanical properties make it a favorable hydrogel in the biomedical and tissue engineering fields. In these fields, micron-sized alginate hydrogel spheres have shown high potential as cell vehicles and drug delivery systems. Although on-chip microfluidic gelation of the produced alginate droplets is common, several challenges remain. Complicated chemical and microfabrication processes are required, and the risk of microchannel clogging is high. In the current study, we present an easy-to-use microfluidic external gelation process to produce highly spherical and monodisperse microspheres from very low-concentrated alginate-RGD solution [0.5% (w/v)]. To accomplish this, gelatin, a thermo-sensitive and inexpensive biomaterial, was incorporated into the alginate solution as a sacrificial biomaterial that mediates the off-chip external gelation of the alginate with Ca2+, and avoids droplet coalescence. Utilizing the methodology mentioned above, we successfully generated monodisperse alginate microspheres (AMs) with diameters ranging from 27 μm to 46 μm, with a coefficient of variation of 0.14, from a mixture of Arg-Gly-Asp (RGD)-modified very low viscosity alginate and gelatin. These RGD-AMs were used as microcarriers for human umbilical vein endothelial cells. The described easy-to-use and cost-effective microfluidic off-chip external gelation strategy exhibits comparable advantages to on-chip external gelation and demonstrates superiority over the latter since clogging is impossible.

Triiodide ionic liquids used for selective and sustainable palladium recovery from waste catalysts

The Pd recovery from waste catalysts (W-catalysts) is a globally significant subject due to the high value of Pd across various industries. However, severe environmental contamination and excessive energy usage are well-known issues in Pd recovery attributed to the use of hazardous leaching agents and poor recovery conditions. Here, we present a new recovery method based on triiodide ionic liquids (ILs) with greatly reduced environmental impact and reagent costs, along with mild reaction conditions. This method enables the selective leaching of waste Pd0 from diverse W-catalysts to produce Pd2+. In a mild (50 °C) and low viscosity (59.8 cP) operating environment, the leaching efficiency of this process is approximately 98.4 %. Moreover, redox mechanism and shrinkage kinematic models are thorough investigation. Notably, economic analysis demonstrates that recycling 1.0 kg of W-catalysts could generate a significant profit of 3036.1 USD. By advancing Pd recovery closer to levels of practical application, this study will foster a more sustainable prospect for W-catalysts.

Effect of acid viscosity on conductivity during online acid-fracturing in ultra-deep carbonate reservoir

The influence of viscosity change in the same acid system on etched-fracture morphology and conductivity was often neglected in many studies that conducted multi-stages alternative acid-etching experiments using different acid systems. In order to address this knowledge gap, the present study investigated the impact of single injections of low viscosity and high viscosity acid, as well as an alternative stages of low and high viscosity acid, on the acid-etched fracture morphology and conductivity. While the online acid-fracturing technology was proposed based on experimental results firstly in ultra-deep wells. The results show that injecting acid with different viscosities is more effective than using a single viscosity acid-etching, as it improves fracture morphology and conductivity. Additionally, the stages of alternating acid have a significant impact on conductivity. Experimental studies reveal that employing three stages of alternating acid with different viscosities enhance the fracture conductivity in the research area. Based on these findings, the P6 well successfully is implemented online acid-fracturing in an ultra-deep well reaching 8000 m firstly in Sichuan Basin. Compared to adjacent wells, this technique exhibited lower friction resistance, enabling higher acid-injection rates.

Synthesis, Characterization, and Optimization of Antimicrobial Biolubricant Derived from Ocimum lamiifolium and Lactic Acid

