Search Results (511)

Polymer-based aerogels have recently received considerable research attention as a favorable option for oil–water separation due to their enhanced porous 3D structure with great specific surface area, low density and outstanding sorption behavior. Additionally, polymer-containing aerogels exhibit more favorable characteristic properties, such as being lipophilic–hydrophobic (superhydrophobic–superoleophilic), hydrophilic–lipophobic (superhydrophilic–underwater oleophobic), or other specific wetness forms, including anisotropic and dual-wettability. In this review, cellulose and cellulose-based materials used as an aerogel for oil–water separation are comprehensively reviewed. This review highlights the significance of cellulose and cellulose-based combinations through structure–property interactions, surface modifications (using different hydrophilic and hydrophobic agents), and aerogel formation, focusing on the light density and high surface area of aerogels for effective oil–water separation. This article provides an in-depth review of four primary classifications of cellulose-based aerogels, namely, cellulose aerogels (regenerated cellulose and bacterial cellulose), cellulose with biopolymer-based aerogels (chitosan, lignin, and alginate), cellulose with synthetic polymer aerogels (polyvinyl alcohol, polyetherimide, polydopamine and others), and cellulose with organic/inorganic (such as SiO₂, MTMS, and tannic acid) material-based aerogels. Furthermore, the aspects of performance, scalability, and durability have been explained, alongside potential prospect directions for the advancement of cellulose aerogels aimed at their widespread application. This review article stands apart from previously published review works and represents the comprehensive review on cellulose-based aerogels for oil–water separation, featuring wide-ranging classifications. Full article

This study focuses on the preparation of poly(HCQM-co-VP) copolymeric nanoparticles (NPs) to enhance the aqueous solubility and bioavailability of the hydrophobic and antitumor molecules HCQ (hydroxychloroquine) and α-TOS (α-tocopheryl succinate). HCQ is covalently incorporated into the polymer backbone, while α-TOS is encapsulated within the nanoparticles by non-covalent interactions. Poly(HCQM-co-VP) was synthesized from a vinyl derivative of HCQ (HCQM) and N-vinylpyrrolidone (VP), with a molar composition of 17% HCQM and 83% VP, providing the optimal hydrophobic/hydrophilic balance for forming, via nanoprecipitation, empty nanoparticles (NPs) with a diameter of 123.6 nm and a zeta potential of −5.8 mV. These nanoparticles effectively encapsulated α-TOS within their hydrophobic core, achieving an encapsulation efficiency (%EE) of 78%. These α-TOS-loaded NPs resulted in smaller diameters and more negative zeta potentials (71 nm, −19.2 mV) compared to the non-loaded NPs. The cytotoxicity of these NPs was evaluated using the AlamarBlue assay on MCF-7 breast cancer cells. The empty NPs showed no toxic effects within the tested concentration range, after 72 h of treatment. In contrast, the α-TOS-loaded NPs, exhibited a pronounced cytotoxic effect on MCF-7 cells with an IC₅₀ value of 100.2 μg·mL⁻¹, thereby demonstrating their potential as controlled drug delivery systems for cancer treatment. These findings contribute to the development of a new HCQ-based polymeric nanocarrier for α-TOS or other hydrophobic drugs for the treatment of cancer and other diseases treatable with these drugs. Full article

Hexagonal boron nitride (h-BN) possesses a unique combination of a wide bandgap, high thermal conductivity, and chemical inertness, making it a key insulating and thermal management material for advanced electronics and nanocomposites. However, its intrinsic hydrophobicity and strong interlayer van der Waals forces severely limit exfoliation efficiency and dispersion stability, particularly in scalable liquid-phase processes. Here, we report a synergistic exfoliation strategy that integrates acid-induced hydroxylation with gallium (Ga) intercalation to achieve high-yield (>80%) production of ultrathin (<4 nm) hydrophilic h-BN nanosheets. Hydroxylation introduces abundant -OH groups, expanding interlayer spacing and significantly increasing surface polarity, while Ga intercalation leverages its native Ga₂O₃ shell to form strong interfacial interactions with hydroxylated basal planes. This oxide-mediated adhesion facilitates efficient layer separation under mild sonication, yielding nanosheets with well-preserved lateral dimensions and exceptional dispersion stability in polar solvents. Comprehensive characterization confirms the sequential chemical and structural modifications, revealing the crucial roles of hydroxylation-induced activation and Ga₂O₃ assisted wettability enhancement. This combined chemical activation–soft metallic intercalation approach provides a scalable, solution-processable route to high-quality h-BN nanosheets, opening new opportunities for their integration into dielectric, thermal interface, and multifunctional composite systems. Full article

