Pervaporation Research Articles

Enriching the conceptual modelling approach with environmental considerations: Application to the partial dealcoholization of wines

In this work, and based on results from conceptual models, an environmental impact assessment was carried out using the ReCiPe midpoint and endpoint methodology for technologies in the partial dealcoholization of wines; namely, evaporative pertraction (EP), nanofiltration (NF), reverse osmosis (RO), pervaporation (PV), pervaporation with heat integration (PVHI) and spinning cone column (SCC). While the first three technologies are analyzed in their hybrid process version including a distillation stage, the PVHI variant considers the energy integration between the retentate and permeate streams through a vapor compression refrigeration system. In all cases, a decrease of ca. two percent points of alcohol in volume is considered.With the same input data the utility costs of each variant were also estimated. In this way, trade-offs between the economic and environmental performance of each alternative were addressed. In all cases, both a partially dealcoholized wine and an ethanol-rich effluent (50 % by volume or more) were obtained with the last sent to a distillery for material valorization.Regardless of the end point chosen, the PVHI variant showed the best environmental performance and thus was the most environmentally friendly alternative followed by variants SCC, PV, RO, NF and EP. On the other hand, from perspective based on utility costs results showed that the SCC variant requires the lowest costs, followed by the PVHI, PV, EP, RO and NF alternatives, respectively.From both economic and environmental point of view EP, NF and RO and were the worst alternatives given by the relatively high steam and cooling water consumptions required for these technologies to both achieve an alcohol-rich distillate with and a reduction in deionized water consumption of the corresponding partial dealcoholization step.In contrast, due to the high ethanol selectivity of the PDMS membrane used in experiments and the high ethanol recovery in conjunction with a high distillate composition achieved in the spinning cone column made alternatives PVHI and SCC as the better ones both in environmental and economic standpoints. It is precisely the possibility of heat integration of the pervaporation that accounts for the better environmental performance of the PVHI variant.

Improved Esterification of Citric Acid and n-Butanol Using a Dense and Acid-Resistant Beta Zeolite Membrane.

In this work, a dense and acid-resistant beta zeolite membrane was applied to improve the esterification of citric acid and n-butanol, for the first time. Through the continuous removal of the by-product water via pervaporation (PV), the conversion of citric acid was significantly enhanced from 71.7% to 99.2% using p-Toluenesulfonic acid (PTSA) as catalyst. PTSA was a well-known strong acid, and the membrane kept almost no change after PV-esterification, indicating the superior acid resistance of beta zeolite membrane. Compared to the use of acid-resistant MOR zeolite membrane by PV-esterification, a consistently higher conversion of citric acid was obtained using a high-flux beta zeolite membrane. The results showed that high water permeation on the beta zeolite membrane, with good acid resistance, had a strong promoting effect on esterification, leading to an improved conversion. In addition, the citric acid conversion of 97.7% could still be achieved by PV-esterification at a low reaction temperature of 388 K.

Effect of Nanofillers on Properties and Pervaporation Performance of Nanocomposite Membranes: A Review.

In recent years, a well-known membrane-based process called pervaporation (PV), has attracted remarkable attention due to its advantages for selective separation of a wide variety of liquid mixtures. However, some restrictions of polymeric membranes have led to research studies on developing membranes for efficient separation in the PV process. Recent studies have focused on preparation of nanocomposite membranes as an effective method to improve both selectivity and permeability of polymeric membranes. The present study provides a review of PV nanocomposite membranes for various applications. In this review, recent developments in the field of nanocomposite membranes, including the fabrication methods, characterization, and PV performance, are summarized.

Graphene Oxide-Carbon Nanotube (GO-CNT) Hybrid Mixed Matrix Membrane for Pervaporative Dehydration of Ethanol.

The pervaporation process is an energy-conservative and environmentally sustainable way for dehydration studies. It efficiently separates close boiling point and azeotrope mixtures unlike the distillation process. The separation of ethanol and water is challenging as ethanol and water form an azeotrope at 95.6 wt.% of ethanol. In the last few decades, various polymers have been used as candidates in membrane preparation for pervaporation (PV) application, which are currently used in the preparation of mixed matrix membranes (MMMs) for ethanol recovery and ethanol dehydration but have not been able to achieve an enhanced performance both in terms of flux and selectivity. Composite membranes comprising of poly (vinyl alcohol) (PVA) incorporated with carboxylated carbon nanotubes (CNT-COOH), graphene oxide (GO) and GO-CNT-COOH mixtures were fabricated for the dehydration of ethanol by pervaporation (PV). The membranes were characterized with Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Raman spectroscopy, Raman imaging, contact angle measurement, and water sorption to determine the effects of various nanocarbons on the intermolecular interactions, surface hydrophilicity, and degrees of swelling. The effects of feed water concentration and temperature on the dehydration performance were investigated. The incorporation of nanocarbons led to an increase in the permeation flux and separation factor. At a feed water concentration of 10 wt.%, a permeation flux of 0.87 kg/m2.h and a separation factor of 523 were achieved at 23 °C using a PVA-GO-CNT-COOH hybrid membrane.

