Poly(ionic liquid)-Coated Meshes with Opposite Wettability for Continuous Oil/Water Separation

Ion transport in helical-helical polypeptide polymerized ionic liquid block copolymers

Helical-helical polypeptide polymerized ionic liquid block copolymers (PPIL BCPs) are synthesized to investigate the role of helical structure on self-assembly and ionic conductivity. PPIL BCPs, consisting of a cationic polypeptide (PTPLG) with bis(trifluoromethane sulfonimide) (TFSI) counterion and varying lengths connected to a length-fixed neutral poly-(γ-benzyl-L-glutamate) (PBLG) block, exhibit stable helical conformations with minimal glass transition (Tg) variation. Here, we show that increasing PIL composition leads to a transition from poorly ordered to highly ordered lamellar (LAM) structures with the highest PIL content BCP forming a bilayer LAM structure with close-packed helices. This morphology yields a 1.5 order of magnitude higher Tg- and volume fraction-normalized ionic conductivity and a morphology factor f > 0.8 compared to less ordered BCPs with f < 0.05 and f = 2/3 for ideal lamellae. These results highlight the critical role of helical structure in optimizing ion transport, offering a design strategy for high-performance solid electrolytes.

A comprehensive review of fundamentals and future trajectories in oil-water separation system designs with superwetting materials

The rapid increase in the production of oily wastewater by industrial and daily activities, oil spill accidents, etc., has led to critical environmental issues. The solution to oil-induced pollution lies in developing efficient oil-water separation technologies. Recently, materials with extreme wettability, particularly those exhibiting superhydrophilic with superoleophobic or superhydrophobic with superoleophilic properties, have emerged as promising solutions for achieving highly efficient and selective oil-water separation. This review offers a comprehensive overview of system designs utilizing such materials for selective oil-water separation. Here, we discuss the rationale underlying the design strategy for the systems used for the separation process. Based on the broad scenarios utilizing oil-water separation, two primary groups of system designs are identified: those handling enclosed oil-water mixtures, such as treating oily wastewater before discharge, and those addressing open-to-air hypaethral oil-water mixtures, such as in the case of oil spills, oil on water bodies post oily wastewater discharge. The review traces the evolution of system designs from batch processing to continuous processing systems, identifies commonalities, and discusses the rationale and underlying design constraints. This analysis can guide the selection of appropriate systems for testing materials in oil-water separation and provides insights into future design development for further real-life deployment.

Recent advances in membrane technologies applied in oil-water separation

Effective treatment of oily wastewater, which is toxic and harmful and causes serious environmental pollution and health risks, has become an important research field. Membrane separation technology has emerged as a key area of investigation in oil-water separation research due to its high separation efficiency, low costs, and user-friendly operation. This review aims to report on the advances in the research of various types of separation membranes around emulsion permeance, separation efficiency, antifouling efficiency, and stimulus responsiveness. Meanwhile, the challenges encountered in oil-water separation membranes are examined, and potential research avenues are identified.

Recent developments in the application of membrane separation technology and its challenges in oil-water separation: A review

In the development and production process of domestic and foreign oil fields, large amounts of oil-bearing wastewater with complex compositions containing toxic and harmful pollutants are generated. These oil-bearing wastewaters will cause serious environmental pollution if they are not effectively treated before discharge. Among these wastewaters, the oily sewage produced in the process of oilfield exploitation has the largest content of oil-water emulsion. In order to solve the problem of oil-water separation of oily sewage, the paper summarizes the research of many scholars in many aspects, such as the use of physical and chemical methods such as air flotation and flocculation, or the use of mechanical methods such as centrifuges and oil booms for sewage treatment. Comprehensive analysis shows that among these oil-water separation methods, membrane separation technology has higher separation efficiency in the separation of general oil-water emulsions than other methods and also exhibits a better separation effect for stable emulsions, which has a broader application prospect for future developments. To present the characteristics of different types of membranes more intuitively, this paper describes the applicable conditions and characteristics of various types of membranes in detail, summarizes the shortcomings of existing membrane separation technologies, and offers prospects for future research directions.

Fabrication of Swellable Organic-Inorganic Hybrid Polymers for CO2-Assisted Hydration of Propylene Epoxide

Swelling is a very common phenomenon in organic substances. However, the swelling behaviors of inorganic substances had rarely been reported. In this study, a new type of swellable organic-inorganic hybrid polymer (PIL@CHT) was designed and successfully synthesized through free-radical copolymerization of polymerizable phosphonium ionic liquid monomer and vinyl-functionalized hydrotalcite (CHT). The swelling behaviors of PIL@CHT in various solvents with a wide range of Hansen solubility parameters (δ_T) were investigated, and PIL@CHT exhibited excellent swellable capacity in the solvents with δ_T > 24.4 MPa^1/2. The swollen state of the hybrid PIL@CHT in water presented a network structure with a diameter of approximately 8-12 μm, and CHT particles were well dispersed to the channel of PIL. PIL@CHT was applied to catalyze the CO₂-assisted hydration of propylene oxide (PO), in which a cascade reaction including the cycloaddition of CO₂ and PO and the subsequent hydrolysis of propylene carbonate (PC) occurred. PIL@CHT, combining the active sites of PIL and CHT, synergistically catalyzed this cascade reaction and achieved a high yield (93.0%) and selectivity (98.2%) of 1,2-propanediol (1,2-MPG) under a low H₂O/PO ratio of 1.5/1. Moreover, the catalyst could be recycled seven times without any significant loss of catalytic activities and had good substrate generality.