The inherent hydrophobicity of poly(vinylidene fluoride) (PVDF) ultrafiltration membranes leads to severe membrane fouling when processing proteinaceous solutions and organic contaminants, significantly limiting their practical applications. This study presents a novel metal-ion mediated co-deposition strategy for fabricating high-performance antifouling poly(vinylidene fluoride) (PVDF) hollow fiber ultrafiltration membranes. Through Zn²⁺ coordination-driven self-assembly, a uniform and stable composite coating of dopamine (DA), tannic acid (TA), and ZIF-8 nanoparticles was successfully constructed on the membrane surface under mild conditions. The modified membrane exhibited significantly enhanced hydrophilicity, with a water contact angle of 21° and zeta potential of −29.68 mV, facilitating the formation of a dense hydration layer that effectively prevented protein adhesion. The membrane demonstrated exceptional separation performance, achieving a pure water permeability of 771 L/(m²∙h∙bar) and bovine serum albumin (BSA) rejection of 97.7%. Furthermore, it showed outstanding antifouling capability with flux recovery rates exceeding 83.6%, 74.7%, and 71.5% after fouling by BSA, lysozyme, and ovalbumin, respectively. xDLVO analysis revealed substantially increased interfacial free energy and stronger repulsive interactions between the modified surface and protein foulants. The antifouling mechanism was attributed to the synergistic effects of hydration layer formation, optimized pore structure, additional water transport pathways from ZIF-8 incorporation, and electrostatic repulsion from negatively charged surface groups. This work provides valuable insights into the rational design of high-performance antifouling membranes for sustainable water treatment and protein separation applications. Full article

In this study the influence of the geological formation environment on the physicochemical properties of two natural sepiolites, as collected, was investigated. The samples analyzed were a lacustrine-derived sample from Tolsa, Spain (ST), and a hydrothermal-derived sample from La Adela, Argentine (SA). Comprehensive characterization was carried out using chemical analysis (XRF), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and evaluations of hydrophobicity/hydrophilicity behavior. The results indicate that the ST sample exhibits a higher SiO₂/MgO ratio and contains amorphous silica impurities, while the SA sample shows a composition more closely aligned with the theoretical stoichiometry of sepiolite. Furthermore, the SA sample demonstrates greater crystallinity compared to the ST sample. Morphological analysis revealed that ST consists of compact, aggregated fibrous structures, while SA is composed of disaggregated, needle-like fibers with high aspect ratios and nanometric diameters. Both samples display predominantly hydrophilic behavior; however, only the SA sample exhibits suspended particles at the interface, suggesting a slightly higher hydrophobic character than ST sample. These findings highlight the significant impact of the geological formation environment on the structural and surface characteristics of sepiolite, which, in turn, influence its performance in applications involving dispersion, adsorption, and interfacial interactions. Full article

Liposomes are nanoscale, spherical vesicles composed of phospholipid bilayers, typically ranging from 50 to 200 nm in diameter. Their unique ability to encapsulate both hydrophilic and hydrophobic molecules makes them powerful nanocarriers for drug delivery, diagnostics, and vaccine formulations. Several FDA-approved formulations such as Doxil^® (Baxter Healthcare Corporation, Deerfield, IL, USA), AmBisome^® (Gilead Sciences, Inc., Foster City, CA, USA), and Onivyde^® (Ipsen Biopharmaceuticals, Inc., Basking Ridge, NJ, USA) highlight their clinical significance. This review provides a comprehensive synthesis of how molecular dynamics (MD) simulations, particularly coarse-grained (CG) and atomistic approaches, advance our understanding of liposomal membranes. We explore key membrane biophysical properties, including area per lipid (APL), bilayer thickness, segmental order parameter ($S_{CD}$), radial distribution functions (RDFs), bending modulus, and flip-flop dynamics, and examine how these are modulated by cholesterol concentration, PEGylation, and curvature. Special attention is given to curvature-induced effects in spherical vesicles, such as lipid asymmetry, interleaflet coupling, and stress gradients across the leaflets. We discuss recent developments in vesicle modeling using tools such as TS2CG, CHARMM-GUI Martini Maker, and Packmol, which have enabled the simulation of large-scale, compositionally heterogeneous systems. The review also highlights simulation-guided strategies for designing stealth liposomes, tuning membrane permeability, and enhancing structural stability under physiological conditions. A range of CG force fields, MARTINI, SPICA, SIRAH, ELBA, SDK, as well as emerging machine learning (ML)-based models, are critically assessed for their strengths and limitations. Despite the efficiency of CG models, challenges remain in capturing long-timescale events and atomistic-level interactions, driving the development of hybrid multiscale frameworks and AI-integrated techniques. By bridging experimental findings with in silico insights, MD simulations continue to play a pivotal role in the rational design of next-generation liposomal therapeutics. Full article