Optimal extraction parameters were determined, yielding 12.4% oil at 4.5 hours, with a particle size of 1.375 mm and a solute-to-solvent ratio of 0.28 w/v. The extracted oil exhibited high yield (15% moisture, 0.92 g/mL specific gravity), a volatile lubricant component (3%), a pH of 4.2-5.91, low ash (11.5%), high saponification value (19.7 g KOH/g) and moderate acid number (8.9 mg KOH/g), iodine value of 35.3 g/L, low viscosity (0.1160 Pa.s), and high diffusion capacity (95%). Chemical analysis using UV-Vis spectrophotometry was employed to identify the constituents present in the extract, while FTIR spectra indicated the presence of alcoholic and phenolic components, suggesting interactions with lactic acid. Through GC/MS analysis, a total of 32 phytochemicals were identified, with seven significant ones: Eugenol (Phenol), Isocaryophyllene, Elemicin (benzene), Hexadecanoic acid with methyl ester, Octadecanoic acid with methyl ester, Neophytadiene and Squalene. Evaluation against E. coli, B. subtilis, S. typhimurium, and S. aureus revealed the O. lamiifolium extract and biolubricants most active against S. aureus and E. coli, suggesting potential for superior antibacterial lubricants with this plant extract and lactic acid.

An alternative filament fabrication method as the basis for 3D-printing personalized implants from elastic ethylene vinyl acetate copolymer

In this work, a novel tool for small-scale filament production is presented. Unlike traditional methods such as hot melt extrusion (HME), the device (i) allows filament manufacturing from small material amounts as low as three grams, (ii) ensures high diameter stability almost independent of the viscoelastic behavior of the polymer melt, and (iii) enables processing of materials with rheological profiles specifically tailored toward fused filament fabrication (FFF). Hence, novel materials, previously difficult to process due to HME limitations, become easily accessible for FFF for the first time. Here, we showcase the production of highly flexible drug-free, and drug-loaded filaments based on ethylene-vinyl acetate polymers with a vinyl acetate content of 28 w% (EVA28) and unprecedented high melt flow rates of up to 400 g/10 min. Owing to their low viscosity, FFF with low print nozzle sizes of 250 μm was achieved for the first time for EVA28. These small nozzle diameters facilitate 3D-printing of high-resolution structures in small-dimensional dosage forms such as subcutaneous implantable drug delivery systems, which can later be used for personalization. Consequently, the material portfolio for FFF is tremendously broadened, allowing material and formulation optimization toward FFF, independent of a preliminary extrusion process.

Effects of particle size, binder wettability, and sintering atmosphere on the microstructural and mechanical properties of binder jetted 18Ni300 alloy

A fully dense 18Ni300 mold steel was firstly prepared by the binder jetting (BJ) process. We developed a water-based binder characterized by its low viscosity, which significantly enhanced the penetration of binder into the fine powder layer. This process resulted in a deep, narrow cross-section due to reduced flow resistance, leading to strong inter-layer bonding and high surface quality of the green part. The densification behavior of 18Ni300 BJ green parts with different particle sizes was meticulously analyzed. A remarkable tensile property of YS=783 MPa, UTS=1012 MPa and EL=8.8% were obtained in sintered 18Ni300 alloy with fine powder under 1460 °C and 50 mTorr vacuum. Building on thermodynamic theory, we introduced a novel criterion to assess the oxidation reactions in 18Ni300 parts fabricated by the BJ method during sintering under different atmospheric conditions.

Freeze-dried wafers containing sesame oil for alleviation of dry mouth

A dry mouth is a condition with significant morbidity. Conventional saliva substitutes are expensive, short-lived, and prone to contamination. This study presents a Freeze-Dried Sesame Oil Emulsion Saliva Substitute (FD-SOESS), which combines the advantages of sesame oil through a freeze-drying process and assesses its effectiveness. High-speed homogenization (HSH) as well as high-pressure homogenization (HPH) techniques were employed to fabricate the FD-SOESS. The formulations that underwent the additional HPH step demonstrated improved physical properties, such as lower viscosity and faster redispersion times, compared to HSH alone. The optimized formulation (F11) possessed a near neutral pH of 6.67 and rapid re-dispersibility that was < 141.5 s), which is acceptable for oral administration. Additionally, the FD-SOESS formulation revealed heterogeneous porous structures with a layered arrangement of different pore sizes, and the resulting formulation had low moisture content (2.76%). The formulation met the microbial limit test. The antioxidant IC₅₀ of sesamin was found to be 0.318 μM. Furthermore, it was not toxic to periodontal cells at 50 μg/mL or 100 μg/mL. Human periodontal cell lines subjected to scratch and treated with FD-SOESS demonstrated notable migration that achieved complete wound closure within two days. The administration of FD-SOESS led to a notable elevation in the mucus concentrations found in the saliva samples of all participants. Overall, the results indicated that FD-SOESS is a highly promising alternative to saliva and may improve oral health for individuals suffering from dry mouth.

