Surfaces, Volume 9, Issue 2 (June 2026) – 29 articles

To understand glycan–protein interactions at biological interfaces, designing surfaces modified with structurally controlled glycans is highly important. In particular, naturally occurring glycosaminoglycans (GAGs) possess periodic sugar arrangements that play important roles in protein recognition, highlighting the need for the development of periodic glycopolymer model systems that can serve as GAG mimics for quantitative interaction analysis. In this study, sequence-controlled periodic glycopolymers were synthesized by reversible addition–fragmentation chain-transfer (RAFT) polymerization and immobilized onto gold surfaces to construct glycan-modified interfaces. The synthesized material was a terminally functionalized periodic glycopolymer with the most basic structure, consisting of alternating maltose-containing vinyl ether (MalVE) units and ethyl maleimide (EtMI) units, with a trithiocarbonate group at the ω-terminal. This trithiocarbonate group was converted to a thiol group for immobilization through Au–S bond formation. Structural characterization by ¹H NMR spectroscopy, size exclusion chromatography (SEC), MALDI-TOF mass spectrometry, and UV–vis spectroscopy confirmed the structure as designed. Quartz crystal microbalance (QCM) measurements verified the stable immobilization of thiol-terminated periodic glycopolymers on the gold surface, and allowed for estimation of graft density and quantitative analysis of glycan-protein interactions at the modified interface. The periodic glycopolymer-modified surfaces exhibited selective binding behavior toward concanavalin A (ConA) compared to bovine serum albumin (BSA), with apparent binding constants on the order of 10⁶–10⁷ L mol⁻¹. This enhanced binding behavior indicated that specific and multivalent interactions with proteins also occurred at periodic pendant maltose residues along the main chain. These results demonstrate that the gold surface modified with end-functional periodic glycopolymers synthesized by RAFT polymerization provides a versatile platform for quantitative analysis of glycan-protein interactions and suggests potential applications for periodic glycopolymers as functional materials. Full article

This study investigates the effect of (3-glycidyloxypropyl)trimethoxysilane (GPTMS) passivation time on the adhesive bonding performance of aluminum substrates using an epoxy adhesive. Alkaline etching was used to generate a chemically active surface prior to silane treatment. GPTMS passivation led to the formation of silane-derived species on the aluminum surface. SEM/EDS indicated the presence of silicon-containing species. ATR-FTIR analysis showed the progressive development of siloxane (Si–O–Si) bonding with increasing passivation time. The mechanical performance of the bonded joints was evaluated using single-lap shear (SLS) testing. The SLS strength increased from 4.3 ± 1.0 MPa in the as-received substrate to 5.5 ± 1.2 MPa after etching. After GPTMS passivation, the strength reached a plateau beginning at 3 min, with a value of 13.5 ± 1.8 MPa. This corresponds to increases of 28% after etching and 223% after GPTMS passivation. This plateau behavior indicates a self-limiting interfacial process. The improved adhesion is attributed to siloxane formation within the silane layer and the chemical compatibility between GPTMS and the epoxy adhesive. A first-order conceptual semi-quantitative model was developed to relate silane surface coverage to adhesion strength. The results demonstrate that adhesion depends on both surface coverage and the development of siloxane bonding within the silane layer. This study highlights the importance of controlled passivation time in improving adhesion performance under the present experimental conditions. Full article

This research is based on the eco-friendly biogenic synthesis of titanium dioxide (TiO₂) and manganese oxide (MnO) nanoparticles using Lawsonia inermis (henna) leaf extract. The biosynthesized NPs were examined via UV–visible spectroscopy, FTIR, FESEM, EDX, TGA, Zeta potential, and DLS to study their optical characteristics, functional group, structural nature, surface morphology, elemental composition, thermal stability, and surface charge. FTIR peaks confirmed the functional groups responsible for nanoparticle formation. FESEM micrographs indicated spherical TiO₂ nanoparticles and irregular MnO nanoparticles. The biosynthesized nanoparticles revealed antibacterial activity against pathogens, including Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Bacillus subtilis. Antioxidant potential was demonstrated using the DPPH assay, with MnO nanoparticles exhibiting higher activity (IC50: 30 µg/mL) than TiO₂ nanoparticles. Cytotoxicity studies on L929 cell lines revealed dose-dependent effects, while wound-healing assays indicated enhanced cell migration, particularly with MnO nanoparticles. This study highlights the L. inermis-mediated nanoparticles as sustainable and biocompatible with biomedical and environmental applications. Full article

