Search Results (6,951)

In the present study, ten type-V natural deep eutectic solvents (NADESs) were synthesized and comprehensively characterized, based on urea as a hydrogen-bond acceptor and three different groups of donors—glycerol, organic carboxylic acids, and carbohydrates. Their physicochemical parameters, spectral characteristics (FTIR), surface tension, and solvatochromic properties were determined using Nile Red, betaine 30, and Kamlet–Taft parameters. The densities of the systems (1.243–1.361 g/cm³) and the high values of molar refraction and polarizability indicate the formation of highly organized hydrogen-bonded networks, with the incorporated carboxyl and hydroxyl groups enhancing the structural compactness of the NADES. Surface tension varied significantly (46.9–80.3 mN/m), defining systems with low, medium, and high polarity. Solvatochromic analysis revealed high E_NR, E_T(30), and E_T^N values, positioning all NADES as highly polar media, comparable or close to water, but with distinguishable H-bond donating/accepting ability depending on the third component. The normalized Kamlet–Taft parameters show that the NADES cover a broad solvent spectrum—from highly H-bond accepting to strongly H-bond donating or dipolar systems—highlighting the potential for fine-tuning the solvent according to target applications. The obtained results highlight the applicability of these NADESs as green, tunable media for the extraction and solvation of bioactive compounds. Full article

To achieve precise in-hand manipulation and feedback control using soft robotic fingers, it is essential to accurately measure their deformable structures. In particular, estimating the three-dimensional shape of a soft finger under contact conditions is a critical challenge, as the deformation state directly affects manipulation reliability. However, nonlinear deformations and occlusions arising from interactions with external objects make the estimation difficult. To address these issues, we propose a soft finger structure that integrates small magnets and magnetic sensors inside the body, enabling the acquisition of rich deformation information in both contact and non-contact states. The design provides a 15-dimensional time-series signal composed of motor angles, motor currents, and magnetic sensor outputs as inputs for shape estimation. Built on the sensing signals, we propose a mode-selection-based learning approach that outputs multiple candidate shapes and selects the correct one. The proposed network predicts the three-dimensional positions of four external markers attached to the finger, which serve as a proxy representation of the finger’s shape. The network is trained in a supervised manner using ground-truth marker positions measured by a motion capture system. The experimental results under both contact and non-contact conditions demonstrate that the proposed method achieves an average estimation error of approximately 4 mm, outperforming conventional one-shot regression models that output coordinates directly. The integration of magnetic sensing is demonstrated to be able to enable accurate recognition of contact states and significantly improve stability in shape estimation. Full article

In the medical industry, strong disinfectants are used to limit bacterial proliferation on the surface of polymer-based materials; however, they may leave hazardous residues. To prevent potential harm to human health, safer disinfection substitutes are continuously searched. This study evaluates the effect of a natural biocidal modifier, geraniol (GR), on the properties of flax-reinforced biocomposites. Biocomposites containing 80 wt% polylactide (PLA) and 20 wt% flax fibres were prepared, and fibres were modified with 1%, 5%, 10%, or 20% GR. The materials were examined using tensile tests, dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), thermogravimetry (TG), contact angle measurements, scanning electron microscopy (SEM), and antibacterial activity tests. The incorporation of flax fibres increased the storage modulus from 2730 MPa (PLA) to 3447 MPa, while GR-modified fibres further enhanced stiffness up to 3769 MPa for the 20% GR sample. Strong antibacterial activity against Escherichia coli and Staphylococcus aureus was achieved in biocomposites containing ≥10% GR, with R = 5 and R ≥ 6, respectively. Surface hydrophobicity also improved progressively, and a water contact angle of 92° was obtained at 20% GR. These results demonstrate that geraniol-modified flax fibres effectively impart antibacterial activity and hydrophobicity to PLA biocomposites, indicating their potential for use in sustainable packaging applications and materials for the medical sector. Full article

