Polymer flooding is a well-established chemical enhanced oil recovery (EOR) method, primarily aimed at improving sweep efficiency. However, the interplay between polymer properties and porous media, particularly the influence on permeability reduction, remains poorly understood. In this study, we investigate how polymer molecular weight, chemistry, and mechanical pre-shearing influence residual resistance factor (RRF) and in situ rheology in Berea sandstone core floods. Post-polymer brine flow exhibits clear non-Darcy behavior, indicating that permeability becomes rate-dependent after polymer adsorption. Application of a Forchheimer-based approach demonstrates that inertial contributions become significant at reservoir-relevant velocities, suggesting enhanced microscopic inertia dissipation associated with interaction between flowing brine and the stationary adsorbed polymer layer. Applying conventional Darcy-based interpretation systematically overestimates RRF under these conditions. RRF increases with polymer molecular weight for polymers with similar bulk viscosities, suggesting that permeability reduction is primarily controlled by effective hydrodynamic size and pore-scale interactions rather than polymer concentration. Mechanical pre-shearing substantially reduces RRF and the non-linear flow contribution, suggesting that laboratory measurements performed on unsheared solutions may overestimate field-scale injectivity impairment. In contrast, an ATBS-containing polymer exhibits relatively low RRF but high apparent viscosity, indicating that alterations in polymer chemistry may override molecular weight as the main factor. The results demonstrate that polymer–surface interactions can induce rate-dependent permeability at reservoir-relevant velocities, and highlight the need for non-Darcy analysis when interpreting polymer core flood experiments for field application.
Robust, lightweight, and thermally insulating building materials, developed according to the In Situ Resource Utilization (ISRU) paradigm, are essential for enabling Moon settlements. With this aim, we have investigated the formulation and characterization of porous geopolymeric materials based on a lunar regolith simulant, focusing on the influence of surfactants and rheology-modifying additives on pore structure and final material performance. As an optimized procedure, a pre-formed TTAB foam was, in fact, incorporated into the geopolymeric precursor slurries to achieve a suitable porosity. Then, the effects of three thickeners (xanthan gum, bentonite, and Actigel-208) were evaluated in view of the possible utilization for the production of building blocks by 3D printing. Observations of the pore structure after the geopolymeric consolidation of the slurries showed predominantly closed-cell networks across all formulations, with a pore morphology strongly dependent on the thickener used. Xanthan gum promoted high porosity but reduced mechanical integrity, whereas bentonite produced denser structures with higher thermal conductivity. Actigel-208 provided the most balanced performance, combining adequate porosity with improved strength. These findings demonstrate the potential of producing thermally insulating, structurally stable solid foams from lunar regolith simulants via a geopolymerization route.
The colloidal particles present in natural soil and groundwater systems possess distinctive properties that enable them to migrate across solid surfaces, thereby exerting a significant influence on the distribution of pollutants. While the attachment of colloidal particles to solid surfaces has been extensively investigated, the mechanisms governing their detachment under varying hydrochemical conditions remain largely unexplored. The common interaction between montmorillonite colloids and solid medium (Al2O3) in soil affects the fate of pollutants such as heavy metals. In our study, Al2O3 was used as solid medium to observe the adsorption and desorption behavior of montmorillonite colloids. It was found that the adsorption capacity of Al2O3 to montmorillonite colloids could reach 4.71 mg g−1 (pH 5.0 and 10 mM NaCl concentration). X-ray photoelectron spectroscopy analysis shows that montmorillonite colloids react with the Al2O3 surface mainly through chemical groups with –O–Si bonds. Desorption experiments show that SDS drives desorption by neutralizing and reversing the surface charge of Al2O3, while CTAB directly modifies montmorillonite colloids and introduces steric hindrance to achieve desorption. These research data contribute to a comprehensive understanding of the migration behavior of montmorillonite colloids on solid phases.
Liposomes are widely recognized as versatile nanocarriers in drug delivery due to their biocompatibility, tunable physicochemical properties, and ability to incorporate both hydrophilic and hydrophobic compounds. In this study, the encapsulation and release of diclofenac, a nonsteroidal anti-inflammatory drug (NSAID), using lecithin-cholesterol liposomes are explored. Encapsulation parameters were first optimized with calcein as a model fluorophore, confirming that cholesterol addition enhances encapsulation efficiency by reducing membrane permeability. Guided by these results, liposomes containing equal weight fractions of lecithin and cholesterol were selected as an optimized formulation, providing calcein and diclofenac encapsulation efficiencies up to approximately 35% while maintaining hydrodynamic diameters below 300 nm with low polydispersity (PdI < 0.2), optimal for intravenous administration and prolonged systemic circulation. Release studies demonstrated sustained drug release over 15 days, with cumulative release exceeding 80%. Weibull modeling yielded theta(infinity) approximate to 1 and beta values up to similar to 1.6 at higher loadings, with beta > 1 indicating a complex, sigmoidal (non-Fickian) release mechanism. These findings support the potential of liposomes as delivery platforms for NSAIDs with solubility and bioavailability limitations.
