Membrane Distillation Performance Research Articles

The Effect of Sharklet Patterns on Thermal Efficiency and Salt-Scaling Resistance of Poly (vinylidene fluoride) Membranes During Direct Contact Membrane Distillation

Membrane distillation (MD) can treat high-salinity brine. However, the system's efficiency is hindered by obstacles, including salt scaling and temperature polarization. When properly implemented, surface patterns can improve the mass and heat transfer in the boundary layer, which leads to higher MD efficiency. In this work, the performance of direct contact membrane distillation (DCMD) using Sharklet-patterned poly (vinylidene fluoride) (PVDF) membranes is investigated. Both non-patterned and patterned PVDF membranes are prepared by lithographically templated thermally induced phase separation (lt-TIPS) process with optimized conditions. Sharklet patterns on the membranes improve the DCMD performance: up to 17 % higher water flux and 35 % increased brine-side heat transfer coefficient. The scaling resistance of the membranes during DCMD is tested by both saturated CaSO4 solution and hypersaline NaCl solutions. Patterned PVDF membranes show an average of 30 % higher water flux and up to 45 % lessened flux decline over time compared with non-patterned membranes when treating high-concentration brines. Post-mortem analysis reveals that Sharklet-patterned membranes display less salt-scaling on surfaces with smaller-sized CaSO4 and NaCl crystals, maintain a relatively cleaner surface, and exhibit better retention of hydrophobicity.

Investigating the performance of direct contact membrane distillation for liquid desiccant regeneration and freshwater production: A CFD-based study

Liquid desiccant air conditioning (LDAC) systems offer a promising solution for enhancing indoor thermal comfort, air quality, humidity control, and energy efficiency. This study focuses on the critical aspect of regenerating liquid desiccants in LDAC systems, which has the potential to enhance system efficiency and performance significantly. Using computational fluid dynamics (CFD) to model direct contact membrane distillation (DCMD) for liquid desiccant regeneration and freshwater production, this research paves the way for improving the performance of LDAC systems. The DCMD process, which involves mass transfer across a membrane driven by a temperature gradient between the permeate and feed channels, is a key area of exploration in this study. The findings of this study have significant implications for the design and operation of LDAC systems. The impact of feed inlet velocity and temperature on vapor flux for liquid desiccant regeneration is substantial, with increasing the feed inlet temperature leading to a fourfold increase in water vapor flux. Similarly, increasing the feed inlet velocity boosts flux due to enhanced convective heat transfer. Membrane characteristics, such as porosity and thickness, are key determinants of system performance. These findings underscore the importance of optimizing these parameters for efficient liquid desiccant regeneration and freshwater production in LDAC systems, thereby enhancing their overall performance and energy efficiency. Finally, a mathematical model for water vapor flux was developed to investigate water vapor flux as a function of key factors such as inlet temperature, velocity, liquid desiccant concentration, and membrane characteristics.

Enhancing air gap membrane distillation performance through electromagnetic force integration

Enhancing air gap membrane distillation performance through electromagnetic force integration

Formation of hydrophobic membranes by surface spray assisted NIPS: Effects of solvent/non-solvent and spraying conditions

Membrane distillation has long been a potential desalination technology. Recently, spray-assisted non-solvent induced phase inversion (SANIPS) was proposed as a facile and effective method to prepare microporous hydrophobic membranes for membrane distillation. However, the membrane formation process is not fully disclosed. In this paper, SANIPS is employed to fabricate hydrophobic PVDF membranes. The influencing factors on membrane structure and performance are investigated. Membrane structure is greatly affected by the choice of solvent and non-solvent spray. The interactions between different non-solvent sprays (water and ethanol) and solvents (TEP, NMP and DMF) and the effects of operating conditions on membrane formation are explored. Thermodynamic and kinetic analyses of the membrane formation process suggest that the membrane formation process is dominated by the kinetic factors with water being the spray while thermodynamic factors play the major role with ethanol being the spray. A hydrophobic membrane with water contact angle of 135.93 ± 4.38° and LEP of 2.5 ± 0.4 bar was successfully prepared by using ethanol as the non-solvent spray, which demonstrates a stable desalination performance (initial flux of 19.88 ± 1.39 kg·m−2·h−1 and salt rejection higher than 99.97 %) in vacuum membrane distillation. This study may provide pertinent insights into the rational control of membrane structure and performance of hydrophobic PVDF membranes.

