Excellent Separation Efficiency Research Articles

Modulation of the Microstructure and Enhancement of the Photocatalytic Performance of g-C3N4 by Thermal Exfoliation

This work explores the impact of reaction temperature during thermal exfoliation treatment of bulk-g-C3N4 in the air atmosphere on the structure and performance of the resulting CN photocatalyst. The analysis conducted using XRD, FT-IR, XPS, SEM, and elements mapping tests, illustrated an increase in nitrogen-vacancy and oxygen content on the surface of the CN photocatalyst, resulting in a porous and sparse structure, changes in crystal size, and improved visible light absorption performance. The photocatalytic reduction experiments of hexavalent chromium (Cr(VI)) showed that the CN-540 showed the highest reduction rate of 96.9%, with a reaction rate constant 6.21 times that of bulk-g-C3N4. After 100 min of illumination, the photocatalytic degradation rates of CN-540 for TC-HCl and RhB were 66.7% and 60.6%, respectively. The TOC test results indicated mineralization rates of 51.5% for TC-HCl and 46.6% for RhB. Room temperature fluorescence spectroscopy (PL), transient photocurrent response (TPC), and electrochemical impedance spectroscopy (EIS) measurements confirmed the excellent photogenerated charge carrier separation and transport efficiency of CN-540. The photocatalytic mechanism for reducing Cr(VI) by CN-540 was elucidated based on the active species •OH and •O2– and Mott-Schottky (M-S) tests. This study provides experimental data for optimizing the photocatalytic performance of g-C3N4 and paves a new way for developing efficient photocatalysts. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Microfluidic Precision Manufacture of High Performance Liquid Chromatographic Microspheres

A key bottleneck in developing chromatographic material is the chemically entangled control of morphology, pore structure, and material chemistry, which holds back precision material manufacture in order to pursue advanced separation performance. In this work, a precision manufacture strategy based on droplet microfluidics was developed, for production of highly efficient chromatographic microspheres with independent control over particle morphology, pore structure and material chemistry. The droplet‐synthesized microspheres display extremely narrow particle size distribution (CV<3%), enabling a 100% production yield due to complete elimination of sieving steps. More importantly, the size of the droplet‐synthesized microspheres is freely adjustable without the need for re‐optimizing chemical recipes or reaction conditions. The resulting materials exhibit excellent separation efficiencies, achieving a reduced plate height of hmin​=1.67. This precision manufacture strategy also allows for flexible pore design and continuous pore size adjustment across three orders of magnitudes, providing a novel vehicle for resolution fine‐tuning targeting protein separation. Besides traditional silica, organic‐inorganic hybrid silica, zirconia, and titania microspheres can also be precisely synthesized on the same platform, supporting various separation applications and operating conditions. Powered by precision manufacture, super‐throughput production, and versatile chemistry, the high‐performance droplet‐synthesized separation material will pave the way towards green and precision chromatographic industry.

Microfluidic Precision Manufacture of High Performance Liquid Chromatographic Microspheres.

A key bottleneck in developing chromatographic material is the chemically entangled control of morphology, pore structure, and material chemistry, which holds back precision material manufacture in order to pursue advanced separation performance. In this work, a precision manufacture strategy based on droplet microfluidics was developed,for production of highly efficient chromatographic microspheres with independent controloverparticle morphology, pore structureand material chemistry.The droplet-synthesized microspheres display extremely narrow particle size distribution (CV<3%), enabling a 100% production yield due to complete elimination of sieving steps. More importantly, the size of the droplet-synthesized microspheres is freely adjustable without the need for re-optimizing chemical recipes or reaction conditions. The resulting materials exhibit excellent separation efficiencies, achieving a reduced plate height of hmin​=1.67. This precision manufacture strategy also allows for flexible pore design and continuous pore size adjustment across three orders of magnitudes, providing a novel vehicle for resolution fine-tuning targeting protein separation. Besides traditional silica, organic-inorganic hybrid silica, zirconia, and titania microspheres can also be precisely synthesized on the same platform, supporting various separation applications and operating conditions. Powered by precision manufacture, super-throughput production, and versatile chemistry, the high-performance droplet-synthesized separation material will pave the way towards green and precision chromatographic industry.