The acquisition of liquid energy sources and basic chemicals from washing water via Kolbe electrolysis is of great significance for achieving the goal of carbon-neutrality. However, oleophilic products tend to adhere to the platinum (Pt) electrode, which results in a shortened working life for Kolbe electrolysis. To address these issues, a novel method for endowing carbon fiber paper electrodes with underwater superoleophobic properties through simple electrodeposition is reported herein. The underwater superoleophobic electrodes improve the efficiency of the Kolbe electrolysis reaction, as oleophilic products can be easily removed from the electrode surface, thereby exposing more active reaction sites. Importantly, the underwater superoleophobic electrodes have fully demonstrated their capability of excellent electrochemical performance, stability, and durability. This work provides a novel approach for the design of high-performance electrodes in organic electro-catalysis.
Palm oil is a major agricultural commodity and an important economic driver in Asia. However, the sustainability and productivity of this crop are constantly threatened by a range of pathogenic fungi, especially Ganoderma boninense. Therefore, this study aimed to develop an eco-friendly hexaconazole-loaded nanoemulsion (Hexa-NE) for effective and targeted fungicide delivery while reducing environmental and health impacts. The optimized Hexa-NE formulation was evaluated for particle size, polydispersity index (PDI), zeta potential, pH, viscosity, and morphology using Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). Fungicide release, stability, and antifungal activity were conducted to assess the overall efficacy and performance of the formulation. The Hexa-NE exhibited particle size of 105.8 nm, a PDI of 0.358, a zeta potential of -53.53 mV. The formulation remained stable over three months of storage. It also demonstrated favourable physicochemical properties including low viscosity (30.24 mPa & centerdot;s), low surface tension (23.87 mN/m), and suitable pH (6.14) for foliar application. TEM and SEM analyses confirmed spherical droplets and revealed significant hyphal damage to G. boninense. The antifungal test showed a higher inhibition of 97.1% at 0.1 & micro;M of Hexa-NE as compared to hexaconazole solution which only 40% at the same concentration. Release studies exhibited a sustained release of hexaconazole, which may prolonged fungicidal activity. In conclusion, Hexa-NE showed promising laboratory-scale antifungal performance against G. boninense. These findings support its potential for further investigation as a nanoformulated fungicide for future greenhouse and field evaluations.
The dangerous potential of chemical warfare requires immediate development of new materials capable of detecting and efficiently adsorbing the toxic nerve agents VX and Novichok (A-234). The current adsorbents fail to achieve sufficient detection efficiency and specific binding capabilities. Our research, conducted through advanced computational modeling, predicts that carbon nanocones (CNCs) could function as effective molecular traps for these toxic substances. The research combines density functional theory (DFT) with molecular dynamics (MD) and Monte Carlo (MC) simulations to explain the basic principles of molecular trapping by these agents. The nanocone shape produces two distinct and selective binding areas. MC shows preferential trapping VX molecules within the internal concave surface (P1), while A-234 molecules are strongly adsorbed on the external convex surface (P2). Docking results complement this by showing that A-234 exhibits stronger single-molecule binding on the more open surface, consistent with its preference for P2. The nanocone captures molecules through van der Waals forces, which produce measurable electronic changes that modify its electronic signature. The research demonstrates that carbon nanocones represent a promising candidate material for the future development of chemical defense systems, potentially including sensitive detection systems and advanced filtration technologies.
High-purity precursors are often required for the targeted synthesis of functional nanomaterials. Molybdenum blue (MB) dispersions are promising precursors for the production of functional materials based on molybdenum oxides and carbides. Here, a facile, spectator-ion-free synthesis of molybdenum blue dispersions via a tailored ion-exchange strategy is reported. By eliminating extrinsic counter-ions, we achieve uniform toroidal nanoclusters (~3.5 nm) of {Mo154} wheel-type molybdenum blue with a precise mixed-valence Mo5+/Mo6+ framework and long time aggregative and sedimentation stability. Moderate reduction ratios yield crystalline monoclinic MoO2, whereas high reduction ratios drive an in situ carbothermal reduction, selectively yielding hexagonal β-Mo2C/η-MoC phases. This approach establishes a versatile, scalable pathway for engineering molybdenum blue nanoparticles as precursors for oxide- and carbide-based advanced functional materials.
