Search Results (1,034)

Silicone elastomers are attractive matrices for transdermal drug delivery systems, but the controlled release of poorly water-soluble drugs from hydrophobic silicone networks remains challenging. Medical-grade silicone elastomers are generally regarded as chemically stable, biologically inert, and highly biocompatible polymer matrices, which supports their use in biomedical and pharmaceutical materials. Here, ibuprofen-loaded silicone/polyol composite films were prepared from hydroxyl-terminated polydimethylsiloxane (PDMS-OH) using glycerol- and 1,2-propylene glycol-derived alkoxysilane cross-linkers and amino-terminated PDMS as a metal-free room-temperature-vulcanising catalyst. The effects of cross-linker composition, glycerol, PEG 200 and selected functional additives on film formation, morphology, apparent ibuprofen release and preliminary Strat-M^® permeation were evaluated. FTIR analysis indicated no covalent reaction between ibuprofen and the silicone network, but suggested hydrogen-bonding interactions with polyol-rich domains, particularly in glycerol-containing systems. Raman mapping supported ibuprofen incorporation within the films, while SEM showed phase-separated microdomains whose morphology depended on the formulation. Apparent release into 0.9% NaCl at 37 °C was formulation-dependent over 72 h. The optimised F-9 film showed approximately 83% cumulative apparent release, whereas the F-10 film containing copper oxide nanoparticles and sea buckthorn oil showed the highest numerical cumulative apparent release, approximately 94%. Kinetic analysis of the apparent release data supported a mainly diffusion-controlled contribution, modulated by hydrophilic microdomains. These results provide preliminary materials-development evidence that silicone/polyol films can be used to tune apparent ibuprofen release and merit further optimisation for local topical or transdermal applications; however, efficient skin permeation and biological performance require dedicated validation. Full article

Oily wastewater commonly contains dissolved organic contaminants such as dyes, antibiotics, and phenolic compounds. Conventional stepwise treatment processes involve complex operation, high energy consumption, and severe membrane fouling. Multifunctional membranes integrating oil/water separation, pollutant adsorption or catalytic degradation, and membrane self-cleaning provide a promising solution for treating complex oily wastewater. This review summarizes recent advances in multifunctional membranes based on metal oxides, two-dimensional (2D) materials, three-dimensional (3D) porous structures, and biomass-derived materials. Key strategies, including micro and nanoscale structure regulation, wettability control, interlayer channel optimization, heterojunction construction, and active site engineering, are discussed together with the synergistic mechanisms involving oil/water separation, adsorption enrichment, photocatalysis, and Fenton reactions. Approaches for improving membrane flux, separation efficiency, degradation activity, antifouling performance, and cycling stability are also reviewed. Finally, challenges related to scalable fabrication, adaptability to real wastewater, long-term stability, and standardized evaluation are outlined, providing guidance for the design and practical application of multifunctional membranes. Full article