Breakthroughs on tailoring membrane materials for ethanol recovery by pervaporation

• Mixed matrix membranes (MMMs) with well-designed membrane structures may provide both high permeability and membrane selectivity to break trade-off effect due to the better control over physi-/chemical micro-environment and cavity/pore size as well as size distribution. • Fillers should be orderly arranged in polymer matrix and form continuous transport channels for ethanol to full play the synergistic effect of polymer and fillers. • Building firm bonding interactions between filler and polymer is one of the most promising methods to strengthen the PV performance of MMMs. • The development of bioinspired materials and structures provides enlightening ideas for the construction of ethanol perm-selective membranes. Bioethanol, as a clean and renewable fuel, has gained increasing attention due to its major environmental benefits. Pervaporation (PV) is a promising and competitive technique for the recovery of ethanol from bioethanol fermentation systems due to the advantages of environmental friendliness, low energy consumption and easy coupling with fermentation process. The main challenge for the industrial application of ethanol perm-selective membranes is to break the trade-off effect between permeability and selectivity. As membrane is the heart of the pervaporation separation process, this article attempts to provide a comprehensive survey on the breakthroughs of ethanol perm-selective PV membranes from the perspectives of tailoring membrane materials to enhance PV separation performance. The research and development of polymeric and organic/inorganic hybrid membranes are reviewed to explore the fundamental structure-property-performance relationships. It is found that mixed matrix membranes with well-designed membrane structures offer the hope of better control overphysi-/chemical micro-environment and cavity/pore size as well as size distribution, which may provide both high permeability and membrane selectivity to break the trade-off effect. The tentative perspective on the possible future directions of ethanol perm-selective membranes is also briefly discussed, which may provide some insights in developing a new generation of high-performance PV membranes for ethanol recovery.

Investigation Of Separability Of DMC/Methanol Azeotropic Mixtures By Chitosan Hybrid Membrane

Dimethyl carbonate (DMC) is a green solvent and an environmentally friendly fuel additive. It is produced by carbonylation of methanol The production cost of DMC is very high by conventional processes because DMC and methanol form azeotrope and cannot be separated by distillation. Its separation can be performed by pervaporation (PV) economically. Pervaporation (PV) is also an environmentally friendly membrane process in which liquid-liquid mixtures are separated under vacuum with high selectivity. Pervaporation selectivity is dependent on sorption selectivity and diffusion selectivity. Membrane used in the pervaporation process is a semi-permeable barrier and provides selective separation and transport. In PV development of an appropriate membrane material is important for obtaining pure substances. Hydrophilic membrane can separate methanol which is a polar component. Chitosan is a harmless, biodegradable, natural polymer and, despite having hydrophilic properties, cannot withstand aqueous conditions. Therefore, it should be modified by crosslinking. Tetraethoxysilan (TEOS) and tungstophosphoric acid (TPA) can be used as crosslinking agents and additive blending components in membrane production for increasing chemical and mechanical stability. In this study, sorption tests were carried out to determine the usability of chitosan-tetraethoxysilan (TEOS) and chitosan-Tungstophosphoric acid (TPA) hybrid membranes in separation of DMC-Methanol mixture with PV.

Economic analysis of biobutanol recovery from the acetone-butanol-ethanol fermentation using molasses

Commercial production of biobutanol via acetone-butanol-ethanol (ABE) fermentation is challenged by the energy-intensive recovery of biobutanol from inherently diluted fermentation broth. Towards the solution of this problem, four combinations (scenarios) of separation techniques such as distillation, gas stripping (GS), liquid-liquid extraction (LLE), and pervaporation (PV) are investigated for the minimum unitary production cost of biobutanol. Cost components for the installation and operation of the plant are estimated using Matlab software and method given by Peters and Timmerhaus. Production costs with significant variables viz. biobutanol yield, price of molasses, and fermenter volume are individually estimated. Gas stripping followed by distillation is found as the most economical scenario with a unitary production cost of INR 74/kg. The optimum values of yield and fermenter volume are found as 0.4 kg ABE/kg sugars and 100 m3, respectively. The optimization of three major variables around the baseline values provides nearly 10% reductions in the cost with present fermentation technology. This economic analysis of biobutanol recovery certainly contributes to the commercial production of biobutanol from renewable raw materials. The economic feasibility of biodiesel production may offer better environment to the mankind.