In this work, a multifunctional surface engineering strategy was developed to impart both flame-retardant and hydrophobic properties to cotton fabrics. In the first stage, cellulose fibers were modified with poly(methylvinyl)siloxane containing trimethoxysilyl groups, 2,4,6,8-tetramethyl-divinyl-bis(trimethoxysilylpropyltioethyl)cyclotetrasiloxane, or tetrakis(vinyldimethylsiloxy)tetrakis(trimethoxysilylpropyltioethyl)octasilsesquioxane (POSS). All modifiers contained alkoxysilyl groups capable of forming covalent bonds with cellulose hydroxyl groups. The modification was performed using a dip-coating process followed by thermal curing. This procedure enabled the formation of Si-O-C linkages and the generation of a reactive organosilicon layer on the cotton surface. In the second step, O,O′-diethyl dithiophosphate was grafted directly onto the vinyl-functionalized fabrics via a thiol-ene click reaction. This process resulted in the formation of a phosphorus- and sulfur-containing protective layer anchored within the siloxane-based network. The obtained hybrid coatings were characterized using Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and SEM-EDS. These analyses confirmed the presence and uniform distribution of the modifiers on the fiber surface. Microscale combustion calorimetry demonstrated a substantial reduction in the heat release rate. Thermogravimetric analysis (TG/DTG) revealed increased char formation and altered thermal degradation pathways. The limiting oxygen index (LOI) increased for all modified fabrics, confirming enhanced flame resistance. Water contact angle measurements showed values above 130°, indicating effective hydrophobicity. As a result, multifunctional textile surfaces were obtained. In addition, the modified fabrics exhibited partial durability toward laundering and retained measurable flame-retardant and hydrophobic performance after repeated washing cycles. Full article

Driven by environmental concerns, the packaging industry is shifting toward high-performance and bio-based coating alternatives. In this research, poly(methylmethacrylate) (PMMA) and modified cellulose nanocrystal (m-CNC) were employed as reinforcing agents to develop sustainable poly (lactic acid)-based coatings for packaging applications. Various formulations, influenced by polymer matrix blends and m-CNC loadings (1–5%), were prepared using solvent and applied as protective coating on cardboard paper substrates. The grammage of polymeric coatings (CG) on paper was also investigated using various wet film thicknesses (i.e., 150–250 μm). Accordingly, key parameters including water contact angle, thermal behavior, mechanical performances and barrier properties were systematically evaluated to assess the effectiveness of the developed nanocomposite coatings. As a result, nonylphenol ethoxylate surfactant-modified cellulose nanocrystals exhibited good dispersion and stable suspension in chloroform for one hour, improving compatibility and interaction of polymer–CNC fillers. The water vapor permeability (WVP) of PLA-coated papers was significantly reduced by blending PMMA and increasing the content of m-CNC nanofillers. Furthermore, CNC incorporation enhanced the oil resistance of PLA/PMMA-coated cardboard. Pronounced improvements in barrier properties were observed for paper substrates coated with dry coat weight or CG of ~20 g/m² (corresponding to 250 μm wet film thickness). Coatings based on blended polymer—particularly those reinforced with nanofillers—markedly enhanced the hydrophobicity of the cardboard papers. SEM-microscopy confirmed the structural integrity and morphology of the nanocomposite coatings. Regarding mechanical properties, the upgraded nanocomposite copolymer (PLA-75%/PMMA-25%/m-CNC3%) exhibited the highest bending test and tensile strength, achieved on coated papers and free-standing polymeric films, respectively. Based on DSC analysis, the thermal characteristics of the PLA matrix were influenced to some extent by the presence of PMMA and m-CNC. Overall, PLA/PMMA blends with an optimal amount of CNC nanofillers offer promising sustainable coatings for the packaging applications. Full article

New nano-biomaterials for specific dentistry applications have been developed thanks to contributions from materials science. The present work aims to characterize the physicochemical properties of a composite nanomaterial scaffold in block form for maxillofacial bone regeneration applications. The scaffold was composed of block-shaped elements and consisted of a mixture of nano-hydroxyapatite, β-tricalcium phosphate, and type I collagen of bovine origin. Collagen I molecule is biodegradable, biocompatible, easily available, and a natural bone matrix component. The biomaterial was analyzed using a range of methods, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), chemical composition microanalysis, and X-Ray diffractometry (XRD). The wettability was measured. This was carried out by measuring the contact angle of a 0.9% NaCl solution on the surface. Differential scanning calorimetry (DSC) was used to measure the phase transformation temperatures. In the SEM and TEM analyses, it was possible to identify the layers of the materials and, with microanalysis, quantify their chemical composition. The XRD spectra showed the presence of nano-hydroxyapatite and ß-TCP. Wettability testing revealed that the material is highly hydrophilic, and BM-MSC culture analyses demonstrated that the biomaterial can promotes cell adhesion and interaction. The higher wettability is due to the higher density of the porous material observed in the SEM analysis. The results of the DSC testing showed that the sample analyzed undergoes endothermic transitions and transformation between 25 and 150 °C. The first phase transformation during heating occurs at 61.1 °C, which is above body temperature. The findings demonstrated that the composite was devoid of any contamination arising from manufacturing processes. It can be concluded that the n-HA/β-TCP and type 1 collagen are free of manufacturing contaminants. They also have high wettability, which increases the spreading of body fluids on the biomaterial’s surface and its interactions with cells and proteins. This makes them suitable for clinical application. Full article

