Application In Oil-water Separation Research Articles

Enhanced separation flux and compressive strength for oil-water separation by adding sodium lignosulphonate

Oil-water separation materials have been deeply developed to solve oil spill problems. However, mechanical strength and separation efficiency remain challenging. Based on the electrostatic repulsion, we design and prepare oil-water separation materials to enhance the separation flux and resistance to pressure by adding sodium lignosulphonate nanoparticles (LSs) to the reduced graphene oxide (rGO), followed by surface modification with trimethoxymethylsilane (MTMS). XRD patterns prove the positive action of LSs for improving interlayer spacing of rGO, which contributes to an excellent separation flux (carbon tetrachloride/water, 43209.71 L⋅m-2⋅h-1) of MLNGA. The compressible recovery ability is enhanced to 49.91 kPa under 80 % strain. The MLNGA presents excellent separation efficiency (∼99.12 %) on a continuous oil-water separation device. All these results indicate the outstanding performances and potential of MLNGA in oil–water separation applications. Moreover, this design concept involves electrostatic repulsion and may be promoted to other anionic macromolecules such as sodium alginate, tannic acid, and pectin.

Magnetic Hyperporous Elastic Material with Excellent Fatigue Resistance and Oil Retention for Oil-Water Separation.

Oily wastewater has caused serious threats to the environment; thus, high-performance absorbing materials for effective oil-water separation technology have attracted increasing attention. Herein, we develop a magnetic, hydrophobic, and lipophilic hyperporous elastic material (HEM) templated by high internal phase emulsions (HIPE), in which free-radical polymerization of butyl acrylate (BA) and divinylbenzene (DVB) is employed in the presence of poly(dimethylsiloxane) (PDMS), lecithin surfactant, and modified Fe3O4 nanoparticles. The adoption of the emulsion template with nanoparticles as both stabilizers and cross-linkers endows the HEM with biomimetic hierarchical open-cell micropores and elastic cross-linked networks, generating an oil absorbent with outstanding mechanical stability. Compressive fatigue resistance of the HEM is demonstrated to endure 2000 mechanical cycles without plastic deformation or strength degradation. By exploiting the synergistic effect of hierarchical structures and low-surface-energy components, the resulting HEM also possesses excellent and robust hydrophobicity (water contact angle of 164°) and good oil absorption capacity, in which Fe3O4 nanoparticles lead to convenient magnetically controlled oil recyclability as well. Notably, the unique biomimetic microporous structure demonstrates superior oil retention capacity (>95% at 1000 rpm and >60% at 10,000 rpm) over the state-of-the-art porous materials for a diverse variety of oils to reduce the risk of secondary oil leakage, along with good recoverability by squeezing owing to the excellent compression resilience. These excellent performances of our HEM provide broad prospects for practical applications in oil-water separation, energy conversion, and smart soft robotics.

Sustainable and efficient oil-water separation using bio tin oxide-based superhydrophobic membrane

