Solvent Permeability Research Articles

Silane-modified bentonite clay-coated membrane development on ceramic support for oil/water emulsion separation using tuning of hydrophobicity

Bentonite clay-coated and silane-modified hydrophobic composite membranes were prepared on the ceramic support by facile sol-gel deposition route to effectively separate various oil-water colloidal solutions. This study explores the correlation of silane content involved in optimizing and modifying surface hydrophobicity, membrane pore characteristics, and the solvent permeation properties in terms of oil permeation rate and water rejection (%) in oil-water emulsion solutions. Membrane surface modifications with relatively higher silane content (∼15%) reduced the membrane pores extensively, increasing the water rejection properties but the oil flux was reduced modestly. The oil flux increases with the introduction of reduced silane content (∼2%) but the water rejection properties were compromised. Silane: solvent ratio of 1:100 (silane loading ∼10%) proved to be efficient for the separation (94–99%) of various hydrocarbons such as hexane, toluene, cyclohexane, and heptane from emulsified solutions with permeate flux of 25–40 Lm−2h−1. Cake filtration model was found suitable to explain the membrane fouling. The optimized membrane also recorded a minimal loss of hydrophobicity and mechanical strength enduring oil atmosphere and corrosive environments. The overall study supported by suitable physicochemical material characterizing techniques reveals that optimizing silane concentration in bentonite-based clay composite membrane surface modification can be an effective oil/water separation strategy.

Thin‐Film Composite Membranes for Organic Solvent Nanofiltration

AbstractOrganic solvent nanofiltration (OSN) is an emerging separation technology. Significant efforts have been dedicated to designing and fabricating thin film composite (TFC) membranes for OSN in recent years. The development and utilization of TFC membranes in OSN are paramount in ensuring the permeability of organic solvent and rejection of solute. Additionally, researchers have delved into optimizing preprocessing and post‐treatment procedures during preparation. The preparation process has emerged as another avenue for improving the separation performance of TFC membranes. Simultaneously, various supports have been explored to enhance the TFC membranes′ performance, including polymer substrates and inorganic substrates, as well as the interlayers between the substrate and the TFC membrane, each with unique advantages and disadvantages, and the choices of support depend on the specific requirements of the intended application. The limitations of conventional membranes could be overcome and thus achieve superior performance via an improved preparation strategy of the TFC membranes. This review presents a comprehensive overview of the preparation process for TFC membranes, including a detailed discussion of the preparation methods, the optimizing processes, and the substrates.

Machine Learning-Assisted Design of Thin-Film Composite Membranes for Solvent Recovery.

Organic solvents are extensively utilized in industries as raw materials, reaction media, and cleaning agents. It is crucial to efficiently recover solvents for environmental protection and sustainable manufacturing. Recently, organic solvent nanofiltration (OSN) has emerged as an energy-efficient membrane technology for solvent recovery; however, current OSN membranes are largely fabricated by trial-and-error methods. In this study, for the first time, we develop a machine learning (ML) approach to design new thin-film composite membranes for solvent recovery. The monomers used in interfacial polymerization, along with membrane, solvent and solute properties, are featurized to train ML models via gradient boosting regression. The ML models demonstrate high accuracy in predicting OSN performance including solvent permeance and solute rejection. Subsequently, 167 new membranes are designed from 40 monomers and their OSN performance is predicted by the ML models for common solvents (methanol, acetone, dimethylformamide, and n-hexane). New top-performing membranes are identified with methanol permeance superior to that of existing membranes. Particularly, nitrogen-containing heterocyclic monomers are found to enhance microporosity and contribute to higher permeance. Finally, one new membrane is experimentally synthesized and tested to validate the ML predictions. Based on the chemical structures of monomers, the ML approach developed here provides a bottom-up strategy toward the rational design of new membranes for high-performance solvent recovery and many other technologically important applications.