This study investigates the influence of PFAS-free superhydrophobic treatment on the performance of NYCO (50% Nylon 50% Cotton) fabric. The primary focus is to assess how these treatments influence key performance attributes, including water repellency, weight gain, air permeability, and color stability. The treatments were formulated using a silica/epoxy diluted with isopropanol (IPA), with the goal of achieving minimal weight gain (<10%) and high water repellency (AATCC22 rating of 80 or above) with a minimal impact on breathability and visual appearance. A series of formulations were prepared with a a constant silica to epoxy ratio (3:7) while varying the solids content of the suspension (1.8 to 5.2 wt.%). Treated fabrics were evaluated through water spray tests (AATCC TM 22), air permeability (ASTM D737), spectrophotometric color analysis, and SEM surface morphology. Samples treated with a formulation containing 2.0 wt.% solids content demonstrated the best performance characteristics: low weight gain, minimal breathability reduction, low color change, and water repellency. The findings reveal the potential for a PFAS-free treatment to achieve high water repellency while maintaining other key fabric performance characteristics. The results contribute to the advancement of sustainable, high-performance protective textiles for military applications. Full article

The pore architecture and textural properties of heterogeneous catalysts affect their intrinsic and extrinsic kinetics, selectivity, and resistance to deactivation. Modelling allows the cheaper and quicker design of new catalyst products, and the optimization of the operation of existing ones. This work particularly reviews major and recent developments in pore network models (PNMs), including image-derived versions, which are a key tool for determining the impact of pore structure and mass transport on catalyst performance. It also briefly considers related areas of multi-scale modelling, first-principles modelling of active sites with DFT, intermediate-scale microkinetic modelling, and recent developments in machine-learning-based approaches. It has been seen that, for some reaction systems, PNMs can predict effectiveness factors a priori, and deliver optimized pore network designs. However, this survey also highlights issues with current models including omission of key controlling structures due to insufficient prior pore characterization, lack of the often-substantial evolution of the pore structure over the catalyst life-stages due to various on-going physical processes, and the neglect of the often-heterogeneous spatial distribution of active sites. Further, this review also considers novel experimental techniques that demonstrate, and remedy, gaps often left out from the current modelling approaches. Full article

The transition toward more sustainable catalytic processes has driven increasing interest in waste-derived reducing agents and biomass-based carbon supports. In this study, silver nanoparticles (Ag NPs) were synthesized via conventional NaBH₄ reduction or through a bio-derived route using orange peel extract (OPE) and subsequently employed either as colloidal catalysts or immobilized on commercial activated carbon (AC) or coconut-derived carbon (CC). Catalytic activity was evaluated through the reduction of p-nitrophenol under pseudo-first-order conditions using UV–Vis spectroscopy. OPE-derived Ag NPs exhibited slightly higher activity than NaBH₄-reduced nanoparticles, while immobilization on carbon supports generally enhanced reaction rates, with Ag/AC_BH showing the highest kinetic constant. In contrast, CC-based systems displayed lower absolute activity but improved cost-normalized performance due to the lower cost of the support. A preliminary cost–performance analysis, based on direct material costs, suggested that catalytic efficiency trends can be significantly altered when economic factors are considered, highlighting that the most active system does not necessarily correspond to the most cost-effective one. Stability tests showed progressive deactivation over reuse cycles, mainly attributed to surface oxidation and/or poisoning phenomena. These results demonstrate that integrating waste-derived reagents with low-cost supports can provide competitive catalytic systems, although further optimization is required to improve their long-term operational robustness. Full article

Green synthesis of metal oxide nanoparticles (NPs) offers an eco-friendly, cost-effective alternative to conventional chemical and physical methods, minimizing energy use and hazardous reagents. This study demonstrates the biogenic production of manganese oxide (MnO) NPs using Catharanthus roseus flower extract as a reducing and capping agent, Comprehensive characterization via FTIR (Mn–O vibrations at 591–405 cm⁻¹ along the capping groups), XRD (confirms the cubic crystalline phase), FESEM (flaky, agglomerated sheets), EDX (Mn 62.37%, O 28.40% and C 9.23%), zeta potential (−0.3 mV), and TGA (33.7% phased mass loss to 985 °C) verified pure and stable MnO NPs. In vitro assays on L929 fibroblasts revealed dose-dependent MTT cytotoxicity (78.77% viability at 20 µg/mL to 39.97% at 100 µg/mL) yet enhanced scratch wound closure (−16.31% area reduction vs. −17.41% control), alongside potent antibacterial activity with highest inhibition zones of 15 mm against Klebsiella pneumoniae and Escherichia coli, and lowest of 4 mm against Pseudomonas aeruginosa at 40–100 µg/mL. These multifaceted properties highlight C. roseus-assisted MnO NPs’ promise for wound healing and antimicrobial applications, warranting dosage optimization and in vivo studies. Full article

