Advancing oil-water separation: Design and efficiency of amphiphilic hyperbranched demulsifiers.

HYPOTHESIS: An innovative strategy for designing high-performance demulsifiers is proposed. It hypothesizes that integrating mesoscopic molecular simulations with macroscopic physicochemical experiments can enhance the understanding and effectiveness of demulsifiers. Specifically, it is suggested that amphiphilic hyperbranched polyethyleneimine (CHPEI) could act as an efficient demulsifier in oil-water systems, with its performance influenced by its adsorption behaviors at the oil-water interface and its ability to disrupt asphaltene-resin aggregates. EXPERIMENTS: Several coarse-grained models of oil-water systems, with CHPEI, are constructed using dissipative particle dynamics (DPD) simulation. Following the insights gained from the simulations, a series of CHPEI-based demulsifiers are designed and synthesized. Demulsification experiments are conducted on both simulated and crude oil emulsions, with the process monitored using laser scanning confocal microscopy. Additionally, adsorption kinetics and small angle X-ray scattering are employed to reveal the inherent structural characteristics of CHPEI demulsifiers. FINDINGS: CHPEI demonstrates over 96.7 % demulsification efficiency in high acid-alkali-salt systems and maintains its performance even after multiple reuse cycles. The simulations and macroscopic experiments collectively elucidate that the effectiveness of a demulsifier is largely dependent on its molecular weight and the balance of hydrophilic and hydrophobic groups. These factors are crucial in providing sufficient interfacial active functional groups while avoiding adsorption sites for other surfactants. Collaborative efforts between DPD simulation and macroscopic measurements deepen the understanding of how demulsifiers can improve oil-water separation efficiency in emulsion treatment.

Construction of an alginate-based aminated lignin composite foam with ultra-high service performance.

Lignin, a complex natural 3D aromatic polymer compound known for its high thermal stability, stiffness, and ability to effectively withstand chemical and biological attacks. When combined with various other natural biomass components, lignin can offer the promise of fortifying the physical, chemical, and biological stability of matrix materials, which has garnered significant interest. Herein, through the incorporation of alginate with aminated lignin using chemical and ionic double cross-linking and freeze-drying techniques, alginate-lignin composite functional foams (SA-NAL) with improved water affinity, mechanical strength, and overall service performance have been successfully developed. Without further chemical modification, the as-fabricated SA-NAL composite foam demonstrates: i) outstanding mechanical robustness, enduring 2000 times its weight without significant deformation in dry condition, and withstanding tensile stress up to 0.67 MPa in wet condition, ii) superior water affinity and underwater superoleophobicity (θoil > 150° for various oils), coupled with effective oil/water separation performance (separation efficiency of 99.5 %, flux of 3.37 L·m-2·s-1, and ultimate operating oil pressure of 2.36 kPa), and iii) exceptional resistance to light, heat and oxidation, and excellent flame retardancy. In summary, the synergy between aminated lignin and alginate materials has resulted in complementary functions for high-value applications of polysaccharide-based alginate materials.

Co-doped Zr-UiO-66-NH2@carboxylated cellulose nanocrystals/PAN membrane for oil/water separation with photocatalysis-PMS synergistic self-cleaning and antibacterial activity.

The development of superwetting membranes is a promising approach for separating emulsified oily wastewater. However, challenges such as low flux without external pressure and membrane fouling have hindered membrane performance. Herein, we fabricated a novel nanofibrous membrane by grafting Co-doped Zr-UiO-66-NH2 (UiO(Zr/Co)) nanoparticles onto carboxylated cellulose nanocrystals (CCNC)-polyacrylonitrile (PAN) mixed matrix electrospinning membrane via chemical bonds through EDC/NHS reaction. CCNC served a dual purpose by enhancing membrane hydrophilicity and providing connection points for UiO(Zr/Co). The as-prepared UiO(Zr/Co)@CCNC/PAN exhibited superhydrophilic/underwater superoleophobic and anti-fouling properties. The membrane demonstrated excellent demulsification and gravity-driven separation capabilities for various oil-in-water emulsions, with superior permeation flux (1588-2557 L m-2 h-1) and separation efficiency (above 99 %). Furthermore, UiO (Zr/Co)@CCNC/PAN could activate peroxomonosulfate (PMS) under visible light to remove both high viscous crude oil-fouling and bio-fouling, exhibiting impressive photocatalytic self-cleaning and antibacterial activity. The generation of reactive radicals (O2-, OH and SO4-) and non-radical (1O2) species in UiO(Zr/Co)@CCNC/PAN+PMS system through multiple pathways was confirmed. Additionally, the band structure of UiO(Zr/Co) and synergistic photocatalytic-PMS activation mechanism were investigated. This work provides new insights into the design and fabrication of MOF modified superwetting nanofibrous membrane with inherent bonding, high permeation flux, anti-fouling and self-cleaning properties.