Molecular Dynamics Simulation of Membrane Distillation for Different Salt Solutions in Nanopores.

Nanoporous membranes offer significant advantages in direct contact membrane distillation applications due to their high flux and strong resistance to wetting. This study employs molecular dynamics simulations to explore the performance of membrane distillation in a single nanopore, mainly focusing on wetting behavior, liquid entry pressure, and membrane flux variations across different concentrations and types of salt solutions. The findings indicate that increasing the NaCl concentration enhances the wetting of membrane pores, thereby decreasing the entry pressure of the solution. However, at the same salt concentration, the differences in wetting and liquid entry pressure among various salts, including CaCl2, KCl, NaCl, and LiCl, are minimal. The presence of hydrated ions significantly reduces membrane flux. As the concentration of NaCl solutions increases, the number of hydrated ions rises, thereby lowering the membrane flux of the salt solution. Furthermore, the type of salt has a pronounced effect on the structure of hydrated ions. Solutions with Ca2+ and Li+ exhibit the smallest first-layer radius of hydrated ions. Under the same salt concentration, KCl solutions demonstrate the highest membrane distillation flux, while CaCl2 solutions show the lowest flux.

Fabrication of omniphobic PVDF membrane with SiO2–FeOOH hierarchical structures for robust membrane distillation

Omniphobic membrane has been demonstrated as an effective strategy to mitigate membrane wetting and fouling risks in membrane distillation (MD) processes. In this work, novel omniphobic membranes with hierarchical re-entrant surface structure were fabricated. Firstly, the FeOOH nanorods were deposited on the polydopamine (PDA) pre-treated poly (vinylidene fluoride) PVDF membrane. After that, the SiO2 nanoparticles (NPs) were coated on the FeOOH nanorods via electrostatic attraction to form hierarchical structures. Finally, the fluorosilane was utilized to reduce the membrane surface free energy, contributing to PVDF based omniphobic membranes. The effects of reaction time, FeCl3·6H2O and SiO2 NPs concentrations on membrane properties, including membrane surface morphology, average pore size, contact angles (CAs), surface roughness and permeate flux, were investigated in detail. The resulting omniphobic membranes showed high CAs towards various tested liquids, such as 0.4 mM sodium dodecyl sulfate (SDS) solution (143.9 ± 0.8°), hexadecane (113.5 ± 3.2°) and mineral oil (132.5 ± 2.8°). This membrane exhibited outstanding performance in a continuous 50-h vacuum membrane distillation (VMD) process with a 10 wt% NaCl feed solution. Besides, the anti-oil-fouling properties were further assessed with a feed solution containing 200-ppm hexadecane and 3.5-wt% NaCl, the omniphobic membrane exhibited steady permeate flux of above 24.18 kg m−2 h−1 and a 99.99 % rejection rate during 50-h testing. Finally, the omniphobic membrane showed high anti-wetting properties by SDS/salt solution. This work introduces a new strategy for fabricating omniphobic membranes that shows significant potential for treating complex industrial wastewaters.

Potential of membrane distillation for water recovery and reuse in water stress scenarios: Perspective from a bibliometric analysis

Climate change and related issues such as water scarcity and the urgent need for a transition to sustainable energy sources have motivated the development of novel processes and techniques that can be applied for water treatment, recovery and reuse. Among these emerging processes, membrane distillation in its different configurations has been extensively studied and reported in the literature. A bibliometric analysis was performed to investigate the research documents published in the scientific database Scopus until 2024, related to use of membrane distillation for water recovery and reuse. The main quantitative attributes of the research during this period were identified. The results of this analysis showed a very low scientific production until 2005, followed by a rapid exponential increase since then. The combined contribution of the two most productive countries (China and USA respectively) accounted for more than 41 % of the total number of publications, followed by Australia and Saudi Arabia, which occupied the third and fourth positions in the ranking. Chemical engineering was the most important subject category (57.4 % contribution), closely followed by environmental sciences. The review of the most cited documents and keywords showed that membrane wetting is one of the main drawbacks that can reduce the performance of membrane distillation and the use of innovative superhydrophobic, omniphobic or Janus membranes resulted an adequate solution to avoid this problem. Moreover, the desalination of seawater, brines and other highly saline solutions can be considered as the most studied application of membrane distillation. The consideration of the energetic aspects of membrane distillation and its coupling with other technologies were identified as relevant topics during the bibliometric network analysis. Special attention was given to the potential of membrane distillation for water recovery and reuse in the Chilean context of water stress for the production of drinking water and the treatment of domestic greywater and wastewater from mining and other industrial activities.