Background/Objectives: Empagliflozin (EMPA) was repurposed for Alzheimer’s disease (AD) treatment via buccal delivery, exploiting novel nanofibers (NFs) integrating chitosan (Cs), silk fibroin (Fb), and poly(lactic acid) (PLA). Methods: EMPA-loaded Cs/Fb/PLA NFs were electrospun in different formulations to optimize the formulation parameters. The optimized formulation was then investigated for its enhanced in vivo effect. Results: Optimized nanofiber diameters ranged from 459 ± 173 to 668 ± 148 nm, possessing bead-free morphology confirmed by SEM and satisfactory mechanical properties. EMPA was successfully well-dispersed in the polymer matrix as evidenced by FTIR, XRD, and drug content. The optimized NFs displayed a hydrophilic surface (contact angle < 90°), and biphasic drug release with sustained EMPA liberation (84.98% over 24 h). In vivo, buccal EMPA-Cs/Fb/PLA NFs in an AlCl₃-induced AD rat model significantly reduced brain-amyloid-β, phosphorylated tau, IL-1β, and AGER expression by 2.88-, 2.64-, 2.87-, and 2.50-fold, respectively, compared to positive controls, and improved locomotor activity (1.86-fold) and cognitive performance (T-maze) (4.17-fold). Compared to pure EMPA, the nanofiber formulation achieved further reductions in amyloid-β (1.78-fold), p-tau (1.42-fold), IL-1β (1.89-fold), and AGER (1.38-fold), with efficacy comparable to memantine. Histopathological examination revealed preservation of the hippocampal neuronal structure. Conclusions: The findings suggest EMPA-loaded Cs/Fb/PLA NFs as a promising non-invasive, sustained-release buccal delivery platform for AD therapy, offering multimodal neuroprotection through modulation of the Aβ–AGER–p-tau axis. Full article

Bacterial biosurfactants have potential applications in green cleaning due to their environmental friendliness. Among all isolated bacterial strains in this study, strain N33 exhibited the most potent oil-displacing activity and was identified as Pseudomonas aeruginosa. Its biosurfactant yield was approximately 550 mg/L, and structural characterization revealed it to be a glycolipid-type biosurfactant. The oil-displacing ring diameters of the biosurfactant against vegetable oil, paraffin oil, and crude oil reached 6.3 ± 0.3 cm, 5.8 ± 0.2 cm, and 3.8 ± 0.5 cm, respectively. Its critical micelle concentration (CMC) was determined to be 150 mg/L, with a corresponding surface tension of 39.55 mN/m. Notably, this bacterial biosurfactant significantly improved interfacial wettability, reducing the contact angles of vegetable oil, paraffin oil, and crude oil on oil-wetted glass slides from 93.0°, 99.0°, and 98.8° to 10.0°, 15.0°, and 19.0°, respectively. The emulsification efficiency for the three oils was 80%, 57%, and 10%, respectively. Furthermore, capillary oil removal assays verified that the biosurfactant could efficiently strip oil films from the inner walls of capillaries. These findings demonstrate that the biosurfactant produced by P. aeruginosa strain N33 possesses considerable oil-removal efficacy, thereby providing a novel candidate for the research, development, and application of green detergents. Full article

Polylactic acid (PLA) films were directly fluorinated using fluorine gas at room temperature under varying conditions: fluorine concentrations of 190–760 Torr and reaction times of 10–60 min. Some of the fluorinated samples were subsequently dried at 70 °C for 2 d. Fourier-transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) analyses verified the successful introduction of fluorine and the formation of -CF_x and C=OF groups on the PLA surface after fluorination. The fluorination level initially increased with increasing reaction time or fluorine concentration but then decreased because of the formation and escape of CF₄ gasification. Drying further reduced the surface fluorine content. Both fluorination and drying increased the glass transition temperature of PLA, which was attributed to the increase in surface polarity and crosslinking density of the polymer. Fluorination significantly improved the surface hydrophilicity of PLA, with the water contact angle decreasing from 64.09°to 18.75°. This was due to the formation of a rough, porous surface caused by the introduction of polar fluorine atoms, as observed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). However, drying the fluorinated samples increased the water contact angle to 91.46°, resulting in hydrophobicity owing to increased surface crosslinking. This study demonstrates a simple and effective method for tuning the hydrophilic–hydrophobic properties of PLA surfaces using direct fluorination and thermal treatment. Full article