IntroductionSuperhydrophobic materials are considered an ideal method for oil-water separation. However, existing oil-water separation methods have the problem of manufacturing complex and toxic chemical reagents. To address the limitation, we proposed a novel approach to sustainable and efficient oil-water separation using a superhydrophobic membrane based on the Bio Tin oxide nanoparticles (Bio-SnO2 NPs).MethodsThe study involves synthesizing Bio-SnO2 NPs from the sunflower leaf extract which was natural and non-toxic and modifying textile fabric with a superhydrophobic coating (S.T.F.). Characterization techniques including SEM, FTIR, and BET analysis are employed to assess the structural and textural properties of the modified membrane.Results and DiscussionThe textile fabric was modified with a superhydrophobic coating (S.T.F.), demonstrating enhanced wettability, oil absorption capacity, and oil-water separation performance. The Bio-SnO2 NPs exhibited crystalline structures with a length of 90 nm and a diameter of 20 nm, as confirmed by SEM analysis. FTIR results revealed characteristic peaks at 3410 cm-1 and 642 cm-1, indicating the presence of hydroxyl group and Sn-O bonds confirming the successful synthesis of Bio-SnO2 NPs. BET analysis showed a substantial specific surface area of 413 m2/g and a pore volume of 0.19 cm3/g, emphasizing the textural properties. The FTIR and SEM techniques were used to study the characteristics of the textile fabric before and after modification with the superhydrophobic coat. The S.T.F. exhibited remarkable superhydrophobicity with a water contact angle of 152° and a water sliding angle of 4°. Absorption capacities for coconut oil, diesel, and hexane were found to be 70.4 g/g, 63.5 g/g, and 49.6 g/g, respectively, with excellent cyclic stability. Separation efficiency for hexane, diesel, and coconut oil was found to be 99.5, 97.1%, and 96.3%, respectively, with excellent cyclic stability. Mechanical stability test revealed superhydrophobicity retention even after an abrasion length of 200 mm. The chemical stability test indicated that the superhydrophobicity was maintained in the pH range of 3-11. Moreover, the flux for hexane, diesel, and coconut oil was 9400 L m−2 h−1, 8800 L m−2 h−1, and 8100 L m−2 h−1, respectively, highlighting the membrane’s efficient oil-water separation capabilities. These results collectively position the developed S.T.F. as a promising and sustainable solution for diverse oil-water separation applications.

Rational design and application of superhydrophobic fluorine-free coating based on double-decker silsesquioxane for oil-water separation

A superhydrophobic coating of methoxysilane-functionalized double-decker silsesquioxane (M-DDSQ) on cotton fabric was synthesized using the dip-coating method. Characterizations using FT-IR, XPS, SEM, and AFM demonstrated that M-DDSQ-fabric has chemically covalently grafted M-DDSQ on the fabric surface and exhibits excellent chemical stability and antifouling properties compared to the pristine fabric. Interestingly, the novel fluorine-free fabric has a superhydrophobicity property with a water contact angle (WCA) of 150°, which efficiently and quickly separates oil from water. The maximum flux reaches 88,420 L m−2 h−1, and the separation efficiency is greater than 99 %. Furthermore, its outstanding superhydrophobic durability against tape-peeling, abrasion, and chemicals such as strong acidic and alkaline solutions is attributed to the strong chemical bonding between M-DDSQ and the fabric surface. This simple and efficient method enables the preparation of a durable superhydrophobic fluorine-free coating, which can be applied to synthesize other superhydrophobic materials for self-cleaning, especially for oil-water separation applications.

Multiresponsive Behavior of the Pickering Emulsifier and Its Application for Collecting Small Oil Droplets in Water.

Responsive Pickering emulsions, with unique nanoparticle interfaces and sensitivity to external stimuli, significantly enhanced the stability and applicability of Pickering emulsions. Multifunctional composite material poly((2-(dimethylaminoethyl methacrylate)-b-(acrylate cyclodextrin))/Fe3O4 nanoparticles, namely P(DMAEMA-b-A-CD)/Fe3O4, with both multiresponsive characteristics and emulsifying capabilities had been designed to remove small oil droplets from water. Using the reversible addition-fragmentation chain transfer (RAFT) method, diblock polymers P(DMAEMA-b-A-CD) were grown in a controlled manner on the surface of Fe3O4. The Fe3O4 core showed responsiveness to a magnetic field, and the block copolymers prepared via the RAFT method demonstrated reactivity to both pH and CO2. The P(DMAEMA-b-A-CD)/Fe3O4 nanoparticles exhibited the capability to form Pickering/Oxford emulsions with exceptional stabilization properties. It could be observed that the introduction of CO2, acid, and a magnetic field led to the breakage of the emulsion, while the emulsion could be restabilized by removing the CO2 and the magnetic field or by adding alkali. Measurements of interfacial tension, ζ-potential, and contact angle demonstrated that the emulsification/breakdown mechanisms associated with pH and CO2/N2 were related to the surface wettability of the nanoparticles. In addition, the emulsifier had an excellent cycling capacity with at least 10 cycles by CO2/N2. Additionally, P(DMAEMA-b-A-CD)/Fe3O4 nanoparticles exhibited excellent stability in oil phases with large polarity differences and various real oil phases with different viscosities. Importantly, the P(DMAEMA-b-A-CD)/Fe3O4 nanoparticles could serve as functional materials for efficiently separating small oil droplets from water through the application of a magnetic field. Therefore, P(DMAEMA-b-A-CD)/Fe3O4 nanoparticles held promising potential as materials with economic and commercial value for oil-water separation applications.