Herein, a cobalt–molybdenum bimetallic oxide precursor was synthesized via a hydrothermal route, followed by a phosphidation strategy in a tube furnace to produce a CoMoP cocatalyst. Subsequently, a CoMoP/BiVO4 composite photoanode was successfully constructed by loading the CoMoP cocatalyst onto the surface of an electrodeposited BiVO4 film using a drop-casting method. A suite of analytical tools such as TEM, XRD, and XPS was utilized to comprehensively examine the material morphology and crystalline features, verifying that CoMoP was effectively anchored on the BiVO4 surface with intimate interfacial contact. Photoelectrochemical (PEC) performance testing indicated that the composite photoanode achieved optimal performance with a 200 µL loading of the CoMoP dispersion (2 mg/mL). Under front-side illumination, the photocurrent density of the CoMoP/BiVO4 composite photoelectrode reached a photocurrent density of 2.8 mA/cm2 at 1.23 V (vs. RHE), which is approximately 3.1 times higher than that of unmodified BiVO4 (0.9 mA/cm2). Under back-side illumination, the composite photoanode generated 3.5 mA/cm2, representing a 2.3-fold improvement over the 1.5 mA/cm2 recorded for bare BiVO4. The bandgap energy of BiVO4 was determined to be approximately 2.44 eV based on UV–vis absorption spectra and the corresponding Tauc plot. Owing to its metallic nature, CoMoP exhibits strong broadband absorption in the visible-light region and does not display an intrinsic semiconductor bandgap behavior. Combined with photoluminescence (PL) spectroscopy and PEC results, it was demonstrated that the CoMoP loading effectively promoted interfacial charge separation and transport while accelerating water oxidation kinetics. These results demonstrate that the CoMoP/BiVO4 system serves as an advanced semiconductor material with excellent performance for photoelectrocatalytic water splitting.
Gum arabic (GA) is a promising polymer for oil microencapsulation due to its emulsifying and film-forming properties and regulatory acceptance. Here we introduce a fully natural, low-energy emulsion–freeze-drying route and a head-to-head screening framework that compares surfactant chemistry and oil identity under identical processing conditions. Rice oil was used as a model to evaluate two oil:GA ratios (1:3 and 1:0.3, solid basis) and three surfactants (Tween 80, sodium cocoyl glutamate (SCG), and lecithin) at 0.1–1%. Emulsions were characterized by Dynamic Light Scattering (DLS) (z-average, PDI), emulsification index, and viscosity, then freeze-dried and evaluated for encapsulation efficiency (EE). High oil load (1:0.3) gave EE = 0% for all conditions, whereas GA-rich emulsions (1:3) enabled encapsulation, with 0.1% surfactant selected as optimal. Using this formulation window, six oils (rice, jojoba, aloe vera, sweet almond, safflower, sesame) were screened, yielding EE values from 0 to 95%. Safflower and sesame showed high EE without surfactant, while rice, sweet almond, aloe vera, and jojoba benefited mainly from SCG or lecithin. Despite producing smaller droplets, Tween 80 generated polydisperse, low-stability emulsions and did not improve EE. Overall, EE is governed by GA–surfactant interfacial cohesion and oil chemistry rather than droplet size alone.
This study investigated heat-induced protein aggregation in skim camel milk by monitoring changes in the volume-weighted mean particle size (d4,3) during isothermal heating (60–90 °C, up to 60 min, four temperature levels and 25 time–temperature conditions). Pronounced increases in d4,3 with both time and temperature confirmed significant thermal aggregation. The reaction kinetics were described using a generalized exponential growth model, which fitted well at intermediate temperatures (e.g., coefficient of determination (R2) = 0.901 at 70 °C and 0.959 at 80 °C) but deviated at the lower (60 °C) and upper (90 °C) extremes, reflecting more complex behavior. Arrhenius analysis of the rate constant yielded an activation energy of 50.61 kJ mol−1, lower than values typically reported for bovine milk systems, indicating that camel milk proteins require less thermal input to aggregate. In parallel, a machine learning model implemented as an artificial neural network (ANN) predicted d4,3 from time-temperature inputs with high accuracy (R2 > 0.97 across training, validation, and testing), capturing nonlinear patterns without mechanistic assumptions. Together, the kinetic and ANN approaches provide complementary insights into the heat sensitivity of camel milk proteins and offer predictive tools to support the optimization of thermal processing, formulation, and quality control in dairy applications.