In-Situ construction of Bulge-like microstructures in sugarcane-based superhydrophobic membranes for efficient separation of water-in-oil emulsions

The separation of oil/water pollution is of great importance to environmental protection. However, the development of superwetting materials for efficient separation of surfactant-stabilized oil/water emulsions still faces challenges. As agricultural waste, sugarcane straw contains many hydrophilic groups and multilayered pore structures, making it suitable for purifying oil/water emulsions by simple chemical modification treatments. Herein, sugarcane-based superhydrophobic membranes (SSMs) were prepared by a facile vacuum impregnation method in hexadecyltrimethoxysilane (HDTMS) solution. The unique bulge-like microstructures were constructed in the intrinsic pores of sugarcane, which significantly increased the roughness and resulted in superhydrophobicity with the water contact angle of 153.5°. More importantly, the bulge-like structure is easy to break the emulsion and thus SSMs offer excellent separation efficiency (> 99 %), suitable fluxes (368 L•m−2•h−1) and strong cycling stability for surfactant-stabilized water-in-oil emulsions. In addition, SSMs can separate oil/water mixtures and directly adsorb oil from water with adsorption rates exceeding 99 %. SSMs have good durability and anti-mold adherence properties, and they do not lose their unique wetting properties even in harsh environments. More importantly, SSMs can be degraded in soil at the end of their life cycle, avoiding secondary pollution for the environment. This simple, in-situ impregnation technique offers a novel way to create green, inexpensive and stable biomass membranes for effective water-in-oil emulsion separation, showing great promise for use in oily wastewater treatment.

Tannic Acid Film Based on One-Dimensional Supramolecular Self-Assembly for Electrical Conductivity and Oil-Water Separation.

Tannic acid is widely regarded as one of the most promising natural polyphenolic compounds. However, current research predominantly focuses on the utilization of its phenolic hydroxyl groups, with limited exploration of the functional potential of its aromatic structure. Herein, one-dimensional nanofibers based on supramolecular self-assembly were successfully prepared through the simple alkylation reaction of tannic acid and the π-π stacking of aromatic structures. These fibers, with lengths reaching tens of micrometers and an average height of 10 nm, were clearly observed using SEM and AFM. A film with excellent electrical conductivity (σ = 37.9 μS/cm) was fabricated by vacuum filtering the organic suspension of these fibers, which was 100-fold higher than that of the TA film. Additionally, the hydrophobic and lipophilic properties of Bn-TA were further investigated through oil-water separation experiments, where the Bn-TA membrane displayed excellent separation efficiency and durability, maintaining stable performance over multiple cycles. This strategy presents opportunities for the high-value utilization of tannic acid.

Enhancing durability and oil-water separation efficiency with plasma-treated graphene oxide coated mesh

In recent years, there has been a surge in interest surrounding the fabrication and utilization of superhydrophobic and superhydrophilic surfaces, driven by their exceptional functionalities and properties. Graphene Oxide (GO) has inherent hydrophilicity and underwater superoleophobicity, which has made this material a particularly capable candidate for oil-water separation. Addressing the persistent challenge of efficient oil-water separation in industrial contexts, this study presents the fabrication of a GO-coated stainless steel mesh via a facile dip coating method augmented by an intermediate two-step O2 plasma treatment. The coated meshes were tested with various oil and water mixtures, including neutral, acidic, saline, and hot water, to find separation efficiency and recyclability. Notably, the meshes can achieve excellent separation efficiency of approximately 98.9 % and a superior flux of 11,464 L m−2 h−1 driven by gravity. This is a significant improvement over GO-coated meshes without O2 plasma treatment. Moreover, the plasma-treated meshes exhibit robust long-term durability and chemical stability, maintaining high underwater oil contact angles ≥119° even after extended immersion in diverse pH mediums and salt solutions for 150 days. This work showcases the practical viability of plasma-treated GO-coated meshes for oil-water separation applications and establishes a framework for systematically evaluating their long-term performance in harsh immersion conditions.