Water flooding in low-permeability, highly heterogeneous reservoirs often causes a rapid increase in water cut and inefficient pressure maintenance because injected water preferentially flows through high-permeability channels. In this study, a field-scale compositional simulation model was established to evaluate CO₂ water-alternating-gas (WAG) enhanced oil recovery in a mature waterflooded reservoir in the Daqing Oilfield. The model was constrained by geological data, experimentally tuned pressure–volume–temperature (PVT) behavior, relative-permeability measurements, and slim-tube tests. The minimum miscibility pressure (MMP) of the CO₂-oil system was estimated to be 19.8 MPa. An 187-month production history was matched using field oil rate, water production, water cut, and reservoir-pressure data. At the current development stage, the reservoir has an oil recovery of 23.6%, an average water cut of 61.34%, and an average reservoir pressure of approximately 6.9 MPa. A 30-year prediction was then performed to compare continued water flooding with several CO₂-WAG development strategies. Sensitivity analyses were conducted for the pressure-restoration level, pre-injection fluid, well-pattern conversion, slug size, and gas/water slug-size ratio. Continued water flooding increased the final oil recovery to only 28.4% and resulted in a water cut of 92.8%. Sequential scenario screening identified a best-performing case among the tested scenarios, consisting of CO₂ pre-injection to restore the average reservoir pressure to 11 MPa, conversion to a staggered line-drive well pattern, a slug size of 0.025 PV, and a gas/water slug-size ratio of 1:1. Under this sequentially selected case, the end-of-forecast oil recovery reached approximately 57.24%, which was the highest value among the cases evaluated in this study and was 28.84 percentage points higher than continued water flooding. The predicted recovery is conditional on the adopted geological, relative-permeability, EOS, and history-matching assumptions. Because the designed average reservoir pressure is below the measured MMP and local pressure above the MMP was not demonstrated, the modeled process is consistently interpreted as immiscible CO₂-WAG. The predicted recovery improvement is interpreted as being associated with pressure support, gas-mobility control, improved sweep efficiency, and compositional CO₂–oil interactions represented by the model, including CO₂ dissolution, oil swelling, and viscosity reduction. The contribution of this work is a field-scale, experimentally constrained workflow for selecting CO₂-WAG operating parameters in mature waterflooded low-permeability reservoirs; CO₂ storage performance should be quantified separately in future work. This study provides an experimentally constrained and history-validated field-scale workflow for identifying a best-performing CO₂-WAG operating case among the tested scenarios in mature waterflooded low-permeability reservoirs. Full article

In this review, I synthesize recent evidence showing how climate acceleration, biosphere disruption, food and freshwater insecurity, pollution, disease, and inequality are increasingly converging into a single, interconnected sustainability challenge. I show that the Anthropocene crisis extends far beyond climate warming and its impacts alone: current national commitments remain consistent with warming of approximately 2.3–2.5 °C under full implementation, while current policies could produce up to 2.8 °C; however, the remaining carbon budget for a 50% chance of limiting warming to 1.5 °C may be exhausted within only a few years, and the oil and gas industry has committed to a 14% increase in upstream production over the period 2024–2030. At the same time, pollution remains responsible for approximately nine million deaths annually; agriculture accounts for roughly 70% of global freshwater withdrawals; and groundwater depletion, continental drying, marine heatwaves, weakening carbon sinks, and intensifying precipitation extremes are destabilizing the ecological and hydrological systems that sustain human health and food security. This review’s incremental contribution is the integration of these trends within a justice-centered sustainability framework that links Earth-system feedback, public health burdens, water insecurity, and institutional failure rather than treating them as separate environmental problems. I argue that because vulnerability is produced not by exposure alone but by unequal access to infrastructure, wealth, governance capacity, and political power, a viable response therefore requires more than decarbonization: it demands ecological restoration, food and water-centered governance, pollution and disease mitigation, and justice-based institutional reform capable of sustaining human dignity, equity, and resilience within planetary boundaries. I encourage resilience and sustainability programs around the world to fold in these additional challenges to their missions and goals. Full article