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.

Design of multiple anti-fouling and honeycomb-like NH2-AgBiS2 @g-C3N4 hydrogel layer onto PAN fiber membrane for multicomponent pollutant-oil-water emulsion treatment.

Nano-structured hydrogel with unique anti-oil fouling property exhibits big advantage in oil/water separation, but its application in complex oily wastewater (contain oils, organic matter, bacteria, etc.) cleanup is hampered by the insufficient capabilities in multi-antifouling and synergistic treatment. Herein, we constructed the amino-rich NH2-AgBiS2/PANI (polyaniline)-g-C3N4 based multi-functional hydrogel functional layer onto the polyacrylonitrile (PAN) fiber membrane via polyphenol-mediated chitosan gelation and vacuum-assisted self-assembly techniques. The unique honeycomb-like structure and super-wetting feature synergistically contributed to the powerful oil resistance and flux breakthrough of composite membrane. Such membrane achieved superior permeability (up to 3558 L-1 m-2 h-1) for various SDS-stabilized oil-in-water emulsions and remarkable synergistic treatment efficiency of multicomponent pollutant-oil-water emulsion. The rational design of hydrogel layer on membrane surface intensified the photo-response ability and multiple electron transport channels, which offered the favorable photocatalytic self-cleaning performance towards degradation of organic dyes. According to the free radical quenching and EPR experiments, the photocatalytic mechanism was proposed. In addition, the inhibition rate of E. coli could reach 100 % under illumination of 24 h. Therefore, the integration of ultra-low oil adhesion, photocatalytic self-cleaning, and antibacterial features endows membrane with exceptional multiple anti-fouling performance, exhibiting unique advantages over traditional membranes in handling complex membrane fouling issues.

Advanced magnetic nanospheres for oil pollutant management: Dual roles in emulsification and demulsification.

Environmental contamination from oil spills and industrial oily wastewater poses significant ecological risks due to the persistence of harmful organic compounds. To address these challenges, magnetic composite nanospheres (CMNP@CHPEI) are systematically developed, with carboxylated Fe3O4 nanoparticles (CMNP) as the core and amphiphilic hyperbranched polyethyleneimine (CHPEI) as the decorated shell. These novel nanospheres combine the controllable size and magnetic responsiveness of "hard" magnetic nanomaterials with the structural complexity and functional diversity of "soft" hyperbranched polymers. This design allows for switching between emulsification and demulsification behaviors by regulating the size of the nanospheres and the amphiphilicity of CHPEI. Specifically, the nanospheres can form Pickering emulsions with oil droplet sizes smaller than 1 µm, maintaining stability for up to 75 days, and achieve rapid oil-water separation with demulsification efficiencies up to 99.8 %. Even after seven recycling experiments, they still retain significant interfacial activity and applicability. Interfacial characteristic experiments and molecular dynamics simulations reveal that particle size directly affects the film structures formed at oil-water interface, while the amphiphilic functional molecules determine the interaction mode of nanospheres with oil-water phases. These achievements introduce a versatile, environmentally friendly material for removing hazardous oil-based pollutants, with promising applications in oil spill remediation and industrial wastewater treatment.

Hydrophobic Cellulose-Based Sorbents for Oil/Water Separation.