Mixed matrix membranes by post-modified UiO-66-NH2 for efficient treatment of dyeing wastewater

The preparation of modified membranes utilizing the UiO-66 framework for wastewater filtration is regarded as one of the most promising approaches to wastewater treatment, owing to its high efficiency and cost-effectiveness. In this study, a post-modified MOF, UiO-66-RSA, was synthesized via the condensation reaction of UiO-66-NH2 and 2,4-dihydroxybenzaldehyde. PVDF mixed matrix membranes (MMMs) were fabricated for the first time by mixing UiO-66-RSA into PVDF using the non-solvent induced phase separation (NIPS) method. Compared to pure PVDF membranes, the newly developed membrane, M4, demonstrated enhanced compatibility and superior mechanical strength. In dyeing wastewater treatment applications, M4 showed excellent separation efficiency for dye and heavy metal mixed wastewater, achieving rejection rates exceeding 90%. Additionally, it maintained a high flux recovery rate (FRR > 90%) and rejection rate (Rejection > 90%) after six filtration cycles of dye-containing wastewater, indicating strong recyclability. These findings suggest that MMMs embedded with UiO-66-RSA hold significant promise for dyeing wastewater treatment.

Thin film nanocomposite membrane ornamented with Z-scheme heterojunction carbon dot/NiFe–LDH for removal of organic contaminants from industrial wastewater

Removal of organics from wastewater is a tedious process and industries are looking for a facile, energy efficient strategy of wastewater treatment for producing clean water and recycling. Membrane technology is one of the efficient processes for wastewater treatment due to its energy efficient nature, simple operation and excellent performance. But, proneness of membrane fouling often limits its path to triumph. In this work, we have designed a ‘carbon dot/NiFe-layered double hydroxide (CD/NiFe–LDH)’ nanocomposite via in situ approach, which is coated on a poly(ethylene terephthalate) (PET) and cellulose based superhydrophillic membrane. The membrane is found to have excellent separation efficiency. The photocatalytic activity of CD/NiFe–LDH shows high oxidative degradation of the accumulated organics contaminants on the membrane surface providing self-cleaning ability and hence enhances the membrane’s lifetime. The membrane exhibits stable performance for 30 days continuous operation under UV-A light. The membrane flux is found to be ∼42 Lm−2 h−1 and 48 Lm−2 h−1 for crude oil–water emulsion and phenol respectively while rejection around ≥99 % is obtained for the both. The flux recovery ratio (FRR) of the post photo irradiated membrane is found to be 88.07 %. The membrane also shows organic solvent resistance property and prevents bacterial pathogens in wastewater.

Construction of sulfur-chloride co-doped triazine/heptazine homojunction carbon nitride photocatalyst for simultaneous production of H2O2 and lignin C-C bond cleavage

Photocatalytic H2O2 production and cleavage of lignin C-C bonds is a typical strategy that follows sustainable development. Unfortunately, the photocatalytic efficiency of these two reactions still faces significant challenges. Herein, a carbon nitride photocatalyst (tri/hep-CN) with sulfur-chloride co-doped triazine and heptazine structures was synthesized. It was simultaneously used for photocatalytic H2O2 production and lignin C-C bond cleavage. In the air atmosphere, the yield of H2O2 reached 1171.9 μmol•g−1•h−1 after the addition of β-1 lignin model 1,2-diphenylethanol (Dpol) to the solvent. The yield of H2O2 increased by 20 times compared with no addition of Dpol. The lignin C-C bond in Dpol is also efficiently broken, producing benzaldehyde and benzyl alcohol. tri/hep-CN has excellent photogenerated carrier separation efficiency and positive valence potential, which improves the photocatalytic H2O2 production and lignin C-C bond cleavage performance. Notably, coupling photocatalytic H2O2 production with lignin C-C bond cleavage to fully use photogenerated electrons and holes is also very important to obtain outstanding photocatalytic performance. Mechanistic studies have shown that photocatalytic H2O2 production follows an indirect reaction mechanism. Meanwhile, the cleavage of lignin C-C bond follows the Cβ radical mechanism and the single electron transfer mechanism. This work is very instructive for simultaneous photocatalytic H2O2 production and lignin C-C bond cleavage studies.

