Search Results (180)

Ion chromatography (IC) serves as a pivotal technique in trace ion analysis, and the separation performance of IC is largely determined by the properties of stationary phases. In contrast to silica-based matrices, polymer-based stationary phases have garnered significant interest owing to their outstanding pH stability and mechanical robustness. However, unmodified polymer matrices usually lack necessary ion exchange functions and selectivity; therefore, precise functional modification is the key to improving their chromatographic separation performance. This paper provides a systematic overview of recent advances in the synthesis and functional modification of polymer-based anion exchange chromatography stationary phases over the past few years. Firstly, the types and characteristics of polymer matrices commonly used for functional modification are summarized; secondly, the origin and improvement of common synthesis methods such as microporous membrane emulsification, droplet microfluidics, suspension polymerization, emulsion polymerization, soap-free emulsion polymerization, precipitation polymerization, dispersion polymerization, and seed swelling are introduced according to the molding methods of polymer matrices; furthermore, the principles, characteristics, and development status of mainstream functionalization strategies, including chemical derivatization, surface grafting, latex agglomeration, and hyperbranching, are emphasized. Finally, the existing challenges and prospective development trends in this field are discussed and outlooked, with the purpose of offering insights for the targeted design and practical application of high-performance polymer-based anion exchange chromatography stationary phases. Full article

The emulsification of a molten fusible metal alloy in a liquid epoxy matrix with its subsequent curing is a novel way to create a highly concentrated phase-change material. However, numerous challenges have arisen. The high interfacial tension between the molten metal and epoxy resin and the difference in their viscosities hinder the stretching and breaking of metal droplets during stirring. Further, the high density of metal droplets and lack of suitable surfactants lead to their rapid coalescence and sedimentation in the non-cross-linked resin. Finally, the high differences in the thermal expansion coefficients of the metal alloy and cross-linked epoxy polymer may cause cracking of the resulting phase-change material. This work overcomes the above problems by using nanosilica-induced physical gelation to thicken the epoxy medium containing Wood’s metal, stabilize their interfacial boundary, and immobilize the molten metal droplets through the creation of a gel-like network with a yield stress. In turn, the yield stress and the subsequent low-temperature curing with diethylenetriamine prevent delamination and cracking, while the transformation of the epoxy resin as a physical gel into a cross-linked polymer gel ensures form stability. The stabilization mechanism is shown to combine Pickering-like interfacial anchoring of hydrophilic silica at the metal/epoxy boundary with bulk gelation of the epoxy phase, enabling high metal loadings. As a result, epoxy shape-stable phase-change materials containing up to 80 wt% of Wood’s metal were produced. Wood’s metal forms fine dispersed droplets in epoxy medium with an average size of 2–5 µm, which can store thermal energy with an efficiency of up to 120.8 J/cm³. Wood’s metal plasticizes the epoxy matrix and decreases its glass transition temperature because of interactions with the epoxy resin and its hardener. However, the reinforcing effect of the metal particles compensates for this adverse effect, increasing Young’s modulus of the cured phase-change system up to 825 MPa. These form-stable, high-energy-density composites are promising for thermal energy storage in building envelopes, radiation-protective shielding, or industrial heat management systems where leakage-free operation and mechanical integrity are critical. Full article

This work investigated the stabilization mechanisms and β-carotene encapsulation characteristics of cellulose nanofibrils (CNFs) stabilized Pickering emulsions (PE) prepared by different emulsification processes. For 48 days of storage, ultrasound-prepared Pickering emulsions (US-PE) stabilized by at least 2.0 wt.% CNFs have obvious cream stabilization, and high-pressure homogenization-prepared Pickering emulsions (HPH-PE) stabilized by over 1.6 wt.% CNFs have excellent cream stabilization. The stabilization of HPH-PE, which was superior to that of US-PE, mainly relied on the steric stabilization of CNFs’ space networks. Although the encapsulation efficiency of β-carotene in US-PE was higher than that in HPH-PE when the CNF concentration was over 1.2 wt.%, the retention rate of β-carotene in US-PE was obviously lower than that in HPH-PE. So, the internal space structure of CNF-stabilized HPH-PE was conducive to stabilizing the emulsion and protecting the bioactive molecule. Full article

