Poly(ethylene terephthalate) (PET) is a widely used commodity polymer owing to its low cost, excellent mechanical properties, and high processability. Chemical modification of PET surfaces to impart specific functionalities represents an effective strategy for transforming PET into high-value-added materials without altering its bulk properties. In this study, we investigated the surface functionalization of PET substrates using surface-initiated atom transfer radical polymerization (SI-ATRP). ATRP initiation sites were introduced onto PET surfaces through mild surface hydrolysis followed by polyethyleneimine coating. To further enhance the grafting density, an inimer-based strategy was employed, in which a bifunctional monomer containing both a polymerizable group and a latent initiation site was used to form hyperbranched polymer structures on the PET surface, thereby amplifying the number of active initiation sites. Using these modified PET substrates, SI-ATRP of functional methacrylate monomers was successfully carried out. Grafting of poly(2,2,2-trifluoroethyl methacrylate) imparted highly hydrophobic surface properties, yielding water contact angles above 120°, whereas grafting of poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) produced hydrophilic surfaces with contact angles below 20°. Surface characterization by X-ray photoelectron spectroscopy confirmed successful graft polymerization and effective surface coverage. While the macroscopic wettability was primarily governed by the chemical nature of the grafted polymers, the inimer-based initiation-site amplification significantly enhanced the surface electrostatic properties of the polycationic polymer–grafted surfaces, increasing the ζ-potential from approximately +20 mV to over +100 mV. Antibacterial tests using Escherichia coli K-12 as a model bacterium demonstrated that PET substrates grafted with poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) exhibited clear contact-active antibacterial activity, achieving up to 2-log reduction in viable bacterial counts after 3 h of contact incubation. These results highlight the importance of molecular-level control of grafting architecture and surface electrostatic properties in the design of functional antibacterial PET surfaces.

While advanced imaging techniques and ordered porous materials like MOFs have gained prominence, gas sorption remains the indispensable tool for characterizing the multiscale heterogeneity of industrially important disordered solids, such as catalysts and shales. This review examines recent developments in gas sorption methodologies specifically tailored for rigid, disordered porous media. We discuss experimental advances, including the choice of adsorbate and the utility of the overcondensation method for probing macroporosity and ensuring saturation. Furthermore, we critically evaluate theoretical approaches for determining pore size distributions (PSDs), contrasting classical methods with Density Functional Theory (DFT) and Grand Canonical Monte Carlo (GCMC) simulations. Special emphasis is placed on the impact of pore-to-pore cooperative effects, such as advanced condensation, cavitation, and pore-blocking, on the interpretation of sorption isotherms. We highlight how complementary techniques, including integrated mercury porosimetry, NMR, and computerized X-ray tomography (CXT), are essential for deconvolving these complex network effects and validating void space descriptors. We conclude that, while “brute force” molecular simulations on image-based reconstructions are progressing, “minimalist” pore network models, which incorporate cooperative mechanisms, currently offer the most empirically adequate approach. Ultimately, gas sorption remains unique in its ability to statistically characterize void spaces from Angstroms to millimeters in a single experiment.

Quaternary Ni-Zn-Mg-Al metallic mixed oxide (MMO) catalysts were synthesized by co-precipitation from layered double hydroxide precursors. The effect of varying Zn content on physicochemical properties and catalytic performance was evaluated. Mg-Al and ternary Ni-Mg-Al and Zn-Mg-Al catalysts were synthetized for comparative purposes. XRD, N2 sorption, MP-AES, CO2-TPD, NH3-TPD, SEM, and EDS characterized the materials’ physicochemical properties. The tested reaction was the transesterification between glycerol and dimethyl carbonate to obtain glycerol carbonate to improve the biodiesel industry. The catalyst containing both Ni and Zn showed the highest glycerol conversion among the evaluated materials. This was related to the increased number and strength of surface basic and acid active sites. Specifically, a high density of strong basic sites and acid ones in the quaternary catalysts was required for the reaction mechanism. The catalyst with 20 at% of Zn (MMO-Ni15Zn20) achieved the highest glycerol carbonate yield (89.6%) under mild reaction conditions and was solvent-free. MMO-Ni15Zn20 catalytic performance was associated with its high total basicity and predominance of strong basic sites and a moderate amount of acid sites. The differences observed between catalytic performances suggest that these results depend on the influence of structural, textural, acid, and basic properties. Reuse tests of the MMO-Ni15Zn20 catalyst showed moderate stability, with a progressive decrease in activity due to the loss of strong basic sites and the formation of agglomerated regions. Nevertheless, MMO-Ni15Zn20 maintained a GC selectivity of 100% in the successive cycles.