Ultra-thin PTMSP nanocomposite membranes incorporated with functionalized MoS2 nanosheets for pharmaceutical concentration and solvent recovery

Organic solvent nanofiltration (OSN) membranes with enhanced separation performance and excellent structure stability are of great benefit in recovering organic solvent and concentrating molecules in pharmaceutical industry. In this study, we developed a smooth and ultra-thin nanocomposite membrane by incorporating sodium dodecylbenzene sulfonate (SDBS) functionalized molybdenum sulfide (MoS2) nanosheets into an ultra-thin poly-trimethylsilylpropyne (PTMSP) skin layer on polysulfone (PSf) substrate via a facile solution coating method. The two-dimensional (2D) SDBS-MoS2 with improved compatibility was employed to provide selective channels for solvent permeation while reducing defect cavities to increase solute rejection. The resulting membrane exhibited a significantly improved methanol permeance of up to 8.38 L m−2 h−1 bar−1, signifying a noteworthy 56 % increment compared to the pristine membrane. Additionally, the RB rejection increased from 95.05 % to 97.72 %. The as-prepared membrane also demonstrated favorable long-term stability and efficient molecules separation capabilities in the pharmaceutical industry. This work demonstrated that the compatibility and dispersibility of 2D MoS2 could be improved by adding SDBS, resulting in a SDBS-MoS2-PTMSP membrane with excellent OSN performance and outstanding long-term stability, making it highly promising for industrial applications.

Robust thin film composite membrane with Cu2+ integrally-crosslinking for organic solvent nanofiltration

Thin film composite (TFC) membranes are commonly used for organic solvent nanofiltration (OSN) application. However, these membranes normally suffer from the layer delamination under harsh conditions. Chemically integral crosslinking is a common method to address this problem, but the resultant tightened polymeric chains and denser microstructure will inevitably bring the reduced solvent permeance. In this work, a facile metal integral crosslinking strategy, which has minimal adverse effect on the solvent permeance, was developed to improve the tolerance to the majority of organic solvents as well as enhance the adhesions of upper selective layers and underlying substrates simultaneously for the first time. The as-developed Cu2+ integrally-crosslinked membranes demonstrated a high permeance for organic solvents and a high rejection towards rose bengal. In comparison to the Cu2+ partially-crosslinked membranes (with substrate crosslinked only), the integrally-crosslinked ones exhibited superior solvent resistance and OSN performance. This improvement was attributed to the enhanced interactions and a defect-free PA layer. Additionally, the effects of solvent activation, crosslinking solution concentration as well as crosslinking time were also studied. It is believed that metal integral crosslinking strategy will offer a novel approach to develop promising TFC membranes with satisfactory OSN performance for practical applications.

Oriented ionic covalent organic framework membranes for efficient organic solvent nanofiltration

Developing effective organic solvent nanofiltration (OSN) membranes to separate molecular solutes from organic solvents is highly desired yet requires a suitable material platform and an in-depth investigation of membrane selectivity. Herein, an oriented ionic covalent organic framework membrane (oi-COM) was fabricated, which features well-ordered channels that are vertically aligned towards the membrane surface and lined with abundant sulfonate groups. Filtration experiments of multifarious organic solvents and solutes with different charges and molecular sizes were conducted. The oi-COM exhibited above 99% rejection for negatively charged dye (Evans blue), much higher than that for positively charged dye with similar molecular size, while maintaining high solvent permeance for ethanol of 63 L m−2 h−1 bar−1. These results demonstrated the significance of electrostatic repulsion effect in membrane selectivity, providing insights for the design of high-performance OSN membranes.

Thin film composite membrane with improved permeance for reverse osmosis and organic solvent reverse osmosis

Reverse osmosis (RO) is a widely used pressure-driven membrane process for desalination. Advancements in membrane materials have driven RO technologies' development and widespread application. Thin-film composite (TFC) membranes of a thin polyamide (PA) layer, porous substrate, and nonwoven fabric support are considered the gold standard in desalination technology. These membranes exhibited excellent separation performance and mechanical strength. Recently, TFC membranes with PA layers have been successfully employed in organic solvent reverse osmosis (OSRO) to differentiate organic liquids molecularly. Developing TFC membranes with improved solvent resistance and permeance is required to expand the applications of TFC membranes beyond solvent-solute systems. This study explored polyketone (PK) membranes as porous substrates in TFC membranes for general reverse osmosis processes. PK membranes offer excellent solvent resistance and are easier to prepare than other membranes. Furthermore, a surface modification approach was proposed to enhance the interfacial polymerization (IP) of the polyamide layer on both PK and polysulfone (PSf) substrates, resulting in improved TFC membranes with enhanced water permeance for RO and increased organic liquid permeance for OSRO while maintaining permselectivity. These findings highlight surface chemistry's significance in controlling crumpled PA layers' formation, ultimately improving the filtration efficiency for general RO applications. This study provides an example of the design of composite structures of TFC membranes for broader RO applications.

