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Nanomaterials with enzyme-like properties are known as 'nanozymes'. Nanozymes are preferred over natural enzymes due to their nanoscale characteristics and ease of tailoring of their physicochemical properties such as size, structure, composition, surface chemistry, crystal planes, oxygen vacancy, and surface valence state. Interestingly, nanozymes can be precisely controlled to improve their catalytic ability, stability, and specificity which is unattainable by natural enzymes. Therefore, tailor-made nanozymes are being favored over natural enzymes for a range of potential applications and better prospects. In this context, metal oxide nanoparticles with nanozyme-mimicking characteristics are exclusively being used in biomedical sectors and opening new avenues for future nanomedicine. Realising the importance of this emerging area, here, we discuss the mechanistic actions of metal oxide nanozymes along with their key characteristics which affect their enzymatic actions. Further, in this critical review, the recent progress towards the development of point-of-care (POC) diagnostic devices, cancer therapy, drug delivery, advanced antimicrobials/antibiofilm, dental caries, neurodegenerative diseases, and wound healing potential of metal oxide nanozymes is deliberated. The advantages of employing metal oxide nanozymes, their potential limitations in terms of nanotoxicity, and possible prospects for biomedical applications are also discussed with future recommendations. [ABSTRACT FROM AUTHOR]

Hydrogel-based soft materials have attracted significant attention in various fields due to their high water content, good biocompatibility, and variable mechanical strength. However, due to the hydrophilic properties of hydrogel networks, most of the hydrogel-based soft materials are easy to swell in water and have monotonous surface wettability. Here, taking advantage of the intrinsic hydrophobicity of siloxane, novel heteronetwork organohydrogels were synthesized by covalently integrating reactive siloxane monomers into the hydrophilic hydrogel networks via emulsion polymerization. The surface of the heteronetwork organohydrogels exhibited adaptive wettability owing to the rearrangement of the surface chemistry induced by varying solvent conditions. Moreover, the heterogeneous networks endowed organohydrogels with excellent anti-swelling abilities in water or oil (n-heptanes). The potential application of the prepared organohydrogels in the field of oil/water separation was also preliminarily explored. The idea and method of integrating polysiloxane into hydrogels in this study might provide a new insight to develop high-performance polysiloxane-based heteronetwork gel materials. [ABSTRACT FROM AUTHOR]

Wire-electrical discharge machining (wire-EDM) is gaining wider acceptance for producing components of Al-matrix composites (Al-MCs) that are hard to machine by traditional methodologies. The related research is primarily limited to ex-situ Al-MCs commonly reinforced with ceramic particles; however, Al-MCs reinforced with in-situ ordered intermetallics have evolved as superior composites nowadays. This research has focused on wire-EDM of in-situ Al/Al3Fe composites developed by the reactive stir-casting route. The influence of three machining variables (pulse-on-time, servo voltage, and peak-current) and one material parameter (vol% of reinforcement) have been studied following the L27 Taguchi design. The integrity of the machined surface has been characterized via measurements of surface roughness (SR) and the alteration of surface chemistry (ASC, ΣCu + Zn + O), in addition to the evaluation of kerf width (KW) as a machining performance indicator. It has been established that all four control factors are significant for KW, while ASC is influenced by all factors except vol% of reinforcement; however, only pulse-on-time is substantial for SR. Analytical models of individual responses are developed while the desirability approach helps to accomplish the multi-response optimization; several confirmation experiments establish the authenticity of these predictions with an error < 8%. Characterizations of machined surfaces and wire electrodes by FESEM and EDS techniques reveal that the surface integrity of in-situ Al/Al3Fe composites varies significantly with machining conditions. [ABSTRACT FROM AUTHOR]

Biochar is a carbon-rich material, produced through the thermochemical conversion of various organic biomass materials, and it has garnered significant attention due to its versatile applications. In recent years, there has been a surge in research, focusing on the modification of biochar to enhance its properties and effectiveness for specific applications. With the rapid development of large-scale biochar production techniques, there has been a significant increase in literature discussing modified biochar and its applications. This review provides a comprehensive overview of various modification methods applied to biochar, including physical, chemical, and biological treatments. These methods include alkalis and acids, polymer coatings, biological inoculation, metal-mediated modifications, heteroatom doping, and the incorporation of other composites such as g-C3N4, ionic liquids, quantum dots, and graphene oxides. These modifications aim to adjust pore size distribution, optimize surface chemistry, and incorporate additives to enhance specific functionalities. Recent research shows a growing interest in modifying biochar, with efforts focused on maximizing its potential to address current environmental and agricultural issues. Thus, in this review, a brief description of the synthesis of the modified biochar materials and their enhanced applicability in specific fields has been discussed along with insights and direction for future research and development initiatives. [ABSTRACT FROM AUTHOR]

In many applied problems one seeks to identify and count the critical points of a particular eigenvalue of a smooth parametric family of self-adjoint matrices, with the parameter space often being known and simple, such as a torus. Among particular settings where such a question arises are the Floquet–Bloch decomposition of periodic Schrödinger operators, topology of potential energy surfaces in quantum chemistry, spectral optimization problems such as minimal spectral partitions of manifolds, as well as nodal statistics of graph eigenfunctions. In contrast to the classical Morse theory dealing with smooth functions, the eigenvalues of families of self-adjoint matrices are not smooth at the points corresponding to repeated eigenvalues (called, depending on the application and on the dimension of the parameter space, the diabolical/Dirac/Weyl points or the conical intersections). This work develops a procedure for associating a Morse polynomial to a point of eigenvalue multiplicity; it utilizes the assumptions of smoothness and self-adjointness of the family to provide concrete answers. In particular, we define the notions of non-degenerate topologically critical point and generalized Morse family, establish that generalized Morse families are generic in an appropriate sense, establish a differential first-order conditions for criticality, as well as compute the local contribution of a topologically critical point to the Morse polynomial. Remarkably, the non-smooth contribution to the Morse polynomial turns out to depend only on the size of the eigenvalue multiplicity and the relative position of the eigenvalue of interest and not on the particulars of the operator family; it is expressed in terms of the homologies of Grassmannians. [ABSTRACT FROM AUTHOR]

Understanding surface stability becomes critical as 2D materials like SnSe are developed for piezoelectric and optical applications. SnSe thin films deposited by molecular beam epitaxy showed no structural changes after a two-year exposure to atmosphere, as confirmed by X-ray diffraction and Raman spectroscopy. X-ray photoelectron spectroscopy and reflectivity show a stable 3.5 nm surface oxide layer, indicating a self-arresting oxidative process. Resistivity measurements show an electrical response dominated by SnSe post-exposure. This work shows that SnSe films can be used in ambient conditions with minimal risk of long-term degradation, which is critical for the development of piezoelectric or photovoltaic devices. [ABSTRACT FROM AUTHOR]

Polymeric aerogels, with their versatile physicochemical properties and capacity for functionalization, are innovative materials being increasingly explored for water treatment applications. In this study, novel millimetric sized alginate-based aerogel granules functionalized with nZVI (nanoscale zero-valent iron) were developed and evaluated for their phosphate sequestration performance. Efficient phosphate removal from water is critical as excessive levels of phosphates can lead to eutrophication and negatively impact water quality. nZVI-aerogel granules exhibited significant enhancements in phosphate removal efficiencies (up to 97%) compared to non-functionalized bare-aerogel granules (15%). Average Langmuir removal capacities of 77 mg-PO43−/g were observed consistently for nZVI-aerogel granules across a broad pH range from 3 to 7, which further increased under alkaline conditions reaching up to 180 mg-PO43−/g at pH 11. Kinetic studies were well described by the pseudo first-order kinetic model in the pH 3–7 range, with rates declining from 0.11 h−1 to 0.07 h−1 as pH increased. In contrast, mixed kinetic trends were observed in alkaline pH with rapid phosphate removal followed by a short-term desorption. Solution pH measurements, and analysis of nZVI-aerogel granule surface chemistry and morphology post batch experiments revealed the involvement of multiple sequestration mechanisms including electrostatic adsorption, ion exchange, and surface precipitation. nZVI-aerogel granule morphology remained stable under all tested conditions (except at pH 11) suggesting their strong potential for facilitating efficient post-treatment separation and recovery. [ABSTRACT FROM AUTHOR]