In this study, cationic surfactant cetyltrimethylammonium bromide (CTAB) and anionic surfactant sodium bis(2-ethylhexyl) sulfosuccinate (AOT) are employed to systematically investigate surface and wetting properties on hydrophobic surfaces, specifically in mixed solvents composed of ethylene glycol (EG) and water at 298.15 K. By varying the concentration of each surfactant within the EG–water mixture, both surface tension and contact angle measurements are performed to elucidate how surfactant type and solvent composition influence interfacial behavior and wettability. PTFE and wax surfaces were chosen as model hydrophobic surfaces. Surface tension measurements obtained in pure water and in water–EG mixtures containing 5, 10, and 20 volume percentage EG reveal a consistent decrease in the premicellar slope (${\displaystyle \frac{d\gamma }{d\mathit{log}C}}$) with increasing EG content. This reduction reflects weakened hydrophobic interactions and less effective surfactant adsorption at the air–solution interface. The corresponding decline in maximum surface excess (${\Gamma }_{max}$) and increase in minimum area per molecule ($A_{min}$) confirm looser interfacial packing due to EG participation in the solvation layer. Plots of adhesion tension (A_T) versus surface tension (γ) exhibit negative slopes, consistent with reduced solid–liquid interfacial tension (${\Gamma }_{LG}$) and greater redistribution of surfactant molecules toward the solid–liquid interface. AOT shows stronger sensitivity to EG compared to CTAB, reflecting structural headgroup-specific adsorption behavior. Work of adhesion (W_A) measurements demonstrate enhanced wettability at higher EG concentrations, highlighting the cooperative impact of co-solvent environment and surfactant type on wetting phenomena. Full article

Metal materials are widely used in power grid infrastructure, but they are prone to metal corrosion due to long-term exposure to various environmental conditions, resulting in significant losses. The existing superhydrophobic coatings have good anti-corrosion performance, but poor wear resistance. Therefore, it is extremely important to improve the wear resistance of superhydrophobic coatings. In this study, a kind of fluorine-modified SiO₂ particle was prepared with pentafluorooctyltrimethoxysilane (FAS-13) as the low surface energy modifier, following the fabrication of a superhydrophobic coating on metal substrate via a PDMS-doped spray deposition method to reinforcement wear resistance property. XPS, FT-IR and Raman spectra confirmed the successful introduction of FAS-13 on SiO₂ particles, as evidenced by the characteristic fluorine-related peaks. TGA revealed that the fluorine modified SiO₂ (F-SiO₂) particles exhibited excellent thermal stability, with an initial decomposition temperature of 354 °C. From the perspective of surface morphology, the relevant data indicated a peak-to-valley height difference of only 88.7 nm, with Rq of 11.9 nm and Ra of 8.86 nm. And it also exhibited outstanding superhydrophobic property with contact angle (CA) of 164.44°/159.48°, demonstrating remarkable self-cleaning performance. And it still maintained CA of over 150° even after cyclic abrasion of 3000 cm with 800 grit sandpaper under a 100 g load, showing exceptional wear resistance. In addition, it was revealed that the coated electrode retained a high impedance value of 8.53 × 10⁸ Ω·cm² at 0.1 Hz after 480 h of immersion in 5 wt% NaCl solution, with the CPE exponent remaining close to unity (from 1.00 to 0.97), highlighting its superior anti-corrosion performance and broad application prospects for metal corrosion prevention. Full article