Regenerated cellulose membranes for efficient separation of organic mixtures

Organic solvent nanofiltration (OSN) is a low-carbon technology for organic mixture separation that usually relies on non-renewable fossil-derived membranes. Cellulose, a biomass material with extensive sources and superior resistance to organic solvents, holds great promise in engineering OSN membranes. Here we studied the mass transport and separation properties of regenerated cellulose membranes (RCMs), which were made from wood pulp using ionic liquid as solvent by phase inversion method. By regulating membrane thickness from 150 μm to 350 μm, the solvent permeance and solute rejection can be finely tuned. The 350-μm-thick RCM membrane (RCM-350) displays better compaction resistance than the thinner ones and harvests high solute rejection with ethanol permeance reaching ∼ 30 L m−2 h−1 bar−1, outperforming the state-of-the-art polymeric membranes and showing long-term stability during cross-flow OSN. When used for solute separation, the RCM-350 membrane provides molecular selectivity of up to 294 and 68 for Alcian blue/Rifampicin and Alcian blue/Tetracycline mixtures, respectively, which depends on the mixture composition. Our findings reveal the potential of regenerated natural cellulose as a high-performance and sustainable alternative membrane material for separating organic mixtures.

Large-Area Soluble Covalent Organic Framework Oligomer Coating for Organic Solution Nanofiltration Membranes.

Covalent organic frameworks (COFs) are a family of engaging membrane materials for molecular separation, which remain challenging to fabricate in the form of thin-film composite membranes due to slow crystal growth and insoluble powder. Here, an additive approach is presented to construct COF-based thin-film composite membranes in 10min via COF oligomer coating onto poly(ether ether ketone) (PEEK）ultrafiltration membranes. By the virtue of ultra-thin liquid phase and liquid-solid interface-confined assembly, the COF oligomers are fast stacked up and grow along the interface with the solvent evaporation. Benefiting from the low out-plane resistance of COFs, COF@PEEK composite membranes exhibit high solvent permeances in a negative correlation with solvent viscosity. The well-defined pore structures enable high molecular sieving ability (Mw = 300g mol-1 ). Besides, the COF@PEEK composite membranes possess excellent mechanical integrities and steadily operate for over 150 h in the condition of high-pressure cross flow. This work not only exemplifies the high-efficiency and scale-up preparation of COF-based thin-film composite membranes but also provides a new strategy for COF membrane processing.

In-silico design of covalent organic framework membranes for efficient water/ethanol separation

Covalent organic frameworks (COFs) have recently emerged as a promising class of nanoporous materials for membrane separation. At present, COF membranes are not efficient for separation of water from ethanol (ethanol dehydration) owing to pervasive challenge to separate small-sized molecular mixture. In this proof-of-concept study, we have computationally designed a series of novel COFs as pervaporation (PV) membranes for efficient ethanol dehydration. We utilized TpPa-1 as a model COF and its framework was rationally modified by attaching several hydrophobic and hydrophilic functional groups, resulting in new COF membranes namely TpPa-1-C5H8, TpPa-1-COOC2H5, TpPa-1-OC3H6OH, TpPa-1-C2Ph, TpPa-1-OC4H8OH and TpPa-1-OC2H4NHOCH3. These membranes possess different functionality and aperture size. Molecular dynamics (MD) simulations demonstrated that the permeation flux of water and ethanol is mostly governed by pore aperture size. The COF with the largest pore aperture holds the highest flux. In contrast, polarity of the pore functional groups governs the separation factor. COF membranes with hydrophobic pore functionalities display a lower separation factor than the membranes with hydrophilic pore functionalities. Among the designed COF membranes, TpPa-1-OC4H8OH has shown superior performance compared to the state-of-art membranes. Also, activation energies for permeation of water and ethanol through the two promising TpPa-1-OC3H6OH and TpPa-1-OC4H8OH membranes are lower than the reported PV membranes. Interestingly, water and ethanol molecules indicate backward movement before leaving the membrane surface at permeate side. The potential of mean force (PMF) shows that free energy barrier for water to enter the pore of highly selective COF membrane is ∼18.84 kJ/mol and the driving force for the water transfer from feed side to permeate side is ∼ −10.5 kJ/mol at PV condition. The current study not only reveals the underlying mechanism for solvent permeation and separation, but also suggests a highly selective COF membrane for water/ethanol separation. We envisage potential applications of the designed COFs as novel materials for sustainable solvent recovery.

Carbon-doped metal oxide interfacial nanofilms for ultrafast and precise separation of molecules.