Magnetic-responsive sensors based on polydopamine macromolecules for highly sensitive detection of trace food colorant residues

As a kind of unique biomimetic macromolecule, polydopamine (PDA) have prominent in-situ reduction ability and interfacial adhesion. In this work, combined with in-situ reduction ability of PDA and excellent magnetic response performance of nickel foam (NF), a strategy was designed to fabricate a series of NF@PDA@AgNPs as magnetic-responsive surface enhancement Raman scattering (SERS) substrates for highly sensitive Rhodamine B (RhB) detection in chili powder. With crystal violet (CV) as probe molecule, the detection limit of SERS substrate could achieve 10−10 M, and the enhancement factor was as high as to 2.22 × 107. In addition, the NF@PDA@AgNPs SERS substrates showed excellent magnetic separation efficiency, good SERS uniformity and storage stability. More importantly, these substrates could achieve highly efficient collection and sensitive detection of RhB residues in chili powder by magnetic adsorption method, and the detection of limit was as low as to be 10−6 g/g. These NF@PDA@AgNPs substrates would be a great prospect for rapid and efficient pernicious contaminant detection in the chemical and biological fields.

Exploring the potential of perovskite structured SrTiO3 ceramics nanoparticles for developing SrTiO3 ceramics-decorated advanced Super-Wettable and photocatalytic self-cleaning membrane and its applications

There is a huge potential in developing robust, highly stable, and covalently crosslinked ceramics-decorated membranes that can be efficiently used for the treatment of oil-contaminated water. Hence, the current work was focused on developing a photo-active strontium titanate (SrTiO3) perovskite ceramics decorated highly stable membrane with photocatalytic self-cleaning, superoleophobic underwater and superhydrophilic in air features. The SrTiO3 perovskite structured ceramics were decorated in the active layer of the membranes through interfacial polymerization on a polyvinylidene difluoride (PVDF) ultrafiltrationsupport. For the sake of photoactive SrTiO3 ceramics nanoparticles to take part in the interfacial polymerization, the SrTiO3 ceramics nanoparticles were functionalized with amino silane using 3-aminopropyltriethoxysilane yielding amino-functionalize-SrTiO3 (F-SrTiO3). Ethylenediamine (EDA) was used as an additional amine for ensuring the suitable cross-linking of the polyamide (PA) network where isophthaloyl chloride (IPC) was used as a crosslinker. The resultant F-SrTiO3/PA@PVDF membrane was thoroughly investigated through several membrane characterization techniques confirming the existence of all the components in the membrane structure. When applied for separating the emulsified and surfactant stabilized oil from water, the F-SrTiO3/PA@PVDF membrane showed excellent separation efficiency reaching >99 % for an emulsion of 200 ppm with a permeance of 56 L m−2 h−1 bar−1. Moreover, the membrane showed an underwater superoleophobic (θO, W = 159.9°) nature owing to the presence of amide linkages and superhydrophilic F-SrTiO3 nanoparticles. These features lowered the evidence of membrane fouling and the photocatalytic self-cleaning potential of F-SrTiO3 resulted in removing the foulants from the membrane surface with a flux recovery of 95 % while keeping the separation efficiency intact. Hence, the current approach of covalently incorporating the photocatalytic, superhydrophilic F-SrTiO3 in the membrane active layer proved to be robust and can be readily scaled up and applied in real-life filtration conditions.