The need for sustainable, biodegradable materials to address environmental challenges, such as oil-water separation, is growing. Cellulose-based absorbents offer an eco-friendly alternative to synthetic materials. However, their hydrophobicity must be enhanced for efficient application. In this study, cellulose-based sorbents derived from Kraft and half-bleached chemo-thermomechanical pulp (BCTMP) were hydrophobized using silanization and alkyl ketene dimer (AKD) techniques. Hydrophobic properties were successfully imparted using methyltrimethoxysilane (MTMOS), n-octyltriethoxysilane (NTES), and N-(2-Aminoethyl)-3-aminopropyltrimethoxysilane (AATMS), with water contact angles ranging from 120° to 140°. The water sorption capacity was significantly reduced to below 1 g/g, whereas the oil sorption capacity remained high (19-28 g/g). The most substantial reduction in water vapor absorption (3-6%) was observed for the MTMOS- and AATMS-silanized samples. These results demonstrate the potential of hydrophobized cellulose-based sorbents as sustainable alternatives for oil-water separation, contributing to environmentally friendly water treatment solutions.

Superhydrophobic microporous membrane based on modified microfibrillated cellulose framework for efficient oil-water separation.

The preparation of stable and efficient cellulose-based oil/water separation membranes is of great significance in solving the problem of industrial oily wastewater. Herein, rod-like hydroxyapatite (HAP) modified microfibrillated celluloses (MFCs) are used to form the fibrous framework to produce a microporous PDMS-MFC-HAP membrane. The membrane shows good superhydrophobicity with a water contact angle of 151.6°. It exhibits the oil-water separation performance for various water-in-oil emulsions. The separation flux of the membrane is up to 3665.3 L·m-2·h-1·bar-1 under 0.5 bar pressure with a separation efficiency of over 99.6 %. The PDMS-MFC-HAP membrane could maintain a high separation efficiency of 98.6 % after 20 cycles. This study provides a simple and effective method to fabricate cellulose-based superhydrophobic membranes, which have a greater potential to achieve oil-water separation for oily wastewater treatment with high efficiency.

3D cellulose scaffold with gradient pore structure controlled by hydrogen bond competition: Super-strength and multifunctional oil/water separation.

Cellulose-based aerogels offer exceptional promise for oily wastewater treatment, but the challenge of low mechanical strength and limited application functions persists. Inspired by the graded porous structures in the animal skeleton and bamboo stem, we firstly report here a stepwise solvent diffusion-induced phase separation approach for constructing the gradient pore-density three-dimensional (3D) cellulose scaffold (GPDS). Benefiting from the regulation of competitive hydrogen bonding between the anti-solvents and the ionic liquid (IL) in cellulose solution, GPDS exhibits the decreased major channels size and increased minor pores amount gradually along the solvent diffusion direction. These endow GPDS with the characteristics of low density (0.019 g/cm) and super strength (high up to 870 KPa). The application of GPDS in the field of oil-water separation has achieved remarkable results, including oil/organic solvent absorption (13-25 g/gGPDS), immiscible oil-water mixture separation (high efficiency up to 99.8 %, flux > 2000 L/m2·h), and surfactant-stabilized oil-in-water emulsion (efficiency up to 97.7 %). Moreover, a simple hydrophobic treatment further realizes the efficient separation of water-in-oil emulsion (98.5 % efficiency). The as-fabricated GPDS accordingly achieves the multifunctional application in oil-water separation field. Thus, a new avenue is opened to construct 3D cellulose porous scaffold as adsorbent materials in oily wastewater treatment.

Preparation of ultra-light, highly compressible, and biodegradable chitosan porous materials for heavy metal adsorption, dye adsorption and oil-water separation.

Chitosan materials are much important in adsorption, separation and water treatment due to their hydrophilicity, biodegradability and easy functionalization. However, they were difficult to form structural materials, which limited its application in engineering. In this paper, a new type of chitosan porous materials was prepared with two-step strategy involving the freezing crosslinking of chitosan with glutaraldehyde to form cryogels, and their subsequent reduction with NaBH4 to transform CN bonds into CN bonds, resulting in remarkable improvement of mechanical property. That is, the strength remained almost unchanged after 80 % deformation. The abundant -NH2 and -OH on the surface of materials, as well as the unique pore structure from cryogels, gave relatively high adsorption capacity for metals and dyes (88.73 ± 4.25 mg·g-1 for Cu(II) and 3261.05 ± 36.10 mg·g-1 for Congo red). The surface hydrophilicity of materials made it possible for selective water permeation with over 95 % separation efficiency for oil-water mixtures. In addition, simple hydrophobic modification using bromotetradecane achieved selective oil permeation with over 96 % separation efficiency for oil-water mixtures. This study not only provides a new strategy to endow chitosan materials with excellent mechanical property, large adsorption capacity and good oil-water separation performance, but also offers environmentally friendly materials for sewage treatment applications.