Membranes with molecular-sized, high-density nanopores, which are stable under industrially relevant conditions, are needed to decrease energy consumption for separations. Interfacial polymerization has demonstrated its potential for large-scale production of organic membranes, such as polyamide desalination membranes. We report an analogous ultrafast interfacial process to generate inorganic, nanoporous carbon-doped metal oxide (CDTO) nanofilms for precise molecular separation. For a given pore size, these nanofilms have 2 to 10 times higher pore density (assuming the same tortuosity) than reported and commercial organic solvent nanofiltration membranes, yielding ultra-high solvent permeance, even if they are thicker. Owing to exceptional mechanical, chemical, and thermal stabilities, CDTO nanofilms with designable, rigid nanopores exhibited long-term stable and efficient organic separation under harsh conditions.

Construction of highly permeable organic solvent nanofiltration membrane via β-cyclodextrin assisted interfacial polymerization

As the key of organic solvent nanofiltration (OSN) technology, OSN membranes could effectively retain small molecules with molecular weight between 200 and 1000 Dalton (Da), but they still face some problems such as low solvent permeance. In this work, we fabricated a poly(amide-ester) selective layer on polyimide substrate surface by introducing β-cyclodextrin (β-CD) into the aqueous phase solution to assist the interfacial polymerization reaction between m-phenylenediamine (MPD) and trimesoyl chloride (TMC), followed by cross-linking and solvent activation treatment. Thus, we successfully fabricated a kind of thin film composite (TFC) membrane with high selective permeability for OSN. We emphasized that extra-low contents were employed for both MPD and β-CD, which were 0.05 wt% and 50 mg L−1, respectively. The effect of β-CD content on the pore size, surface shape, surface hydrophilicity, surface chemistry, filtration performance, as well as durability performance of the OSN membrane was studied in depth. β-CD endows the selective layer with better hydrophilicity and larger pore size. The optimized OSN membrane possesses a Rhodamine B (RDB, 479 Da) rejection of 99.2 % and an ethanol permeance of 70.6 L m−2 h−1 MPa−1. Furthermore, the optimized OSN membrane remains above 99 % RDB rejection after being immersed in DMF at 25 °C for 1000 h, which demonstrates its superb solvent resistance. Additionally, the optimized OSN membrane exhibits outstanding long-time performance and possesses a rejection of 98 % for Jacobsen catalyst during more than 106 h semi-continuous filtration using Jacobsen catalyst/ethyl acetate solution as feed, indicating its vast potential in the recovery of catalyst.

Surface Hydrophobicity and Guest Permeability in Polydimethylsiloxane-Coated MIL-53 as Studied by Solid-State Nuclear Magnetic Resonance Spectroscopy.

Experimental characterization of the hydrophobic porous materials at the atomic and molecular levels is of great significance, but exploring their hydrophobicity characteristics and interactions with guest molecules with distinct polarity is still challenging. In this work, solid-state NMR is employed to characterize the surface hydrophobicity and explore the guest solvent permeability in polydimethylsiloxane (PDMS)-coated MIL-53. It was found that the PDMS-coated MIL-53 was hydrophobic to water and infiltrated to methanol, acetone, benzene, toluene, and ethylbenzene solvents. In addition, two types of guest solvents (methanol, acetone, benzene, toluene, and ethylbenzene), inside the pore and outside the pore of PDMS-coated MIL-53, were clearly identified using two-dimensional 1H-1H homo-nuclear correlation NMR experiments. Moreover, the membrane thickness of the PDMS-coated MIL-53 could be determined from the analysis of the 1H-1H spin diffusion buildup curves. Furthermore, the permeability of benzene, toluene, and ethylbenzene at different PDMS coating levels was extracted from 1H MAS NMR. The increase of the hydrophobic PDMS layer resulted in a decrease of the penetration of aromatic guests to the internal pore of MIL-53. This work provides deep insights into the understanding of guest solvent permeability of hydrophobic layer-coated MOFs in the application fields of catalysis and separation.

Thin film nanocomposite polyamide membrane doped with amino-functionalized graphene quantum dots for organic solvent nanofiltration