Separation of n-butanol from aqueous mixtures using TiO2 and h-BN functionalized MIL-101(Cr) incorporated PVDF mixed matrix membranes

In the present work, polyvinylidenefluroide (PVDF) mixed matrix membranes (MMMs) membranes are synthesized for selective separation of n-butanol from an aqueous mixture through organophilic pervaporation (PV). Hydrophobic MIL-101(Cr) surface-modified with TiO2 and h-BN nanoparticles (NPs) are incorporated into the PVDF membrane. The prepared nanocomposites and MMMs are characterized by various analytical techniques: FESEM, AFM, HRTEM with SAED pattern, PXRD, FTIR, XPS, TGA, porosity and water contact angle measurements. The prepared MMMs are applied to recover the 1.5 wt% n-butanol/water mixture. The hydrophobic nature of MIL-101(Cr) enhances the adsorption selectivity for butanol, resulting in enhanced butanol flux and selectivity. Experimental data show that the total flux and selectivity boost with increased feed composition and temperature. The modified membranes show enhancement in total flux and selectivity by 19.03 % and 63.25 % (A2), 80.03 % and 284.72 % (A3), and 90.99 % and 145.13 % (A4), respectively. Incorporating h-BN NPs into the MIL-101(Cr) increases the affinity for water molecules to pass through membranes, reducing the butanol selectivity of the membranes. From the experimental data, it can be concluded that adding hydrophilic nanoparticles such as TiO2 and h-BN into the MIL-101(Cr) enhances each membranes total flux and separation factor. The significant separation results are found for A3 membrane with total flux of 3139.21 g m−2 h−1 and separation factor of 95.04. Also, the A3 membrane shows good long term performance stability of 160 h. Overall, good physiochemical characteristics and separation performance show the practical applicability of the butanol separation for the prepared membranes.

Nanoarchitectonics of High‐Performance Bis(triethoxysilyl)methane (BTESM) Hybrid‐Silica Membrane for Pervaporative Desalination Applications

AbstractAs an emerging technology, desalination by pervaporation (PV) has excellent potential in freshwater supply from saline waters. However, the investigation of stable membrane materials needs still to address separation issues such as fouling in desalination applications. Ceramic membranes, especially hybrid‐silica membranes, possess the required properties for pervaporation desalination and remain potentially tolerant to various saline waters which conventional membranes cannot withstand. Herein, we report the preparation of a thin, short‐chain BTESM hybrid‐silica membrane on cheap macroporous alumina supports for desalination applications through pervaporation. The fabricated membrane delivered water flux of 9.1 kg m−2 h−1 and 6.7 kg m−2 h−1 at 60 °C for simulated and real based sampled seawater, respectively, with a high rejection of >99.5 %. The fabricated membrane delivers excellent separation for various salt ranges and different salt solutions, including KCl, MgCl2, and CaCl2. Further, the PV performance of fabricated membranes implies that hybrid silica based membranes can be potential candidates for commercial desalination markets.

Separation of Soluble Benzene from an Aqueous Solution by Pervaporation Using a Commercial Polydimethylsiloxane Membrane.

A developed polydimethylsiloxane (PDMS) membrane was used to separate soluble benzene compounds (C6H6) from an aqueous solution via a pervaporation (PV) process. This membrane was characterized by scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, contact angle (CA), and energy-dispersive spectroscopy (EDS). To evaluate the performance of the membrane, the separation factor and permeation flux were estimated in various operating conditions, including the feed temperature, initial benzene concentration, and feed flow rate. The experiments to maximize the separation factor and permeation flux were designed using the response surface method (RSM) that is built into Minitab 18. A quadratic model (nonlinear regression equation) was suggested to obtain mathematical expressions to predict the benzene permeation flux and the separation factor according to the effect of the parameters' interaction. The optimization of the PV was performed using an RSM that was based on the analysis of variance (ANOVA). The optimal values of the benzene permeation flux and separation factor were 6.7 g/m2·h and 39.8, respectively, at the optimal conditions of temperature (30 °C), initial concentration of benzene (1000 ppm), and feed flow rate (3.5 L/min). It was found that the feed concentration was the most influential parameter, leading to a significant increase in the permeation flux and separation factor of the PDMS membrane.