Superhydrophobic and environmentally friendly bovine bone biomass based cellulose membrane for oil-water separation.

With the development of superhydrophobic materials for oil-water separation, there is an urgent need to develop environmentally friendly, low-cost, and novel hydrophobic materials. In this paper, based on bovine bone biomass raw materials, bone ash particles are obtained by calcination and grinding, and then bovine bone ash/cotton fabric cellulose membranes are prepared by vacuum filtration and impregnation methods. The pore size of the membrane is regulated and the hydrophobicity of the material is enhanced by constructing the surface microstructures. Results indicate that the membranes possess good hydrophobicity with a contact angle of 161° and the flux can reach 53,635.2 L/m2h for light oil. The separation efficiencies for petroleum ether, cyclohexane, kerosene, and dichloromethane all reach >99 %. In addition, the separation efficiency of the cellulose membrane is still >99 % in the 40-day separation test and always exceeds 90 % for 30 cycling test, indicating that it has good stability and recoverability. Interestingly, the cellulose membrane is prepared from biodegradable and renewable raw materials, which reduces environmental pollution and effectively utilize natural resources.

Catechol-Fe(III) complexes modified PVDF membrane for hazardous pollutants separation and antifouling properties.

Organic pollutants, such as toluene and xylene, in industrial wastewater negatively impact the environment. Membrane treatment is one of the best methods to reduce impurities in wastewater. Existing membranes that coat the water surface with hydrophilic material only effectively resist the initial fouling, resulting in poor oil and water selectivity. Here we report a simple and efficient method to enhance the water flux and antifouling properties of polyvinylidene fluoride (PVDF) membranes. This method involves developing and applying Catechol-Fe(III) complexes with a rough surface to the PVDF surface. Forming Catechol-Fe(III) complexes on the surface better anchors them to the membrane than the dip-coating method. The PVDF membranes with rough Catechol-Fe(III) complexes are superoleophobic, with an oil contact angle of 152 ° and high permeability, with pure water flux of 10487 Lm-2h-1bar-1 and 1 wt% toluene in water emulsion flux of 4697 Lm-2h-1bar-1. Overall, the straightforward manufacturing process, increased permeability, and outstanding antifouling capabilities of the PVDF membrane incorporating rough nanoparticles offer promising prospects for designing and implementing suitable membranes for oil in water emulsion separation applications.

Separation performance of boron nitride nanotube stainless-steel filter.

In this study, boron nitride nanotubes (BNNTs) were utilized as covering and reinforcing materials owing to their extraordinary insulation and extremely high hydrophobicity. The gas-liquid-solid annealing process was used to manufacture the BNNT stainless-steel filter, with a 120 mesh stainless steel filter serving as the substrate and B2O3 as the raw material. Scanning electron microscopy showed that the average diameter of the nanotubes was 0.40 µm. The BNNTs were bamboo shaped, and the BNNT stainless-steel filter was superhydrophobic, with a water contact angle was 150.49°. The materials demonstrated good separation performance, as indicated by the separation results obtained under four different test conditions (0 and 0.3 MPa, 3 and 10 mL/min). The solid-liquid separation effect of the BNNT stainless-steel filter was better than that of the Teflon filter. In oil-water separation experiments with varying water contents (1.2 and 5.8 wt%), the BNNT stainless-steel filter was more hydrophobic. Based on the results, the role of the hydrodynamic method in the separation of two superhydrophobic materials is discussed. The method introduced in this study can serve as a reference for the application of other filtration separation technologies. Furthermore, the superior separation performance of the superhydrophobic BNNT stainless-steel filter may enable the quick, effective, and continuous collection of water contaminated with oil, giving it a wide range of potential applications.

Fabrication of Non-Wetting Mg(OH)2 Composites with Photoresponsive Capabilities and Their Environmental Restoration Performance.