Plasmid DNA (pDNA) purification plays a key role in the development of vaccines and gene therapies. Affinity chromatography stands out as a promising method for plasmid purification, leveraging a range of biological and synthetic ligands to achieve selectivity. This study investigates the potential of a synthetic ligand library consisting of triazine-based bifunctional compounds designed to mimic the side chains of amino acids that are known to bind nucleic acids. A high-throughput screening method was employed to assess the binding ability of 158 ligands within the library to single-stranded, FITC-labeled homo-oligonucleotides (G and T), each comprising 20 nucleotides, under both hydrophilic and hydrophobic conditions. High-affinity ligands were identified for both T and G oligonucleotides. Follow-up microscale chromatographic screening uncovered some false positives from the initial FITC-based screening, narrowing the selection to 22 ligands for further investigation. In the next phase of the study, the binding affinity of these ligands towards double-stranded oligonucleotides (AT and CG) was assessed. Ligand 1/2, a mimic of Ala-Lys or Gly-Lys, and ligand 2/3, a mimic of Lys-Tyr, were chosen as initial candidates for evaluating plasmid DNA purification from an Escherichia coli crude extract. The results obtained with 0.4 M ammonium sulfate in 20 mM Tris-HCl (pH 8.0) as the binding buffer were similar to those observed when purifying plasmid DNA from E. coli clarified lysates by hydrophobic interaction chromatography. The affinity resins retained RNA, while the less hydrophobic plasmid DNA was excluded in the initial fractions. Future research will be directed towards exploring the potential of the most promising ligands to separate pDNA isoforms. Full article

This study investigates key factors affecting the adsorption behavior of proteins on the multimodal chromatographic adsorbent Capto MMC, aiming to enhance selective protein separation strategies. Batch equilibrium experiments were conducted using six model proteins to explore the combined effects of pH, ionic strength, and the nature of salts (kosmotropic and chaotropic) on protein–ligand interactions. Given that the Capto MMC ligand supports multiple interaction modes beyond cation exchange, particular focus was placed on acidic proteins (pI 4–5), which exhibited binding even at moderately elevated pH values—conditions ineffective for conventional cation exchangers. Hydrophobic interactions were identified as critical for stable binding of proteins like BSA and fetuin, while hydrophilic proteins such as ovalbumin showed minimal adsorption. Chromatographic column experiments were performed to evaluate elution performance under various buffer conditions, revealing that prolonged adsorption phases can reduce recovery yields for proteins with less stable tertiary structures. The findings highlight how salt type, pH, and protein hydrophobicity interplay to modulate multimodal binding mechanisms, providing practical insights for the design of tailored purification protocols. Full article

Maximizing the efficient utilization of critical apatite resources through flotation necessitates the exploration of effective and innovative collectors. This study investigates the potential of a fatty acid mixture (FAM) synthesized from saturated palmitic and stearic acids, monounsaturated oleic and palmitoleic acids, and polyunsaturated linoleic acid. The saponified collector FAM and the depressant sodium alginate (NaAl) achieved a direct flotation of apatite from calcite and quartz (97% apatite, 10% calcite, and 7% quartz). The flotation performance with the tested combination exhibited a highly effective enrichment of apatite, mainly from calcite, which aligns with the surface chemistry assessments. Adsorption tests and zeta potential measurements confirmed the micro-flotation results. They provided compelling evidence of a chemisorption interaction between Ca²⁺ sites on calcite and the carboxyl and hydroxyl groups of NaAl. FTIR analyses suggested a reaction between the apatite surface and the carboxyl groups of saturated and unsaturated acid groups in FAM, even those conditioned with NaAl before, facilitating the complex formation. Remarkably, the synergistic effect of the functional groups demonstrates dual functionality, serving as both a hydrophilic entity for calcite and a hydrophobic entity for apatite flotation. The universal mechanism unveils substantial potential for the extensive application of FAM within apatite flotation. Full article