Magnetic polymer nanocomposites (MPNCs) have attracted considerable attention as advanced multifunctional materials for water purification due to their high adsorption capacity, magnetic recoverability, and excellent reusability. This review presents a comprehensive overview of recent developments in the synthesis, characterization, and environmental applications of MPNCs for wastewater treatment. Particular emphasis is placed on the principal synthesis strategies, including in situ and ex situ approaches, and their influence on nanoparticle dispersion, interfacial interactions, and the physicochemical properties of the resulting nanocomposites. The review covers the most widely investigated magnetic nanomaterials, such as Fe₃O₄, γ-Fe₂O₃, CoFe₂O₄, ZnFe₂O₄, and other ferrites, incorporated into natural and synthetic polymer matrices including chitosan, cellulose, alginate, polyaniline, polypyrrole, poly(vinyl alcohol), and polystyrene. Advanced characterization techniques, including X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM/TEM), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), and superconducting quantum interference device (SQUID) measurements, are discussed to evaluate the structural, chemical, thermal, and magnetic properties of these hybrid materials. The adsorption performance and underlying mechanisms of MPNCs for the removal of heavy metals, dyes, pharmaceutical compounds, organic pollutants, and oil contaminants are critically analyzed, highlighting the roles of polymer functionalization, nanocomposite architecture, and magnetic separation in enhancing treatment efficiency and reusability. In addition, the contribution of density functional theory (DFT) to understanding adsorption mechanisms and guiding the rational design of high-performance adsorbents is reviewed. Finally, current challenges and future perspectives, including green synthesis, multifunctional and stimuli-responsive materials, scalable manufacturing, and industrial implementation, are discussed. This review provides a comprehensive framework for the design and development of next-generation magnetic polymer nanocomposites for sustainable water remediation applications. Full article

Cosmetic wastewater is increasingly recognized not only as a disposal problem but also as a potential source of recoverable water and formulation-derived compounds. This review critically examines the relationship between cosmetic formulation chemistry, wastewater composition, pollutant removal mechanisms, membrane separation, fouling behaviour, and reuse-oriented treatment design. Cosmetic wastewater shows high compositional variability, with reported COD values ranging from approximately 2400 mg O₂/L to more than 100,000 mg O₂/L, depending on product type, cleaning practices, and raw material losses. Surfactants, emulsifiers, oils, polymeric thickeners, preservatives, fragrances, UV filters, dyes, and microplastics contribute differently to organic load, emulsion stability, toxicity, and treatment resistance. Conventional treatment processes reduce coarse, suspended, emulsified, and biodegradable fractions, but they are limited by low biodegradability, sludge generation, inhibitory compounds, and incomplete removal of persistent micropollutants. Advanced oxidation, adsorption, electrochemical processes, and hybrid systems can improve the transformation, phase transfer, retention, and polishing of recalcitrant compounds, with AOPs typically achieving COD removal of approximately 55–85% and hybrid systems improving overall performance by about 10–25% compared with biological treatment alone. Membrane technologies are evaluated as selective barriers enabling clarification, polishing, water reuse, and resource recovery. MBRs can remove more than 90–95% of COD and BOD₅, while NF/RO polishing may reject more than 90–95% of selected recalcitrant organics and microcontaminants. The novelty of this review lies in shifting the discussion from end-of-pipe wastewater treatment toward source-oriented recovery, integrated treatment trains, and mechanism-based selection of technologies before cosmetic wastewater becomes diluted, mixed, and difficult to reuse. Full article

Open-surface coalescence of microdroplets is essential for droplet-based microreactors, emulsion processing, and multiphase microfluidics, yet existing methods often require closed channels or patterned electrodes. Here, we report a corona-driven open-oil-film platform that achieves voltage-regulated coalescence of aqueous microdroplets in a simple needle–plate electrode configuration. Positive corona discharge induces coupled electrohydrodynamic effects—including ion transport, interfacial charge redistribution, and Maxwell stresses—that drive oil-film contraction and charge-regulated droplet bouncing, thereby reducing inter-droplet spacing and promoting successive merging. The coalescence rate and final droplet size are tunable via the applied voltage and oil volume: complete coalescence into a single droplet is achieved at 12 kV, and an optimal oil volume of 60 μL maximizes confinement efficiency. To enable quantitative, frame-by-frame analysis, we develop an improved YOLOv5–OC-SORT framework that yields an overall mAP@0.5 of 0.905 for automatic droplet detection and tracking. As a proof-of-concept, the platform achieves electro-demulsification of a surfactant-stabilized water-in-oil emulsion, increasing the average droplet diameter from ~0.005 mm to ~0.2 mm and enabling effective oil–water separation. This work provides a simple, electrode-pattern-free strategy for controllable droplet coalescence and open-surface emulsion breaking. Full article