Whether copper fundamentally alters Mo-centered redox thermodynamics or mainly tunes hydrogen adsorption in Ni–Mo electrocatalysts under alkaline hydrogen evolution reaction (HER) conditions remains unresolved. Density functional theory calculations combined with a field-corrected computational hydrogen electrode framework are used to evaluate the thermodynamic stability of H₃Mo, H₃MoOH, H₂Mo(OH)₂, and MoO(OH)₃ on Cu(111) and Ni(111) and to construct surface Pourbaix diagrams under electrochemical conditions. The results show that substrate identity reorganizes the redox stabilization hierarchy of these Mo intermediates. Across the examined conditions, at least one of H₃Mo, H₃MoOH, or MoO(OH)₃ is thermodynamically favored over H₂Mo(OH)₂ on both surfaces. However, only Cu(111) exhibits measurable pH-dependent free-energy shifts, reaching 0.25 eV on the reversible hydrogen electrode scale. The magnitude of this electrostatic modulation is comparable to the intrinsic substrate-dependent relative Gibbs free-energy differences, suggesting that Cu reshapes Mo redox thermodynamics rather than merely weakening hydrogen binding strength. Electronic structure and vibrational analyses further show that Cu(111) preferentially weakens Mo–O interactions, whereas Ni(111) more strongly perturbs Mo–H bonding in hydrogen-rich complexes. Overall, these results establish that substrate identity governs the electrostatic modulation of Mo redox thermodynamics under alkaline HER conditions and provide mechanistic insight into substrate effects relevant to Cu-containing Ni–Mo systems. Full article

The present work investigates the combined effect of precursor source and solvent on the structural, morphological, and optical properties of ZnO thin films prepared by the spin-coating technique. Three precursor sources (zinc acetate dihydrate, zinc chloride, and zinc nitrate hexahydrate) and four solvents (ethanol, 2-methoxyethanol, 2-propanol, and 1-methoxy-2-propanol) were systematically explored. X-ray diffraction analysis confirms that all films crystallize in the hexagonal wurtzite structure, with a pronounced (002) preferential orientation for zinc acetate-derived and most of the zinc chloride-derived films. Scanning electron microscopy reveals that both precursor and solvent strongly influence surface morphology. Zinc acetate yields smoother and more compact films, zinc chloride promotes larger hexagonal grains, and zinc nitrate leads to relatively porous structures. Among the solvents, 2-methoxyethanol produces the most uniform and dense films regardless of the precursor. Optical measurements show that transmittance is highly dependent on synthesis conditions, reaching up to 90% in the visible range for zinc acetate-based films, particularly with 2-methoxyethanol. The optical band gap varies between 3.20 and 3.37 eV, reflecting differences in crystallinity and defect density. Overall, these results highlight the key role of precursor–solvent interactions in tailoring ZnO thin film properties for optoelectronic applications. Full article

The extensive use of oxytetracycline (OTC) poses significant threats to aquatic ecosystems, necessitating efficient removal strategies. While photocatalytic technology is a promising approach, single catalysts, like UiO-66-NH₂ and Bi₂MoO₆, suffer from rapid photogenerated carrier recombination and narrow light absorption. To address this, a Z-scheme heterojunction photocatalyst, Bi₂MoO₆/UiO-66-NH₂, was synthesized via a solvothermal method to enhance OTC degradation. Characterization results showed that the composite expanded visible-light absorption and improved electron-hole separation. Under simulated sunlight, the optimized composite (BUN80) achieved an OTC removal efficiency of 87.68% within 120 min under optimized conditions. The catalyst retained photocatalytic activity over five consecutive cycles, although a decrease in removal efficiency was observed. Radical trapping experiments indicated that h⁺ and •O₂⁻ were the main reactive species, and a proposed Z-scheme charge transfer pathway was suggested based on band structure analysis and photoelectrochemical results. LC-MS analysis identified 17 intermediate products, and ECOSAR-based toxicity prediction suggested a decreasing trend in aquatic toxicity during the degradation process. These findings indicate that Bi₂MoO₆/UiO-66-NH₂ is a promising photocatalyst for OTC degradation in water. Full article