Investigation of performance and entropy generation rate of Direct Contact Membrane Distillation (DCMD) with Static Mixer (SM): 3D CFD study

This study investigated the performance of Direct Contact Membrane Distillation (DCMD) with a Static Mixer (DCMDSM) and compared it to conventional DCMD using 3D Computational Fluid Dynamics (CFD) under steady-state conditions. The permeate flux and total entropy generation rate (TEGR) were explored as functions of various parameters, including temperature differences between feed and permeate flow, inlet velocity, salt mass fraction, membrane porosity, membrane thermal conductivity, and membrane pore radius. The study revealed that the maximum permeate flux of DCMDSM was 79 % higher than DCMD. Additionally, the average TEGR of DCMDSM was 67 % lower than that of DCMD. Furthermore, increasing the inlet velocity led to higher permeate flux in both DCMD and DCMDSM. The results showed that the performance of the DCMDSM at lower velocities was better than at higher inlet velocities. Moreover, increasing the temperature difference between feed and permeate, salt mole fraction, and porosity showed similar effects on permeate flux for both DCMD and DCMDSM, with the permeate flux of DCMDSM consistently exhibiting 60 % higher permeate flux than DCMD across all parameter ranges. Finally, the analysis of membrane thermal conductivity indicated that higher thermal conductivity of the membrane resulted in better permeate flux for DCMDSM than DCMD. Additionally, the TEGR analysis revealed that it was minimized at lower temperature differences, higher inlet velocities, and lower membrane thermal conductivities for both DCMD and DCMDSM.

Improving membrane distillation performance by Fe(II) activated sodium percarbonate oxidation during the treatment of shale gas produced water

Membrane distillation (MD) offers promise for recycling shale gas produced water (SGPW), while membrane fouling is still a major obstacle in standalone MD. Herein, sodium percarbonate (SPC) oxidation was proposed as MD pretreatment, and the performance of the single MD, SPC-MD hybrid process and Fe(II)/SPC-MD hybrid process for SGPW treatment were systematically evaluated. Results showed that compared to raw SGPW, the application of SPC and Fe(II)/SPC led to the decrease of the fluorescent organics by 28.54 % and 54.52 %, respectively. The hydrophobic fraction decreased from 52.75 % in raw SGPW to 37.70 % and 27.20 % for SPC and Fe(II)/SPC, respectively, and the MD normalized flux increased from 0.19 in treating raw SGPW to 0.65 and 0.81, respectively. The superiority of SPC oxidation in reducing the deposited membrane foulants and restoring membrane properties was further confirmed through scanning electron microscopy observation, attenuated total reflection fourier transform infrared, water contact angle and surface tension analyses of fouled membranes. Correlation analysis revealed that hydrophobic/hydrophilic matters and fluorescent organics in SGPW took a crucial role in MD fouling. The mechanism of MD fouling mitigation by Fe(II)/SPC oxidation was attributed to the decrease in concentrations and hydrophobicity of organic by synergistic oxidation, coagulation and adsorption.

Impact of surfactants used in oil and gas extraction on produced water treatment by membrane distillation

Produced water from unconventional oil and gas reservoirs often contains non-ionic surfactants that are added to the hydraulic fracturing fluid to facilitate water release and enhance gas production. This study investigates the impact of currently used surfactants (i.e., nonylphenol ethoxylates (NPEOs) and octylphenol ethoxylates (OPEOs)) and proposed alternative surfactants on the performance of membrane distillation (MD) for produced water treatment. The impact of NPEOs and OPEOs on wetting of PTFE membranes was studied as a function of their concentrations and ethoxylate (EO) chain length in a lab-scale DCMD system. Additionally, alternative surfactants, including linear alcohol ethoxylates (LAEs), branched secondary alcohol ethoxylates (BAEs), and alkyl polyglycosides (APGs), were evaluated for their potential to replace NPEOs and OPEOs. Experimental results indicate that the increase in the number of EO units in NPEOs decreased their tendency to cause membrane wetting by reducing their interaction with hydrophobic surfaces. It was also observed that LAEs and APGs that are environmentally friendly alternatives did not cause membrane wetting. This study provides valuable insights into the underlying mechanisms of surfactant-membrane interactions and offers guidelines for surfactant alternatives that can potentially improve hydraulic fracturing and lower environmental concerns while facilitating the use of MD for produced water treatment and recovery.