Horizontal wells combined with multi-stage fracturing are key techniques for extracting tight oil formation. However, due to the ultra-low permeability and porosity of reservoirs, energy depletion occurs rapidly, necessitating external supplements to sustain production. During the hydraulic fracturing process, large volumes of fracturing fluid are injected into reservoirs, increasing its pressure to a certain extent. However, due to the oil-wet nature of the formation, the fracturing fluid cannot penetrate the rock, failing to enhance oil recovery during the shut-in period. Surfactant-based nanofluids have been introduced as fracturing fluid additives to reverse rock wettability, thereby boosting imbibition-driven recovery. Although the imbibition has been studied to inspire the tight oil recovery, few studies have demonstrated the imbibition in enhanced fossil hydrogen energy, which further promotes the imbibition recovery. In this paper, complex nanofluid dispersions (CND) have been proved to enhance the tight reservoir pressure. Through contact angle and imbibition experiments, it is shown that CND can transform oil-wet rock to water-wet, reduce the adhesion of oil, and improve the ultimate oil recovery through the imbibition effect. Then, core flow testing experiments were conducted to show CND can decrease the flow resistance and improve the swept area of the injected fluid. In the end, pressure transmission tests were conducted to show CND can enhance the formation energy and production after fracturing. Results demonstrate that CND enables the fracturing fluid to travel further away from the hydraulic fractures, thus decreasing the depletion of tight formation pressure and maintaining a higher oil production rate. Results help optimize the design of the hydraulic fracturing of tight offshore reservoirs. Full article

This paper introduces a constraint-aware optimization framework for designing spherical multi-camera rigs that achieve complete panorama coverage while adhering to physical and field-of-view limitations. The approach assesses coverage using solid-angle geometry and calculates the sampling density in pixels per steradian, providing a measurable, traceable basis for panoramic optical measurement. By viewing panoramic imaging as a directional measurement challenge, the framework aligns with principles of optical metrology and guarantees uniform, non-contact optical sensing around the sphere. The optimization process includes capsule-based collision constraints, soft coverage losses, and field-of-view intersection modeling to produce physically feasible rig configurations. Experiments show that the optimized rigs provide improved coverage uniformity and less redundancy, with validation through Blender-generated synthetic panoramas confirming the practical performance of the designed optical systems. The proposed approach allows for systematic, measurement-driven design of spherical camera rigs for use in immersive imaging, robotic perception, and structural inspection. Full article

This article presents the results of the first stage of a four-phase research program aimed at the comprehensive evaluation and enhancement in the functional properties of polymeric packaging films intended for active food packaging systems through their modification with detonative nanodiamonds (DND). Stage I involved the characterization of ten commercial single- and multi-layer films without the addition of DND, differing in structure, base material, thickness, and intended application. The scope of analyses included the assessment of biological and physicochemical properties relevant to food contact, such as surface wettability (contact angle), thermal stability (TGA, DSC), antimicrobial and antiviral activity (using E. coli and M. luteus models), as well as the quality of thermal seals examined by SEM. Biological activity was assessed in accordance with ISO 22196:2011. The results revealed significant differences among the tested samples in terms of microbiological resistance, surface properties, and thermal stability. Films with printed layers exhibited the highest antimicrobial activity, whereas some polypropylene samples showed no activity at all or even supported microbial survival. Cross-sectional analysis of welds indicated that the quality of thermal seals is strongly dependent on the surface properties of the base material. The obtained results provide a reference point for subsequent research stages, in which DND-modified films will be analyzed regarding their effects on mechanical, barrier, and biological properties. Preliminary trials with nanodiamonds confirmed their high application potential and the possibility of producing films with increased hydrophilicity or hydrophobicity and durability, which are crucial for the development of modern active food packaging systems. Full article

The wettability differences among macroscopic coal lithotypes constitute a critical issue requiring in-depth investigation in the development of low-rank coalbed methane. To elucidate the impact of wettability variation on methane adsorption/desorption, this study employed vitrain and durain samples from Jurassic low-rank coals in the Huanglong Coalfield. We analyzed changes in adsorption/desorption characteristics before and after wettability modification and conducted coal seam desorption experiments under simulated extraction conditions to explore the influence of wettability on methane adsorption/desorption behavior. The results indicate that vitrain exhibits greater full-scale pore volume (0.04073–0.07975 cm³/g) and specific surface area (132.302–170.919 m²/g) compared to durain (0.03646–0.05187 cm³/g and 114.572–122.827 m²/g, respectively). The coal–water interface contact angles of the low-rank coals are below 90°, indicating a weakly hydrophilic nature. Both cationic (CTAC) and zwitterionic (BS-12) surfactants effectively improved coal wettability. Following wettability modification, the maximum reduction in saturated adsorption capacity reached 48.24%, while the maximum increases in desorption ratio and recovery efficiency were 35.56% and 24.39%, respectively. Durain, due to its stronger inherent hydrophilicity, exhibited greater changes than vitrain. Under simulated extraction conditions, the combined effects of pore structure and wettability differences between the lithotypes led to preferential methane production along the vitrain–durain interfaces. Full article