Combining game theory and evolutionary algorithms for optimizing hybrid RDWC–pervaporation–vapor permeation process equipped with solar heating system

A new hybrid RDWC–pervaporation (PV)–vapor permeation (VP) process equipped with a solar heating system was designed and optimized to produce ETBE. Steam is required for feed preheating and RDWC reboiler, and PV heaters. A parabolic trough collector (PTC), one of the most conventionally used commercial solar collectors, was used to produce steam. Tehran, the Capital of Iran, was selected for solar energy analysis, but the results can be generalized to other places with different weather conditions. PV and VP processes can be placed besides RDWC in five zones. The game theory selected the PV and VP processes as two competitors in the hybrid process with RDWC. The combination of PV and PV processes in the hybrid process with RDWC was studied with the help of the hybrid GA–PSO optimizer algorithm. According to the optimization results, the proposed process reduced TAC and CO2 emissions by 72% and 94% compared to the conventional ETBE process. The main reason for the high efficiency of the proposed method is the use of solar energy and eliminating over 70% of the need for hot utility. The PV–VP combination reduced the number of RDWC trays and PV modules, decreasing the total annual cost (TAC).

Hollow fiber composite membranes of poly(paraterphenyl-3-bromo-1,1,1-trifluoroacetone) and PVA/glycine for ethanol dehydration

Thin film composite hollow fiber membranes (TFC-HFMs) usually have permeate flux of less than 2 kg m−2 h−1 for pervaporation (PV) dehydration of ethanol, as well as complicated and pragmatic preparation process, limiting their application in the PV. In this study, the TFC-HFMs with excellent PV performance are fabricated on newly-developed poly(paraterphenyl-3-bromo-1,1,1-trifluoroacetone) (PTB) hollow fiber supports. The PTB hollow fiber supports exhibit low mass transfer resistance as a result of high pure water permeance of 1.6 × 103 L m−2 h−1 bar−1, high porosity of 63.8% and mean pore size of 2.53 μm. Furthermore, self-assembly sandwich structure dense-selective layers are formed on the lumen side of PTB hollow fiber supports via heterostructured evolution that derives from a mixture of polyvinyl alcohol (PVA) and glycine (Gly). The resulting TFC-HFMs display the excellent separation performance. Especially, the TFC4.1-HFMs show a high permeate flux of 3.49 kg m−2 h−1, 91.1 wt% water in the permeate and excellent stability for dehydrating 85 wt% ethanol aqueous solution at 50 °C. The newly developed TFC-HFMs should have a wide application in the PV dehydration of ethanol due to simple preparation progress and efficient separation.

Low-temperature cross-linking fabrication of sub-nanoporous SiC-based membranes for application to the pervaporation removal of methanol

Separating azeotropic organic-organic mixtures using membranes is of great importance in the chemical and petrochemical industries, but remains extremely challenging because membranes must be able to withstand harsh working conditions while providing adequate permselectivity. Silicon carbide (SiC)-based membranes have attracted a great deal of interest due to their high level of structural stability, mechanical strength, and corrosion resistance. Herein is an account of the first study focused on a systematic investigation into the physicochemical and pore structural variations of polycarbosilane (PCS)-derived SiC-based membranes under different air-curing and pyrolysis temperatures. Air curing for cross-linking behavior was found to occur at temperatures as low as 150 °C, and the completion of polymer-to-ceramic conversion for PCS was observed at 750 °C. In addition, the pore structure and surface properties (hydrophilicity/hydrophobicity) of PCS membranes could be tuned by the pyrolysis temperature. PCS membranes derived from air curing at a temperature as low as 150 °C possessed sub-nanopores that ranged from 0.5 to 0.66 nm depending on the pyrolysis temperature. The formation of these sub-nanopores was attributed to sparsely cross-linked networks. Subsequently, the pervaporation (PV) performance of methanol/methyl acetate, methanol/toluene, and methanol/methyl tert-butyl ether were evaluated and discussed with respect to any effects of different pore sizes of the membranes and operating parameters. The most outstanding separation performance emerged from SiC-based membranes with a pore size of 0.50 nm that were air-cured at 150 °C and then pyrolyzed at 750 °C. The impressive PV separation capability was attributed to the surface hydrophilicity, suitable pore size, and high quality of the SiC-based membranes. Furthermore, the PV performance correlated well with single-gas permeation, suggesting that PV performance could be predicted based on single-gas permeation. The developed SiC-based membranes have excellent separation performance and are a promising candidate for the PV separation of MeOH from organic mixture systems.