Thin film nanocomposite (TFN) organic solvent nanofiltration (OSN) membrane with improved separation performance was fabricated via interfacial polymerization reaction between amine-functionalized graphene quantum dots (af-GQDs) doped aqueous monomer solution of m-phenylenediamine (MPD) and n-hexane solution containing trimesoyl chloride (TMC) monomer. We emphasize the employment of extra-low content for both af-GQDs and MPD, so that we could maximize the function of these nanomaterials and eliminate their aggregation at the same time. The af-GQDs nanomaterials could regulate the interfacial polymerization process and could be strongly anchored in the polyamide film via covalent bonding, hence could prevent their loss while providing more channels for faster solvent penetration. As a result, the optimized OSN membrane, TFN-50, shows a super-smooth surface, with a surface roughness as low as 4.3 ± 0.2 nm, and excellent pure solvent permeances which reach 135.8, 112.7, and 69.8 L m−2 h−1 MPa−1 for methanol, DMF and ethanol, respectively, as well as a very high Rhodamine B (RDB, 479 Da) rejection of up to 99.2%, and an ethanol permeance of 61.4 L m−2 h−1 MPa−1. Furthermore, the TFN-50 OSN membrane still shows excellent filtration performance after being submerged in DMF for 336 h or continuous crossflow filtration with Rose bengal (RB, 1017 Da)/DMF solution for 136 h, demonstrating its excellent solvent resistance.

Ultrathin Polyamide Nanofilms with Controlled Microporosity for Enhanced Solvent Permeation.

Organic solvent nanofiltration (OSN) technology shows reduced energy consumption by almost 90% with great potential in achieving low-carbon separation applications. Polyamide nanofilms with controlled intrinsic and extrinsic structures (e.g., thickness and porosity) are important for achieving such a goal but are technically challenging. Herein, ultrathin polyamide nanofilms with controlled microporosity and morphology were synthesized via a molecular layer deposition method for OSN. The key is that the polyamide synthesis is controlled in a homogenous organic phase, rather than an interface, not only involving no monomer kinetic diffusion but also broadening the applicability of amine monomers. The particular nonplanar and rigid amine monomers were superbly used to increase microporosity and the nanofilm was linearly controlled at the nanometer scale to decrease thickness. The composite membrane with the polyamide nanofilms as separation layers displayed highly superior performance to current counterparts. The ethanol and methanol permeances were up to 5.5 and 14.6 L m-2 h-1 bar-1, respectively, but the molecular weight cutoff was tailored as low as 300 Da. Such separation performance remained almost unchanged during a long-term operation. This work demonstrates a promising alternative that could synergistically control the physicochemical structures of ultrathin selective layers to fabricate high-performance OSN membranes for efficient separations.

Unlocking complex chemical and morphological transformations during thermal treatment of O-hydroxyl-substituted polyimide of intrinsic microporosity: Impact on ethanol/cyclohexane separation

In this work, we investigated the pervaporation separation performance of an ethanol – cyclohexane mixture using a thin-film composite membrane based on a heat-treated, o-hydroxyl-substituted polyimide of intrinsic microporosity (PIM-6FDA-OH). We report in detail the complex chemical and structural transformations that are associated with the development of thermally-rearranged (TR, 400–450 °C), and carbon molecular sieve (CMS) membranes (>500 °C). These transformations strongly affect the affinity-related (e.g. swelling behavior) and morphology-related (e.g. microporosity) properties of the TR and CMS membrane materials which translate into a complex molecular-level separation behavior toward an organic solvent mixture during pervaporation. We show that excellent separation performance (total flux ∼ 4 kg/m2h and ethanol/cyclohexane separation factor of ∼1250) can be achieved after precise thermal treatment at the onset of the CMS formation. In addition, we highlight the unique property of pervaporation where, in contrast to liquid solvent permeation, the downstream side of the membrane remains essentially dry due to exposure to high vacuum. As a result, a sharp molecular cut-off can be achieved within this dry downstream region of the membrane despite considerable overall swelling/penetrant concentration in the upstream region of the membrane.

Fabrication of organic solvent nanofiltration membranes with graphene oxide - Enhanced covalent organic framework via interfacial polymerization

Membrane-based filtration offers many benefits like lower energy consumption and operating cost for separation in harsh solvents. In particular, such membranes need to have high nanofiltration separation efficiency and high resistance to organic solvents. Unfortunately, the common thin film composite (TFC) - based organic solvent nanofiltration membranes often give low solvent permeance due to the dense skin layer atop the substrate. To address this, we fabricated a covalent organic framework (COF) - incorporated TFC membrane through the in-situ formation of benzene-1,3,5-tricarboxaldehyde (TFB) and graphene oxide (GO) in p-Cymene, a less toxic solvent, with p-Phenylenediamine (PPD) in aqueous phase via interfacial polymerization. The PES-COF-GO membranes exhibited optimal solvent permeance and separation efficiency at an intermediate 0.8wt% GO, which gave the highest water permeance of 16.2L/m2 h bar and a molecular weight cut-off (MWCO) of around 325 gmol-1. In addition, the crosslinked GO-COF layer endowed the membrane with chemical stability in non-polar solvents. The mechanical strength of PES-COF-GO membrane was also improved due to the COF-GO layer atop the PES substrate making the surface tighter and mechanically stronger.