Here we review scanning tunneling microscopy research on the surface determination for various types of kagome materials, including 11-type (CoSn, FeSn, FeGe), 32-type (Fe3Sn2), 13-type (Mn3Sn), 135-type (AV3Sb5, A = K, Rb, Cs), 166-type (TbMn6Sn6, YMn6Sn6 and ScV6Sn6), and 322-type (Co3Sn2S2 and Ni3In2Se2). We first demonstrate that the measured step height between different surfaces typically deviates from the expected value of ±0.4 ∼0.8Å, which is owing to the tunneling convolution effect with electronic states and becomes a serious issue for Co3Sn2S2 where the expected Sn-S interlayer distance is 0.6Å. Hence, we put forward a general methodology for surface determination as atomic step geometry imaging, which is fundamental but also experimentally challenging to locate the step and to image with atomic precision. We discuss how this method can be used to resolve the surface termination puzzle in Co3Sn2S2. This method provides a natural explanation for the existence of adatoms and vacancies, and beyond using unknown impurity states, we propose and use designer layer-selective substitutional chemical markers to confirm the validity of this method. Finally, we apply this method to determine the surface of a new kagome material Ni3In2Se2, as a cousin of Co3Sn2S2, and we image the underlying kagome geometry on the determined Se surface above the kagome layer, which directly visualizes the p-d hybridization physics. We emphasize that this general method does not rely on theory, but the determined surface identity can provide guidelines for first-principles calculations with adjustable parameters on the surface-dependent local density of states and quasi-particle interference patterns. [ABSTRACT FROM AUTHOR]

The growing demand for sustainable products has spurred research into renewable materials, with cellulose-based materials emerging as prominent candidates due to their exceptional properties, abundance, and wide-ranging applications. In this context, there is a need to develop a better fundamental understanding of cellulose interactions such that we can continue to design and improve sustainable materials. Individual interactions can be difficult to assess in bulk fibre-based materials and therefore cellulose model materials have become indispensable tools for researchers as they can facilitate the study of cellulose interactions at a molecular level enabling the design of sustainable materials with enhanced properties. This study presents a new methodology for studying the effects of surface treatments on the individual fibre–fibre joint strength using wet-spun cellulose nanofiber (CNF) filaments as model materials. The Layer-by-Layer assembly technique is used to modify the surface chemistry of the model materials as well as bleached and unbleached hardwood Kraft fibres, demonstrating its potential to enhance adhesive properties and overall mechanical performance of papers made from these fibres. The study further explores the impact of increasing network density through wet-pressing during paper preparation, showcasing a comprehensive approach to molecularly tailor fibre-based materials to achieve superior mechanical properties. The proposed methodology provides a time-efficient evaluation of chemical additives in paper preparation. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) monometal boron nanosheets (BNS) are emerging as a promising candidate, demonstrating high catalytic performance by virtue of their tunable surface chemistry, large surface area, superb hydrophilicity, and swift charge transfer kinetics. Nonetheless, oxidation and restacking of these nanosheets in ambient air make it challenging for practical applications. The introduction of transition metals in BNSs helps to suppress interlayer restacking of the sheets. Further, the addition of bimetallic atoms help to diminish the overpotential value, correspondingly boosting the catalytic activity and onset potential required for reaction kinetics. Accordingly, herein, structural and electronic engineering of BNS using bimetallic atoms (Ag:Cu) at different doping concentrations are investigated and characterized using x-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, and x-ray photoelectron spectroscopy studies. Finally, the electrocatalytic performance towards hydrogen evolution reaction was investigated through cyclic voltammetry and electrochemical impedance spectroscopy to study the charge transfer rate. Here, optimized sample shows lowest overpotential value of 101 mV and Tafel slope of 59 mV dec−1 with highest exchange current density of 7.86 mA cm−2 and minimum charge transfer resistance of 15.9 Ω. Thus, current findings could help in developing the ideas for the surface modifications to significantly enhance the electrocatalytic performance. [ABSTRACT FROM AUTHOR]

This research developed a novel composite of MOF-NH2 and graphene oxide (GO) for enhanced CO2 capture. Employing the response surface methodology-central composite design (RSM-CCD) for experiments design, various MOF-NH2/GO samples with GO loadings from 0 to 30 wt% were synthesized. The results of SEM, XRD, EDS, and BET analysis revealed that the materials maintained their MOF crystal structure, confirmed by X-ray diffraction, and exhibited unique texture, high porosity, and oxygen-enriched surface chemistry. The influence of temperature (25–65 °C) and pressure (1–9 bar) on CO2 adsorption capacity was assessed using a volumetric adsorption system. Optimum conditions were obtained at weight percent of 22.6 wt% GO, temperature of 25 °C, and pressure of 9 bar with maximum adsorption capacity of 303.61 mg/g. The incorporation of amino groups enhanced the CO2 adsorption capacity. Isotherm and kinetic analyses indicated that Freundlich and Fractional-order models best described CO2 adsorption behavior. Thermodynamic analysis showed the process was exothermic, spontaneous, and physical, with enthalpy changes of − 16.905 kJ/mol, entropy changes of − 0.030 kJ/mol K, and Gibs changes energy of − 7.904 kJ/mol. Mass transfer diffusion coefficients increased with higher GO loadings. Regenerability tests demonstrated high performance and resilience, with only a 5.79% decrease in efficiency after fifteen cycles. These findings suggest significant potential for these composites in CO2 capture technologies. [ABSTRACT FROM AUTHOR]

Stimuli-responsive or smart polymers are macromolecules that can change their physicochemical structure in response to environmental changes such as temperature, pH, UV irradiation, solvent exchange, magnetic field, and ionic factors. Thermo-responsive hydrogels benefit from temperature changes as a trigger for sol-gel transition. They are advantageous for some biomedical applications because they do not require organic solvents, chemical additives, or external fields. Biocompatible and biodegradable polymers that are liquid at room temperature and gel at physiological temperature can be utilized as injectable biomaterials with unique applications in drug delivery, cell encapsulation, and tissue engineering. Therapeutic agents or cells can be incorporated into the sol solution and injected into the target site, forming an in-situ gel with minimal invasiveness and pain. This review summarizes thermoresponsive hydrogels made from natural and synthetic polymers that are used in wound healing. The versatility, simplicity, and convenience of administration, along with the untapped potential of thermo-responsive polymeric materials, make them the most promising interfaces for chemistry and biology in tissue engineering applications. [ABSTRACT FROM AUTHOR]

In the present work, a La-based sealing procedure was developed for the anodized AZ31B magnesium alloy. The effects of sealing time and temperature on the electrochemical behavior of the samples were investigated. The corrosion resistance was evaluated in 3.5 wt.% NaCl solution using potentiodynamic polarization tests. Scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS) were used to examine the morphology and composition of the sealing films. The results were discussed based on the interplay between film composition, morphological aspects and surface roughness. The best corrosion resistance was obtained for the sample sealed for 20 minutes at 50 °C that exhibited the widest passive range, surpassing that of the anodized (unsealed) sample by more than three times. As indicated by the SEM and XPS results, the formation of a uniform sealed layer comprised of a mixture of La2O3 and La(OH)3 enhanced the corrosion resistance of the anodized AZ31B. [ABSTRACT FROM AUTHOR]