This study investigates the apparent surface-active and emulsifying behaviour of raw Albizia amara (AA) powder suspended in water, reflecting its traditional mode of use. AA suspensions (0.1–1% w/v) were prepared without extraction and evaluated for apparent surface tension, droplet size distribution, emulsification capacity, and emulsion stability. Increasing AA concentration reduced apparent surface tension from 57.13 ± 2.17 mN/m to 48.9 ± 0.06 mN/m, plateauing at higher concentrations. Both blending and high-shear mixing produced oil-in-water emulsions. Blending generated smaller initial droplets (1–10 µm), whilst high-shear mixing produced more uniform distributions (d₅₀ = 31.23 ± 0.95 µm). Emulsion capacity and stability increased with AA concentration, reaching 95.19 ± 3.39% and 89.81 ± 0.02% at 0.8% AA. As the system contains undissolved plant material, all measurements represent the apparent behaviour of a heterogeneous suspension. The specific molecular contributors to surface activity cannot be identified within this study. These findings provide a baseline physicochemical assessment of raw AA powder and support future work involving extraction, purification, and chemical characterisation to establish the mechanisms underlying its surface-active properties. Full article

In the field of enhanced oil recovery in low-permeability reservoirs, the application of nanomaterials has attracted widespread attention. However, conventional nanomaterials exhibit issues such as large particle size and poor dispersion stability. This study selected SiO₂ nanoparticles with a particle size of 10 nm and combined them with 12 types of commonly used oilfield surfactants. After aging at 120 °C for 48 h, using dispersion stability and interfacial tension (IFT) as evaluation criteria, hexadecyltrimethylammonium bromide (CTAB) was ultimately identified as the optimal modifier. The structure and morphology of the SiO₂ particles were characterized in detail using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM). The system evaluated the dispersion stability of nanofluids before and after modification, as well as the interfacial properties (IFT reduced to the 10⁻¹ mN/m range) and wettability (oil-wet surfaces reversed to strongly water-wet, with contact angles decreasing to 30°) of nanofluids with different modification degrees. Considering economic factors, the modified nano-SiO₂ system with a ratio of 1:0.5 was selected. Microvisualization experiments revealed that the modified nanoscale system achieves residual oil displacement through three mechanisms: emulsification (reducing residual oil droplet size to enhance mobility), wetting reversal (lowering contact angle to weaken adhesion), and structural separation pressure (counteracting capillary forces to destabilize residual oil). Displacement experiments reveal that in rock cores with permeability ranging from 1 to 100 mD, the modified system exhibits a recovery rate trend that initially increases and then decreases. Nevertheless, it consistently enhances recovery rates, maintaining them above 12%, demonstrating strong application potential. Full article

This article focuses on the oil–water emulsification problem during steam injection in heavy oil thermal recovery. Emulsions were prepared through one-dimensional flow experiments, and key parameters including the inversion point water cut and micro-morphological characteristics (particle size and distribution range) of the emulsions were systematically measured under varied conditions (temperature: 150–360 °C; salinity: 0–7500 mg/L; water cut: 10.07–72.22%). By analyzing the experimental data, the emulsification mechanism and influencing rules were revealed: under the combined conditions of high temperature (150–360 °C), high salinity (up to 7500 mg/L), and low water cut (10.07–19.35%), crude oil and formation water form oil-in-water emulsions under the shear action of porous media. During this process, active substances in crude oil react with inorganic salts in formation water to generate natural surfactants, which reduce the oil–water interfacial tension and enhance emulsion stability, enabling the emulsion to maintain stability even at a high water cut of up to 72.22%, with particle sizes ranging from 1 μm to 350 μm and distribution spans varying from 4 μm to 50 μm. The formation of such emulsions leads to a significant increase in viscosity, adversely affecting oil recovery. In production practice, it is recommended to add chemical agents during the early stage of steam huff and puff development (water cut: 10.07–37.50%). This measure aims to destroy the oil–water liquid film, promote water droplet coalescence (narrowing the particle size distribution span), and facilitate emulsion breaking and phase inversion, thereby effectively mitigating the adverse impacts of oil–water emulsions and improving heavy oil recovery efficiency. Full article