To address the persistent challenge of membrane wetting during oil-gas separation in transformer condition monitoring, an omniphobic composite membrane was developed to facilitate the reliable online detection of dissolved gases. An F-CNTs/Teflon AF/PVDF composite membrane, featuring a loofah-like hierarchical structure and omniphobic properties, was fabricated via spraying-deposition strategy on the polyvinylidene fluoride (PVDF) substrate. The morphology, surface chemical composition, wettability and stability of the F-CNTs/Teflon AF/PVDF composite membrane were systematically characterized. Subsequently, the oil-gas separation performance of the composite membrane was evaluated using standard transformer oil containing dissolved gases as the feed solution. The results indicated that fluorinated carbon nanotubes (F-CNTs) were successfully modified onto the membrane surface, creating a re-entrant morphology composed of an intersecting nanotube network that mimics the hierarchical architecture of a loofah. The F-CNTs/Teflon AF/PVDF composite membrane exhibited exceptional omniphobicity, achieving contact angles of 168.2 ± 1.5° and 127.5 ± 1.0° towards DI water and mineral insulating oil, respectively. Additionally, the loofah-inspired composite membrane demonstrated robust thermal and ultrasonic stability. In oil-gas separation tests, the omniphobic membrane displayed a rapid response and high efficiency for dissolved gas extraction, achieving dynamic equilibrium within 64 min. Furthermore, the modification improved permeation efficiency by 25.6%. These results suggest that the developed omniphobic membrane is a promising alternative for oil-gas separation in the condition monitoring of oil-filled electrical equipment. Full article

Membrane separation technology has been extensively applied to treat oily effluent given its high performance and ease of operation. However, conventional polymer membranes are resistant to natural degradation after use, leading to severe environmental concerns. Consequently, the development of biodegradable membranes that combine satisfactory oil–water separation performance with ecological safety has emerged as a critical research priority. In this work, we fabricated a biodegradable membrane consisting of chitosan (CS), sodium methacrylate (SMa) and polyvinyl alcohol (PVA) via electrospinning, with anionic super-hydrophilic polyacrylamide (PAM) incorporated to enhance wettability. No toxic chemicals were used throughout the fabrication process. The resulting membrane with an interpenetrating network and beaded structure not only rendered the crosslinked nanofiber more hydrophilic but also improved the porosity of membranes, which significantly enhanced the separation performance and fouling resistance of the membrane. Specifically, the CS/PVA/SMa-PAM membrane achieved a separation flux of 2.7 × 10⁴ L·m⁻²·h⁻¹·bar⁻¹ for oil–water emulsions. After 20 emulsion separation cycles, the flux of the modified membrane was stable at 2.5 × 10⁴ L·m⁻²·h⁻¹·bar⁻¹. Benefiting from its excellent anti-fouling properties, high separation efficiency, eco-friendly biodegradability, and toxic-reagent-free fabrication, the as-prepared CS/PVA/SMa-PAM membrane offers a promising and sustainable option for oily wastewater treatment. Full article

Natural hydrogen is a promising zero-carbon resource, but its small molecular size and high diffusivity make nuclear magnetic resonance (NMR) logging interpretation difficult. This study develops a pore-network and random-walk simulation framework to analyze hydrogen and methane responses in hydrogen-rich sandstones. The model couples pore structure, fluid properties, magnetic-field gradients, and acquisition parameters. Transverse relaxation time (T₂) spectra are inverted with Tikhonov regularization and generalized cross-validation. The effects of waiting time (TW), echo time (TE), pore size, gradient strength, and burial depth are quantified. Results show clear T₂ separation among water, oil, methane, and hydrogen. Dual-TW difference spectra improve fluid discrimination, and hydrogen shows the strongest TW sensitivity. TW mainly controls amplitude, while TE and gradient mainly control diffusion attenuation. Because hydrogen diffuses faster, it is more sensitive than methane to both factors. Greater depth and larger pores shift peaks to longer T₂, but strong diffusion attenuation weakens hydrogen’s pore-size sensitivity. These results clarify the distinct NMR response mechanism of hydrogen. These findings can directly support NMR logging workflows for natural hydrogen reservoir identification by guiding TW–TE parameter design and gradient control, and by improving H₂-CH₄ discrimination in mixed-gas intervals. They can also reduce interpretation uncertainty in deep, heterogeneous formations, thereby improving confidence in identifying and evaluating natural hydrogen reservoirs. Full article