Investigation of Performance and Entropy Generation Rate of Direct Contact Membrane Distillation (DCMD) with Metal Foam: A CFD Study

Investigation of Performance and Entropy Generation Rate of Direct Contact Membrane Distillation (DCMD) with Metal Foam: A CFD Study

Construction of robust silica-titania polydopamine composite membrane with light-absorption property for photothermal vacuum membrane distillation

A robust silica-titania polydopamine composite membrane was fabricated adding a photothermal polydopamine coating to the surface of polypropylene membrane for photothermal vacuum membrane distillation. Detailly, the surface of an inert PP membrane was modified with atomically controllable titanium and silicon to enhance the hydroxyl groups on the membrane surface, then, a photothermal effect layer of polydopamine was generated on the composite membrane surface through the self-polymerization reaction of dopamine. The polydopamine coating has significant light absorption and heating properties, and it can act as a local heater when exposed to light sources. This local heating effect significantly raises the temperature at the membrane interface, creating a thermal gradient that drives the evaporation of water molecules. Specifically, we quantitatively analyzed the three reasons (surface energy, free radicals, and photothermal effect) for the increase in evaporation rate of the pristion PP membrane caused by the membrane composite membrane. Among these reasons, the photothermal effect caused by black polydopamine is the most important factor for improving evaporation efficiency. The dark-illumination alternating experiment revealed that the PP-TiO2-SiO2-PDA composite membrane delivered a noteworthy enhancement in vacuum membrane distillation performance (approximately 40%), while the improvement of the PP membrane was only 1.7%.

Investigating Permselectivity in PVDF Mixed Matrix Membranes Using Experimental Optimization, Machine Learning Segmentation, and Statistical Forecasting.

This research examines the correlation between interfacial characteristics and membrane distillation (MD) performance of copper oxide (Cu) nanoparticle-decorated electrospun carbon nanofibers (CNFs) polyvinylidene fluoride (PVDF) mixed matrix membranes. The membranes were fabricated by a bottom-up phase inversion method to incorporate a range of concentrations of CNF and Cu + CNF particles in the polymer matrix to tune the porosity, crystallinity, and wettability of the membranes. The resultant membranes were tested for their application in desalination by comparing the water vapor transport and salt rejection rates in the presence of Cu and CNF. Our results demonstrated a 64% increase in water vapor flux and a salt rejection rate of over 99.8% with just 1 wt % loading of Cu + CNF in the PVDF matrix. This was attributed to enhanced chemical heterogeneity, porosity, hydrophobicity, and crystallinity that was confirmed by electron microscopy, tensiometry, and scattering techniques. A machine learning segmentation model was trained on electron microscopy images to obtain the spatial distribution of pores in the membrane. An Autoregressive Integrated Moving Average with Explanatory Variable (ARIMAX) statistical time series model was trained on MD experimental data obtained for various membranes to forecast the membrane performance over an extended duration.

Integration of two-stage membrane distillation and fenton-based process for landfill leachate treatment: Ammonia and water recovery and advancement towards zero liquid discharge

The recovery of resources from landfill leachate (LL) represents a more sustainable approach, as it combines meeting release standards with the valorization of raw materials and contributing to the circular economy. Therefore, this study aims to evaluate the performance of a two-stage Direct Contact Membrane Distillation (2S-DCMD) for the recovery of water and ammonia from LFL integrated with the Fenton-based process for the treatment of the membrane concentrate generated in the second stage, aiming to obtain zero effluent discharge. In the first stage, the hot LFL flows through the shell side of the polypropylene hollow fiber membrane module, while the sulfuric acid solution passes through the lumen side·NH3 is recovered in the form of ammonium sulfate. In the second stage, the hot effluent from the first stage flows through the hot channel of the poly(tetrafluoroethylene) sheet membrane module, while the cooled distilled water flows through the other side in countercurrent. Despite the high efficiency of MD, disposing of the concentrate presents challenges, as pollutant concentrations can escalate by an additional 25 % to 50 % compared to the original contaminants in the raw feed. To address this issue, an advanced oxidative process of Fenton (AOP/Fenton) was optimized for treating the concentrate. In the first stage, NH3 removal reached 97.84 %, accompanied by a recovery rate of 79 %. In the second stage, a permeate with high quality was produced. Substantial removal rates were observed in this stage: colour (99.96 %), turbidity (99.89 %), COD (99.33 %), and Sulfates (90.08 %). The AOP/Fenton under optimal conditions (21.50 g/L of Fe2+ and 80 mL of H2O2) the removal of COD was 88.69 %. Thus, this route emerges as a viable alternative for landfill leachate treatment with the recovery of important resources.