Vat photopolymerization of silicon carbide strengthened alumina ceramic composites with honeycomb structure for heat insulation and oil/water separation

In this study, the effects of different silicon carbide (SiC) particle sizes on the viscosity and curing behavior of alumina (Al2O3) ceramic suspensions were thoroughly investigated. The findings revealed that increasing the size of SiC particles led to a noticeable decrease in the viscosity of the suspension. The Al2O3 ceramic suspension with 0.6 μm SiC powder demonstrated a shallower cure depth and wider excess width compared to the suspension with 1.0 μm SiC powder. Sintering tests demonstrated that the properties of the SiC–Al2O3 ceramics improved at higher sintering temperatures. Moreover, a high-performance honeycomb ceramic was successfully designed and fabricated with a porosity and compressive strength of 30.8 % and 188 MPa, respectively. Finally, the SiC–Al2O3 honeycomb ceramics were effectively applied in heat insulation and oil-water separation applications, demonstrating their remarkable capabilities.

Structure-property relationship of polyhedral oligomeric silsesquioxanes/polydimethylsiloxane superhydrophobic coatings for cotton fabrics

Cotton fabrics are extensively utilized in daily life due to striking advantages such as softness, breathability, skin-friendliness, and cheapness. However, they are susceptible to being contaminated owing to inherent amphiphilicity, severely affecting service lifespan and aesthetic perception. To address this issue, three distinct types of the POSS/PDMS composite coatings are explored, and applied to cotton fabrics, respectively. Subsequently, the correlations between structures of POSS and properties of the composite coatings on the modified cotton fabrics are discussed. The results show that the three types of the POSS/PDMS composite coatings impart the modified fabrics with robust superhydrophobicity even in harsh environments including mechanical damage, chemical corrosion and UV-irradiation. Notably, the damaged POSS/PDMS composite coatings on cotton fabrics can exhibit excellent superhydrophobic self-healing capability by simple heating. Meanwhile, the modified fabrics also show excellent performances in self-cleaning, anti-fouling, anti-icing and oil-water separation applications. Additionally, due to multifunctional groups of MTPOSS, the cotton fabric treated by the MTPOSS/PDMS composite coating exhibits more excellent thermal, mechanical, and UV protection properties without significantly compromising its air permeability as compared to those of the other coated cotton fabrics. This work will pave the way to exploitation and applications of novel multifunctional textiles.

Silane and fluorine free facile hydrophobicization of water hyacinth biomass for oil-water separations

As the adverse effects of using plastics and perfluorinated alkyl substances become more apparent, there is a growing need for sustainable hydrophobic products. Cellulose and its derivatives are the most abundant and widely used polymers, and cellulose-based products have great potential in industries where plastics and other hydrophobic polymers are used, such as stain-resistant fabrics, food packaging, and oil-water separation applications. In this study, we extracted cellulose from water hyacinth (WH) biomass, known for its negative environmental impact, and converted it into hydrophobic cellulose. This addresses the issue of managing WH waste and creating an environmentally friendly hydrophobic material. Initially, aldehyde groups were introduced through oxidation with periodate, followed by direct octadecyl amine (ODA) grafting onto dialdehyde cellulose (DAC) via a Schiff base condensation. The resulting ODA modified cellulose (ODA-C) was dispersed in ethanol and used to coat various materials, including cotton fabric, cellulose filter paper, and packaging paper. The modified materials showed excellent hydrophobicity as measured by their water contact angles (WCAs), and the application of the coating was demonstrated for oil-water separation, stain-resistant hydrophobic fabric, and paper-based packaging materials. FTIR, XRD, and WCA analysis confirmed the successful modification of cellulose. A high separation efficiency of 99% was achieved for diesel/water separation using modified filter paper (MoFP), under gravity. On application of the coating, cotton fabric became hydrophobic and resisted staining from dye, and paper-based packaging materials became more robust by becoming water-resistant. Overall, the facile synthesis, low cost, high efficiency, and use of environmentally friendly sustainable materials make this a promising strategy for hydrophobically modifying surfaces for a wide range of applications while reducing the menace of water hyacinth.