The KSF-clay is a material that presents a high density of acidic active sites, ideal for being a heterogeneous acid catalyst with outstanding activity. For this study, KSF-clay was characterized by X-ray photoelectron spectroscopy and temperature-programmed desorption of ammonia. Additionally, studies of the adsorption of ethanol, propan-2-ol, and acetic acid molecules over KSF-clay surface to establish their thermal stability species were studied by diffuse reflectance infrared Fourier transform spectroscopy. The relationship between the properties of KSF-clay and the adsorption-interaction process with organic molecules is related to its performance as an acid catalyst. [ABSTRACT FROM AUTHOR]

Surface-modified bacterial cellulose, namely, BC-g-PMMA fiber, was synthesized by graft polymerization. The BC-g-PMMA fiber was employed as a surface modifying agent for a porous polylactic acid (PLA) scaffold, which was prepared through phase inversion. In this study, BC-g-PMMA 1:1 (BC: MMA mole ratio of 1:1), BC-g-PMMA 1:3 (BC: MMA mole ratio of 1:3), and BC-g-PMMA 1:6 (BC: MMA mole ratio of 1:6) were prepared using methyl methacrylate (MMA) as a grafting monomer under sonication-assisted reactions. Various characterization methods, including FTIR, DSC, and TGA, were employed to confirm that BC-g-PMMA exhibited an amphiphilic structure. Next, the PLA/BC-g-PMMA composite scaffold was successfully prepared using a solvent-induced phase inversion technique involving a solvent exchange step (dioxane diffused out while water diffused in); due to this process, the honeycomb structure of the PLA/BC-g-PMMA composite contained amphiphilic surfaces, and the wettability and cell adhesion behavior of the porous material were manipulated. In the absence of BC-g-PMMA, porous PLA exhibited a hydrophobic surface and no wicking properties. In contrast, the PLA/BC-g-PMMA composites showed an ability to wick, which was related to the grafted PMMA moiety; the higher the grafted PMMA ratio was, the slower the wicking ability due to the decrease in the surface energy of the composites. Due to their tailored surface chemistry, these materials played a role in the adherence of the composites to proteins and human gingival fibroblasts. Therefore, amphiphilic spongy PLA/BC-g-PMMA composites are promising materials for tissue engineering and spheroid (3D cell structure) scaffolds. [ABSTRACT FROM AUTHOR]

The fines fraction in mechanical pulp, produced during wood processing can impact the mechanical properties of the resulting paper positively or negatively, making them potential additives for paper strength improvement at the right loading level. To enhance fines' effectiveness as paper strength additives that have heterogeneous surface chemistries, this work employed a regioselective surface esterification method conducted under mild conditions in acetone, with the addition of succinic anhydride and imidazole. This approach converted surface hydroxyl groups of fines into carboxylic acid groups, resulting in a final content of near 0.5 mmol g−1. This modification increased fines' hydrophilicity, as evidenced by enhanced moisture absorption capacity in dynamic vapor sorption analysis. These fines with additional functionality strengthened intermolecular bonding, leading to over 150% enhancement in tensile strength and Young's modulus when cast into thin films. Fines were substituted at 10–20 wt.% concentration to the fiber fraction of softwood thermomechanical pulp (TMP) and bleached chemi-thermomechanical pulp (BCTMP) forming handsheets. It was observed that fines modified with succinic anhydride and imidazole were more effective in enhancing paper strength, including tensile (up to 30%), burst (up to 39%) and tear (up to 4%) indices. This improvement was likely due to enhanced intermolecular bonding between modified fines and the fiber surfaces. By modifying mechanical pulp fines with succinic anhydride and imidazole, we have converted a potential heterogeneous waste product from the industry into a valuable by-product to enhance paper performance. [ABSTRACT FROM AUTHOR]

The wire-electrical discharge machining (wire-EDM) is increasingly recommended for the machining of complex-shaped components with high surface finish and geometrical accuracy, specifically for difficult-to-machine advanced materials like Al-matrix composite (Al-MCs). The related research is primarily restricted to ex-situ Al-MCs, although in-situ ordered intermetallics reinforced Al-MCs are receiving growing attention due to their superior comprehensive mechanical properties. The present work deals with an Al-2Mg/20 vol.% in-situ Al3Fe composite manufactured by the reactive stir-casting method and focuses on its machining by wire-EDM via experimental and computational approaches. Experiments have been conducted following the response surface method (RSM) considering four process variables, namely, pulse-on time (TON), servo voltage (SV), peak current (IP) and wire feed rate (WFR). The integrity of the machined surfaces has been characterized by evaluating the change in surface chemistry (CSC) and surface roughness (SR), while the material removal rate (MRR) has been determined as the machining performance index. Analysis of variance (ANOVA) and RSM-based mathematical models reveal that TON is the most influencing parameter, and it raises MRR and SR but reduces CSC considerably. The optimization of machining conditions has been performed by metaheuristic approaches, namely, Teaching and Learning-based optimization (TLBO) and Artificial Bee Colony (ABC) apart from multi-objective RSM (MORSM) based on the trade-off analysis. The performances of TLBO and ABC techniques are found to be identical and provide much greater MRR at the cost of diminished surface integrity, i.e., higher SR and CSC, when compared with the MORSM technique. The robustness of the developed models has been validated by confirmatory experiments with a calculated overall error of ≤ ± 8%. Finally, the surface integrity aspects are reaffirmed and correlated with input variables through detailed characterizations of the machining surfaces by FESEM-EDS. [ABSTRACT FROM AUTHOR]

The composition and chemical properties of template could influence the morphology, texture and surface chemistry of the resultant carbon and their performances for supercapacitor. Herein, we systematically investigated the component effect of templates from magnesium oxide to magnesium/zinc oxides and zinc oxide on the morphology, texture, surface chemistry and supercapacitor performances. The results indicate that single component of MgO and ZnO favors the formation of nanosheet morphology, while binary oxides favor the creation of stack morphology. As to the surface chemistry, it was found that the surface basicity of template greatly influences the residual oxygenic functionalities, in which the weak basicity oxide (ZnO) favors the construction of hydroxyl, while the strong basic oxide (MgO) benefits the formation of carbonyl. Due to the differences of the resultant products in morphology, textual properties and surface chemistry, as electrode for supercapacitor, the ZnMgC0.2-based electrode achieves the largest capacitance of 357 F/g@1.0 A/g among the four electrodes, while the ZnC-based electrode owns the best rate capability with capacitance retention of 92.8% from 1.0 to 20 A/g. Moreover, the symmetric supercapacitor devices test indicates that the ZnC-based device promises a large potential in practical energy storage since it delivers the largest energy density of 25 Wh/kg@900 W/kg among the four devices and some latest reported ones. Importantly, the present work can offer a reference on the choice of template to prepare porous carbon with specific aim. [ABSTRACT FROM AUTHOR]

A new method to assess the quality of additive manufacturing (AM) metal powders using the triboelectric charging concept is demonstrated using CpTi, Ti6Al4V, AlSi10Mg, IN 738, and SS 316L powders. For each powder tested, the surface chemical composition was first analyzed using X-ray photoelectron spectroscopy (XPS) to determine the composition of the passivation layer. Some modifications to the current GranuCharge™ setup, developed by GranuTools™, were then performed by incorporating a flow rate measuring tool to assess how tribocharging is affected as a function of flow rate. Variations in the tribocharging response have been found with the flow rate of CpTi, AlSi10Mg and SS 316L powders. Moreover, results suggest that the tribocharging behavior might not be the same even with powders fabricated with the same passivation process. Finally, the compressed exponential model of Trachenko and Zaccone was used to reproduce the tribocharging behavior of the powders. The models were found to work best when the stretch constant β = 1.5, which is identical to the value found in other systems such as structural glasses, colloidal gels, entangled polymers, and supercooled liquids, which experience jamming when motion of individual particles become restricted, causing their motion to slow down. [ABSTRACT FROM AUTHOR]

