Monomer Reactivity Research Articles

A soluble highly-sulfonated polybenzimidazole with high molecular weight as membrane for vanadium flow battery with enhanced performance and long-term stability

A series of novel sulfonated polybenzimidazole (SPBI) membranes containing flexible double ether segments, having high ion exchange capacity (IEC), good solubility as well as high molecular weight, are designed for vanadium flow batteries (VFBs). The bis-ether structure of self-synthesized sulfonic acid monomer, 4,4'-((2-sulfo-1,4-phenylene)bis(oxy))dibenzoic acid, improves the solubility of produced SPBI and the microphase separation structure of prepared membrane by disrupting the regularity of the backbone through a non-planar structure and attenuating the interchain stacking effect of the polymer backbone. Such a highly reactive bis-ether monomer also leads to high molecular weights (2.37−2.82 dL g−1). The copolymerization using another sulfonic acid monomer, Monosodium-5-Sulfoisophthalate monomer, leads to a high IEC of up to 2.08 mmol g−1. As a result, the SPBI membrane shows a low area resistance of 0.21 Ω cm2 and a low vanadium ion permeability of 3.36 × 10−9 cm2 s−1. The VFB cell employing SPBI membrane achieves a very high energy efficiency exceeding 82 % at 200 mA cm−2. In addition, an ultra-long lifetime of over 3400 cycles is accomplished.

Direct evidence for the mechanism of early-stage geopolymerization process

Geopolymer, an alternative construction material to cement, acquires strength and endurance through the geopolymerization process. However, the study on the early-stage geopolymerization is rare since it occurs rapidly and involves liquid phase, viscous slurry, and gel-like material, making the observation of this process complicated. This research addresses the challenge of observing this process by providing real-time evidence through in situ techniques: Fourier-transformed infrared (FTIR) spectroscopy, X-ray absorption spectroscopy (XAS), and environmental scanning electron microscopy (E-SEM). These methods consistently confirm the formation of aluminosilicate oligomers, short chains of silicate and aluminate species, in the polycondensation Stage I within the initial 5 minutes. This stage involves the reaction of Si-O and Al-O monomers, released during a dissolution process, with available Na2SiO3 from alkaline solutions in the system. In the subsequent polycondensation Stage II, aluminosilicate oligomers polymerize, creating a three-dimensional network of aluminosilicate chains through the crosslinking of Si-O-Si and Si-O-Al bonds. This process continues beyond the initial 5 minutes, gradually nearing completion around 30 minutes, as consistently confirmed by various experimental techniques. Rheological studies on the geopolymer paste flow rate support these interpretations. The study provides compelling direct evidence into the mechanisms of early-stage geopolymerization, significantly contributing to the research field and paving the way for widespread utilization in geopolymer applications.

Vat photopolymerization of poly(styrene-b-isoprene-b-styrene) triblock copolymers

Vat photopolymerization (VPP) additive manufacturing (AM) produces complex geometries with micron-scale resolution and smooth surface finish from a wide range of photocrosslinkable polymeric precursors. However, mass transport limitations typically constrain VPP amenable precursors to viscosities less than 10 Pa·s. Reactive oligomers and monomers comprise the majority of VPP polymeric precursors, which result in highly crosslinked and brittle 3D objects upon printing. This work describes colloidal high molecular weight ABA triblock copolymers, or latex, as a feedstock for aqueous photoreactive compositions to enable AM of thermoplastic elastomers (TPE). Photorheological analysis determined 15 wt% aqueous reactive monomers and oligomers generated a structural scaffold that achieved sufficiently high modulus to maintain feature fidelity for iterative layer formation. Subsequent thermal post-processing removed water and promoted polymeric particle coalescence throughout the scaffold resulting in an interpenetrating network (IPN) that exhibited an isotropic dimensional shrinkage of 25 %. Small-angle X-ray scattering (SAXS) confirmed microphase-separated morphologies typical of triblock copolymers, revealing a characteristic length scale of 30 nm. Using commercially available VPP printers, ABA triblock copolymer poly(styrene-b-isoprene-b-styrene) latex yielded printed elastomers with precise feature fidelity and tensile extensibility exceeding 800 %.

Conjugated diacetylene polymers with intrachain D-A block heterostructure for efficient photocatalytic hydrogen production

Solar-driven photocatalytic hydrogen production has been considered as a promising candidate technology for supplying green and sustainable energy source alternative to fossils. But its low solar-to-hydrogen conversion efficiency level hampers its practical application, and lack of effective structure for promoting charge separation is one of the accounts. Herein, intrachain heterojunction structure comprised of donor-acceptor (D-A) blocks has been proved to be one of effective structures for addressing such an issue. Utilizing the facile oxidative coupling polymerization reactions of diacetylene monomers and oligomers, a block heterojunction polymeric photocatalyst named PDTPDPA-BP bearing D-A blocked heterostructure was synthesized by first separative oligomerizations of diacetylene-functionalized dibenzothiophene sulfone (DTP) and triphenylamine (TPA) monomers and then mixed together and undergoing further polymerization. In photocatalytic hydrogen production, PDTPDPA-BP displayed a hydrogen evolution rate of 2164 μmol g−1 h−1, which is much larger than those of PDTP (1270 μmol g−1 h−1) and PTPA (57 μmol g−1 h−1) synthesized by homopolymerization of DTP and TPA monomers, respectively, and their 1:1 molar ratio physical blend (363 μmol g−1 h−1). By means of Fluorescence spectroscopy and photo-responsive measurements, it was found PDTPDPA-BP has narrower bandgap and more efficient charge separation than the other polymers. Therefore, the work highlights intrachain heterojunction structure promotes exciton dissociation into free charge carries, and thus deserves the consideration in the design of high performance organic photocatalysts.