Chitosan-amidated lignin aerogel beads efficiently loaded with lanthanum hydroxide for phosphate removal from aqueous solutions

Developing phosphorus removal adsorbents with high adsorption performance and excellent structural stability remains a challenge. Herein, a chitosan (CS) - amidated lignin (AL) gel-bead adsorbent with high efficiency in immobilizing lanthanum hydroxide (La(OH)3) was fabricated via an in situ precipitation and freeze-drying strategy (abbreviated as La@ALCSx). The abundant hydroxyl and amino groups in CS promoted excellent loading of La(OH)3 on the surface and inside of the adsorbent. The introduction of lignin enhanced the structural stability of the beads along with the mass transfer efficiency. Owing to the porous structure and high La utilization, the adsorption capacity of La@ALCS2 reached 130.52 mg P g−1. Intra-sphere complexation of La(OH)3 with phosphate resulted in high adsorption selectivity of La@ALCS2. Moreover, the millimeter-sized of La@ALCS2 has favourable recoverability and maintains high adsorption performance after five adsorption-desorption cycles. Characterization analysis indicated that electrostatic attraction and ligand exchange were the main adsorption mechanisms. The excellent phosphorus removal efficiency, separation efficiency and recyclability of La@ALCSx provide a viable solution for the remediation of phosphate contaminated waters.

Donor-acceptor type of triazine-based conjugated organic polymers with excellent charge separation for efficient photocatalytic production of hydrogen peroxide

Hydrogen peroxide (H2O2) was widely utilized as an environmentally friendly and efficient chemical in various fields. The photocatalytic production of H2O2 using conjugated organic polymers as photocatalysts is promising. However, conjugated organic polymers have limited applications due to the high recombination rate of photogenerated carriers, poor electron mobility rate, and long synthesis time. Herein, we rapidly prepared a novel triazine-based conjugated organic polymer (CTP-TT) for efficient photocatalytic production of H2O2 using a facile sonochemical method. The H2O2 photosynthesis rate of CTP-TT reached 3383 μmol · g−1·h−1 in pure water without the addition of sacrificial agents. The experimental and characterization results confirmed that CTP-TT possessed dual H2O2 production pathways of 2e− oxygen reduction reaction (ORR) and 2e− water oxidation reaction, with 2e− ORR dominating. The theoretical calculations indicated that the excellent charge separation efficiency of CTP-TT was due to its unique donor–acceptor structure. This study provides novel design ideas for improving the photocatalytic performance of conjugated organic polymers, which is expected to promote the development of photocatalytic production of H2O2 applications and the rational design and preparation of organic semiconductor photocatalysts.

A multifunctional coating with switchable wettability for efficient oil-water and emulsions separation

Superwettable materials with switchable wettability have been attracting tremendous attention in the field of oil-water separation. In this work, a multifunctional coating with switchable wettability was designed for efficient oil-water and emulsions separation. Fe3O4 was combined with TiO2 nanoparticles and hydrophobically modified by low surface energy stearic acid (SA) to form the Fe3O4/TiO2@SA coating with uniform micro-nanostructures. The introduction or removal of amino group via ammonia treatment or heating treatment endowed the coating with reversible conversion between hydrophilicity and hydrophobicity. By switching hydrophilicity and hydrophobicity, the coating could separate oil/water/oil ternary mixtures in sequence with high separation efficiency of more than 99.9 %. More importantly, it displayed excellent separation efficiency with oil rejection above 99.5 % for oil-in-water (O/W) emulsions and water rejection above 98.7 % for water-in-oil (W/O) emulsions. Moreover, this coating showed reliable reusability and mechanical stability after 10 cycles of O/W and W/O emulsions separation and 20 cycles of sandpaper abrasion. Fe3O4 and TiO2 imparted magnetic and photocatalytic properties to the coating, allowing it to be used for magnetic navigation of oil absorption and photocatalytic degradation of organic dyes. The unique features of multifunctional coating with switchable wettability provide the blueprint for treating oily wastewater and marine oil spills.