Effects of surfactant properties on pore wetting of membrane distillation

Pore wetting is a major constraint to the performance of membrane distillation (MD) for hypersaline brine treatment. Despite the existence of surfactants with diverse properties, an explicit relationship between the properties of surfactants and their capabilities of inducing pore wetting has yet to be established. In this study, we perform a comparative analysis of the wetting behaviors of various surfactants with different charges and molecular weights in MD desalination. The induction time of surfactants to initiate pore wetting was correlated to the apparent contact angle and surface tension of the feedwater. Our results show that different surfactants resulting in similar feedwater surface tensions can lead to drastically different wetting potential, suggesting that both charge of the head group and molecular weight of surfactants have a significant influence on membrane pore wetting. Further, we demonstrate that parameters that have been commonly used to indicate wetting potential, including apparent contact angle and solution surface tension, are not reliable in predicting the wetting behavior of MD membranes, which is intricately linked with surfactant properties such as charge and molecular size. We envision that our results not only improve our fundamental understanding of surfactant-induced wetting but also provide valuable insights that necessitate thorough consideration of surfactant properties in evaluating wetting potential and membrane wetting resistance for MD desalination.

Performance prediction model for desalination plants using modified grey wolf optimizer based artificial neural network approach

Desalination represents an effective method for alleviating water scarcity, applying algorithmic techniques to predict the performance of reverse osmosis (RO) desalination plants, Modified Grey Wolf Optimizer (MGWO) based Artificial Neural Networks (ANN) can predict the performance of membrane distillation (MD) equipment. Four experimental inputs are selected: feed salt concentration(35–140 g/h), feed flow rate(400–600 L/h), evaporator inlet temperature (60–80 ℃), and condenser inlet temperature (20–30 ℃). The permeate flux (L/h m2) is selected as the experimental output. Ten prediction models were proposed and compared with the existing models (ANN, WOA-ANN, and GWO-ANN). The results showed that the MGWO-ANN model-5 showed the best regression results: R2 = 99.3 %, mean square error (MSE)= 0.004. This model outperformed the existing ANN model (R2 =98.8 %, MSE=0.060), WOA-ANN model (R2 =99.1 %, MSE=0.005) and GWO-ANN model (R2 =98.9 %, MSE=0.007). Model-5 has a single hidden layer (H=1), 13 hidden nodes (n = 13), 10 search agents (SA=10), and 75 %− 20 %− 05 % dataset division. Its residual error is within acceptable limits (spanning −0.1 to 0.2). Optimizing the number of hidden layer nodes (n) and the number of search agents (SA) can improve the training efficiency and prediction accuracy of the model, and the MGWO-ANN model is capable of more accurately predicting the performance of desalination plants.

Bead-Containing Superhydrophobic Nanofiber Membrane for Membrane Distillation.

This study introduces an innovative approach to enhancing membrane distillation (MD) performance by developing bead-containing superhydrophobic sulfonated polyethersulfone (SPES) nanofibers with S-MWCNTs. By leveraging SPES's inherent hydrophobicity and thermal stability, combined with a nanostructured fibrous configuration, we engineered beads designed to optimize the MD process for water purification applications. Here, oxidized hydrophobic S-MWCNTs were dispersed in a SPES solution at concentrations of 0.5% and 1.0% by weight. These bead membranes are fabricated using a novel electrospinning technique, followed by a post-treatment with the hydrophobic polyfluorinated grafting agent to augment nanofiber membrane surface properties, thereby achieving superhydrophobicity with a water contact angle (WCA) of 145 ± 2° and a higher surface roughness of 512 nm. The enhanced membrane demonstrated a water flux of 87.3 Lm-2 h-1 and achieved nearly 99% salt rejection efficiency at room temperature, using a 3 wt% sodium chloride (NaCl) solution as the feed. The results highlight the potential of superhydrophobic SPES nanofiber beads in revolutionizing MD technology, offering a scalable, efficient, and robust membrane for salt rejection.