AF2400/polyketone composite OSRO membrane for organic solvent mixture separation

An organic solvent reverse osmosis (OSRO) membrane was fabricated by spin-coating a copolymer of perfluoro-2,2-dimethyl-1,3-dioxole and tetrafluoroethylene (Teflon® AF2400) onto a polyketone support membrane. The purpose of this research was to develop an OSRO membrane with different separation properties from a polyamide membrane already published in the literature. The prepared membranes had a dense and smooth active layer on the support membrane. In the pure organic solvent permeation tests, aliphatic hydrocarbons (nonpolar solvents) and aromatic hydrocarbons (nonpolar solvents) permeated through the membrane, whereas almost no alcohol permeation (polar solvents) was observed under our evaluation conditions. The separation performances of the nonpolar/polar solvent mixture systems and nonpolar/nonpolar solvent mixture systems were investigated. In the separation of 1,3,5-triisopropylbenzene from toluene, a separation factor of 31.3 with a toluene permeance of 0.07 LMH/bar was obtained, suggesting the successful separation of nonpolar organic solvents from a mixture of nonpolar solvents.

Polyamide composite membrane with 3D honeycomb-like structure via acetone-regulated interfacial polymerization for high-efficiency organic solvent nanofiltration

High-performance organic solvent nanofiltration (OSN) membranes play an indispensable role in chemical separation processes. However, conventional OSN membranes such as thin-film composite polyamide (TFC-PA) membranes exhibit insufficient perm-selectivity. In this study, we developed a high-performance TFC-PAOSN membrane on a porous polyketone (PK) support by regulating interfacial polymerization (IP) with acetone as an organic co-solvent. The effect of the acetone co-solvent on the IP reaction and PA nanofilm morphology was investigated. Acetone serves as a regulator to mediate the IP reaction by facilitating the convective diffusion of monomers at the aqueous/organic interface. Furthermore, experimental results and molecular dynamics (MD) simulation analysis confirmed that the addition of acetone increases the width of the IP reaction zone, facilitates more violent exothermic reactions, and induces aggravated vaporization of acetone, resulting in the formation of a 3D honeycomb-like structure with an ultrahigh specific surface area. Compared with the TFC-PA membrane prepared by the conventional IP method, the TFC-PA-acetone membrane prepared by acetone-regulated IP (ARIP) exhibited 2.6 times higher methanol solvent permeance (7.0 LMH/bar) and comparable methyl orange rejection (94.6%). This work explores the underlying mechanism of acetone-regulated IP, providing a facile strategy for tailoring the membrane morphology with high-efficiency organic solvent nanofiltration.

Triazinane-based thin-film composite membrane fabrication via heterocycle network formation from formaldehyde and amines for organic solvent nanofiltration

Thin film composite (TFC) membranes are generally used in organic solvent nanofiltration (OSN). However, most of the studies that have explored the chemistry of TFC membranes have focused on polyamide and polyester network polymers. This study focuses on the fabrication of a novel polytriazinane network polymer for TFC membranes via interfacial polymerization (IP) using formaldehyde and a primary amine such as priamine or 1,3,5-tris(4-aminophenyl)benzene. This approach enables the formation of a solvent-stable network polymer using only bis-functionalized amines. Along with small-molecular model reactions, the membranes were characterized using Fourier transform infrared spectroscopy, solid-state nuclear magnetic resonance spectroscopy, and X-ray photoelectron spectroscopy to confirm the proposed triazinane structure. The membranes demonstrated high stability in a wide range of organic solvents, but they were susceptible to acidic hydrolysis. The molecular weight cutoff and methanol permeance of the TFC membranes were 555–698 g mol−1 and 7.5–131 L m−2 h−1 bar−1, respectively. A polyimide aerogel support was used in TFC fabrication to achieve high solvent permeance. The three-dimensional structure of the aerogel support was visualized using electron tomography to demonstrate its high porosity and pore interconnectivity. The stability of the TFC membranes was confirmed through long-term cross-flow filtration tests showing no significant change in solute rejection or methanol permeance over three days at 10 bar. A carcinogenic impurity from a semi-synthetic macrolide antibiotic was successfully removed using these membranes. To summarize, heterocyclization resulting in triazinane structures during IP opens new options for TFC membrane fabrication.