A capacitor electrode has been developed, obtained by electrophoretically filling the nanosized pores of anodic alumina with carbon particles and PVDF. By pre-thinning the barrier anode layer, direct contact of carbon with the aluminum current collector has been achieved. The multilayer electrode from {carbon particles and PVDF}/{carbon black and porous AAO}/{aluminum current collector} was studied using Raman spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis, and atomic force microscopy. The analyses demonstrate the highly developed surface of the electrodes and the good binding ability of the PVDF. The electrochemical properties of the electrodes were investigated in a 0.5 M Na₂SO₄ aqueous electrolyte using cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge–discharge. The electrode allows operation at a high voltage window of 5.75 V. The electrochemical results show that the electrodes have a specific capacitance of 4.25 ± 0.35 F g⁻¹, a specific energy density of 19.3 Wh kg⁻¹ and specific power of about 5600 W kg⁻¹ with stable operation over 10,000 cycles. Therefore, the strategy of using electrophoretic deposition of carbon materials seems promising for obtaining inexpensive capacitive layers with good adhesion to aluminum, operating stably in a wide voltage window. Full article

Flexible implantable electrodes require biocompatibility, mechanical stability, and sufficient electrical conductivity for effective neural interfacing. This work examines ultrasonic treatment during poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) impregnation of electrospun poly(D,L)-lactide (PLA) nonwoven scaffolds as a route to improve filler distribution and functional performance. Four sample types were studied: pristine PLA (untreated and sonicated) and PLA–PEDOT:PSS composites prepared with and without ultrasonication. Scanning electron microscopy shows that ultrasonic treatment suppresses the formation of continuous surface films and promotes homogeneous three-dimensional penetration of PEDOT:PSS throughout the fibrous network. As a result, electrical resistivity decreases by a factor of 7.3, from 294.4 to 40.2 Ω·m. Contact-angle measurements reveal markedly enhanced wettability, with sonicated composites exhibiting rapid water uptake (5–13 s), unlike non-sonicated controls. These findings demonstrate that ultrasound-assisted PEDOT:PSS impregnation yields conductive, highly wettable, and structurally stable scaffolds, highlighting their potential for flexible implantable neural electrodes. Full article

A comprehensive study was conducted to develop structurally robust, crack-suppressed superhydrophilic nanocomposite coatings comprising poly(acrylic acid) (PAA) and silica nanoparticles. We systematically investigated the critical trade-off between particle loading, which drives surface wettability and stress-induced crack formation driven by capillary forces and shrinkage mismatch. Our findings identify a distinct structural failure threshold between 25 and 30 vol.% silica under conventional drying. By strategically optimizing drying kinetics (an initial flash-dry at 120 °C for 1 h followed by a 24 h ambient cure), we successfully fabricated transparent, crack-suppressed superhydrophilic coatings at elevated silica loadings up to 47 vol.%, establishing a practical, scalable framework for advanced functional surface engineering. The crack-suppressed mechanism was hypothesized to be related to internal stress. Full article

MnO₂ is widely investigated for electrochemical capacitors; however, its practical performance is often limited by low electrical conductivity and inefficient charge utilization in thick films. In this work, we investigate the combined effects of controlled electrodeposition and ionic liquid (IL)-assisted growth of MnO₂ films onto nickel foam at 0.6 V vs. Ag/AgCl for supercapacitor applications. The deposition time revealed a non-linear structure–performance relationship, with optimal electrochemical response obtained at an intermediate deposition time (240 s). The incorporation of ILs (e.g., [TEA-PS][BF₄] and [BMIM][BF₄]) enabled direct modulation of nucleation and growth dynamics. While [TEA-PS][BF₄] resulted in decreased performance, adding [BMIM][BF₄] significantly enhanced the electrochemical response. Our results reveal that without additives the films were dense and cracked; with [BMIM][BF₄], they became more open and nanostructured. Consequently, the optimized electrode exhibited a 25% higher specific capacitance, totaling 149.83 F·g⁻¹ at 10 mV·s⁻¹, compared to 119.87 F·g⁻¹ for the unmodified electrode. These findings demonstrate that IL-assisted electrodeposition is an effective strategy for optimizing MnO₂-based supercapacitor electrodes. Full article