The van der Waals (vdW) interaction energy is a crucial factor in evaluating the potential destabilization of colloidal systems, such as those found in drinking-water treatment, where particles are often assumed to be spherical. Although the explicit dependence of the vdW interaction energy on the radii of spherical particles and their distances is known, a simple view is lacking due to the complexity of the relations. Here, we propose explicit, algebraically simple, approximate relations that provide insight into the fundamental influence of the input geometrical parameters. These relations, when combined with the exponentially decaying potential generated by the electrical double layer, can provide an approximate evaluation of the onset of raw water destabilization in drinking-water treatment, in other words, establishing the conditions under which pollutants in raw water begin to aggregate.
Thyme oil (TO) is emerging as a promising candidate to counteract antimicrobial resistance due to its renowned antimicrobial and anti-inflammatory properties. However, rapid gastric absorption of its bioactive compounds limits its intestinal delivery, where its action is required, so the protection of these components is necessary. This pilot study optimized TO-loaded emulsions for targeted intestinal release. High-shear homogenization and membrane emulsification were compared to formulate single oil in water (O/W) and double water in oil in water (W/O/W) emulsions, screening emulsifiers (lecithin, Tween 20, Tween 80) and functional biopolymers (pectin, sodium alginate). High-shear homogenization with lecithin (0.5%), pectin (1.80%), and sodium alginate (0.2%) yielded stable submicron O/W emulsion (Span = 0.5; d(v,0.5) = 0.21 µm), achieving electrostatic stabilization (ζ-potential = −51.5 ± 1.5 mV) at a target poultry dosage. A pH-responsive behavior was observed: protective hydrogel formed in gastric conditions (d(v,0.5) = 2.64 µm) and maintained stability at intestinal pH (d(v,0.5) = 3.03 µm). Membrane emulsification enabled precise droplet control under mild conditions, producing monodisperse O/W emulsions (d(v,0.5) = 38–59 µm; Span ≤ 1.0) and W/O/W double emulsions (d(v,0.5) = 26.5 µm; Span = 0.6) with ultra-low interfacial tension (0.52 mN·m−1). Repeated membrane passes reduced droplet size to ~6.6 µm. These systems represent a foundational step toward bioactive intestinal delivery, providing a viable antibiotic-free strategy for sustainable livestock production.
Antimicrobial resistance is driving the urgent need for novel antimicrobials. Nanoemulsions (NEs) offer alternatives to traditional antimicrobials by improving the physiochemical and biological properties of bioactive compounds. Artemisia absinthium essential oil (Art-EO) has antimicrobial and antioxidant properties, although its medical applications are limited by hydrophobicity and potential cytotoxicity. To improve these properties, this study investigated an NE loaded with Art-EO (Art-EO NE) extracted via hydrodistillation from A. absinthium grown in Saudi Arabia. Extracted with 0.92% (v/w) yield from the aerial parts of A. absinthium, Art-EO was analysed by gas chromatography–mass spectrometry, revealing 29 compounds. The Art-EO NE, prepared using ultrasonication, showed a droplet size of 116 ± 0.2 nm, polydispersity index of 0.14 ± 0.0, and zeta potential of −23.9 ± 1.0 mV determined by dynamic and electrophoretic light scattering. The NE remained physically stable for two months and exhibited antimicrobial activity for one week. Compared to the Art-EO aqueous extract (minimum inhibitory concentration (MIC): 20% v/v Art-EO), the Art-EO NE enhanced antibacterial activity against Staphylococcus aureus by 32-fold (MIC: 0.625% v/v Art-EO). The NE also exhibited potent antioxidant activity and produced an acceptable in vivo safety profile. These findings present Art-EO NEs as effective antimicrobial and antioxidant agents.
In this preliminary study, chitosan-based molecularly imprinted polymers crosslinked with glutaraldehyde were synthesized and evaluated for the selective removal of m-cresol, a volatile phenol associated with the sensory defect known as smoke taint in wine. Three formulations of chitosan-based molecularly imprinted polymers (MIP-Gs) were synthesized using glutaraldehyde as a crosslinker and m-cresol as a template. Non-imprinted polymers (NIP-Gs) served as controls. The polymers were characterized by Fourier-transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy, which confirmed successful crosslinking and structural differences between MIPs and NIPs. Adsorption performance was evaluated using solid-phase extraction cartridges packed with the synthesized polymers, employing a Cabernet Sauvignon wine. The MIPs exhibited higher adsorption efficiency and selectivity toward m-cresol compared to NIPs, achieving removal rates of 15% to 40%, depending on polymer formulation and analyte concentration. Molecular dynamics simulations were used to investigate polymer–analyte interactions at the molecular level, providing mechanistic insight into the preferential binding of m-cresol within the imprinted cavities. Physicochemical analyses of red wine showed that m-cresol removal occurred with minimal impact on key phenolic parameters, supporting the functional selectivity of MIPs. These results demonstrate that chitosan-based MIPs constitute a promising class of materials for selective adsorption applications in complex liquid systems.