Stretchable electronics commonly assemble multiple material modules with varied bulk moduli and surface chemistry on one packaging substrate. Preventing the strain-induced delamination between the module and the substrate has been a critical challenge. Here we develop a packaging substrate that delivers mechanically stable module/substrate interfaces for a broad range of stiff and stretchable modules with varied surface chemistries. The key design of the substrate was to introduce module-specific stretchability and universal adhesiveness by regionally tuning the bulk molecular mobility and surface molecular polarity of a near-hermetic elastic polymer matrix. The packaging substrate can customize the deformation of different modules while avoiding delamination upon stretching up to 600%. Based on this substrate, we fabricated a fully stretchable bioelectronic device that can serve as a respiration sensor or an electric generator with an in vivo lifetime of 10 weeks. This substrate could be a versatile platform for device assembly. Preventing the strain-induced delamination between the module and the substrate has been a critical challenge. The authors developed a stretchable packaging substrate that enables stable module/substrate interfaces under large deformation, preventing the interfacial delamination of stretchable electronics. [ABSTRACT FROM AUTHOR]

This paper is a fundamental exploration of the dynamic area of nanocatalysis, offering a detailed analysis of recent advancements and practical applications. Tailored for researchers and professionals, this article begins with a historical overview, emphasizing nanocatalysis' pivotal role in contemporary science and industry. It delves into foundational principles, covering nanoparticle synthesis, characterization, surface chemistry, and reactivity mechanisms at the nanoscale. Advanced sections explore the design of nanomaterials for catalysis, hybrid catalyst synthesis, and the integration of computational approaches. Mechanistic insights are presented through a detailed examination of reaction pathways and cutting-edge spectroscopic techniques. Practical applications span energy conversion, sustainable synthesis, and environmental remediation, with illustrative case studies. The article concludes by addressing current challenges, outlining future perspectives, and highlighting emerging trends, making it an essential guide for those navigating the multifaceted landscape of nanocatalysis. [ABSTRACT FROM AUTHOR]

To date, smart surfaces with controllable wettability have received extraordinary attention due to their great importance in both fundamental research and practical applications. Chemical composition and surface topography are the two key factors to affect the wettability of solid surfaces. Applying external stimuli to change the surface chemistry and/or topography is considered to be a valuable approach for driving the transition between hydrophilicity and hydrophobicity of surfaces. In this study, poly o-toluidine nanofibers were synthesized by a facile aqueous/organic interfacial polymerization, and superhydrophobic coatings of poly o-toluidine were prepared via a room-temperature spraying process. The reversible wettability conversion between the superhydrophobic and the hydrophilic state of the obtained poly o-toluidine coating under ultraviolet irradiation and electric stimulation was investigated. From the X-ray photoelectron spectroscopy analysis, this intelligent switching wetting behavior under ultraviolet light irradiation was confirmed to have a high correlation with the change in surface chemical composition. When the electric stimulation was applied, the wettability switch was caused by the redistribution of charge and electric dipole along the liquid–solid interface. [ABSTRACT FROM AUTHOR]

Atomic layer deposition (ALD) is a promising technique for fabricating high-quality thin films. For improving the process conditions and material quality of ALD, understanding the surface chemical mechanisms at the molecular level is important as the entire ALD process is based on the reactions of precursors on the substrate surfaces. Zinc oxynitride (ZnON) is gaining significant research interest as a p-type semiconductor material. Although the ALD of ZnON can be performed by dosing H2O and NH3 as oxygen and nitrogen sources, respectively, the elemental ratio of O and N in the deposited film differs considerably from that in the gaseous sources. In this study, the surface reactions of ZnON ALD are analyzed employing density functional theory calculations. All the ALD surface reactions of ZnO and ZnN are facile and expected to occur rapidly. However, the substitution of a surface *NH2 by H2O to form *OH is preferred, whereas the inverse reaction is implausible. We propose that the differences in the reactivity could originate from the higher bond energy of Zn–O than that of Zn–N. [ABSTRACT FROM AUTHOR]

Solid–water interfaces are crucial for clean water, conventional and renewable energy, and effective nuclear waste management. However, reflecting the complexity of reactive interfaces in continuum-scale models is a challenge, leading to oversimplified representations that often fail to predict real-world behavior. This is because these models use fixed parameters derived by averaging across a wide physicochemical range observed at the molecular scale. Recent studies have revealed the stochastic nature of molecular-level surface sites that define a variety of reaction mechanisms, rates, and products even across a single surface. To bridge the molecular knowledge and predictive continuum-scale models, we propose to represent surface properties with probability distributions rather than with discrete constant values derived by averaging across a heterogeneous surface. This conceptual shift in continuum-scale modeling requires exponentially rising computational power. By incorporating our molecular-scale understanding of solid–water interfaces into continuum-scale models we can pave the way for next generation critical technologies and novel environmental solutions. Chemistry at solid-water interfaces is crucial for all aspects of human life. Here, authors propose to use a probability-based paradigm for formalizing chemical reactions at solid-water interfaces in continuum scale models. [ABSTRACT FROM AUTHOR]

Aluminum alloy 2024 is the most widely used metal alloy in aircraft due to its superior characteristics. Although the effects of surface chemistry and topography on the wettability transition have been investigated in the literature, it has not yet been clarified which mechanism is more dominant. In this study, the super-hydrophobic Al2024 sample surfaces were obtained over time in a single step using a nanosecond pulsed fiber laser. Different micro- and nano-structures were produced by changing the laser output power and scanning speed. The effects of laser parameters on the wettability of the Al2024 samples were examined. As with the untreated sample, all fresh laser-treated samples have a hydrophilic or super-hydrophilic surface property. It was found that the fresh laser-treated aluminum alloy surfaces were super-hydrophilic. Then, the Al2024 samples were exposed to ambient air for a certain period. It was found that the contact angles (CAs) of all laser-treated Al2024 samples increased over time. Also, the water drop moved away from the surface of some super-hydrophobic samples at angles of less than 10°. With more than 150° water contact angle and less than 10° sliding angle, it was proved that the lotus effect was obtained at various time scales. The icing properties of the lotus sample were investigated. The surface icing characteristics of the lotus sample have been improved. The XPS high resolution analyses show that the Al-C bond could be responsible for the wettability transition of the laser-ablated samples from hydrophilic to super-hydrophobicity (lotus). [ABSTRACT FROM AUTHOR]

C − H bond activation is a ubiquitous reaction that remains a major challenge in chemistry. Although semiconductor-based photocatalysis is promising, the C − H bond activation mechanism remains elusive. Herein, we report value-added coupling products from a wide variety of biomass and fossil-derived reagents, formed via C − H bond activation over zinc-indium-sulfides (Zn-In-S). Contrary to the commonly accepted stepwise electron-proton transfer pathway (PE-ET) for semiconductors, our experimental and theoretical studies evidence a concerted proton-coupled electron transfer (CPET) pathway. A pioneering microkinetic study, considering the relevant elementary steps of the surface chemistry, reveals a faster C − H activation with Zn-In-S because of circumventing formation of a charged radical, as it happens in PE-ET where it retards the catalysis due to strong site adsorption. For CPET over Zn-In-S, H abstraction, forming a neutral radical, is rate-limiting, but having lower energy barriers than that of PE-ET. The rate expressions derived from the microkinetics provide guidelines to rationally design semiconductor catalysis, e.g., for C − H activation, that is based on the CPET mechanism. The knowledge of semiconductor photocatalysis in C − H bond activation remains limited. Here, the authors report comprehensive mechanistic studies to unveil the semiconductor-rare concerted proton-coupled electron transfer mechanism for C − H bond activation over Zn-In-S. [ABSTRACT FROM AUTHOR]