Janus stainless steel mesh-based membrane with asymmetric wettability for highly efficient gravity-driven oil-water emulsion separation

With the asymmetric wettability of the membrane due to its unique transmission features and functions, the application of oil-water separation achieved rapid development. Nevertheless, their practical application is severely restricted due to poor mechanical durability and low flux in the absence of external pressure. Herein, the Janus ZIF-8/stainless steel mesh/polydopamine (DZIF-8/SSM/PDA) membrane was successfully prepared using electrodeposition, in-situ growth, and shell ligand exchange reaction methods. The Janus membrane surface was created through the combination of 5, 6-dimethylbenzimidazole (DMBIM) modified superhydrophobic nanoparticles ZIF-8 (DZIF), and PDA, exhibiting underwater superoleophobicity (UWOCA 156°), superhydrophobicity (WCA 154°), and excellent anti-oil (light and heavy oil) pollutants ability. By manipulating the molecular repulsion forces on the Janus membrane surface, a stable interfacial hydration layer is created in conjunction with the micro-nano structure. This combination enables the achievement of interfacial demulsification and gravity-driven separation of emulsified oil, according to the Molecular Dynamics (MD) simulation process. The water-in-oil emulsion achieved an oil flux of 601 L m−2 h−1 with a separation efficiency of 99.1 %, while the oil-in-water emulsion demonstrated a water flux of 62 L m−2 h−1 with a separation efficiency of 99.7 %. The Janus DZIF-8/SSM/PDA demonstrated acid and alkali resistance, mechanical stability and reusability, and resistance to E. coli bacteria. Overall, this research anticipates advancing the production of durable asymmetric Janus membranes with superior separation efficiency under gravity, providing a novel solution for oil-water separation.

Benzoxazine/ thermoplastic polyurethane nanofibrous membranes with superior mechanical properties for efficient oil-water separation

The integration of membrane separation and electrospinning technologies has significantly advanced oil-water separation processes. However, enhancing the mechanical robustness, corrosion resistance, and durability of oil-water separation membranes remains a challenge. In this paper, we utilized the electrospinning technique to fabricate a micro-nanostructured nanofibrous (NFs) membrane by blending benzophenone monomer (BPAF-an) with thermoplastic polyurethane elastomer (TPU). By optimizing the solid content, the mass ratio of compounds to polymers, and the solvent composition in the spinning precursor solution, we determined the optimal electrospinning parameters for fabricating the TPU/BPAF-an NFs membrane. The incorporation of BPAF-an, known for its low surface energy, significantly enhanced the hydrophobicity of the nanofiber membrane. The TPU/BPAF-an NFs membrane demonstrated excellent mechanical properties, exhibiting a tensile strength of 7.38 MPa and an elongation at break of 292 %. The membrane had good hydrophobicity and its water contact Angle is up to 145.2°. It also displayed exceptional separation efficiency, exceeding 99 % for oil-in-water emulsions and various oil-water mixtures. Even in harsh environments such as strong acids, alkalis and salts, they have prominent hydrophobicity, lipophilicity and chemical stability. In addition, the membrane maintained a high flux rate of 1995.37 L m−2 h−1 and a separation efficiency of 96 % even after 100 cycles of oil-water separation. Consequently, the TPU/BPAF-an NFs membrane, with its superior mechanical properties and cycle stability, holds substantial promise for application in oil-water separation.