Water pollution seriously affects the development of society and human life. There are various kinds of pollutants, including soluble pollutants and insoluble floaters on the water surface. Herein, the photocatalyst semiconductor BiOCl and superhydrophobic functional particles Mg(OH)2 were deposited on the surfaces of canvas and polyester felt to construct superhydrophobic canvas and polyester felt. The contact angles of the synthetic superhydrophobic canvas and polyester felt were measured as 152° and 155.3°, respectively. The selective adsorption of hexadecane was achieved using the wetting difference between the surface of water and pollutants floating on the surface. For dissolved pollutants, the surface wettability needed to be changed with the help of ethanol. The degradation efficiencies were all greater than 90%, demonstrating the versatility of the synthetic superhydrophobic canvas and polyester felt.

Construction of CS-SDAEM long-chain polysaccharide derivative on TA@CNTs coated PVDF membrane with effective oil-water emulsion purification and low contamination rate.

Currently, the most effective way to improve the anti-fouling performance of water treatment separation membrane is to enhance the hydrophilicity of the membrane surface, but it can still cause contamination, leading to the occurrence of flux reduction. The construction of a strong hydration layer to resist wastewater contamination is still a challenging task. In this study, a defect-free hydration layer barrier was achieved by grafting chitosan polysaccharide derivatives (CS-SDAEM) on the membrane, which achieved in effective fouling prevention and low flux decline rate. A layer of tannic acid-coated carbon nanotubes (TA@CNTs) has been uniformly deposited on the commercial PVDF membrane so that the surface was rich in -COOH groups, providing sufficient reaction sites. These reactive groups facilitate the grafting of amphiphilic polymers onto the membrane. This modification strategy achieved in enhancing the antifouling performance. The modified membrane achieved low contamination rate with DR of 16.9 % for wastewater filtration, and the flux recovery rate was above 95 % with PWF of 1100 (L·m-2·h-1). The membrane had excellent anti-fouling performance, which provided a new route for the future development of water treatment membrane.

Perfluoroalkyl Functionalized Superhydrophobic Covalent Organic Frameworks for Excellent Oil-Water Membrane Separation and Anhydrous Proton Conduction.

Rapid economic development has led to oil pollution and energy shortage. Membrane separation has attracted much attention due to its simplicity and efficiency in oil-water-separation. The development of membrane materials with enhanced separation properties is essential to improve the separation-efficiency. Proton exchange membrane fuel cells (PEMFCs) are expected to replace conventional engines due to their high-power-conversion rates and other favorable properties. Anhydrous-proton-conducting materials are vital components of PEMFCs. However, developing stable proton-conducting materials that exhibit high conductivity at varying temperatures remains challenging. Herein, two covalent organic frameworks (COFs) with long-side-chains are synthesized, and their corresponding COF@SSN membranes. Both membranes can effectively separate oil-water mixtures and water-in-oil emulsions. The TFPT-AF membrane achieves a maximum oil-flux of 6.05 × 105 g h-1 m-2 with an oil-water separation efficiency of above 99%, which is almost unchanged after 20 consecutive uses. COF@H3PO4 doped with different ratios of H3PO4 is prepared, the results show that the perfluorocarbon-chain system has  excellent anhydrous proton conductivity , achieving an ultra-high proton-conductivity of 3.98 × 10-1 S cm-1 at 125 °C. This study lays the foundation for tailor-made-functionalization of COF through pre-engineering and surface-modification, highlighting the great potential of COFs for oil-water separation and anhydrous-proton-conductivity.

One-Step Phase Separation and Mineralization Fabrication of Membranes for Oily Wastewater Treatment.

Oily wastewater threatens the environment and the human health. Membrane technology offers a simple and efficient alternative to separating oil and water. However, complex membrane modifications are usually employed to optimize the separation performance. In this research, we develop an extremely simple one-step method to in situ calcium carbonate (CaCO3) nanoparticles onto a porous polyketone (PK) membrane via a nonsolvent induced phase separation (NIPS)-mineralization strategy. We utilized the unique chemical property of PK, which allows it to dissolve in a resorcinol aqueous solution. PK was mixed with tannic acid (TA) and calcium chloride (CaCl2) in a resorcinol aqueous solution to fabricate a casting solution. The activated membrane was cast and immersed into a sodium carbonate (Na2CO3) aqueous solution for taking the one-step NIPS-mineralization process. This proposed NIPS-mineralization mechanism comes to two conclusions: (i) the resulting membrane with comprehensive oleophobic properties and enhanced permeation flux for applications of oil/water separation with ultralow fouling and (ii) simplified the procedure to optimize the membrane performance using regular NIPS steps. The current work explores a one-step NIPS-mineralization technique that offers a novel approach to preparing membranes with highly efficient oil/water separation performance.