Bismuth vanadate (BiVO4) has been regarded as a valuable semiconductor material for photocatalytic decomposition of organic pollutants thanks to its narrow band gap and environmental friendliness. However, its practical application is restricted by its small specific surface area, severe photo-generated carrier recombination, and low photocatalytic degradation efficiency. Herein, a microemulsion method followed by a hydrothermal process is developed to prepare a flower-like BiVO4 microsphere constituted of thin nanosheets. Because of increase in reactive sites, facilitation of photo-induced carrier transfer, and generation of high-activity superoxygen (•O2−) and hydroxyl (•OH) radicals, the photocatalytic degradation efficiency of the flower-like BiVO4 microparticle (synthesized with a hydrothermal duration of 6 h) for Congo red reaches 86.2% with a high degradation rate constant of 0.0134 min−1. Moreover, the cyclic degradation test proves the reasonable photocatalytic stability of the flower-like BiVO4 microparticle, showing its great application potential for photocatalytic degradation of organic pollutants.
Wettability determination is of crucial importance for multiphase flow in porous media. Currently available methods are either applied to simplified geometries (sessile drop) or are time-consuming (Amott, USBM) and cost-intensive (micro-CT scanning). The purpose of this study is to systematically test the streaming potential method as a fast, cheap, and in situ applicable method for surface probing and determination of the wetting state of soda lime glass beads through zeta potential. Different wetting states are achieved by means of silanization and are characterized by an average contact angle. Comparison of contact angles measured by sessile drop on plate geometries and contact angles derived from bead pack micro-CT images confirmed that the treatment is transferable to the bead packs. The correlation between the zeta potential of the single bead size packing with a single wetting state and the contact angle is non-unique over the entire range of tested treatment volume ratios. The contact angle plateaus at higher degrees of silanization, while the zeta potential values still change. Before the plateau, a correlation between contact angle and zeta potential is present. Zeta potential measurements on the mixtures of the same-sized beads with two different wetting states confirm the existing theory that the apparent zeta potential is a surface area-weighted average of constituents. For a mixture where the zeta potential is size dependent, a new correlation for a dual bead system was derived. The non-unique correlation between zeta potential and contact angle, combined with a bead size-dependent zeta potential, will limit the use of zeta potential for contact angle derivation for the system of soda lime glass beads with various silanization coatings used here. Monitoring relative changes of wetting conditions might still be possible.
The oral delivery of polyphenolic compounds such as rosmarinic acid (Ros) is limited by poor gastrointestinal stability and early release, resulting in low bioaccessibility. Herein, carboxymethylated guar gum (cmGG)-based nanoparticles were developed as a pH-responsive colloidal delivery system to enhance Ros stability, prevent early release, and improve intestinal bioaccessibility. In this context, pH-responsiveness refers to pH-dependent modulation of degradation, and stabilization along the gastrointestinal tract, rather than an abrupt pH-triggered burst release. Guar gum was chemically modified to different degrees of carboxymethylation to enhance its colloidal stability under gastrointestinal conditions, reduce polymer degradation, and enable a more controlled release of the phenolic compound Ros. Comparative evaluation of cmGG systems with varying degrees of carboxymethylation revealed that nanoparticles prepared from highly substituted cmGG exhibited superior colloidal stability and acid resistance, contributing to effective protection of Ros under gastric conditions. Ros-loaded guar gum nanoparticles effectively suppressed release at acidic pH while enabling controlled and sustained release at intestinal pH. Simulated gastrointestinal digestion studies demonstrated that Ros-loaded carboxymethylated guar gum nanoparticles significantly enhanced the gastrointestinal stability and bioaccessibility of Ros compared with non-carboxymethylated guar gum nanoparticles. Overall, these findings indicate that the degree of carboxymethylation is a critical design parameter for tuning colloidal behavior and release performance under the varying pH conditions encountered throughout the gastrointestinal tract in guar gum-based nanoparticle systems.
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 (dγdlogC) 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 (Γmax) and increase in minimum area per molecule (Amin) confirm looser interfacial packing due to EG participation in the solvation layer. Plots of adhesion tension (AT) versus surface tension (γ) exhibit negative slopes, consistent with reduced solid–liquid interfacial tension (ΓLG) 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 (WA) measurements demonstrate enhanced wettability at higher EG concentrations, highlighting the cooperative impact of co-solvent environment and surfactant type on wetting phenomena.