Emulsified oily wastewater from industrial activities remains challenging to treat because kinetically stable oil droplets hinder efficient separation, threatening water resources and ecological environments. To address this issue, this work develops an inclined solar-driven evaporator based on a polypyrrole (PPy)-coated bacterial cellulose (BC) gel (PPy-BC gel), which has enlarged effective evaporation areas and an environmental heat effect. Under one sun (1 kW m⁻² under standard solar illumination), the PPy-BC gel achieves an evaporation rate of 2.14 kg m⁻² h⁻¹, which is 494% higher than that of the uncoated BC gel. In diesel-in-water emulsions with oil concentrations ranging from 0 to 15 vol%, the gel maintains stable evaporation performance, achieving an oil removal efficiency exceeding 99% across all tested concentrations. After 15 consecutive cycles of treating actual oily wastewater, no significant performance degradation is observed. The collected condensate exhibits excellent water quality, with removal efficiencies for total organic carbon (TOC), chemical oxygen demand (COD), and total dissolved solids (TDS), and ionic conductivity (IC) exceeding 94%. This work presents a solar-powered evaporation platform, which demonstrates potential in the stable treatment of complex oily wastewater, and offers a sustainable reference solution for decentralized industrial wastewater management. Full article

This work introduces a Targeted Emulsified-Solvent Injection (TESI) process for extracting bitumen from oil sands. In TESI, a solvent is emulsified near the emulsion phase inversion point (PIP), where the interfacial tension and the emulsion stability are very low. This allows the solvent to be easily emulsified and then deposited onto the bitumen-coated porous media (under lower shear conditions, where the emulsion breaks), mixing with bitumen, decreasing bitumen viscosity, and enabling mobilization and diluted bitumen recovery. The design of the surfactant-solvent formulation was guided by the Hydrophilic-Lipophilic-Difference and Net-Average-Curvature (HLD-NAC) frameworks. The HLD-NAC was used to identify a formulation with less than 1% surfactant exhibiting ultralow interfacial tension (~10⁻³ mJ/m²), at the PIP, where HLD = 0. This formulation was injected into columns packed with bitumen-coated sands at varying salinities and water-to-solvent ratios. Using optimal conditions, bitumen recoveries of up to 83% can be obtained at room temperature, without the need for steam or high-pressure injection, a condition suitable for intermediate-depth reservoirs. The effluent emulsion of diluted bitumen can be gravity-separated, allowing for the recycling of the aqueous solution containing the surfactant. The recovery curves were modeled using a continuous stirred tank reactor (CSTR) model coupled with a Capillary number model for thin viscous films that allowed the prediction of effluent diluted bitumen viscosities and an estimation of the pressure drops in the column that were consistent with experimental observations. Full article