This article reviews the state of the art of laser ablation and deposition techniques applied so far to more than 50 elements, including metals, metalloids and lanthanides, yielding a wide variety of compounds in the form of thin films. Laser deposition processes have been performed in high-vacuum (HV) reactors at pressure values ranging between 10⁻¹ and 10⁻⁵ Pa, namely pulsed laser deposition (PLD), or, under different reactive gas ambient (O₂, N₂, CH₄, NH₃ and many others), so-called reactive pulsed laser deposition (RPLD), with the aim to form thin films with desirable chemical compositions. While a few metals have not been deposited as pure metallic films because they have no immediate technological interest, others, like alkali and alkaline earth metals, cannot be deposited in pure metallic form due to their very strong reactivity with oxygen, water vapor and hydrogen molecules which are always present, even in ultra-high-vacuum (UHV) systems, at pressure values of 10⁻⁵–10⁻¹⁰ Pa. Furthermore, elements of the Mendeleev periodic table with an atomic number higher than 88, such as actinides and synthetic elements, are dangerous to handle and deposit in the form of thin films due to their high radioactivity; therefore, they are excluded from this review. The inclusion of the non-metal thin films of carbon (C) and related chemical compounds prepared by PLD and RPLD in the present review is justified by the extensive research and the numerous scientific articles reported in the field. All the results obtained by PLD and RPLD techniques so far are discussed and presented in tabular format to guide the reader. Full article

A facile and scalable strategy is presented in this work for the direct fabrication of binder-free copper (Cu) oxide nanospheres on the Cu foam surface via femtosecond (fs) laser ablation for energy storage applications, primarily in supercapacitors. XRD and EDX analyses confirmed the presence of Cu oxides. At the same time, SEM images indicated that the resulting Cu oxide nanospheres range from ~70 to 700 nm in size, with hierarchical surface features such as laser-induced periodic surface structures (LIPSS), which provide additional active sites for reversible redox reactions. The prepared fs laser-ablated Cu foam samples, with Cu oxide nanospheres (Femto-Cu), can store 8 to 10 times more energy than the bare Cu foam, with ~87.7% capacitance retention after 10,000 charging–discharging cycles. Further, in-depth kinetic investigations revealed that the charge is stored through both surface-controlled capacitive behavior and a diffusion-controlled mechanism. These findings highlight the effectiveness of fs laser-induced structuring in improving the charge-storage characteristics of Cu foam and provide a promising route for developing high-performance, binder-free electrodes in a single step. Full article

We performed a theoretical analysis (the PBE-D2/DNP level of the density functional theory with the use of the DSPP pseudopotentials) of the geometries, bonding and frontier orbital energies, spin and charge distribution for the entire series (from La to Lu) of lanthanide atoms interacting with I_h−C₈₀ cage, for both η⁵ and η⁶ exohedral coordination patterns. In certain regards, the exohedral η⁵ and η⁶ coordination of Ln atoms to the C₈₀ fullerene cage exhibits similar qualitative and semi-quantitative trends (the bonding strength, shortest Ln^…C distances, charge and spin of lanthanide atoms). The most interesting aspect is the molecular spin of the complexes, where we observed different patterns of ferromagnetic and antiferromagnetic coupling. Three complexes represent an extreme, when the antiferromagnetic coupling results in zero or close-to-zero molecular spin. In some cases, the molecular spin is a simple sum of 2 e of the isolated C₈₀ cage and the spin of an isolated Ln atom. However, the most common situation is when another 2 e spin adds: it is best illustrated with Eu (spin of 7 e for the atomic ground state), where the molecular spin of its η⁵ and η⁶ complexes is not about 9 e but reaches almost 11 e. Full article

The increasing accumulation of poly(ethylene terephthalate) (PET) waste poses a significant environmental challenge and highlights the need for sustainable, value-added recycling strategies. In this study, porous carbon derived from PET was synthesized via carbonization and chemical activation and subsequently combined with manganese dioxide (MnO₂) to fabricate hybrid electrodes for aqueous supercapacitors. The PET-derived carbon exhibits a highly microporous structure with a large specific surface area and functions as a conductive and mechanically stable matrix that improves MnO₂ dispersion, charge transport, and electrochemical utilization. Systematic electrochemical investigations reveal strongly electrolyte-dependent charge-storage behavior. In an alkaline electrolyte, the capacitance is dominated by MnO₂ pseudocapacitive redox reactions, whereas in a neutral electrolyte, the response is primarily governed by electric double-layer charge storage. In a ferricyanide-containing redox-active electrolyte, additional electrolyte-mediated faradaic processes significantly enhance the apparent electrochemical performance. Under these conditions, the hybrid electrodes deliver a high apparent specific capacitance of 240–250 F g⁻¹ at moderate current densities. The electrodes further demonstrate stable cycling behavior and high apparent Coulombic efficiency, reflecting time-dependent utilization of both MnO₂ pseudocapacitance and redox-active electrolyte species during charge–discharge. Crucially, this work demonstrates that PET-derived carbon/MnO₂ hybrid electrodes exhibit complex, electrolyte-controlled charge-storage mechanisms and underscores the critical role of electrolyte selection in accurately interpreting electrochemical metrics and optimizing the performance of sustainable supercapacitors based on recycled polymer-derived carbons. Full article