Composition-Dependent Diffusion and Viscosity Behavior in Liquid Ti-Al-Ni Ternary Alloys

We conducted ab initio molecular dynamics simulations to investigate the dynamic properties of the liquid Ti-Al-Ni ternary alloy system at 2033 K. Through simulations across the entire composition range, we revealed the complex compositional dependence of self-diffusion coefficients and viscosity. The self-diffusion coefficients of Ti, Al, and Ni exhibit nonlinear distribution characteristics, while viscosity shows non-monotonic compositional dependence, with lower viscosity in Al-rich regions and higher viscosity in Ni-rich regions. To understand the structural origins of these behaviors, we analyzed chemical short-range order and local fivefold symmetry structures using Warren-Cowley parameters and fivefold symmetry parameters, uncovering a close correlation between atomic-scale structural features and dynamic properties. Evaluation of the Stokes-Einstein relation revealed varying degrees of deviation from its predicted viscosity values across composition regions. We observed a negative correlation between free volume fraction and viscosity, with varying strengths in different regions. These findings provide new perspectives for understanding the complex dynamic properties of Ti-Al-Ni liquid alloys.

Molecular insight into the dissolution-degradation process of cellulose bunch in ionic liquids

Ionic liquids (ILs) as green solvents have been utilized in dissolving cellulose and fabricating regenerated cellulose fibers. Imidazolium-based ILs with acetate or phosphate anions present advantage, due to its lower viscosity and melting point, as well as its excellent ability to form hydrogen bonds (H-bonds) with the hydroxyl groups of cellulose molecular chains. In this work, the microscopic dissolution processes of a cellulose bunch in four ILs were reproduced via molecular dynamics (MD) simulations. The cellulose bunch dissolution capabilities of these four ILs are [Emim][OAc] > [Emim][DMP] > [Emim][DEP] > [Bmim][DMP], as verified through an in-situ polarized optical microscope. It is important to note that cellulose may degrade in some ILs during dissolution, affecting the performance of regenerated cellulose, while the underlying mechanism is unclear, and the strength of H-bonds formed between ILs and cellulose molecular chains can reflect their degradation strength Combined with density functional theory (DFT) calculations, the H-bonds formed between different anions and cellulose hydroxyl groups were analyzed in depth and the order of H-bond strength is [OAc]− > [DEP]− > [DMP]−, which is different from the dissolution order of cellulose bunch in [Emim][DEP] and [Emim][DMP]. Further analysis combined with MD simulation revealed that the difference in diffusion coefficients leads to faster dissolution of cellulose in [Emim][DMP]. This study elucidates the dissolution and degradation processes of cellulose in ILs at the molecular level, offering theoretical insights crucial for the development of novel ILs that are efficient in the process of cellulose spinning.

Simulation method for dynamic characteristics of rotor-support system subjected to environmental loads