Preparation of superhydrophobic cellulose aerogel sponge from waste paper and its application in oil-water separation

Preparation of superhydrophobic cellulose aerogel sponge from waste paper and its application in oil-water separation

Polylactic acid/ zinc oxide decorated multi-wall carbon nanotubes fibrous membranes and their applications in oil-water separation

The frequent occurrence of oil spills and oily wastewater leakage has increased the demand for oil-water separation materials with good hydrophobicity. Herein, a novel polylactic acid composite fibrous membrane is reported to address this problem. The zinc oxide decorated multi-wall carbon nanotubes were synthesized via the hydrothermal reaction and composited with polylactic acid to prepare a series of fibrous membranes via electrospinning. The wetting behavior of the prepared fibrous membranes conformed to Cassie's equation, proving that the introduced zinc oxide-decorated multi-wall carbon nanotubes enhanced the surface roughness of the prepared fibrous membranes. Such rough surfaces of the fibrous membranes have enhanced the hydrophobicity and increased the water contact angle to 138.5° (in air) and 159.3° (under oil), respectively. The oil uptake of the prepared fibrous membranes has reached 73.2 g/g. The prepared fibrous membrane was able to absorb oil on the water surface, underwater, or emulsion. Therefore, the prepared polylactic acid/zinc oxide-decorated multi-wall carbon nanotubes fibrous membrane can be a good candidate material for treating oily wastewater.

Fluorine-Functionalized Covalent Organic Framework Superhydrophobic Modified Melamine Sponge for Efficient oil-water Separation.

Hydrophobic sponges have attracted significant interest in oil spills and water-oil separation as potential absorption materials due to their desirable absorptivity, selectivity, and elasticity. In this paper, a hydrophilic melamine sponge (MS) is transferred into a superhydrophobic sponge via polydimethylsiloxane (PDMS) modification followed by in situ growth of fluorine-functionalized covalent organic framework (denoted as TFA-COF) nanoparticles. Therefore, the PDMS@TFA-COF@MS sponge was successfully prepared for efficient oil-water separation. The resultant PDMS@TFA-COF@MS exhibits superhydrophobic properties with a water contact angle of 156.7°. The superhydrophobic sponge has selectivity adsorption for different organic solvents and oils from water as well as oil-water separation efficiency (96% after 30 cycles) and oil absorption capacity (12 646% after 30 cycles). Meanwhile, the PDMS@TFA-COF@MS sponge exhibits strong thermal stability and flame retardancy in addition to having exceptional resistance to chemical corrosion in acidic, alkaline, and salt solutions. Moreover, the surfactant-stabilized oil-in-water emulsion could be efficiently separated by the sponge. Therefore, the prepared superhydrophobic PDMS@TFA-COF@MS sponge demonstrates possible uses for long-life oil-water separation applications.

Bio-carbon coil aerogels from tea waste: A sustainable solution for efficient oil-water separation

Discharging wastewater containing oils, fats, and organic solvents into water bodies poses a significant threat to the already limited freshwater resources. In recent years, three-dimensional (3D) porous adsorbent materials, such as aerogel materials, have gained attention for their high separation effectiveness in adsorption technology. However, the poor mechanical strength of existing aerogel materials limits their application in oil–water separation. To address this challenge, this study proposes to use carbon coils obtained from tea waste as a template for producing low-cost, ultra-light, elastic, and highly recyclable bio-carbon coil aerogels (BCCA). The BCCA, featuring high porosity and a hierarchical porous structure, demonstrated exceptional performance in oil–water separation applications. Specifically, it exhibited a high adsorption capacity for organic solutions (39 ∼ 117 g/g) and oils (32 ∼ 41 g/g), respectively, along with excellent selectivity, rapid adsorption time of approximately 30s, and good reuse capability, maintaining an adsorption efficiency of 85 %. These remarkable properties can be attributed to the exceptional hydrophobicity of the BCCA, with a contact angle of 134°, and the rapid capillary action facilitated by the helical network structure. The use of tea waste-derived carbon coils as a precursor for producing efficient and sustainable carbon coil aerogels presents a promising solution for environmental remediation, particularly in oil–water separation applications. This research addresses the issue of wastewater contamination and contributes to the utilization of tea waste, a readily available and abundant biomass resource, in the development of value-added materials for environmental sustainability.