Design of carboxymethyl cellulose/alginate aerogels with anti-fouling and light-driven self-cleaning for enhanced oily wastewater remediation.

With the increase of oily wastewater discharge and the growing demand for clean water supply, high throughput green materials for oil-water separation with anti-pollution and self-cleaning ability are urgently needed. Herein, the polysaccharide-based composite aerogels of CMC/SA@TiO2-MWCNTs (CSTM) with fast photo-driven self-cleaning ability have been prepared by a simple freeze-drying and ionic cross-linking strategy. The introduction of TiO2 /MWCNTs nanocomposites effectively improves the underwater oleophobic and mechanical properties of polysaccharide aerogels and enables their photo-driven self-cleaning ability for efficient oil-water separation and purification of complex oily wastewater. For immiscible oil-water mixtures, a high separation flux of about 7650 L m-2 h-1 and a separation efficiency of up to 99.9 % was obtained. For surfactant-stabilized oil-in-water emulsion, a flux of 3952 L m-2 h-1 was achieved with a separation efficiency of up to 99.3 %. More importantly, the excellent photoluminescent self-cleaning ability and low oil adhesion contribute to the high contamination resistance, excellent reusability, and robust durability of CSTM aerogel. With the advantages of simple preparation, remarkable performance, and recyclability, this aerogel is expected to provide a green, economical, and scalable solution for the purification of oily wastewater.

Enhanced demulsification of alkaline-surfactant-polymer flooding O/W emulsion by multibranched polyether-polyquaternium based on the size effect of oil droplets.

In the alkaline-surfactant-polymer flooding emulsion, oil droplets with various sizes exhibited different interfacial properties, resulting in different stabilization and destabilization behaviors. In view of this, it is expected to achieve outstanding oil-water separation efficiency by screening targeted demulsifier for oil droplets with different size ranges (0-1, 1-5 and 5-10 µm). Based on the size effect of oil droplets, a series of multibranched polyether-polyquaternium demulsifiers that integrated different charge neutralization and interfacial displacement functionalities were designed by regulating the cationicity and EO:PO ratios. As a result, the most effective polyether-polyquaternium variant for each size range of oil droplet was screened out. By employing these three selected polyether-polyquaternium variants in a sequential batch demulsification test, the maximum demulsification efficiency of 95.1% was obtained, which was much higher than that using a single polyether-polyquaternium variant (82.5%, 80.5% and 83.8%). The adsorption behaviors of polyether-polyquaternium variants on the oil/water interface were investigated by the molecular dynamics simulation. Moreover, the interfacial properties and oil droplet size variations during the demulsification process were monitored, so as explore the demulsification mechanism. This demulsification protocol based on the size effect of oil droplets with its excellent oil-water separation performance offered significant technical promise for the emulsified oil wastewater disposal.

Preparation Method and Application of Porous Poly(lactic acid) Membranes: A Review.

Porous membrane technology has garnered significant attention in the fields of separation and biology due to its remarkable contributions to green chemistry and sustainable development. The porous membranes fabricated from polylactic acid (PLA) possess numerous advantages, including a low relative density, a high specific surface area, biodegradability, and excellent biocompatibility. As a result, they exhibit promising prospects for various applications, such as oil-water separation, tissue engineering, and drug release. This paper provides an overview of recent research advancements in the fabrication of PLA membranes using electrospinning, the breath-figure method, and the phase separation method. Firstly, the principles of each method are elucidated from the perspective of pore formation. The correlation between the relevant parameters and pore structure is discussed and summarized, subsequently followed by a comparative analysis of the advantages and limitations of each method. Subsequently, this article presents the diverse applications of porous PLA membranes in tissue engineering, oil-water separation, and other fields. The current challenges faced by these membranes, however, encompass inadequate mechanical strength, limited production efficiency, and the complexity of pore structure control. Suggestions for enhancement, as well as future prospects, are provided accordingly.