An improved finite element method was proposed to investigate the dynamic characteristics of rotor system with environmental loads (temperature and aerodynamic forces) in aeroengines. According to the axial temperature distribution within shaft elements, the polynomials were established for physical properties of material. The derivation for coefficient matrices under thermal loads, and the tensile stiffness matrix considering axial aerodynamic forces were completed, based on the Timoshenko beam theory. A high-pressure rotor was simulated with operating temperature 200∼600∘C, and the magnitude of aerodynamic force is 105N. Furthermore, a squeezed film damper (SFD) was adopted to this rotor-support system, its steady responses were solved by the equivalent coefficient method, and the Newmark-HHT method was utilized to solve the transient responses. The results indicate that the first two critical speeds are reduced by 1.85% and 2.07%, which is mainly caused by thermal loads. The rising temperature leads to lower elastic modulus, higher Poisson's ratio and expansion ratio. With the amount of a mass unbalance being 500 g·mm located at the 1st-stage compressor disk (CD1): the 1st resonance peaks at CD1 and turbine disk (TD) increase by 4.56% and 4.98%, respectively, and the 2nd resonance peaks at CD1 and TD rise 5.88% and 5.00%, separately. Owing to SFD damping, the first two resonance peaks at CD1 and TD decrease by 69% and 51%, respectively. Compared to 40°C, the first two resonance peaks at CD1 increase by 88% and 55% at the oil temperature 100°C. The oil-film damping deteriorates significantly due to the lower oil viscosity in higher temperature. When operating near the first-order critical speed, the transient responses of rotor perform as simple harmonics, circular precession trajectory, dominant rotational frequency, and periodic motions. Overall, the dynamic characteristics of rotor-SFD-support systems exposed to environmental loads can be predicted by the proposed simulation method.

Design of novel bracket structure for falling film devolatilizer and numerical simulation of its film-forming property

The falling film devolatilizer is a new type of devolatilization equipment, which has the advantages of high film-forming efficiency and no mechanical transmission. In this study, a devolatilizer with an open falling film substrate was designed, and the film-forming performance and surface renewal performance of high viscosity fluids under the falling film structure were numerically simulated. The results indicate that the opening of the falling film substrate makes the liquid film thinner, which is beneficial for the stretching of the liquid film. The advantages of the falling film under low viscosity and high flow rate conditions are more significant. Simultaneously, four bracket structures were designed. Compared with the rectangular bracket, the renewal frequency of fan-shaped brackets can be increased by more than 20%, and the flow rate can be increased by about 10%. The improvement of the two can directly improve the falling film devolatilization performance, so as to improve the polymer polymerization degree and improve the product performance. Therefore, exploring the falling film support frame with high devolatilization performance provides a certain engineering practical significance for the design of devolatilization equipment.

Investigating the impact of shear and bulk viscosity on the damping of confined acoustic modes in phononic crystal sensors

Phononic crystal (PnC) sensors are recognized for their capability to control acoustic wave propagation through periodic structures, presenting considerable potential across various applications. Despite advancements, the effects of fluid viscosity on PnC performance remain intricate and inadequately understood. This study theoretically investigates the influence of shear (dynamic) and bulk viscosity on acoustic wave damping in defective one-dimensional phononic crystal (1D PnC) sensors designed for detecting liquid analytes. Acetic acid with varying viscosities is considered to fill a cavity layer intermediated by a multilayer stack of lead and epoxy. The effects of dynamic and bulk viscosity on the resonance characteristics of the defective mode were analyzed. Numerical results reveal that increased dynamic viscosity leads to substantial broadening and decreased intensity of resonance peaks, accompanied by a shift to higher frequencies due to enhanced elastic wave attenuation and damping. At low dynamic viscosity (η = 0.2 ηd), numerous resonance peaks with varying intensities are observed. However, at higher viscosities (η = 2.0 ηd to η = 10.0 ηd), only one prominent peak appears in the spectrum. The intensity of this resonant peak starts at 98% for η = 2 ηd and decreases to 58.8% as the dynamic viscosity increases to η = 10 ηd. Additionally, the combined effect of dynamic and bulk viscosity introduces further damping, causing a strong shift of the resonance peak to higher frequencies, along with an increase in the full width at half maximum (FWHM) and a decrease in the quality factor (QF). These findings emphasize the necessity of incorporating both shear and bulk viscosity in the design of PnC sensors to enhance their sensitivity and accuracy in practical applications. This theoretical framework provides critical insights for optimizing sensor performance and bridging gaps between theoretical predictions and experimental observations, especially in 1D PnCs, offering potential solutions to challenges in real-world PnC sensor applications.

Effect of the Autoclaving-Cooling Cycle on the Chemical, Morphological, Color, and Pasting Properties of Foxtail Millet Starch.