The ability to precisely control the electronic bandgap is crucial for tailoring two-dimensional (2D) materials for optoelectronic applications. In this work, we systematically investigate the electronic structure of 2D tin monoxide (SnO) across various layer thicknesses (monolayer to tetralayer) and crystallographic symmetries using first-principles calculations. Our results reveal a strong dependence of the bandgap on the number of layers, which decreases dramatically from 3.94 eV in the monolayer to nearly metallic in the tetralayer. Furthermore, different space group symmetries are found to significantly influence the bandgap, providing an additional degree of freedom for property tuning. This bandgap engineering is quantitatively linked to enhanced interlayer electronic coupling, as evidenced by a progressive increase in interlayer charge transfer with layer count. Our findings establish a clear structure–property relationship and offer practical guidance for designing SnO-based devices in flexible electronics and tunable optoelectronics.

Resistance spot welding of aluminum alloys causes the electrode materials to degrade rapidly. This is due to diffusion processes occurring between the sheet materials and the copper electrodes at process temperatures of up to 600 °C. This significantly limits the electrode life, resulting in less than 60 weld cycles before the joint quality becomes insufficient. Thin-film diffusion barriers can increase electrode life and improve joint quality. This article describes the generation of barrier layers of nickel and tungsten using physical vapor deposition. These layers directly influence the welding process by altering the electrical resistance and friction coefficients in the contact area. Nanoindentation is used to determine the specific properties of the barrier layers within the 2.5–3 µm layer thickness range. Hardness and modulus of elasticity are determined by indentation tests. Scratch tests determine the friction coefficients and adhesion strength of the coating against plastic deformation. Nanoindentation is also used to investigate the degradation process of the electrode base material and barrier layers. This reveals which damage mechanisms occur with uncoated electrodes and demonstrates how thin-film diffusion barrier coatings can prevent aluminum diffusion.

A detailed understanding of the mechanistic role of solid surface microstructures in modulating capillary forces and liquid transport in liquid bridge systems is crucial, for liquid bridges between rough surfaces are omnipresent in nature and various industries. In this work, Gibbs free energy expression was derived for a liquid bridge system confined between a smooth surface and a microstructured surface, based on the principle of minimum thermodynamic potential. Furthermore, by analyzing the energy conversion during spacing variation between the two solid surfaces, an analytical expression for the capillary force of the liquid bridge was derived that incorporates the geometric parameters of the microstructures and the contact angle. Finally, numerical simulations were performed using the Fluent UDFs (User-Defined Functions) to validate the proposed capillary force model. The simulation results validated the analytical expression and revealed the influence of the microstructures on the force distribution on the upper and lower surfaces of the liquid bridge, and on the droplet transport performance.

Oily wastewater is a critical environmental concern, and the high costs and fouling of conventional membranes drive the search for low-cost, efficient alternatives. This study evaluates surface-modified quartz particles for oil–water separation, focusing on hydrophilic and hydrophobic coatings. Quartz samples underwent washing, hydrophobic coating, and hydrophilic coating, with morphological and elemental changes assessed using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDS). Oil and grease (O&G) content was determined via the EPA 1664 method under high-solids conditions. The untreated oil–water mixture contained 142,955.9 mg/L O&G. Hydrophilic-coated quartz achieved the greatest reduction, producing water with only 751.3 mg/L O&G, indicating excellent oil rejection and water selectivity. Washed quartz performed similarly at 837.1 mg/L. Hydrophobic-coated quartz, while yielding higher residual oil in water (64,198.9 mg/L), demonstrated strong oil affinity, making it more suitable for oil recovery applications. Raw quartz, tested without heavy oil loading, showed a baseline of 13.4 mg/L. These results confirm that surface engineering of quartz enables tunable separation properties, where hydrophilic surfaces favor water purification and hydrophobic surfaces enhance oil capture. The findings provide a pathway for scalable, cost-effective, and application-specific oily wastewater treatment solutions.