Water permeation in gas and liquid phases through organosilica membranes: A unified theory of reverse osmosis, pervaporation, and vapor permeation

Reverse osmosis (RO), pervaporation (PV), vapor permeation (VP), and gas separation (GS) are the possible permeation modes for molecular separation via membranes. In the present study, the relationship among them was formulated based on thermodynamics and verified via experiments. Water permeation via RO, PV, and VP was performed at a constant temperature of 150 °C and at a transmembrane pressure of 100 kPa using a recently developed hydrothermally stable organosilica membrane. This allowed an accurate evaluation of the permeance obtained from RO, PV, and VP, which confirmed the formulated model. In addition, the effect of concentration in the membrane pores was further included in the model, which successfully predicted the permeance of not only water but also methanol and hydrogen under different levels of pressure. The present study provides a general understanding of permeation and enables estimation of the performances of RO, PV, VP, and GS.

Toluene/water separation using MCM-41/ PEBA mixed matrix membrane via pervaporation process

Pervaporation (PV) process with the mixed matrix membrane (MMM) is a feasible and cost-effective alternative to conventional volatile organic compounds (VOC) removal methods. In this study, the mesoporous silicate MCM-41 was synthesized by a new and rapid sol-gel method and incorporated into the polyether-block-amide (PEBA-2533) polymer network. Prepared MMM and MCM-41 were characterized by XRD, FESEM, TEM, AFM, TGA, DSC, FTIR, contact angle, and mechanical analyses. Effect of MCM-41 calcination on the performance of MMM for toluene/water solution separation was studied using a PV setup. Experiments were conducted to determine the effects of MCM-41 loading, feed concentration, and feed temperature on total flux, component flux, separation factor, and pervaporation separation index (PSI). For a 300 ppm toluene aqueous solution at 30 °C, the separation factor, from 44.4 to 203.7 (358.7% increment), and toluene flux, from 3.9 to 10.5 g m−2 h−1 (163.8% increment), were improved by using 7.5% uncalcined MCM-41 loading. The PSI value of this sample was attained at 67290 g m−2 h−1, which was 412% higher than that of a neat PEBA membrane (13142 g m−2 h−1).

Novel Polymeric Membranes Preparation and Membrane Process

Polymer-based membranes have advanced or novel functions in the various membrane separation processes for liquid and gaseous mixtures, such as gas separation, pervaporation (PV), reverse osmosis (RO), nanofiltration (NF), ultrafiltration (UF), microfiltration (MF), and in other critical applications of membranes such as water purification, solvent concentration, and recovery [...]

ZSM-5/Thermoplastic Polyurethane Mixed Matrix Membranes for Pervaporation of Binary and Ternary Mixtures of n-Butanol, Ethanol, and Water

In this work, the performance of a ZSM-5/thermoplastic polyurethane (TPU) mixed matrix membrane (MMM) is presented for pervaporation (PV) of n-butanol and ethanol from dilute aqueous solutions as a cheap and easy to fabricate replacement for the benchmark polydimethylsiloxane (PDMS) membranes. When compared to other PDMS alternatives, such as HTPB–PU, HBPE, or PEBA, the developed ZSM-5/TPU MMM has superior separation performance in many cases. ZSM-5 loadings were varied from 0 to 30 wt % in an effort to enhance the overall selectivity and permeability of the MMMs. Binary systems of n-butanol–water and ethanol–water were tested along with a ternary system of n-butanol–ethanol–water. Experimental results indicated that the 20 wt % ZSM-5/TPU MMM displayed the best selectivity and separation factor. By varying the operating conditions, it was also discovered that n-butanol’s flux is more sensitive to temperature changes when compared to water. Further analysis revealed that n-butanol permeability was dissolution-dominated, while water permeability was diffusion-dominated. PV of n-butanol–water had a maximum selectivity and separation factor of 2.24 and 12.77, respectively. For the ethanol–water mixture, a maximum selectivity and separation factor of 0.20 and 2.27 were obtained, respectively. PV of the ternary mixture yielded maximum selectivities of 1.97 and 0.23 for n-butanol and ethanol, respectively, with the corresponding separation factors of 11.53 and 2.55. This study provides valuable evidence for further research into TPU MMMs as an easy-to-fabricate, robust, and economical competitor for PV due to their superior separation performance when compared to other alternatives.