The preparation of manganese substituted iron oxide magnetic nanoparticles by polyol synthesis route. Due to the unique properties, diethylene glycol (DEG) and tri-ethylene glycol (TEG) used as a solvent in synthesis method with different volumetric variations. The structural, morphological and hyperthermic properties of prepared samples are investigated. Formation of single-phase cubic spinel lattice for all compositions confirmed by X-ray diffraction and crystallite size was found to be decreased from 20.6 ± 1.3 to 15.2 ± 1.7 nm with varying ratio of DEG/TEG. Transmission electron microscopy (TEM) analysis displayed spherical grains with an agglomeration of the MnFe2O4 magnetic nanoparticles (MNPs). Heating ability of MNPs studied with an induction heating system under different magnetic field strengths at 20 kA/m and 26.6 kA/m by varying nanoparticle concentrations at fixed frequency of 278 kHz. Antimicrobial activity on E. coli and antifungal activity on C. albicans showed effectiveness of MNPs at 10 mg/mL for such activities. Additionally, ROS induction in presence of MNPs illustrates probable action against E. coli and C. albicans and as antibacterial and antifungal agent in the medical field due to ROS generation ability.It has been shown that these optimized MNPs will play multifaceted roles for magnetic hyperthermia therapy as heat mediators, and antibacterial/antifungal agents owing to their magnetic induction heating properties and biological activities. [ABSTRACT FROM AUTHOR]

The consumption of renewable energy should increase by 300% by 2050 compared to 2010 due to the rising demand for green electricity, stringent government mandates on low-carbon fuels, and competitive biofuel production costs, thus calling for advanced methods of energy production. Here we review the use of activated carbon, a highly porous graphitic form of carbon, as catalyst and electrode for for energy production and storage. The article focuses on synthesis of activated carbon, hydrogen production and storage, biodiesel production, energy recovery, and the use of machine learning. The textural properties and surface chemistry of activated carbon can be engineered using acid and base treatments, hetero-atom doping, and optimization of the activation conditions to improve the efficiency of renewable energy production and storage. Machine learning allows to optimize the synthesis of catalysts, electrodes and bioproducts, with benefits to the biorefinery industries. [ABSTRACT FROM AUTHOR]

Transmission electron microscopy (TEM) facilitates the direct observation of individual catalytic materials with atomic-level spatial resolution, offering crucial structural insights into catalyst performance. Furthermore, the recent integration of in situ analysis techniques with TEM has enabled the real-time monitoring of dynamic structural changes in catalysts within a reaction environment over time, yielding novel findings that are challenging to obtain through conventional bulk characterization methods. In this prospective, we explore advanced TEM technologies employed for precisely examining the structure of a catalyst surface, emphasizing the dynamic chemistry inherent in heterogeneous catalysis, exclusively validated through in situ TEM. Finally, we propose future directions for in situ TEM studies on heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

This work contributes to the understanding of an interplay between surface chemistry, morphology, and wettability properties, crucial for advancing biomaterial coatings in drug delivery systems. The surface properties of multilevel scaffolds, including a titanium frame, a calcium phosphate (CaP) coating and a poly(lactide-co-glycolide) (PLGA) layer are studied. It is shown that CaP coatings have complex internal morphologies with branched pore structures and spheroidal surface elements. A 5 wt.% PLGA modification, however, does not alter the structure, increasing the PLGA concentration to 8−10 wt.%, leading to the formation of a homogeneous polymer film, changing the porous structure and reducing the surface roughness. The FTIR spectra confirm the presence of various functional groups, correlating with changes in properties. A systematic analysis of the hydrophilic/hydrophobic nature, free surface energy, and surface roughness of pure CaP and pure PLGA surfaces as well as CaP/PLGA samples is given. The pure CaP coating and pure PLGA are found to be hydrophilic, with the water contact angles lower than 26° and 74°, respectively. An application of PLGA to the CaP coatings resulted in hydrophobization, with the water contact angles exceeding 94°. [ABSTRACT FROM AUTHOR]

It is of great significance to synthesize carbon dots (CDs) with desirable hydrophilicity for the ever-growing application of CDs in different fields. In this study, the hydrophilic and hydrophobic CDs were facilely prepared by solvothermal treatment of o-dihydroxybenzene and urea in N,N-dimethylformamide (DMF). Optimization experiments revealed that the solvothermal temperature has a great impact on the surface states of the CDs. The hydrophobic CDs with a contact angle of 110.7° was obtained at 200 °C. The structural and optical characterizations, along with theoretical calculations elucidated that the lipophilic nature of the CDs was resulting from the formation of polymer chains. The presence of extended conjugated sp2-domains and amino groups contributed to the red emission of the CDs synthesized at low reaction temperatures (160–200 °C). With the further increase of solvothermal temperature, the hydrophobic CDs were gradually transformed to the hydrophilic state accompanying the blue shift of the fluorescence of the CDs. The highly hydrophilic CDs with a contact angle of 25.9° were obtained at 240 °C due to the increased formation of hydrophilic functional groups on the surface of CDs. The red emissive CDs exhibited a sensitive color and fluorescence response to ethanol content while the fluorescence of the blue emissive CDs remained constant. By combining the two kinds of CDs, a dual-emission sensor was constructed, which was successfully applied for the evaluation of the alcoholic strength in commercial Baijiu commodities in both fluorometric and colorimetric modes. [ABSTRACT FROM AUTHOR]

This work demonstrated enhanced adsorption capabilities of lignin nanoparticles (LNPs) synthesized via a straightforward hydrotropic method compared to pristine lignin (PL) powder for removing methylene blue dye from aqueous solutions. Kraft lignin was used as a precursor and p-toluenesulfonic acid as the hydrotrope to produce spherical LNPs with ~ 200 nm diameter. Extensive characterization by SEM, AFM, DLS, zeta potential, and BET verified successful fabrication of microporous LNPs with fourfold higher specific surface area (14.9 m2/g) compared to PL (3.4 m2/g). Significantly reduced particle agglomeration and rearranged surface chemistry (zeta potential of −13.3 mV) arising from the self-assembly of lignin fractions under hydrotropic conditions enabled the application of LNPs and superior adsorbents compared to PL. Batch adsorption experiments exhibited up to 14 times higher methylene blue removal capacity, from 20.74 for PL to 127.91 mg/g for LNPs, and ultrafast equilibrium uptake within 3 min for LNPs compared to 10 min for PL. Kinetic modeling based on pseudo-first-order and pseudo-second-order equations revealed chemisorption as the predominant mechanism, with a rate constant of 0.032825 g/mg·h for LNPs—over an order of magnitude higher than PL (0.07125 g/mg·h). Isotherm modeling indicated Langmuir monolayer adsorption behavior on relatively uniform lignin surface functional groups. The substantially augmented adsorption performance of LNPs arose from the increased surface area and abundance of surface functional groups, providing greater accessibility of chemically active binding sites for rapid dye uptake. Overall, this work demonstrates that tailoring lignin nanoparticle structure and surface chemistry via scalable hydrotropic synthesis is a simple and sustainable approach for producing highly efficient lignin-based nano-adsorbents for organic dye removal from industrial wastewater. [ABSTRACT FROM AUTHOR]