This study investigated the effect of the autoclaving-cooling (AC) cycle and the starch-to-water ratio on the chemical, morphological, color, and pasting properties of foxtail millet starch to improve its utilization in the food industry. Starch suspensions were prepared using different starch-to-water ratios (i.e., 1:1 and 1:4), with one to three AC cycles for each ratio. Subsequently, the chemical, morphological, color, and pasting properties of native and autoclaved-cooled foxtail millet starch (ACFS) were determined. The results showed that ACFS had higher overall resistant starch (RS) content than native starch. AC treatment reduced the lightness and whiteness index, gelatinization time, and pasting temperature while increasing particle sizes with irregular shapes and surfaces. Starch treated with distilled water at a 1:1 ratio with two AC cycles (1:1-2C) exhibited the highest amylose, starch, and RS contents with stable pasting properties compared with that in other AC treatments. Pasting stability was indicated by the low breakdown viscosity and high trough and final viscosity. The findings suggest that ACFS treated with 1:1-2C could be a stabilizer and functional food.

Polymer concentration regimes from fractional microrheology

In this work, a framework for deriving theoretical equations for mean squared displacement (MSD) and fractional Fokker–Planck is developed for any arbitrary rheological model. The obtained general results are then specified for different fractional rheological models. To test the novel equations extracted from our framework and bridge the gap between microrheology and fractional rheological models, microrheology of polystyrene in tetrahydrofuran solutions at several polymer concentrations is measured. By comparing the experimental and theoretical MSDs, we find the fractional rheological parameters and demonstrate for the first time that the polymer concentration regimes can be distinguished using the fractional exponent and relaxation time data because of the existence of a distinct behavior in each regime. We suggest simple approximations for the critical overlap concentration and the shear viscosity of viscoelastic liquidlike solutions. This work provides a more sensitive approach for distinguishing different polymer concentration regimes and measuring the critical overlap concentration and shear viscosity of polymeric solutions, which is useful when conventional rheological characterization methods are unreliable due to the volatility and low viscosity of the samples.

Preparation and Application of a Novel Liquid Oxygen-Compatible Epoxy Resin of Fluorinated Glycidyl Amine with Low Viscosity

A liquid oxygen-compatible epoxy resin of fluorinated glycidyl amine (TFEPA) with a low viscosity of 260 mPa·s in a wide range of temperatures, from room temperature to 150 °C, was synthesized and used to decrease the viscosity of phosphorus-containing bisphenol F epoxy resins. And the forming process and application performances of this resin system and its composite were investigated. The viscosity of the bisphenol F resin was decreased from 4925 to 749 mPa·s at 45 °C by mixing with 10 wt.% TFEPA, which was enough for the filament winding process. Moreover, the processing temperature and time windows were increased by 73% and 186%, respectively. After crosslinking, the liquid oxygen compatibility was preserved, and its tensile strength, elastic modulus, and breaking elongation at −196 °C were 133.31 MPa, 6.59 GPa, and 2.36%, respectively, which were similar to those without TFEPA. And the flexural strength and modulus were 276.14 MPa and 7.29 GPa, respectively, increasing by 21.73% in strain energy at flexural breaking, indicating an enhanced toughness derived from TFEPA. Based on this resin system, the flexural strength and toughness of its composite at −196 °C were 862.73 MPa and 6.88 MJ/m3, respectively, increasing by 4.46% and 10.79%, respectively.