Effect of membrane performance variability with temperature and feed composition on pervaporation and vapor permeation system design for solvent drying.

The presence of water in organic solvents and biofuels can complicate their production and reuse because many hydrophilic solvents form difficult-to-separate mixtures with water (e.g., azeotropes). Pervaporation (PV) and vapor permeation (V⋅P) remove water from such mixtures via selective solution-diffusion transport through a membrane material. A recent article reviewed design factors that impact the effectiveness of PV/V⋅P solvent dehydration processes (J. Chem. Technol. Biotechnol 95: 495-512 (2020)). For the sake of simplicity, the earlier work assumed constant membrane permeabilities. The objective here is to explore the impact of variable permeabilities on predictions of PV/V⋅P system performance. A multiparameter expression relating permeability to process conditions was incorporated into the spreadsheet calculators from the previous work. Use of the expression was demonstrated with literature ethanol/water PV data for a NaA zeolite material and two poly (vinyl alcohol) (PVA) membranes. The variable permeabilities of the membranes yielded membrane area requirements that were 20-30% different from those calculated using permeances fixed at either end of the target water range. The impact of composition-dependent permeabilities was most pronounced on the fraction of ethanol transferred to the permeate for the NaA membrane. The inclusion of membrane permeabilities that vary with fluid composition and temperature noticeably altered predictions of the membrane area required to carry out water removal from ethanol by PV and of the transfer of ethanol to the permeate stream. Unless a PV/V⋅P process is expected to operate at a constant temperature and in a narrow concentration range, process performance estimates would be improved by inclusion of concentration- and temperature-dependent permeabilities or permeances.

Hydrophobic ZSM-5/styrene-butadiene-styrene (SBS) membrane for the removal of pyridine from aqueous solutions via pervaporation

New mixed matrix membranes (MMMs) of poly(styrene-butadiene-styrene) (SBS) incorporated with hydrophobic ZSM-5 zeolite (calcinated and non-calcinated) were prepared and characterized by various analyses. The performance of fabricated membranes was investigated in a pervaporation (PV) experimental setup for removing pyridine from aqueous solutions and the results indicated a notable increase in total flux. The influence of feed temperature (25–55ºC) on the pure SBS membrane performance was studied and the results were compared. It was found that an increase in feed temperature increased the permeation flux and decreased the separation factor. Incorporating ZSM-5 into the membrane matrix substantially influenced the separation performance of the fabricated membranes. The sample with 20 wt% calcinated zeolite (C.ZSM-5) represented the highest separation factor. C.ZSM-5 loading up to 20 wt% reduced total flux while it was increased with further increments in zeolite content. The highest separation factor and pervaporation separation index (PSI) for 20 wt% C.ZSM-5 sample at 45ºC feed temperature obtained at about 72 and 80,223 (g/m2h), respectively.

Highly selective PDMS-PVDF composite membrane with hydrophobic crosslinking series for isopropanol-1,5 pentanediol pervaporation

An energy-efficient pervaporation (PV) facile approach was designed to remove isopropanol during α, ω-diol production. Accordingly, a series of polydimethyl siloxane (PDMS) membranes were prepared by tuning their surface chemistry through trifunctional (PFTES and OTMS) and traditional tetrafunctional (TEOS) crosslinkers and casting on a polyvinylidene fluoride (PVDF) membrane. Additional hydrophobic tail enrichment on the membrane surface because of alkyl (OTMS) and fluoroalkyl (PFTES) groups from the tri-functional crosslinker was confirmed by FTIR, XPS, and DSC. TGA and XRD revealed that the tetra crosslinking site promoted a denser structure across the membrane than the trifunctional crosslinker. In the water contact angle measurements of the different series of membranes, the contact angle was proportional to the hydrophobic site. When a series of PDMS membranes were tested for PV of the novel feed PDO/IPA (90/10 w/w) system, the highest flux was delivered from the fluoroalkyl type crosslinked membrane, which was attributed to its superior hydrophobicity and amorphous nature, with excellent IPA selectivity from all the membranes. As a result, a stabilized flux of 235.8 g/m2h and excellent separation factor (IPA content in permeated >99.95%) in a 40 h continuous PV test was achieved using the PDMS PFTES membrane.