Wood and bamboo products with log-term carbon storage, less energy consumption, and CO2 emission face the challenge of fungal infection. Their antifungal property can be enhanced by Cu-based nanoparticles. Herein, Cu2O-coated Cu (Cu2O@Cu) aggregates were grown in situ on the surface of pine wood (PW), beech wood (BW), oak wood (OW), and bamboo via vacuum impregnation. Morphology, crystalline structure, elemental ratio, and chemical state of Cu2O@Cu and Cu2O@Cu-loaded specimens were characterized. Uniformly distributed agglomerates composed of Cu2O@Cu exhibited an average size of 2 μm (Cu2O@Cu-loaded PW and Cu2O@Cu-loaded BW) and several hundred nanometers (Cu2O@Cu-loaded OW and Cu2O@Cu-loaded bamboo) on the surfaces. A strong mold resistance for Aspergillus niger was achieved after cultivating Cu2O@Cu-loaded specimens for 28 days. Infection values were grade 0 for Cu2O@Cu-loaded PW and grade 1 for Cu2O@Cu-loaded BW, Cu2O@Cu-loaded OW, and Cu2O@Cu-loaded bamboo (p < 0.05), which were significantly better than those of pristine specimens (grade 2 for PW and grade 4 for BW, OW and bamboo). A low leaching rate of 5.23–7.81% with three repetitions presented a monotonically positive relation with the loading atomic content of Cu (12.6–27.1 at. %), demonstrating an excellent stability of Cu2O@Cu-loaded specimens. This study highlighted the potential of Cu-based preservatives in the field of wood and bamboo preservation.

Adhesion of cell membranes is relevant to many biological processes and arises from the specific binding of membrane-anchored receptor proteins to their ligands present in the apposing membrane. Here, we employ a statistical–mechanical model and perform Monte Carlo simulations to study a system of adhered membranes in which the receptor and ligand proteins exhibit affinity for association with so-called lipid rafts, which are fluctuating nanoscale molecular clusters enriched in sphingolipid and cholesterol. We focus on equilibrium properties of the adhered membranes in the mixed phase, where both the membrane-anchored proteins and lipid rafts are distributed more-or-less uniformly within the membranes. Our simulation results show that lateral attraction between lipid rafts enhances the receptor–ligand binding, affecting the adhesion of the membranes. On the other hand, the receptor–ligand binding causes lipid rafts to be distributed less uniformly within the membranes and, simultaneously, leads to an increased co-localization of the membrane-anchored proteins with lipid rafts. We quantify and discuss all these effects, providing a detailed picture of the complex interplay between the adhesion of the membranes and the lateral distribution of the membrane-anchored proteins and lipid rafts. Our results broaden the understanding of the physical mechanisms that determine the supra-molecular organization of lipid rafts and membrane receptors in cell membranes. This understanding may help to elucidate how lipid rafts function in biological processes such as cell signaling and immune responses.

We present a buffer-pH-modulated electrokinetic concentration strategy in MEMS microchannels that harnesses simple pH shifts to neutralize and charge proteins, reversibly “pausing” them at a planar electric-gate electrode by tuning to their isoelectric point (pI) and mobilizing them with slight pH offsets under an applied field. This synergistic coupling of dynamic pH control and electrode-gated focusing, which requires only buffer composition changes, enables rapid and tunable protein capture and release across diverse channel geometries for lab-on-chip, preparative, and point-of-care diagnostics. Moreover, it dovetails with established MEMS biomedical platforms ranging from diagnostics to drug delivery and microsurgery to gene and cell-manipulation devices. Future work on tailored electrode coatings and optimized channel profiles will further boost selectivity, speed, and integration in sub-100 µm MEMS devices.