Photopolymerization-based 4D-printing of shape-memory materials containing high-performance polymers

High-performance aromatic heterochain polymers are engineering thermoplastics with exceptional mechanical and thermal properties that have attracted great interest in various areas ranging from aerospace to biomedicine. However, there have been a number of difficulties to 3D-print materials based on such polymers with new promising performance characteristics. Herein, a number of new photosensitive compositions (PSCs) based on high-performance polyetherimide (PEI) or polysulfone (PSU), reactive functional monomer (N,N-dimethylacrylamide) and oligomer (bisphenol A ethoxylate diacrylate) has been developed. It has been shown that the use of the developed PSCs allows the formation of 3D-structures with high printing resolution by LCD 3D-printing. Subsequent thermal post-curing of 3D-printed green-state samples at 250°С for 1 h led to the fabrication of materials with the highest tensile strength (up to 41.9 ± 3.1 MPa), glass transition temperature (141 °C) and thermal stability (above 350 °C). In addition, 3D-printed structures demonstrate high-temperature shape memory effect with shape fixity ratio > 99% and shape recovery ratio up to 97.1%.

Polymer dispersity modulation by statistical copolymerization of (α-alkyl)acrylate monomers with disparate reactivity: Enhanced monomer conversion and tailored dispersity for dielectric elastomer application

Polymer dispersity (Ð) is an important parameter in determining polymer properties. We report a new strategy for Ð modulation by statistically copolymerizing steric-hindered itaconates with methacrylate and acrylate monomers via organocatalyzed controlled radical polymerization. Due to the disparate monomer reactivity, Ð values can be tunable in a broad range (1.1–1.6) in a batch system. This strategy has demonstrated the sequential and topological generality for Ɖ modulations, serving as a model tool for Ð modulation in any segment of A-B diblock, B-A-B and A-B-A triblock, and 3-arm star A-B diblock copolymers. The unique aspects of this method are that the segment after Ð modulation can initiate polymerization of various types of monomers (e.g., methacrylate, acrylate) by the labile tertiary carbon-iodide chain-end without any external assistance or special initiator and monomer selection, the metal-free nature and the renewable substitution of petroleum-based methacrylate and acrylate monomers with bio-based itaconates without sacrificing inherent properties. This work broadens the application scope of Ð modulation to many other emerging technologies, such as antifreezing thermoplastic dielectric elastomers used as film capacitors in the field of energy storage.

Theoretical Studies on the Insertion Reaction of Polar Olefinic Monomers Mediated by a Scandium Complex

This study aimed to investigate the insertion reaction of the polar monomers mediated by the cationic rare earth metal complex [(C5H5)Sc(NMe2CH2C6H4-o)]+ utilizing a combination of density functional theory (DFT) calculations and multivariate linear regression (MLR) methods. The chain initiation step of the insertion reaction could be described by the poisoning effect and the ease of monomer insertion, which could be represented via the DFT-calculated energy difference between σ- and π-coordination complexes (ΔΔE) and insertion energy barrier (ΔG≠), respectively. The results indicate that ΔΔE and ΔG≠ can be predicted by only several descriptors using multiple linear regression methods, with a root mean squared error (RMSE) of less than 2.5 kcal/mol. Furthermore, the qualitative analysis of the MLR models provided effective information on the key factors governing the insertion reaction chain initiation.

Acid acceptor modulated interfacial polymerization with piperazine-2-carboxylic acid as diamine monomer for ultrathin polyamide nanofiltration membrane

When introducing acid groups in the diamine monomer for the fabrication of polyamide (PA) membranes through interfacial polymerization (IP), the acid groups not only reduce the diffusion flux of diamine monomer for the polymerization to prepare ultrathin membrane but also provide the negative charges on the membrane surface. However, the introduction of acid groups often weakens the reactivity of diamine monomers, resulting in the formation of thick and loose PA membranes with low rejection of ions. This study proposes a strategy of modulating the IP process of piperazine-2-carboxylic acid (CPIP) by employing an acid acceptor (NaOH) to prepare thin nanofiltration membranes. The acid acceptor can neutralize the HCl to prevent CPIP from being protonated during the IP process, thereby facilitating the cross-linking reaction rate. The thickness of the resulting membrane decreases from 180 nm to 30 nm, accompanied by the fortification of the negative charge, an increase in cross-linking density, and a reduction in pore size. The resulting PA-AA/CPIP_1.0 membrane exhibits a water permeance of 44.6 L m−2 h−1 bar−1, with a significantly increased Na2SO4 rejection of 98.4 % compared with 50.4 % of the PA-AA/CPIP_0 membrane fabricated without acid acceptor. This work may open a new avenue to fabricating high-performance PA membranes for nanofiltration.