Colloidal quantum-dot light-emitting diodes (QLEDs) are rapidly gaining recognition as formidable contenders in the realm of next-generation lighting and display devices. Notwithstanding, the journey to commercialization of QLED devices encounters a roadblock in the form of inadequate flexibility exhibited by the electron transport layer, which is typically made of ZnO nanoparticles. The hindrance stems from the substantial specific surface area, existence of surface defect states, and the fixed ZnO bandgap. To surmount these obstacles, we delved into the potential of integrating Mg element as a dopant in ZnO, aiming to enhance the surface chemistry, electrical characteristics, and film morphology of colloidal ZnO nanoparticles. The results clearly indicated that Mg doping played a critical role in diminishing surface defects in ZnO, while simultaneously reducing the density of oxygen vacancies, thereby regulating its electron mobility. Through modulation of the Mg doping concentration, the bandgap width of ZnO can be fine-tuned, leading to the creation of a more suitable electron transport layer. The inverted QLED devices based on Zn1−xMgxO electron transport layers exhibited remarkable advancements, with a peak external quantum efficiency and current efficiency of 6.7% and 29 cd A−1, respectively. These values surpassed those of reference devices by 35 and 28%, underscoring the efficacy of Zn1−xMgxO as a viable approach for enhancing the efficiency of QLED devices. [ABSTRACT FROM AUTHOR]

Surface complexation models (SCMs) based on Gouy-Chapman theory are often used to describe adsorption of ions onto mineral surfaces. To compensate for the buildup of charge at a solid surface, the composition of the electric diffuse layer next to the surface must balance the surface charge. To calculate the diffuse layer composition, several nonlinear equations and integrals must be solved, usually with an iterative approach. Before convergence, charge balance is typically not fulfilled. One numerical difficulty is that, because of these charge balance errors, the iterative solver may attempt to take the square root of a negative number. Herein, we show that for electrolytes containing only monovalent or divalent ions (i.e., most electrolytes encountered in practice), we can greatly simplify the integrals and eliminate the appearance of complex-valued integrands; it is even possible to derive explicit analytical formulas. Furthermore, using the new method prevents converging to non-physical roots of the Grahame equation, which links surface potential to surface charge. To the best of our knowledge, the presented formulation has not been implemented in geochemical modelling software before, although similar mathematical expressions have been presented in the literature. In Gouy-Chapman theory, ions can only be distinguished by their charges, but this is not consistent with all experimental findings. We present a model that allows for the preferential accumulation of ions in the diffuse layer. The model, which is implemented mathematically by including ion exchange sites with a variable exchange capacity, is flexible and more numerically tractable than the standard models for the diffuse layer. [ABSTRACT FROM AUTHOR]

This study details the successful creation of a nanocomposite consisting of reduced graphene oxide (rGO) and Yb2O3 using a hydrothermal-assisted simple solution method. The research underscores the significance of this rGO: Yb2O3 composite material, which has emerged as a focal point of interest. The comprehensive analysis of the composite's structural features, as revealed by various techniques, offers vital insights into its distinctive properties. These insights hold profound implications for potential applications, especially in the field of advanced materials. The structural characterization techniques not only enhance our understanding of the composite's crystal structure, molecular vibrations, elemental composition, and surface chemistry but also highlight its potential as a superior material for various scientific and technological endeavors. Furthermore, this study emphasizes the importance of research and development efforts dedicated to rGO: Yb2O3 composite materials, particularly in the context of supercapacitor applications. Morphological examinations confirm the uniform distribution of Yb2O3 nanoparticles on both sides of the rGO sheets, with sizes below 50 nm. Notably, the nanocomposite exhibits significantly enhanced specific capacitance (1382.72 Fg−1 at 5 mVs−1) compared to pristine Yb2O3 nanoparticles (753.27 Fg−1 at 5 mVs−1). This improvement can be attributed to the synergistic interaction between rGO and Yb2O3, which enhances the charge storage capacity. Electrochemical characterization reveals dominant pseudo-capacitance behavior typical of batteries, making the nanocomposite a promising candidate for energy storage applications. In summary, this study illuminates the potential of graphene-based nanocomposites as high-performance energy storage materials and offers valuable insights for future research endeavors, including optimizing synthesis parameters and evaluating long-term stability. The rGO: Yb2O3 nanocomposite exhibits tremendous promise for advanced energy storage systems. [ABSTRACT FROM AUTHOR]

This study investigates the feasibility and effectiveness of employing waste ceramic (WC) in rigid pavement as a replacement for fine aggregate. WC was integrated into concrete; untreated and treated with a silane compound, where 30 wt.% and 50 wt.% sand was replaced with WC. The workability, compressive strength, water absorption, skid resistance, microstructural analysis, and surface chemistry of mixtures were evaluated. The results illustrated the positive impact of using treated WC on the water absorption of mixtures, where a maximum reduction of 19% was achieved in the mixture with 50% treated WC. Moreover, concrete with 30% treated WC attained a higher compressive strength of 43 MPa than its untreated counterpart, which achieved 29 MPa, when tested at 28 days. The integration of treated and untreated WC in concrete pavement reduced its skid resistance due to the presence of glaze in the untreated mixture and silane in the treated mixture. The morphological and surface chemistry analyses confirmed the development of C–S–H, CaCO3, and SiO2 in high contents in concrete with silane-treated WC. Also, a strong bonded interfacial transition zone was noticed in concrete with silane-treated WC, unlike concrete with untreated WC, which had a poor interfacial transition zone. [ABSTRACT FROM AUTHOR]

This study synthesized a new thiomalic acid–modified rice husk biochar (TMA-BC) as a versatile and eco-friendly sorbent. After undergoing chemical treatments, the mercerized rice husk biochar (NaOH-BC) and TMA-BC samples showed higher BET surface area values of 277.1 m2/g and 305.8 m2/g, respectively, compared to the pristine biochar (BC) sample, which had a surface area of 234.2 m2/g. In batch adsorption experiments, it was found that the highest removal efficiency for malachite green (MG) was achieved with TMA-BC, reaching 96.4%, while NaOH-BC and BC exhibited removal efficiencies of 38.6% and 27.9%, respectively, at pH 8. The engineered TMA-BC exhibited a super adsorption capacity of 104.17 mg/g for MG dye at pH 8.0 and 25 °C with a dosage of 2 g/L. The SEM, TEM, XPS, and FTIR spectroscopy analyses were performed to examine mesoporous features and successful TMA-BC carboxylic and thiol functional groups grafting on biochar. Electrostatic forces, such as π − π interactions, hydrogen bonding, and pore intrusion, were identified as key factors in the sorption of MG dye. As compared to single-solution adsorption experiments, the binary solution experiments performed at optimized dosages of undesired ions, such as humic acid, sodium dodecyl sulfate surfactant, NaCl, and NaSCN, reflected an increase in MG dye removal of 2.8%, 8.7%, 5.4%, and 12.7%, respectively, which was attributed to unique mesoporous features and grafted functional groups of TMA-BC. Furthermore, the TMA-BC showed promising reusability up to three cycles. Our study indicates that mediocre biochar modified with TMA can provide an eco-friendly and cost-effective alternative to commercially accessible adsorbents. [ABSTRACT FROM AUTHOR]

The tree species composition has a significant impact on the biogeochemical cycle of forest ecosystems, which in turn affects nutrient leaching and stream water quality. We have formulated a hypothesis that nutrient leaching varies depending on the tree species composition owing to the properties of surface soil chemistry characterized by the tree species composition. To test this hypothesis, we have collected soil water samples below the root zone in Japanese cedar plantations (CF) and natural forests (NF) and compared nutrient leaching. We analyzed major ion chemical characteristics, net N mineralization, and net nitrification in the surface soil (A layer) to determine possible causes for differences in nutrient leaching. Our results revealed that calcium (Ca2+) and nitrate (NO3−) concentrations in soil water below the root zone were significantly higher in CF than in NF. Additionally, the Ca2+ and NO3− contents in surface soil were higher in CF than in NF, which may explain the higher concentrations of Ca2+ and NO3− in soil water in CF. In contrast, there was no significant difference in soil net nitrification rates between CF and NF. Correlations between NO3− and Ca2+ concentrations in soil solution suggest that the higher availability of Ca2+ from surface soils in CF could partially account for the higher NO3− leaching from CF. Our study suggests that the properties of surface soil chemistry characterized by the tree species composition are responsible for causing the differences in nutrient leaching. [ABSTRACT FROM AUTHOR]