Cyclodextrins (CDs), cyclic oligosaccharides formed by α-1,4-glycosidic-bonded D-glucopyranose units, feature unique hydrophobic cavities and hydrophilic exteriors that enable molecular encapsulation via host–guest interactions. CDs form supramolecular host–guest complexes with diverse molecular entities, establishing their fundamental role in supramolecular chemistry. This review examines fabrication strategies for CD-based supramolecular hydrogels and their applications in tissue engineering and regenerative medicine, with focused analysis on wound healing, corneal regeneration, and bone repair. We critically analyze CD–guest molecular interaction mechanisms and innovative therapeutic implementations, highlighting the significant potential of CD hydrogels for tissue regeneration while addressing clinical translation challenges and future directions. Full article

Lost circulation is a major challenge in oil and gas drilling operations, severely restricting drilling efficiency and compromising operational safety. Conventional bridging and plugging materials rely on precise particle-to-fracture size matching, resulting in low success rates. Self-healing gels penetrate loss zones as discrete particles that progressively swell, accumulate, and self-repair in integrated gel masses to effectively seal fracture networks. Self-healing gels effectively overcome the shortcomings of traditional bridging agents including poor adaptability to fractures, uncontrollable gel formation of conventional downhole crosslinking gels, and the low strength of conventional pre-crosslinked gels. This work employs stearyl methacrylate (SMA) as a hydrophobic monomer, acrylamide (AM) and acrylic acid (AA) as hydrophilic monomers, and graphene oxide (GO) as an inorganic dopant to develop a GO-based self-healing organic–inorganic hybrid plugging material (SG gel). The results demonstrate that the incorporation of GO significantly enhances the material’s mechanical and rheological properties, with the SG-1.5 gel exhibiting a rheological strength of 3750 Pa and a tensile fracture stress of 27.1 kPa. GO enhances the crosslinking density of the gel network through physical crosslinking interactions, thereby improving thermal stability and reducing the swelling ratio of the gel. Under conditions of 120 °C and 6 MPa, SG-1.5 gel demonstrated a fluid loss volume of only 34.6 mL in 60–80-mesh sand bed tests. This gel achieves self-healing within fractures through dynamic hydrophobic associations and GO-enabled physical crosslinking interactions, forming a compact plugging layer. It provides an efficient solution for lost circulation control in drilling fluids. Full article

Janus nanoparticles (JNPs) extend the concept of amphiphilicity beyond classical molecular surfactants into the nanoscale. Amphiphilic behavior is defined by the presence of hydrophobic and hydrophilic moieties within a single molecular structure. Traditionally, such molecular structures are known as surfactants or amphiphiles and are capable of reducing interfacial tension, adsorbing spontaneously at interfaces, stabilizing emulsions and foams, and forming micelles, bilayers, or vesicles. Recent experimental, theoretical, and computational studies demonstrate that these behaviors are scalable to nanostructured colloids such as JNPs. Amphiphilic JNPs, defined by anisotropic surface chemistry on distinct hemispheres, display interfacial activity driven by directional wetting, variable interfacial immersion depth, and strong interfacial anchoring. They can stabilize liquid/liquid and liquid/gas interfaces, and enable templated or spontaneous self-assembly into supra-structures, such as monolayer sheets, vesicles, capsules, etc., both in bulk and at interfaces. Their behavior mimics the “soft” molecular amphiphiles but also includes additional particularities given by their “hard” structure, as well as contributions from capillary, van der Waals, hydrophobic, and shape-dependent forces. This review focuses on compiling the evidence supporting amphiphilicity as a scalable property, discussing how JNPs function as colloidal amphiphiles and how geometry, polarity contrast, interfacial interactions, and environmental parameters influence their behavior. By comparing surfactant behavior and JNP assembly, this work aims to clarify the transferable principles, the knowledge gap, as well as the emergent properties associated with amphiphilic Janus colloids. Full article