Effects of cohesion and viscosity on lava dome growth following repose

Lava domes result from effusive eruption of high viscosity lava. These viscous lava extrusions range in shape from flat-topped domes with small height-to-width aspect ratios, to spine-like columns exhibiting large height-to-width aspect ratios. A primary control on morphology during early dome growth is thought to be the variation in rheological characteristics of extruded material. In this work, we present new scaled analogue models of lava dome growth that consider extrusion of a frictional plastic upper-conduit plug followed by viscous magma. We simulate the brittle plug using a sand-plaster mixture, the cohesion of which is varied by plaster content. We model the magma using sugar syrup, the viscosity of which is controlled by the weight percent of added crystalline sugar. The models both qualitatively and quantitatively reproduce part of the spectrum of natural dome morphology not previously obtained in most past analogue modelling studies. Model aspect ratios of 0.02 to 0.9 capture approximately 90 % of the reported aspect ratio variation in nature. Increasing plug cohesion results in extrusions with higher aspect ratios and spinier morphologies. Low viscosity fluid typically erupts through the brittle dome, whilst high viscosity fluid tends to promote endogenous growth or emerge as exogenous lobes. Particle Image Velocimetry shows that fracture localisation at the dome surface is cohesion-dependent, and eruption of fluid follows shear fractures within the dome. Where fluid remains contained within the dome, we see lateral spread leading to a wider and flatter dome morphology. Evolution of lava dome morphology, deformation, and associated hazards is guided by the complex rheological properties of the extruded material; we suggest that during episodic dome growth, these properties are largely defined in the conduit prior to their eruption.

Tailoring Wetting Properties of Organic Hole‐Transport Interlayers for Slot‐Die‐Coated Perovskite Solar Modules

The strategy of incorporating self‐assembled monolayers (SAMs) with anchoring groups is an effective and promising method for interface engineering in perovskite solar cells with metal oxide charge‐transporting layers. However, coating SAM layers in upscaled perovskite solar modules (PSMs) using slot‐die coating is challenging due to the low viscosity and wettability of the solutions. In this study, a triphenylamine‐based polymer poly([{5‐[4‐(diphenylamino)phenyl]‐2‐thienyl}(4‐fluorophenyl)methylene]malononitrile) (pTPA)–TDP, blended with SAM based on 5‐[4‐[4‐(diphenylamino)phenyl]thiophene‐2‐carboxylic acid, is integrated to address these challenges. And, p–i–n‐oriented PSMs on 50 × 50 mm2 substrates (12 sub‐cells) are fabricated with a NiO hole‐transport layer and organic interlayers for surface modification. Wetting angle mapping shows that ununiform regions of the slot‐die‐coated SAM has extreme hydrophobicity, causing absorber thickness fluctuations and macro‐defects at buried interfaces. The blended interlayer at the NiO/perovskite junction homogenizes surface wettability and mitigates lattice strain, enabling the effective use of SAM properties on large surfaces. This improved energy level alignment, enhancing the power conversion efficiency of the modules from 13.98% to 15.83% and stability (ISOS‐L‐2, T80 period) from 500 to 1630 h. In these results, the complex effects of using SAM in slot‐die‐coating technology for large‐scale perovskite photovoltaics are highlighted.

Physicochemical Assessment of Vegetable Oil used to Fry some Nigerian Food items

The escalating global energy demand, projected to rise from 442 EJ in 2023 to between 623-710 EJ by 2035, has intensified the search for sustainable energy alternatives to fossil fuels. Biodiesel, particularly from waste cooking oil (WCO), presents a promising solution due to its affordability and environmental benefits. This study investigates the physicochemical properties of neat and waste sunflower oil used to fry bean cakes (Akara), fish, and puff-puff in Nigeria, aiming to identify the impact of frying duration and fried substances on oil quality. The study's findings reveal significant changes in the oil's properties post-frying, with notable variations in pH, moisture content, boiling point, density, viscosity, flash point, saponification value, protein content, fat content, acid value, free fatty acids (FFA), and fatty acid methyl esters (FAME). The results indicated that the moisture content increased from 34.6% in neat oil to 47.9% in oil used for frying bean cakes, while the boiling point decreased from 243°C to 226°C in oil used for frying fish. The kinematic viscosity and density also varied, with the lowest viscosity (26.48 mm²/s) observed in oil used for frying fish and the highest density (911 kg/m³) in oil used for frying bean cakes. The flash point of WCO samples ranged from 248-258°C compared to 260°C in neat oil, and the saponification values varied significantly, indicating different levels of oxidation and deterioration. The study concludes that frying fish has the most detrimental effect on oil quality, as evidenced by the highest acid value (7.2 mgKOH/g) and significant changes in FFA and FAME concentrations. These insights into the physicochemical alterations of WCO highlight the potential for its optimized use in biodiesel production, offering a sustainable energy source while addressing waste disposal challenges.