Transparent conducting aluminum-doped tin oxide (ATO) thin films were prepared on unheated glass substrates by a high-target utilization system (HiTUS). The effect of oxygen flow rates on the structural, optical, and electrical properties of ATO thin films were comprehensively examined. X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM) were utilized to analyze the films' structural properties, x-ray photoemission spectroscopy (XPS) was employed to investigate their surface chemistry, UV–visible transmittance curves were recorded to study their optical properties, and Hall-effect measurements determined their electrical properties. At room temperature, the ATO thin films with 3 wt.% aluminum dopant concentration demonstrated resistivity, carrier concentration, and mobility values of 2.16 Ω m × 10−1 Ω m, 2.32 m−3 × 1014 m−3, and 1.24 m2 V−1 s−1 × 10−3 m2 V−1 s−1, respectively. The sheet resistance of the films was approximately 43 Ω/□, and the average optical transmittance between 400 nm and 800 nm exceeded 80%. These findings strongly suggest that ATO thin films exhibit great potential for use in multiple optoelectronic device applications, making them an attractive option. [ABSTRACT FROM AUTHOR]

Antibiotics are life-saving drugs that fight bacterial infections by killing or inhibiting their reproduction. However, the overuse and misuse of this drug can contaminate water as it can reach the water surface very quickly through various pathways. The consumption of contaminated water may lead to the development of antibiotic resistance, which has been proliferating across the world recently. Azithromycin (AZM), an essential antibiotic drug, has been identified in wastewater and surface water, prompting apprehension regarding its potential environmental and public health consequences. The present investigation assessed the efficacy of photocatalytic degradation of AZM in water samples under sunlight. Exploiting the surface chemistry and high surface area of cellulose nanocrystals (CNC), nanocomposites with high loading (80 wt%) of titanium dioxide (TiO2) nanoparticles on a minimal amount of scaffold (20 wt% CNC) were synthesized and used as catalysts. Maximum removal efficiency of 98.8% was achieved in 5 h at a catalyst dose of 175 mg/L for an AZM solution with 10 mg/L concentration. Synthesized CNC–TiO2 nanocomposites demonstrated superior performance both in terms of high degradation efficiency and lowest catalyst loading per the g of AZM compared the material reported in the literature for the degradation of AZM. In conclusion, CNC–TiO2 nanocomposites are highly effective catalysts for the photocatalytic degradation of AZM. The developed method further ensures the hygiene of water sources and prevents the spread of antibiotic resistance. [ABSTRACT FROM AUTHOR]

The full utilization of two-dimensional transition metal dichalcogenides (2D TMDCs) faces several challenges, among which is realizing uniform material deposition on the 2D surface. Typical strategies to enable material growth lead to a poor interface quality, degrading the 2D TMDC's properties. In this work, a sacrificial, graphene oxide-based seeding layer is used (1) as passivation layer, protecting the underlying 2D TMDC and (2) as nucleation layer, enabling uniform material growth. Graphene is transferred on monolayer WS2, establishing a high-quality van der Waals interface. After transfer, the polymeric residues on graphene are cleaned via a combination of wet- and dry treatments and functionalized via dry UV/O3 oxidation. The rate of graphene oxidation is shown to be substrate dependent, which is explained by UV light-induced ultrafast charge transfer between the graphene and WS2 monolayer. The carbon-oxygen functionalities serve as nucleation sites in a subsequent HfO2 ALD process, achieving more uniform dielectric growth and faster layer closure compared to direct deposition. The graphene-based nucleation- / passivation approach offers adaptability, allowing for tailored surface chemistry to enable any alternative material growth, while maintaining a prefect van der Waals interface. [ABSTRACT FROM AUTHOR]

Superhydrophobic TiO2/BC nanocomposites with reversibly wettability surfaces were fabricated by a simple self-anchoring method on the natural bacterial cellulose (BC) fibers. Under UV light irradiation, the organosilicon-modified TiO2/BC surfaces (M-TiO2/BC) exhibited a surface transition from superhydrophobic (water contact angle of 158° ± 1°, sliding angle of 3°) to superhydrophilic (water contact angle of 10° ± 1°) within only 20 min. Besides pure water, for different kinds of liquid including milk, orange juice, synthetic blood, and seawater, M-TiO2/BC exhibited excellent self-clean performance. The XRD, SEM, TEM, FTIR, TGA, BET and XPS analyses were employed to characterize the morphological features and surface chemistry of the M-TiO2/BC films enclosed by different amounts of TiO2 nanoparticles with the average size of 2.85 nm. Furthermore, the effect of deposition time and Ti precursor concentration on the superhydrophobicity was carefully compared and analyzed. Interestingly, the UV light source with the maximal peak at ~ 365 nm (UVA) exhibited better performance of reversible switching than the light source with the maximal peak at ~ 245 nm (UVC). After three successive recycles, the M-TiO2/BC films remained stable for the UV–thermal induced reversible wettability. The simple and self-anchored synthesis of TiO2/BC hierarchical structures is believed to be helpful for the further expansion of multifunctional soft materials. [ABSTRACT FROM AUTHOR]

The growing need to examine the adsorption capabilities of innovative materials in real-world water samples has encouraged a shift from single to multicomponent adsorption systems. In this study, a novel composite, PANI-g-SM was synthesized by covalently grafting a lignocellulosic biomass, Saccharum munja (SM) with polyaniline (PANI). The as-synthesized composite was investigated for the simultaneous adsorption of cationic (Methylene Blue (MB); Crystal Violet (CV)) and anionic dyes (Reactive Red 35 (RR); Fast Green FCF (FG)) from four single components and two binary systems, MB + RR and CV + FG. Further, the effect and interaction of pH (2–11), dosage (0.01–0.04 g/10 mL), and initial concentration (0.0313 to 0.1563 mmol/L) on the elimination of dyes by PANI-g-SM were studied through a novel design of Box-Behnken of Response Surface Methodology (RSM) technique which was found to be highly useful for revealing the chemistry of interfaces in multi-component systems. The extended Langmuir model for the binary system indicated the presence of synergism, as result the maximum monolayer adsorption capacity increased by 44.44%, 645.83%, 67.88%, and 441.07% for MB, RR, CV, and FG dye, respectively. Further, the adsorption process mainly followed a pseudo-second-order kinetic model, and the thermodynamic studies revealed the exothermic nature of adsorption for RR and FG dye while endothermic for MB and CV dye, respectively with Δ G varying from − 1.68 to − 6.12 kJ/mol indicating the spontaneity of the process. Importantly, the efficacy of the composite was evaluated for the treatment of textile industry effluent highlighting its potential as an adsorbent for wastewater treatment. [ABSTRACT FROM AUTHOR]

Titanium (Ti)-based alloys are eye-catching biomaterials extensively utilized in human implants due to their outstanding ability to facilitate cell growth. This research aims to propose a new approach to explore the ultrafast laser processing on alloy surfaces for achieving and regulating the proliferation of biological cells. The study is to directly use the polarization of ultrafast laser irradiation on the surface of chromium-titanium nitride (CrTiN) thin film to fabricate the periodic structures, which can promote cell proliferation. This improvement is accomplished by employing surface patterning and creating nanocrystalline structures. The nanocrystalline layer is treated with laser-induced periodic surface structures (LIPSS), forming subwavelength ripples directly on the surface. The ripples are preferentially formed perpendicular to the direction of laser polarization by controlling the fluence. Through the straightforward technique of ultrafast laser treatment, the wettability transition is contributed to by the combination of LIPSS and modified surface chemistry. It is indicated by the findings that the laser-irradiated CrTiN alloy film exhibits surface ripples and a nanocrystalline phase. This work has the potential to enhance cell proliferation for biomedical engineering applications. [ABSTRACT FROM AUTHOR]