Recent advances in bio-inspired ionic liquid-based interfacial materials from preparation to application

Natural creatures always display unique and charming functions, such as the adhesion of mussels and the lubrication of Nepenthes, to maintain their life activities. Bio-inspired interfacial materials infused with liquid, especially for ionic liquids (ILs), have been designed and prepared to meet the emerging and rising needs of human beings. In this review, we first summarize the recent development of bio-inspired IL-based interfacial materials (BILIMs), ranging from the synthesis strategy to the design principle. Then, we discuss the advanced applications of BILIMs from anti-adhesive aspects (e.g., anti-biofouling, anti-liquid fouling, and anti-solid fouling) to adhesive aspects (e.g., biological sensor, adhesive tape, and wound dressing). Finally, the current limitations and future prospects of BILIMs are provided to feed the actual needs.

Preparation and Separation Properties of Electrospinning Modified Membrane with Ionic Liquid Terminating Polyimide/Polyvinylpyrrolidone@Polydopamine

In this paper, superhydrophilic polyimide (PI) membranes were prepared using the electrostatic spinning method, capped with a hydrophilic ionic liquid (IL), and blended with polyvinylpyrrolidone (PVP). Using this preparation, the surface of the fiber membranes was coated in polydopamine (PDA) by means of an in-growth method. Scanning electron micrographs showed prepared blend films can form continuous fibers, for whom the distributions of diameter and pore were uniform. Post-modification (carried out by adding hydrophilic substances), the ability of the membrane surface to adhere to water was also significantly improved. The water contact angle was reduced from 128.97 ± 3.86° in unmodified PI to 30.26 ± 2.16°. In addition, they displayed a good separation effect on emulsified oil/water mixtures. The membrane flux reached a maximum value of 290 L·m⁻²·h⁻¹, with a maximum separation efficiency reached of more than 99%. After being recycled 10 times, the separation efficiency maintained a level exceeding 95%. The purpose of this study is to demonstrate the simplicity and efficiency of this experiment, thereby providing new ideas for the future application of membrane separation technology in wastewater treatment.

NaOH-Induced Fabrication of a Superhydrophilic and Underwater Superoleophobic Styrene-Acrylate Copolymer Filtration Membrane for Effective Separation of Emulsified Light Oil-Polluted Water Mixtures

Oil-polluted water mixtures are difficult to separate, and thus, they are considered as a global challenge. A superior superhydrophilic and low-adhesive underwater superoleophobic styrene-acrylate copolymer filtration membrane is constructed using a salt (NaOH)-induced phase-inversion approach. The as-fabricated filtration membrane provides a hierarchical-structured surface morphology and three-dimensional high density open-rough porous geometry with a special chemical composition including highly accessible hydrophilic -COO^- agents, which all are of great importance for long-term usage of immiscible/emulsified (light) oil-polluted wastewater separation. The separation is performed with a high efficiency and a high flux under either a gravity-driven force or a small applied pressure of 0.1 bar. The filtration membrane indicates an excellent anti-fouling property and is easily recycled during multiple cycles. The outstanding performance of the filtration membrane in separating oil-polluted water mixtures and the cost-effective synthetic approach as well as commercially scaled-up initial materials all highlight its potential for practical applications.

Strategies to Achieve a Ferrocene-Based Polymer with Reversible Redox Activity for Chiral Electroanalysis of Nonelectroactive Amino Acids

In the past, various chiral isomers accompanied by electroactive units have been distinguished using electrochemical techniques, which can produce electrochemical signals by themselves. However, it is still difficult to use an electrochemical technique to detect nonelectroactive samples. To address this bottleneck, an electroactive chiral polymer (S,S)-p-CVB-Fc that contains one redox-active ferrocene unit was designed and synthesized in this study. The electroactive polymer can give electrochemical signals as an alternative to the tested chiral samples, regardless of whether the isomers have electroactive units. Then, it was fixed on the surface of a glassy carbon electrode as an electrochemical chiral sensor. When nonelectroactive amino acids including proline, threonine, and alanine were examined by the sensor, clear discrimination in the response of peak current could be observed toward l- and d-isomers at pH 6.5. The peak current ratios (I_L/I_D) for proline and alanine were 1.47 and 1.48, respectively. In contrast, for threonine, the d-isomer exhibited a higher peak current than the l -isomer with a ratio of 2.59. In summary, the results ensure that the current work can enlarge the testing scope of chiral samples in the field of chiral electroanalysis using an electroactive sensor.

Poly(ionic liquid)s with superior swelling and enrichment properties in solvents

The molar swelling ratio and enrichment factor of poly(ionic liquid)s were linearly positively correlated with the Hansen solubility parameter of the solvent and the difference between the Hansen solubility parameters of mixed solvents, respectively.