Understanding how plant proteins interact with polyphenols under different pH conditions is key to unlocking the full functional potential of natural ingredients in food systems. This study investigates the pH-dependent binding mechanisms and structural transformations of three underutilized plant proteins: mustard protein concentrate (MP), primrose protein meal (PP), and sunflower meal protein isolate (SMP) in complexation with red cabbage polyphenols (RC) using spectroscopic and microscopic techniques, we show that alkaline conditions (pH 7–9) enhance anthocyanin binding, driven by hydrogen bonding and hydrophobic interactions, particularly in PP and SMP. However, this increased binding is accompanied by greater protein unfolding and aggregation, which affects solubility and colloidal behavior. PP9 demonstrated the strongest antioxidant activity, while MP3 retained anthocyanin stability in acidic conditions. Emulsification and foaming properties varied across proteins and pH: PP showed the highest emulsification at acidic pH, MP had superior emulsion stability at alkaline pH, and SMP maintained performance across all conditions. CLSM imaging confirmed that SMP-based emulsions were the most structurally stable. These findings provide molecular insight into how pH governs the assembly, stability, and functionality of protein–polyphenol complexes, paving the way for the rational design of next-generation plant-based food formulations. Full article

Lipid-polymer hybrid nanoparticles (LPHNPs) are the next-generation nanocarriers that integrate the mechanical strength and sustained-release capacity of polymeric cores with the biocompatibility and high drug-loading efficiency of lipid shells. Various design strategies and architectures that enhance encapsulation efficiency, stability, and targeted delivery of diverse therapeutic agents are reviewed. Commonly employed polymers, lipids, and surfactants that enable controlled drug release and enhanced pharmacokinetic performance are summarized in tabular form, while fabrication methods such as single-step, emulsification-solvent evaporation, and microfluidic techniques are discussed for their scalability and reproducibility. The therapeutic potential of LPHNPs in delivering poorly soluble drugs, phytochemicals, and genetic materials achieving synergistic therapeutic outcomes in oncological applications is comprehensively highlighted. The manuscript also includes details on ligand-based functionalization and the integration of imaging and stimuli-responsive elements to enhance targeted delivery and develop multifunctional theranostic LPHNPs systems. Furthermore, non-oncologic applications of LPHNPs in ocular, topical, and oral delivery are discussed, emphasizing their potential in treating inflammatory, infectious, and autoimmune disorders with sustained release and enhanced therapeutic efficacy. Recent patents focusing on improved biocompatibility, dual-drug encapsulation, and mRNA delivery are summarized. However, challenges such as large-scale production, reproducibility, safety, and regulatory standardization must be addressed through quality by design approaches and advanced manufacturing technologies to fully realize the clinical and commercial potential of next-generation LPHNPs. Full article

Ophthalmic drug delivery encounters unique challenges due to the anatomical and physiological ocular barriers, necessitating the development of novel drug delivery systems (NDDSs). This review focuses on emerging therapeutic platforms, including nanoemulsions (NEs), microemulsions (MEs), self-emulsifying drug delivery systems (SEDDSs) such as self-nano emulsifying drug delivery systems (SNEDDSs) and self-micro emulsifying drug delivery systems (SMEDDSs), emulgels, and in situ-forming emulgels, as novel strategies for enhancing ocular drug delivery. NEs and MEs, due to their small globule size, excellent drug solubility, stability, and bioavailability, offer promising solutions for effective ocular therapy. SEDDSs further enhance the stability and bioavailability of hydrophobic drugs through self-emulsification in aqueous environments. Emulgels, combining the benefits of emulsions and gels, provide sustained and controlled release of therapeutic agents, improving the ocular retention time and therapeutic efficacy. Additionally, in situ-forming emulgels offer the advantage of liquid-to-gel transition upon contact with ocular surfaces, optimizing drug delivery. The review discusses various ocular diseases, challenges for ocular delivery of conventional formulations, updates on emulsion-based novel drug delivery systems for ophthalmic drug delivery, mechanisms of enhanced ocular permeation, formulation strategies, advantages, and challenges, design-of-experiment considerations for optimization, characterizations, and recent advancements in these systems including patents and clinical trials, highlighting their potential for improving the treatment of various ocular diseases. Furthermore, this review explores marketed ophthalmic emulsions and future prospects for integrating these NDDSs into clinical ophthalmology, emphasizing their ability to overcome ocular barriers and enhance therapeutic efficacy. Full article