Urushiol, the main active compound in raw lacquer, is a catechol derivative with long alkyl side chains. Its use in traditional coatings has long been held back by slow enzymatic curing, UV sensitivity, and its own allergenicity. Over the past decade, greener ways to extract it have emerged—ultrasound- and microwave-assisted methods, plus vortex-assisted matrix solid-phase dispersion and ball-milling-enhanced microextraction. These approaches have been shown to recover urushiol efficiently, using less solvent and lowering operator risk. The catechol structure explains its many uses: fast-curing UV coatings that resist corrosion, antibacterial materials (both plain and metal-coordinated), superwetting surfaces for oil–water separation, and selective uptake of heavy metals and rare-earth ions. Early biomedical work also hints at its potential as a bioactive scaffold, drug carrier, or low-toxicity starting point. To balance performance and safety, multiple strategies have been proposed to reduce allergenicity: protecting the hydroxyl groups, modifying specific sites on the ring, and designing synthetic mimics. Still, a few bottlenecks are holding back industrial scale-up. These include large-scale green extraction, long-term material stability, and the lack of solid biocompatibility data. Future work needs to integrate three core research directions: high-throughput structure–activity–toxicity screening, cross-disciplinary molecular design, and life-cycle assessment. The integrated development of these three directions will facilitate the industrial transformation of urushiol-based materials from laboratory prototypes to high-value commercial products. This review summarizes and outlines a roadmap for green extraction, functional polymer applications, and the safe use of urushiol. Full article

This study presents a green approach for polyethylene terephthalate (PET) upcycling using a biphasic system of subcritical water and castor oil. This system enables efficient conversion without an external catalyst and facilitates product separation. Hydrolysis of castor oil generates fatty acids in situ, which catalyze PET conversion to selectively produce low-molecular-weight oligoesters (Mn ≈ 1500 g/mol). These oligoesters are inherently immiscible with the bio-medium at room temperature, allowing straightforward separation by centrifugation. Orthogonal experiments show that temperature is the dominant factor affecting PET conversion, with the optimal conditions being 200 °C, a water-to-oil mass ratio of 1:5, and a reaction time of 10 h for complete conversion. Under the practical optimum condition, the castor oil phase remained highly effective over five consecutive depolymerization cycles. The functionalized oligoesters were used in polyurethane synthesis. At 6% loading, they gave adhesives with a T-peel strength of 8.09 N/15 mm and tensile strength of 25.14 MPa, and excellent damp-heat stability (only 0.62% loss in T-peel and 0.47% in 180° peel after aging). Thermogravimetric analysis confirmed enhanced thermal stability, with increases of 19.52 °C in T_5% and 16.50 °C in T_50% compared with the unmodified system. These results demonstrate the practical potential of the obtained oligoesters in high value adhesive applications. Full article

The growing deployment of green hydrogen technologies is increasing pressure on freshwater resources, motivating the exploration of alternative water sources that do not compete with human consumption. In this work, the direct use of untreated produced water from the Shushufindi 78 oil well (Ecuador) as an electrolyte for the hydrogen evolution reaction (HER) was experimentally evaluated. A comprehensive physicochemical characterization combined with electrochemical techniques, electrochemical impedance spectroscopy (EIS), and gas chromatography (GC-TCD) was performed to correlate electrolyte composition with electrochemical performance. Despite the high salinity and complex composition of the electrolyte, hydrogen production was achieved without pretreatment. Quantitative GC-TCD analysis yielded 10.29 µmol of H₂ after 4 h of electrolysis under non-optimized laboratory conditions, corresponding to a faradaic efficiency of 43.8%. These results demonstrate the feasibility of direct hydrogen generation from untreated produced water under realistic operating conditions. Additional experiments conducted in a membrane separated H-type electrolyzer evaluated mixtures of produced water and KOH, the electrolyte commonly employed in alkaline water electrolysis. Hydrogen production increased significantly under alkaline conditions, with the PW 10% + KOH 90% electrolyte exhibiting the highest hydrogen yield and faradaic efficiency among the investigated systems. Electrochemical impedance spectroscopy revealed that KOH addition reduced solution resistance and improved ionic transport, while differences in interfacial behavior were observed depending on electrolyte composition. The combined electrochemical and chromatographic results demonstrate that untreated produced water can be directly utilized for hydrogen production and can also be partially integrated into alkaline electrolysis systems without compromising electrochemical performance. These findings highlight the potential of produced water as a non-conventional water resource for sustainable hydrogen generation and industrial wastewater valorization. Full article