Structural materials in nuclear energy, aerospace, and electronics face long-term irradiation by high-energy particles, triggering microscopic defect evolution and macroscopic performance degradation that limits service safety. This review provides a systematic overview of irradiation damage mechanisms, with particular emphasis on the role of surfaces. The discussion traces the evolution from initial defect generation through energy deposition and displacement cascades to the migration and aggregation of defects toward surfaces, culminating in their interactions with near-surface microstructures. A comparative analysis of damage behaviors in metals, ceramics, silicon-based materials, and polymers is presented, elucidating how distinct mechanisms arise from fundamental differences in crystal structure and chemical bonding. The integration of multiscale simulation techniques with advanced in situ characterization is highlighted as a critical approach for deciphering the cross-scale processes. Current strategies for enhancing radiation resistance including composition optimization, microstructure regulation, and interface design are summarized. Finally, the review outlines key challenges such as multi-field coupling damage characterization and long-term predictive modeling. Future research directions are foreseen to emphasize closer simulation–experiment integration and the design of smart, self-adapting materials, thereby providing comprehensive theoretical and technical support for the development of next-generation radiation-tolerant materials. Full article

Cellulose ether, like hypromellose (HM), is an extremely versatile material that is widely used in pharmaceutical products as film coatings. To modify the surface properties of HM films, additives are routinely included during the film formulation process, which are typically hydrophobic lubricants or hydrophilic plasticizers. Plasticizers increase the flexibility and reduce the brittleness of the film. The first goal of this study is to demonstrate that plasticization of HM films by low-molecular-weight (400 g∙mol⁻¹) polyethylene glycol (PEG) allows tuning adhesion and friction properties of HM films, both at nano- and macroscales. Surface morphology, surface energy, nano/macro adhesion, and nano/macro friction coefficient were studied by atomic force microscopy (AFM) in adhesion or friction modes at the nanoscale, wettability, and probe-tack adhesion, as well as pin-on-disk friction experiments at the macroscale. The results show that the addition of PEG decreases the Young’s modulus and the Tg of HM-plasticized films while increasing their strain at break and surface energy. The macroadhesion force increases from 9 to 90 mN by the addition of 40% w/w of PEG, whereas the macrofriction coefficient is reduced by 50%. The hypothesis of insertion of plasticizer molecules in HM chains’ nano-domains is evidenced and explains these results. The second goal of this study is to investigate nanoscale versus macroscale correlation of adhesion and friction properties and the role of adhesion in friction experiments. The results show, first, that the evolution of the adhesion energy at the macroscale as a function of adhesion energy at the nanoscale is linear. On the contrary, a high friction coefficient at the nanoscale corresponds to a low friction coefficient at the macroscale and vice versa, showing a first linear decrease for PEG contents ranging from 0 to 30% (w/w) and the second linear decrease, less pronounced, is observed for PEG contents ranging from 30 to 40% (w/w). The hypothesis of a difference in contact pressure applied on the probe at both scales, as well as HM-PEG surface phase separation at a high PEG content (>30% w/w), is proposed to explain this difference. The variations in friction coefficients are linear according to the PEG plasticizer content and suggest its lubricant role in HM-Plasticized films. Finally, the interplay between adhesion and friction, in friction experiments, is evidenced and appears dominant at the nanoscale. Full article

The quasi-steady low-Reynolds-number flow induced by a linear chain of multiple slip spheres translating along their common axis in a Newtonian fluid is investigated. The particles are allowed to differ in radius, Navier slip coefficient, migration velocity, and interparticle spacing. A semi-analytical solution of the governing Stokes equation is obtained using a boundary collocation method. Hydrodynamic interactions among the particles are shown to be significant under appropriate geometric and surface conditions. For the two-sphere configuration, the computed hydrodynamic forces agree closely with previously published asymptotic solutions derived via the twin multipole expansion method. In the three-sphere case, the presence of a third particle substantially modifies the forces acting on the other two, demonstrating non-negligible many-body interaction effects. The interaction strength is found to be more pronounced for smaller particles or those with lower slip coefficients. Calculations for longer particle chains further reveal a clear hydrodynamic shielding effect within the assembly. Full article