Fractured lost circulation remains a major drilling challenge due to low compatibility between conventional plugging materials and fractures. By utilizing thermosetting resin emulsification and high-temperature crosslinking coalescence, this study developed a temperature-activated nanomaterial enhanced liquid–solid phase transition plugging emulsion. The system adapts to varying fracture apertures, forming plugging particles with a broad size distribution and high strength upon thermal activation. The structural characteristics, mechanical properties, and fracture-plugging performance of the plugging particles were systematically investigated. Results demonstrate that the optimized system, comprising 8 wt.% emulsifier, 0.16 wt.% dispersant, 0.4 wt.% crosslinker, 0.4 wt.% viscosifier, 70 wt.% distilled water, and 2 wt.% nano-silica (all percentages relative to epoxy resin content), can produce particles with a size of 1–5 mm at formation temperatures of 80–120 °C. After 16 h of thermal aging at 180 °C, the particles exhibited excellent thermal stability and compressive strength, with D(90) degradation rates of 3.07–5.41%, and mass loss of 0.63–3.40% under 60 MPa. The system exhibits excellent injectability and drilling fluid compatibility, forming rough-surfaced particles for stable bridging. Microscopic analysis confirmed full curing in 140–180 min. Notably, it sealed 1–5 mm fractures with 10 MPa pressure, enabling adaptive plugging for unknown fracture apertures. Full article

Single-type viscosity reducers often fail to meet the application requirements of specific oilfields for high-viscosity heavy oils. This study focused on Henan heavy oil, systematically investigating the viscosity reduction performances of oil-soluble viscosity reducers, emulsifiers, and their composite systems. Experimental results indicated that the oil-soluble ethylene-vinyl acetate copolymer (EVA) achieved optimal efficiency at a concentration of 500 ppm, with a viscosity reduction rate of 44.2%. Among the screened emulsifiers, acrylonitrile-ethylene-styrene (AES) exhibited the highest viscosity reduction rate (99.9%), which basically complied with relevant industrial application standards. When EVA and AES were compounded, the resulting composite reducer showed a significantly higher viscosity reduction rate than single EVA, and the stability of the formed oil-in-water (O/W) emulsion was further enhanced. The synergistic mechanism was clarified as follows: EVA first disrupts the aggregation of heavy components (resins and asphaltenes) and modifies wax crystal morphology, creating a favorable microfoundation for subsequent emulsification; AES then promotes the formation of stable O/W emulsions, ultimately achieving a “1 + 1 > 2” synergistic viscosity reduction effect. Furthermore, the potential action mechanism of the EVA-AES composite system was verified using multiple characterization techniques. This study provides a valuable reference for the selection and practical application of heavy oil viscosity reducers in oilfield operations. Full article

In this study, two γ-carbon-substituted dialkylphosphinic acids—symmetrical di-(3,5,5-trimethylhexyl)phosphinic acid (P355) and unsymmetrical (2-ethylhexyl)(3,5,5-trimethylhexyl)phosphinic acid (P227-355)—were synthesized via a precise free radical addition method. Their chemical structures were fully characterized using ESI-HRMS, ¹H NMR, ³¹P NMR, and FT-IR. Their middle REE extraction/separation performance, anti-emulsification behavior, and underlying mechanisms were investigated. Key results showed that P355 had better Dy saturation capacity (357.51 mg/L) and good selectivity for middle REEs (their average value of β_{N + 1/N} = 3.18), while P227-355 showed higher back-extraction efficiency (≈90% Dy stripping at ≥0.02 mol/L H₂SO₄). Methyl n-pentyl ketone (MNPK) eliminated emulsification and boosted saturation capacity (324.18 mg/L Sm and 357.51 mg/L Dy for P355). Mechanistically, the extraction followed cation exchange (Sm³⁺ + 2(HL)₂ ↔ Sm·L₃·(HL) + 3H⁺); MNPK formed hydrogen-bonded associates (HL·MNPK) with free extractants, slightly reducing the effective concentration of (HL)₂ but not altering the core cation exchange mechanism. Full article