Microbiologically-influenced corrosion (MIC) is a common operational hazard to many industrial processes. The focus of this review lies on microbial corrosion in the maritime industry. Microbial metal attachment and colonization are the critical steps in MIC initiation. We have outlined the crucial factors influencing corrosion caused by microorganism sulfate-reducing bacteria (SRB), where its adherence on the metal surface leads to Direct Electron Transfer (DET)—MIC. This review thus aims to summarize the recent progress and the lacunae in mitigation of MIC. We further highlight the susceptibility of stainless steel grades to SRB pitting corrosion and have included recent developments in understanding the quorum sensing mechanisms in SRB, which governs the proliferation process of the microbial community. There is a paucity of literature on the utilization of anti-quorum sensing molecules against SRB, indicating that the area of study is in its nascent stage of development. Furthermore, microbial adherence to metal is significantly impacted by surface chemistry and topography. Thus, we have reviewed the application of super wettable surfaces such as superhydrophobic, superhydrophilic, and slippery liquid-infused porous surfaces as "anti-corrosion coatings" in preventing adhesion of SRB, providing a potential avenue for the development of practical and feasible solutions in the prevention of MIC. The emerging field of super wettable surfaces holds significant potential for advancing efficient and practical MIC prevention techniques. [ABSTRACT FROM AUTHOR]

Due to the growth of automotive industries, the requirement for engine and structural parts having longer lifetime has been also increased. Transition metal nitrides, especially thin films, attract attention due to their effective mechanical and tribological features. In this study, hierarchal nanostructural coatings (nanocauliflower, nanopyramids and nanoflakes) of zirconium nitride (ZrN) were deposited by reactive magnetron sputtering system on a low-carbon steel plate (LCSP) substrate. The fabricated nanoflake (ZrNNF) coating show promising properties such as higher elastic modulus (335.195 ± 16.75 GPa) and high hardness (33.173 ± 1.65 GPa). It has been assessed how the friction coefficient varies with cycle time. The surface chemistry, structure and hardness of the coatings covering the surface effect wear volume and friction levels. The dominant wear mechanisms were identified using FE-SEM, EDX and XPS analyses. During the process of wear, zirconium oxynitrides (O-Zr-N) were formed in the ZrNNF coating, which can have a positive effect on automotive applications. The wear volume of the ZrN nanoflake hard coating was lower compared to pristine samples. The nanostructures such as nanocauliflower, nanopyramids and nanoflakes can be a plausible explanation for the improved tribological performance. [ABSTRACT FROM AUTHOR]

Hydrophobicity plays a pivotal role in mitigating surface fouling, corrosion, and icing in critical marine and aerospace environments. By employing ultrafast laser texturing, the characteristic properties of a material's surface can be modified. This work investigates the potential of an advanced ultrafast laser texturing manufacturing process to enhance the hydrophobicity of aluminium alloy 7075. The surface properties were characterized using goniometry, 3D profilometry, SEM, and XPS analysis. The findings from this study show that the laser process parameters play a crucial role in the manufacturing of the required surface structures. Numerical optimization with response surface optimization was conducted to maximize the contact angle on these surfaces. The maximum water contact angle achieved was 142º, with an average height roughness (Sa) of 0.87 ± 0.075 µm, maximum height roughness (Sz) of 19.4 ± 2.12 µm, and texture aspect ratio of 0.042. This sample was manufactured with the process parameters of 3W laser power, 0.08 mm hatch distance, and a 3 mm/s scan speed. This study highlights the importance of laser process parameters in the manufacturing of the required surface structures and presents a parametric modeling approach that can be used to optimize the laser process parameters to obtain a specific surface morphology and hydrophobicity. [ABSTRACT FROM AUTHOR]

This study investigates the durability of silicone rubber compounds employed as sealants in polyelectrolyte membrane fuel cells (PEMFCs), focusing on their cross-linking network topology. Compounds are formulated with varying curing systems, including hydrosilylation and peroxide curing, and different filler content, sizes, and surface chemistries. The findings indicate that compounds cured by hydrosilylation exhibit enhanced hardness and storage modulus, along with reduced compression set and damp factor, in comparison to those cured by peroxide. These superior mechanical properties are attributed to a homogeneous cross-linking network topology with fewer "in-elastic chains." Furthermore, strong interactions between silicone rubber and nanosilica contribute to network topology by establishing physical cross-links. Remarkably, these interactions intensify during chemical aging in a simulated PEMFC environment, resulting in increased hardness and reduced compression set. In contrast, compounds containing hydrophobic surface-modified nanosilica experience severe mechanical deterioration due to higher chain degradation during chemical aging. In summary, this study highlights the critical role of cross-linking network topology and interactions with nanosilica in determining the durability of silicone rubber compounds for PEMFC applications. [ABSTRACT FROM AUTHOR]

The issue of cigarette butts is an environmental crisis that has affected the world. Despite their small size, CBs are one of the most common types of solid waste found in public places, particularly in coastal areas. The aim of this study was to investigate the adsorption behavior of microfibers obtained from cigarette butts on tetracycline before and after aging. 1 g of CBs was added to 50 mL of distilled water and stirred at 220 rpm for 2 h, then filtered through Whatman 0.45 µm filter paper, and the resulting MFs were dried at 60 °C for 24 h. To simulate aging, the MFs were subjected to an ultrasonic treatment at a frequency of 80 Hz and a power of 70 W for 4 h. The adsorption behavior of aged and fresh MFs was investigated using solutions containing TTC in the range of 5–20 mg/L. This study showed that ultrasonically aged MFs had a greater tendency to adsorb TTC than fresh MFs due to an increased surface area and changes in surface chemistry. It can be concluded that as the age of MFs increases, they adsorb more concentration of pollutants. This can lead to increased contamination of MFs in the presence of contaminants. [ABSTRACT FROM AUTHOR]

Highlights: A low-strength-centrifugation-assisted approach for rapid gelation of Ti3C2Tx MXene with a very low dispersion concentration into multifunctional 3D architectures is developed. On the basis of pH-induced surface termination changes, the MXene gels exhibit reconfigurable internal structures and tunable rheological, tribological, electrochemical, infrared-emissive and photothermal-conversion properties. By adopting a gel with optimized pH value, high lubrication, remarkable capacitance, long-term capacitance retention and high-precision screen- or extrusion-printing into high-resolution anticounterfeiting patterns can be achieved. Due to the mutual repulsion between their hydrophilic surface terminations and the high surface energy facilitating their random restacking, 2D MXene nanosheets usually cannot self-assemble into 3D macroscopic gels with various applications in the absence of proper linking agents. In this work, a rapid spontaneous gelation of Ti3C2Tx MXene with a very low dispersion concentration of 0.5 mg mL−1 into multifunctional architectures under moderate centrifugation is illustrated. The as-prepared MXene gels exhibit reconfigurable internal structures and tunable rheological, tribological, electrochemical, infrared-emissive and photothermal-conversion properties based on the pH-induced changes in the surface chemistry of Ti3C2Tx nanosheets. By adopting a gel with optimized pH value, high lubrication, exceptional specific capacitances (~ 635 and ~ 408 F g−1 at 5 and 100 mV s−1, respectively), long-term capacitance retention (~ 96.7% after 10,000 cycles) and high-precision screen- or extrusion-printing into different high-resolution anticounterfeiting patterns can be achieved, thus displaying extensive potential applications in the fields of semi-solid lubrication, controllable devices, supercapacitors, information encryption and infrared camouflaging. [ABSTRACT FROM AUTHOR]