Polyethersulfone (PES) membranes are essential in separation processes; however, their inherent hydrophobicity can limit their effectiveness in water-intensive applications. This study aims to enhance PES membranes by modifying them with a NiFe₂O₄–nanoclay composite nanoparticle to improve both their hydrophilicity and photocatalytic potential as a photocatalytic membrane. The nanoparticles were synthesized using the sol–gel auto-combustion method and incorporated into PES membranes through mixed-matrix embedding (1 wt% and 3 wt%) and surface coating. X-ray diffraction confirmed the cubic spinel structure of the composite nanoparticles, which followed the second order kinetic reaction during the photodegradation–adsorption of crystal violet. The mixed-matrix membranes displayed a remarkable 170% increase in water flux and a 25% improvement in mechanical strength, accompanied by a slight decrease in contact angle at 1 wt% of nanoparticle loading. In contrast, the surface-coated membranes demonstrated a significant reduction in contact angle to 18°, indicating a highly hydrophilic surface and increased roughness. All membranes achieved high dye removal rates of 98–99%, but only the coated membrane system exhibited approximately 50% photocatalytic degradation, following mixed kinetics. These results highlight the critical importance of surface modification in advancing PES membranes, as it significantly reduces fouling and enhances water–material interaction qualities essential for future filtration and photocatalytic applications. Exploring hybrid strategies that combine both embedding and coating approaches may yield even greater synergies in membrane functionality. Full article

Antimicrobial resistance arises from treatment non-adherence and ineffective delivery systems. Optimal wound dressings combine localized drug release, exudate management, and bacterial encapsulation through hydrogel-forming nanofibers for enhanced therapy. In this work, polylactic acid (PLA) and polyvinylpyrrolidone (PVP) fibers loaded with chlorhexidine (CHX) were developed using Solution Blow Spinning (SBS), a scalable electrospinning alternative that enables in situ deposition. Molecular interactions between CHX and polymers in solution (by UV-Vis and fluorescence spectroscopy) and in solid state (by FTIR, XRD and thermal analysis) were studied. The morphology of the polymeric fibers was determined by optical microscopy, showing that PVP fibers are thinner (1625 nm) and more uniform than those of PLA (2237 nm). Finally, drug release from single-polymer fibers discs, overlapping fibers discs (PLA/PVP/PLA and PVP/PLA/PVP), and solid dispersions was determined by UV-Vis spectrometry. PVP-based fibers exhibited faster CHX release due to their hydrophilic nature, while PLA fibers proved sustained release, attributed to their hydrophobic matrix. This study highlights the potential of PLA/PVP-CHX fibers made from SBS as advanced wound dressings, combining biocompatibility and personalized drug delivery, offering a promising platform for localized and controlled antibiotic delivery. Full article

The SARS-CoV-2 main protease (Mpro) is a validated therapeutic target for inhibiting viral replication. Few compounds have advanced clinically, underscoring the difficulty in optimizing both target affinity and drug-like properties. To address this challenge, we integrated machine learning (ML), molecular docking, and molecular dynamics (MD) simulations to investigate the balance between pharmacodynamic (PD) and pharmacokinetic (PK) properties in Mpro inhibitor design. We developed ML models to classify Mpro inhibitors based on experimental IC₅₀ data, combining molecular descriptors with structural insights from MD simulations. Our Support Vector Machine (SVM) model achieved strong performance (training accuracy = 0.84, ROC AUC = 0.91; test accuracy = 0.79, ROC AUC = 0.86), while our Logistic Regression model (training accuracy = 0.78, ROC AUC = 0.85; test accuracy = 0.76, ROC AUC = 0.83). Notably, PK descriptors often exhibited opposing trends to binding affinity: hydrophilic features enhanced binding affinity but compromised PK properties, whereas hydrogen bonding, hydrophobic, and π–π interactions in Mpro subsites S2 and S3/S4 are fundamental for binding affinity. Our findings highlight the need for a balanced approach in Mpro inhibitor design, strategically targeting these subsites may balance PD and PK properties. For the first time, we demonstrate antagonistic trends between pharmacokinetic (PK) and pharmacodynamic (PD) features through the integrated application of ML/MD. This study provides a computational framework for rational Mpro inhibitors, combining ML and MD to investigate the complex interplay between enzyme inhibition and drug likeness. These insights may guide the hit-to-lead optimization of the novel next-generation Mpro inhibitors of SARS-CoV-2 with preclinical and clinical potential. Full article