Enhanced performance of electrospun PVDF membranes modified with rare-earth metal oxides for membrane distillation: A systematic study

In the presented studies, the novel type of separation materials dedicated to membrane distillation was generated and systematically analyzed. Utilizing poly(vinylidene fluoride) (PVDF) electrospun membranes as a base, hybrid organic-inorganic materials were developed to enhance performance. These materials exhibited high hydrophobicity, featuring superhydrophobicity on a micro-scale due to fractal-like structures on the inorganic domain surface. Rare-earth metal oxides (REMO) were implemented for the first time as smart modifiers, covalently attached to the functionalized membrane surface. Three REMO types were selected to investigate their impact on membrane performance in air-gap membrane distillation (AGMD) for the desalination process. Chemical attachment via long enough linkers formed a flexible active surface structure, facilitating transport and separation. Dynamic goniometric studies evaluated membrane wetting stability. Particularly noteworthy was the membrane enhanced with Ho2O3 particles, with high flux and salt rejection rates of 14.41 ± 1.35 kg m−2 h−1 and >99.5 %, respectively. The membrane stability and affinity were further examined using Hansen Solubility Parameters and Pearson's hard–soft acid–base (HSAB) theory. The potential of the hybrid membranes is seen not only in desalination. With the ability to control surface properties by using different silane linkers, oleophobicity/oleophilicity can be achieved, and practical use in wastewater treatment or oil/water separation is possible.

Pondering performance of hybrid microfiltration and membrane distillation (MF-MD) process for purifying chromium-contaminated groundwater: Optimization, fouling control, and long-term operation

Nowadays, a hazardous compound such as Chromium (Cr) in groundwater is an emerging issue worldwide due to its environmental and health impacts. Membrane distillation (MD) is a promising technique to purify Chromium-contaminated groundwater (CCG). Assisted microfiltration (MF) is lodged to overcome a major problem in MD, specifically membrane fouling. In this work, a hybrid MF-MD process is proposed with fouling control incorporated into long-term operation. Derived from the results, mixed cellulose ester with 0.1 μm of pore size (MCE0.1) at 3-min ultrasonication cleaning is chosen as the optimal parameter in the MF process, because of superior flux recovery ratio (FRR) with negligible flux deficiency of approximately 10 %. Permeate flux and total suspended solids (TSS) rejection of MCE0.1 was achieved around 440 Lm−2h−1bar−1 and > 90 %, respectively. The optimized parameters in MD were selected accordingly: feed temperature of 80 °C, and feed and coolant flow rates at 4 L/min. Eventually, the long-term batch operation was executed by obtaining average flux and permeate conductivity was 7.5 LMH and around 10 μs/cm, respectively. The Cr concentration in permeate was relatively stable around 0.05 mg/L, which meets the wastewater discharge limit of 0.5 mg/L.

Optimization of laser-induced graphene membrane for simultaneous photo- and electro-thermal membrane distillation

To optimize the Laser-Induced Graphene (LIG) Janus membrane, this study investigated the effects of membrane pore structure, polydimethylsiloxane (PDMS) coating sequence and addition of silver (Ag) nanoparticles on membrane distillation (MD) performance. This study aimed to enhance the photothermal characteristics of graphene while using the intrinsic electrical conductivity for simultaneous photo- and electrothermal MD. Operating at the same photo- and electro-thermal power input, the LIG Janus membrane made by treating the membrane face with smaller pores (i.e., shiny side) gave an improved flux performance of up to 53.6% and a decrease in specific energy of 35.4% compared to that by treating the membrane face with larger pores (i.e., dull side). The effect of the PDMS coating sequence also depended on the pore structure. For the face with smaller pore structures, coating PDMS before laser irradiation (PDMS-BLSS) gave a flux improvement of up to 24.5% and a decrease in specific energy of 19.7%, compared to coating PDMS after laser irradiation (PDMS-ALSS). As for the face with larger pore structures, coating PDMS before laser irradiation (PDMS-BLDS) resulted in a flux reduction of up to 20.8% and an increase in specific energy of 27.1%, compared to coating PDMS after irradiation (PDMS-ALDS). The LIG Janus membranes embedded with Ag nanoparticles led to improved photothermal heating properties, improving flux by 43.1–65.8% and decreasing specific energy by 15.2–30.5% while maintaining similar electrothermal heating properties. Carrying out simultaneous photo- and electro-thermal MD indicates that only the Ag-doped Janus LIG membrane gave a synergistic effect whereby the flux of the combined heating mode was higher than the summation of the fluxes obtained when operating in the individual heating modes.