Superoleophilic cotton fabric decorated with hydrophobic Zn/Zr MOF nanoflowers for efficient self-cleaning, UV-blocking, and oil–water separation

Oil spills significantly threaten aquatic life, human health and the environment, necessitating oil–water separation methods. To address these environmental concerns, a hydrophobic Zn/Zr bimetallic metal–organic framework nanoflowers (H-Zn/Zr MOF-NF) functionalized superhydrophobic cotton fabric is developed for oil–water separation. Hydrophilic amine-terminated bimetallic Zn/Zr MOF with distinctive flower-like morphology is hydrothermally synthesized and functionalized with myristic acid. Finally, cotton fabric is coated with a hydrophobic emulsion of H-Zn/Zr MOF-NF and polydimethylsiloxane (PDMS) via dip-coating,enhancing surface roughness and lowering surface energy. The developed superhydrophobic cotton fabric shows exceptional water-repellency with a water contact angle (WCA) and water slidingangle (WSA) of 161° and 4°, respectively. The Zn/Zr MOF-NF coated superhydrophobic cotton fabric with a porous structure efficiently separates diesel oil, n-hexane, toluene, and chloroform from water mixtures with over 98% separation efficiency and high flux. The coated cotton fabric demonstrates remarkable reusability, upholding superior separation efficiency over 95% and retaining WCA at 156° after 12 cycles with excellent physical and chemical stability. The modified cotton fabric also exhibits enhanced UV-blocking properties and self-cleaning characteristics. The designed emulsion is also applied to other surfaces, such as sponge, wood, and filter paper, demonstrating promising superhydrophobicity. This study opens new possibilities for manufacturing multifunctional superhydrophobic surfaces for oil–water separation applications using bimetallic hydrophobic MOFs.

Growth of Double-Network Tough Hydrogel Coatings by Surface-Initiated Polymerization.

Hydrogel coatings exhibit versatile applications in biomedicine, flexible electronics, and environmental science. However, current coating methods encounter challenges in simultaneously achieving strong interfacial bonding, robust hydrogel coatings, and the ability to coat substrates with controlled thickness. This paper introduces a novel approach to grow a double-network (DN) tough hydrogel coating on various substrates. The process involves initial substrate modification using a silane coupling agent, followed by the deposition of an initiator layer on its surface. Subsequently, the substrate is immersed in a DN hydrogel precursor, where the coating grows under ultraviolet (UV) illumination. Precise control over the coating thickness is achieved by adjusting the UV illumination duration and the initiator quantity. The experimental measurement of adhesion reveals strong bonding between the DN hydrogel coating and diverse substrates, reaching up to 1012.9 J/m2 between the DN hydrogel coating and a glass substrate. The lubricity performance of the DN hydrogel coating is experimentally characterized, which is dependent on the coating thickness, applied pressure, and sliding velocity. The incorporation of 3D printing technology into the current coating method enables the creation of intricate hydrogel coating patterns on a flat substrate. Moreover, the hydrogel coating's versatility is demonstrated through its effective applications in oil-water separation and antifogging glasses, underscoring its wide-ranging potential. The robust DN hydrogel coating method presented here holds promise for advancing hydrogel applications across diverse fields.

Dual-responsive emulsion system: Unraveling pH and host-guest interactions for emulsion stability and enhanced oil recovery