Self-assembled perylene diimide decorated g-C3N4 heterojunction catalyst with strong interfacial charge transfer through π-π interaction for efficient boosted photocatalytic degradation of tetracycline

Perylene diimide (PDI) organic material and its derivatives as photocatalysts possesses excellent charge separation efficiency and are renowned as among the top n-type organic semiconductors capable of absorbing visible light owing to their narrow band gap (∼1.69 eV). Heterojunction photocatalysts with efficient electron transfer and excellent photocatalytic performance are of great significance for the degradation of organic compounds in the environment. In this work, a series of heterojunction catalysts (CNPDI) with robust interfacial charge transfer via π-π interaction were prepared using g-C3N4 and different mass ratio of the self-assembled PDI as precursors, subsequently utilized as efficient visible-light-driven photocatalysts for the degradation of organic tetracycline. SEM and TEM results indicated that porous CN was completely wrapped around PDI nanorod structure formed by strong π-π interactions. In the presence of activating potassium peroxymonosulfate (PMS) substances, the kinetic rate constant of the CNPDI photocatalytic system clocked in at 0.026 min−1, marking 2.36 fold increase compared to the original CN (0.011 min−1). The bolstered degradation performance was attributed to the built-in potential formed by the self-assembled PDI and CN, promoting the separation of electron-hole pairs and redistribution of charge density in the interface region. This work presents a useful insight into the crafting of PDI-based heterojunction photocatalysts for degradation environmental pharmaceutical pollutants.

Lowering Schottky barrier in MoC-based cocatalyst via heteroatoms tunning for enhanced photocatalytic hydrogen evolution

The simultaneous construction of efficient hydrogen evolution surfaces and the establishment of effective electron transport channels are crucial for improving the efficiency of photocatalytic hydrogen evolution reactions (PHERs). Molybdenum carbide materials are considered strong substitutes for Pt co-catalysts in PHERs because their electronic structure is similar to that of Pt. However, it is still challenging to enhance the kinetics of molybdenum carbide for hydrogen evolution reactions (HERs) while improving interface electron transport properties. In this study, low electronegativity heteroatoms P were introduced into metalloid MoC to adjust the overpotential of HERs while tuning the Schottky barrier between MoC and Zn0.5Cd0.5S. Due to the excellent charge separation efficiency in photocatalysts driven by the atomic-scale tuning of interfacial energetics on the prerequisite of not impairing the kinetics for surface reactions, the optimal P-MoC-modified Zn0.5Cd0.5S displayed a hydrogen evolution rate of 28.98 mmol·g−1·h−1, which was 11.59 and 1.51 times higher than that of pure Zn0.5Cd0.5S and Pt-modified Zn0.5Cd0.5S, respectively. This study provides a reference for the design of a high-efficiency co-catalyst and provides a new way for the regulation of the Mott–Schottky barrier.

One-pot construction of gradient colloidal gel coating for stable and efficient emulsion separation

Gradient gel coatings possess superior interfacial bonding strength and surface wettability, providing new ideas for the structure design of separation materials. However, simply and effectively combining colloidal gels that have excellent separation potential with gradient structure design remains a great challenge. Herein, a polymerization-induced microphase separation strategy based on metal ions is developed for constructing colloidal gel coatings with gradient structure on the stainless steel mesh. The colloidal gel is formed by hydrogen-bond complexation and microphase separation of acrylamide and methacrylic acid during polymerization. The metal ions generated by the hydrogen evolution corrosion of stainless steel mesh can not only be used to construct a continuous gradient structure by influencing the microphase separation process but also enhance the mechanical properties and stability of the gel coating. The preparation strategies of traditional gradient materials are limited in the manufacturing and application processes due to their complicated preparation procedures and potential requirement for special equipment assistance. In contrast, this strategy can simply and efficiently prepare colloidal gel coatings with continuous gradient structure by one-pot method under strict monomer ratio. Its unique colloid network demonstrates better wettability and permeability than conventional polymer gel. The prepared gradient colloidal gel coating exhibits excellent separation efficiency (above 99.9 %) and water flux recovery rate (≈98.75 %) in separating surfactant-stabilized emulsion. Therefore, this work provides new insights into the design and preparation of gradient colloidal gels, promoting their development in the field of water treatment.