Three-dimensional (3D) epicuticular wax coverage on plant surfaces contributes to multifunctional surface properties, such as enhanced water repellence, reduced pathogen adherence, modified optical properties, and reduced insect adhesion. The diversity in wax projection morphology, size, abundance, and spatial arrangement among plant species results in a broad spectrum of anti-adhesive effects, reflecting both phylogenetic history and ecological function. This study presents a numerical model consisting of 3D tubular-shaped structures randomly deposited on a substrate and forming a highly porous layer. The simulations based on this model demonstrate a strong reduction in adhesion to the contacting insect adhesive pad. It is found that a structure formed by sufficiently long tubes, where the length is enough to support the tubes in space and build a porous 3D structure with a very low density, at relatively weak attraction to the underlying substrate, leads to the weakest adhesion. The model is constructed on the basis of our recent works combining discrete and continuous approaches in biological modeling. It mainly exploits the technique of the movable digital automata, allowing modeling of numerous numerically elastic cylinders that can be moved in 3D space, elastically collide with one another and with boundaries, and build self-consistent surface structures, which can be used to mimic nano- or microscale surface coverages of real plants. Full article

This study investigates the inhibitory effects of alkali metal chlorides lithium chloride, sodium chloride and potassium chloride (LiCl, NaCl, and KCl) on sodium dodecyl sulfate (SDS) foams, focusing on the transition from interfacial to bulk-driven destabilization mechanisms. The research demonstrates that foam collapse at high electrolyte concentrations is governed by a massive increase in bulk cohesive pressure and specific ion-pairing (SIP), which leads to interfacial dehydration and the mechanical decoupling of the surface from the bulk phase. It is shown that while surface adsorption reaches a plateau, the thermodynamic state of the solvent becomes the primary driver for film drainage. The results indicate that KCl acts as the most potent defoamer due to its optimal matching of water affinities with the surfactant head groups. These findings provide a new theoretical framework for understanding foam stability in concentrated electrolytic environments, emphasizing the role of bulk cohesive stress over traditional interfacial elasticity. Full article

Charge-trapping memory (CTM) exhibits significant potential in high-density memory, yet reliability degradation resulting from the coupling of program/erase (P/E) cycles and electrical stress remains a key bottleneck for large-scale commercialization. This study focuses on a Au/Al₂O₃/TiO₂/p-Si CTM device, systematically investigating the device failure mechanism under continuously operating P/E cycles and constant voltage stress (CVS), with emphasis on elucidating the synergistic effect of bulk and interface defects on performance decay. Mechanistically, oxygen vacancies in TiO₂ serve as defect precursors, which form Frenkel pairs under electric field stress and further promote the formation of new defect precursors, thereby driving a self-sustaining defect evolution process. Interface traps, by contrast, arise from the cleavage of interfacial Si-H bonds triggered by electric field stress, resulting in a net elevation of the interface state density. The passive effects from the bulk and interface defects may give rise to issues, such as threshold voltage drift and decreased P/E speed. This work provides in-depth insights into the device failure mechanism of CTM, offering critical theoretical support for optimizing fabrication processes and enhancing long-term reliability. Full article

This study aimed to develop new catalysts, based on MoS₂, for the hydrogenation of bromoquinolines without C-Br bond cleavage. The mechanochemical exfoliation of the bulk MoS₂ in the presence of NaCl resulted in the formation of the material (MoS₂-1), consisting of flat plates of size between ca. 40 × 100 and ca. 250 × 400 nm². Similar grinding of MoS₂ in the presence of NH₄Cl produced smaller nanoplates of size between ca. 10 × 30 and ca. 50 × 300 nm² (MoS₂-2). These materials were characterized using powder XRD, TEM, SEM, Raman spectroscopy and XPS. The specific surface area of the MoS₂-1 and MoS₂-2 samples was estimated using the analysis of N₂ adsorption isotherms. Both materials were catalytically active in the hydrogenation of quinoline; 1,2,3,4-tetrahydroquinoline (THQ) was the sole product and its yield grew proportionally to the accessible surface area of the catalyst. The hydrogenation of 5- and 8-bromoquinolines in the presence of MoS₂-1 and MoS₂-2 led to the respective bromo-THQs with almost quantitative yields, while the hydrogenation of 6-bromoquinoline resulted in the formation of the respective 6-bromo-THQ with the yield up to 30%. In the case of 7-bromoquinoline, N-methylated 7-bromo-THQ was formed almost quantitatively. Full article