Surfactants facilitate the formation of crude oil emulsions in the petroleum reservoir and reduce oil-water interfacial tension, playing a crucial role in tertiary oil recovery. The host-guest interactions between β-cyclodextrin (β-CD) and surfactant molecules can regulate the solubility and hydrophobic interactions of surfactants, further regulating the interfacial and solution aggregation behaviors of the system. A ternary system composed of β-CD, nonionic surfactant Span 80, and anionic amino acid surfactant was designed to act as emulsion stabilizers and promote emulsion formation. Due to the pH responsiveness of the amino acid surfactant and host-guest interactions between the hydrophobic tail of the surfactant and β-CD, the emulsions exhibit dual responsiveness. The pH and β-CD host-guest interaction dual responsiveness determines the emulsion properties. By adjusting the proportion of β-CD in the ternary system and solution pH, the stability, droplet morphology, and rheological properties of the emulsions are all significantly affected. Interactions among emulsion stabilizers as well as their interfacial behaviors were analyzed using 1H NMR spectroscopy and interfacial tension analysis. This type of emulsion was also tested in core flooding experiments, clearly showing that the response of the emulsions to host-guest interactions can enhance crude oil recovery. Incorporating a higher concentration of β-CD into the system can boost additional secondary oil recovery by approximately 32%, while its pH responsiveness facilitates the demulsification of the system after the flooding. These research findings not only highlight the unique properties of the multi-responsive emulsion but also deepen our understanding of the interactions between surfactants. The ternary stabilizer system developed in this study demonstrates broad potential applications in flooding and oil-water separation.

Preparation of a PVDF–PDA–DETA@PVP@HNT membrane for high efficiency oil–water emulsion separation

Membrane technology is considered to be an effective method for the treatment of oily wastewater.

Facile preparation of lightweight and robust carbon aerogel monoliths for high-temperature thermal insulation and oil-water separation

Lightweight carbon aerogels (CAs) are urgently required for thermal insulation and organics absorption. However, a facile preparation method of ambient pressure drying (APD) remains a challenge since the large surface tension causes severe shrinkage, collapse or even cracking of porous network. Herein, a series of lightweight, robust and large-sized CA monoliths (0.240–0.327 g/cm3) are prepared through sol-gel polymerization of resorcinol-formaldehyde (RF) followed by solvent exchange-free APD using cotton fibers as reinforcement precursor. The deliberate tailoring of synthesis parameters and the appropriate introduction of cotton fibers jointly bring the advantages of facilitating sol-gel of RF solution.reducing drying shrinkage of hydrogels, and improving compatibility of carbonization shrinkage between fibers and matrix. Consequently, for instance, the CA composite with a density of 0.283 g/cm3, have high compressive strength (3.66 MPa), low thermal conductivity (0.070 W/(m·K)), excellent hydrophobicity (water contact angle as high as 145°), and high-volume organic absorption capability (74.8–95.7%). The facile preparation of CA composites through solvent exchange-free APD with monomer polymerization should be a promising approach to their further application in thermal insulation and oil-water separation.

Superhydrophobic Al2O3/MMT-PDMS Coated Fabric for Self-Cleaning and Oil-Water Separation Application.

This study introduces a novel superhydrophobic coating applied to the fabric surface through spray coating of the Al2O3/MMT nanocomposite and PDMS polymer to enhance the surface roughness and reduce the surface tension, respectively. The as-prepared coating exhibits a remarkable superhydrophobic property with a water contact angle (WCA) of ∼174.6° and a water sliding angle (WSA) < 5°. Notably, the fabric demonstrates a self-cleaning property through removing dust and dirt via adhering to water droplets. Moreover, the insignificant loss of WCA (3.2 and 1%) after exposure to alkaline and acidic media for 10 days verifies the promising chemical stability of the coated layer, whereas WCA > 160° after 24 h of immersion in various organic solvents further indicates the layer resistance. Besides, the layer sustains WCA of 174.5, 172.5, and 168.45° after 1 month of air exposure, ultrasonic washing, and 50 cycles of home laundry. The mechanical resistance of the fabric was verified by maintaining a WCA of 158.73° after 200 abrasion cycles. Also, the layer exhibits thermal resistance with <4.1% of WCA loss in the temperature range of -10 to 180 °C. Additionally, the superhydrophobic coating excels in oil-water separation, achieving >99% separation efficiency for various oils. These exceptional properties position the fabric for diverse applications, including protective clothing, outdoor gear, medical textiles, and sportswear, emphasizing its versatility and novelty in the realm of superhydrophobic materials.