Background/Objectives: Glaucoma is a multifactorial eye disease that can cause optic nerve damage and irreversible blindness. It is considered a significant public health problem worldwide. Topical intraocular pressure (IOP)-lowering eye preparations are used to prevent or slow further damage. Previously, we demonstrated that nimodipine (NMD), a calcium channel blocker, significantly reduced IOP after a single drop of NMD/HPMC suspension. The current study was designed to develop NMD chitosan nanoparticles (NMD-CS NPs) to improve the NMD IOP-lowering efficacy. Methods: NMD-CS NPs were prepared using the spontaneous-emulsification solvent diffusion method. Three different types of chitosan, carboxymethyl CS (CMCS), low molecular weight CS (LCS), and medium molecular weight CS (MCS), were used. Different concentrations of polymers, various stabilizers, and two pHs were used for formulation optimization. NMD-CS NPs were characterized regarding their particle size, polydispersity index (PDI), zeta potential, DSC, FTIR, and encapsulation efficiency. NMD-CS NPs were incorporated into eye drops and characterized in terms of their in vitro release, cytotoxicity, transcorneal permeability, and in vivo efficacy. Results: The optimized NMD-CS NPs demonstrate a small particle size with a narrow size distribution and acceptable zeta potential values. DSC and FTIR results confirmed the complete entrapment of NMD inside the NPs. NMD-CS NP eye drops successfully sustained NMD release without any burst effect. These NPs demonstrated a Higuchi non-Fickian diffusion mechanism and 79.41% improved corneal permeability. Cytotoxicity studies revealed that NMD formulations are nontoxic. After a single topical ocular application, NMD-MCS NP eye drops induced a significantly superior effect to Timolol maleate eye drops with regard to the %IOP reduction and duration of action. Conclusions: Evaluation results of NMD-CS NP eye drops show their positive effect in a preclinical animal model as a promising glaucoma therapy. Full article

The transition to a sustainable energy mix is essential to mitigate climate change. Enhanced Oil Recovery (EOR) using low-salinity water (smart water) has emerged as a promising strategy for reducing environmental impacts in the petroleum industry, producing a highly valuable energy source due to both its energy density and market value. This study critically reviews intermediate technological readiness levels (TRL), applying a patent-based approach (TRL 4–5) and a review of articles (TRL 3) to analyze various aspects of smart water for EOR, including its composition. A total of 23 patents from the European Patent Office (Questel Orbit) and 1395 articles from Elsevier’s Scopus database were analyzed, considering annual trends, country distribution, international collaborations, author and applicant affiliations, citation dependencies, and factorial analyses. Both patents and articles show exponential growth; however, international collaboration is more frequent in the scientific literature, while patents remain concentrated in a few countries aligned with their markets. Technologies are focused on wettability, surface complexation, CO₂ interactions, emulsification, aerogels, reinjection water treatment, carbonate reservoirs, effluent treatment, nanofluidics, and ASP fluids. Recent topics include CO₂ associations, permeability, fractured reservoirs, gels, reservoir water, wettability alteration, and reservoir/oil heterogeneity. The findings indicate the need for multivariated development of customized smart waters to address complex interfacial synergistic mechanisms. International Joint Industry Projects and global regulations on the safe use and composition of hybrid injections are recommended to accelerate development, reduce environmental impacts, and enhance the efficient use of existing fields, alleviating the challenges of finding new reservoirs. Full article

To overcome the production bottleneck induced by the high viscosity of extra-heavy oil and resolve the issues of limited efficiency in traditional thermal oil recovery methods (including cyclic steam stimulation (CSS), steam flooding, and steam-assisted gravity drainage (SAGD)) as well as the fragmentation of existing viscosity reducer evaluation systems, this study establishes a multi-dimensional evaluation system for the effectiveness of viscosity reducers, with stage-averaged remaining oil saturation as the core benchmarks. A “1D static → 2D dynamic → 3D synergistic” progressive sequential experimental design was adopted. In the 1D static experiments, multi-gradient concentration tests were conducted to analyze the variation law of the viscosity reduction rate of viscosity reducers, thereby screening out the optimal adapted concentration for subsequent experiments. For the 2D dynamic experiments, sand-packed tubes were used as the experimental carrier to compare the oil recovery efficiencies of ultimate steam flooding, viscosity reducer flooding with different concentrations, and the composite process of “steam flooding → viscosity reducer flooding → secondary steam flooding”, which clarified the functional value of viscosity reducers in dynamic displacement. In the 3D synergistic experiments, slab cores were employed to simulate the SAGD development process after multiple rounds of cyclic steam stimulation, aiming to explore the regulatory effect of viscosity reducers on residual oil distribution and oil recovery factor. This novel evaluation system clearly elaborates the synergistic mechanism of viscosity reducers, i.e., “chemical empowerment (emulsification and viscosity reduction, wettability alteration) + thermal amplification (steam carrying and displacement, steam chamber expansion)”. It fills the gap in the existing evaluation chain, which previously lacked a connection from static performance to dynamic displacement and further to multi-process synergistic adaptation. Moreover, it provides quantifiable and implementable evaluation criteria for steam–chemical composite flooding of extra-heavy oil, effectively releasing the efficiency-enhancing potential of viscosity reducers. This study holds critical supporting significance for promoting the efficient and economical development of extra-heavy oil resources. Full article