This study investigates the formation mechanism of lactic-acid-derived coatings produced by open-air atmospheric-pressure plasma polymerization. A comparison of nebulization and bubbling precursor-delivery methods using FT-IR and XPS showed that the bubbling method facilitated plasma-assisted chemical bonding, including the possible formation of copper(II) lactate-like interfacial species and the retention of carbonyl-containing functional groups. However, the present dataset does not provide direct, discriminating evidence for a specific metal-lactate interfacial species, and alternative interpretations such as adsorption, oxidation, hydroxylation, or generic oxygenated carbon deposition cannot be excluded. Time-dependent analysis revealed a transition from oxygen-rich functional layers at short plasma exposure to carbon-rich overlayers at longer exposure, suggesting a fragmentation-recombination mechanism that is consistent with the formation of a metal-lactate-like interfacial region and a carbon-rich overlayer, while alternative interpretations related to signal attenuation and non-uniform coverage remain possible. Antibacterial testing revealed that the observed bacterial responses were not attributable to an intrinsic antibacterial property of the deposited films, but were instead strongly dependent on the underlying substrate chemistry and exposure time. C1100 retained the inherent antibacterial activity of copper, SUS430 showed no activity due to the absence of film formation, and SPCC exhibited only a transient effect attributed to lactic-acid-induced local acidification. Overall, the study elucidates the plasma-assisted deposition mechanism of lactic-acid-derived coatings under open-air conditions and highlights the critical role of interface chemistry in achieving stable and substrate-independent functional properties. Full article

In this work, the so-called characteristic function method is proposed as a new approach to describe and interpret the diffusion process with interacting adsorbates in terms of surface coverage. In this context, the intermediate scattering function is identified as a characteristic function that is very well defined in probability theory. From this function, the generating functions of the moments and cumulants of the jump probability distribution are straightforwardly obtained at any order. This analysis is carried out in two stages. First, the dilute limit, corresponding to non-interacting adsorbates or very low surface coverage, is briefly reviewed. Second, the method is extended to low and intermediate coverages, where adsorbate-adsorbate interactions become relevant. A further consequence of the present analysis is that the static structure factor is also a characteristic function of the adsorbate separation distance distribution. This method thus provides a compact and physically transparent route for connecting scattering observables, diffusion coefficients, and coverage-dependent structural correlations. Full article

Boron coatings were deposited by RF magnetron sputtering in an Ar atmosphere at a constant power of 80 W, varying the working pressure in the 0.6–5 Pa range. Plasma diagnostics were performed by means of a Langmuir probe to determine the electron temperature and electron density under different operating conditions. Within the investigated pressure range, the deposition rate remained nearly constant, whereas a significant decrease in coating mass density was observed with increasing pressure. The coatings display a columnar structure at all investigated pressures, with no significant differences in bulk morphology. Pressure primarily affects the surface features, leading to an increase in the density, lateral dimensions, and height of surface agglomerates with increasing pressure. Compositional analysis by EDX revealed a substantial oxygen incorporation in the films, with the lowest oxygen content (~11 at.%) measured for the coating deposited at 0.6 Pa. XPS depth profiling confirmed the presence of oxygen and evidenced the formation of boron oxide species, while the boron concentration exceeded 80 at.% in all samples. These results highlight the strong sensitivity of boron film density and oxygen uptake to sputtering pressure. Full article

This work provides an integrated experimental and computational evaluation of the cationic surfactant Quaternium-22 (Q-22) as a potentially eco-compatible corrosion inhibitor for carbon steel (CS) in 1 M hydrochloric acid. Gravimetric analysis and electrochemical techniques, including electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP), were employed over a temperature range of 20–50 °C. Q-22 exhibited mixed-type inhibition behavior, with efficiency rising to 97% at an optimal concentration of 277 μmol L⁻¹. Performance was concentration-dependent but diminished with increasing temperature, indicating partial inhibitor desorption at elevated temperatures. Thermodynamic evaluation confirmed a spontaneous adsorption process consistent with the Langmuir isotherm, involving a combined physisorption and chemisorption mechanism. Surface characterization via scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle (CA) measurement, and X-ray photoelectron spectroscopy (XPS) confirmed the formation of a coherent, hydrophobic inhibitor layer that substantially reduced surface roughness and corrosion damage. Theoretical investigations using density functional theory (DFT), natural bond orbital (NBO) analysis, and molecular dynamics (MD) simulations revealed strong adsorption energies and favorable electronic properties consistent with the inhibitor’s high experimental efficacy. Overall, the results demonstrate that Q-22 is a highly effective, eco-compatible corrosion inhibitor for CS in acidic environments, operating through a stable adsorptive film-forming mechanism. Full article