0D/2D Schottky heterojunction of CsPbBr3 nanocrystals on MoN nanosheets for enhancing charge transfer and CO2 photoreduction

Solar-driven conversion of CO2 to value-added chemical fuels has been regarded as a promising strategy for solving the climate problem and energy crisis. To realize this goal, it is vital to design photocatalysts with abundant catalytic active sites and excellent charge separation efficiency. Here, perovskite nanocrystals (CsPbBr3) were anchored on two-dimensional molybdenum nitride (MoN) using an in-situ growth method, forming a new and effective 0D/2D CsPbBr3@MoN (CPB@MoN) nanoheterosturcture with close contact interface for CO2 photoreduction. The introduction of MoN, acting as a charge transfer channel, could quickly trap the photoinduced charge from CsPbBr3 and provide abundant catalytic sites for CO2 photocatalytic reactions. For optimized CsPbBr3@MoN composites, the CO yield was 13.86μmol/gh−1 without any sacrificial reagent, which was a 4.5-fold enhancement of the pure CsPbBr3. Further, in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) revealed the catalytic mechanism for the CO2 photoreduction process. This work provides a new platform for constructing superior perovskite/MoN-based photocatalysts for photocatalytic CO2 reduction.

Superhydrophobic cotton for addressing fatbergs through oily wastewater treatment

Fats, oils and grease (FOGs) deposits in sewers have recently become a significant problem, causing financial strain on water companies, damaging sewer lines, and exposing the environment to dirty water through sanitary sewer overflows. Despite the proactive use of grease traps/interceptors for physical oil-water separation, the issue of FOG deposits persists. This study proposes the use of adsorption-based oil-water separation, employing superhydrophobic cotton, as a new alternative method for removing FOGs. Durable superhydrophobic cotton was successfully prepared using a simple two-step sol-gel method, with octadecyltrimethoxysilane (ODTMS) as a modifying silane. The resulting cotton samples demonstrated remarkable superhydrophobicity, evidenced by water contact angle (WCA) above 154°. Additionally, it exhibited exceptional durability and stability when exposed to hot water, harsh acidic and alkaline solutions, as well as during a laundry test. Moreover, the cotton displayed excellent oil-water separation efficiency (> 98 %) and maintained consistent performance throughout 20 reuse cycles, highlighting its high reusability. This approach holds the potential to address the prevailing FOG deposit issues and contribute to more efficient and sustainable wastewater management practices.

Superhydrophobic hierarchically porous polymer modified by epoxidized soybean oil and stearic acid synergy for highly efficient sustainable oil-water separation

Environmental and human health are adversely affected by oil and organic wastewater pollution of water resources. However, it has always been difficult to develop an adsorption material that is multifunctional and able to remove multiple pollutants. A new hierarchically porous polymers have been synthesized using high internal phase emulsions (HIPE) template, and further modification by a physico-chemical synergy method of epoxidized soybean oil (ESO) coupled with stearic acid (STA). The modified polyHIPE (E/S-polyHIPE) exhibit superhydrophobic properties with water contact angle as high as 161.12°, and exhibit excellent robustness and chemical resistance. Oil/water mixtures can be separated using E/S-polyHIPE with a high separation efficiency (99.00–99.42 %), and it has a high oil absorption capacity (16–28 g/g) for a wide range of oil types. After 15 separation cycles, the E/S-polyHIPE exhibits excellent separation efficiency (＞ 97 %) because of its promising mechanical durability. E/S-polyHIPE still performed outstanding oil absorption capacity for floating oil, underwater oil, and emulsified oil, also it can be used as a continuous in-situ oil-water separator. An innovative approach to the fabrication of a sustainable multifunctional absorbent for oily wastewater is presented in this work, which illustrates the great potential for large-scale practical application.