Functionalized Unsaturated Polyester as Electrical Insulation Varnish

AbstractSilsesquioxanes (SQs) are mostly used to provide high‐temperature electrical insulation of resins. Here, SQ is used to functionalize unsaturated polyester (UPE) varnish and investigate the effect of functionalization on the thermal and electrical properties of UPE varnishes. The solvent‐free varnish incorporates a reactive diluent to decrease viscosity and a catalyst to expedite hardening, eliminating the need for solvents. Vinyl toluene (VT) and 1,4‐butanediol dimethacrylate (BDDMA) serve as hardening agents, consistent with prior research. Various characterization tests, including Fourier transform infrared, thermogravimetric analyzer, assessment of thermal conductivity coefficient, and determination of electrical volume–surface resistance, are conducted to determine the physical, thermal, chemical, and electrical properties of the synthesized SQ‐functionalized UPE (UPES) varnishes. Results indicate that the UPES–BDDMA varnish demonstrates the highest thermal decomposition temperature at 438.0 °C, while the UPES–VT varnish exhibits the highest electrical volume resistance of 2.85 × 1015 Ω cm. Volatile organic compound levels in UPE coatings range between 4.9% and 5.10% reflecting the growing demand for eco‐friendly products. It is shown in this study that the use of BDDMA and VT reactive monomers in the synthesis of SQ‐functionalized UPE resin and the properties of the resulting varnishes, especially electrical insulation and thermal stability, are improved.

Fabrication of flame-retardant PA6/three-dimensional braided glass fiber composites via in situ polymerization

Reaction injection molding method is employed to improve flame retardancy and mechanical properties of three-dimensional braided glass fiber (3D-braided-GF) reinforced in situ polymerized polyamide 6 (PA6) composites. The kernel lies in adding flame retardants, hexaphenoxycyclotriphosphazene (HPCTP), to the reactive monomers to allow it to be in situ filled into composites during preparing PA6 through anionic polymerization, which enables flame retardants to achieve better dispersion. In addition, extremely low-viscosity reactive monomers are easier to immerse in 3D-braided-GF, ameliorating interfacial adhesion between GF and PA6. The preliminary research indicates that samples with 10 wt.% HPCTP concentration can achieve the best mechanical properties and a satisfied flame-retardant grade (UL 94 HB). However, with the incorporation of 15 wt.% HPCTP into samples, the optimum flame-retardant grade (UL 94 V2) and the reduced mechanical performance are obtained. Furthermore, a dual flame retardancy mechanism in both gaseous and condensed phases of samples is further elucidated. This study can provide a reference for scenarios with high requirements for the flame-retardant and mechanical properties, such as high-speed rail and aircraft.

P‐186: A Novel Liquid Crystal Material for Shortening the UV2 Process of Polymer‐stabilized Vertically Aligned Liquid Crystal Displays

The production of polymer‐stabilized vertically aligned (PSVA) displays requires two UV processes for liquid crystal (LC) alignments. UV1 is usually short for pre‐tilt angle formation, while UV2 takes approximately 90 minutes to consume the remaining reactive monomers (RMs). Therefore, shortening the UV2 process can significantly reduce the power consumption and maintenance costs of UV lamps during LCD fabrication. Herein, we report a novel LC material consisting of fast‐reaction RMs. With the addition of fast‐reaction RMs, the UV2 process can be dramatically decreased from 90 min to 20 min. Furthermore, the reduction of the UV2 process shows competitive optical properties, reliabilities and pre‐tilt angle stabilities compared with the reference. Overall, new fast‐reaction LC materials are beneficial to energy saving and the cost competitiveness of the company.

Well-designed flame retardants for epoxy resin composites that simultaneously improve heat resistance, mechanical properties and fire safety

Epoxy resin (EP) flammability severely limits its application in some industrial fields, while flame retardant epoxy resin (FREP) often suffers from the problem of not being able to balance flame retardant properties with mechanical properties. To solve the problem, in this work, HDP, a reactive flame retardant was succeeded in synthesizing by the one-pot method using protocatechuic aldehyde (PH), 2,4-diamino-6-phenyl-1,3,5-triazine (DPT), and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) as reactive monomers, was used to improve the flame retardancy of EP. And evaluated the effect of HDP on the curing reaction, heat resistance and mechanical property of EP. The introduced of four phenolic hydroxyl groups and two secondary amine groups enhanced the compatibility of the flame retardant HDP in EP and improved process performance. The apparent activation energy (Ec) was reduced by 8.1 %, facilitating the curing of EP/DDM. When 5 wt% of HDP (with only 0.36 wt% phosphorus content) was added to EP, the flexural strength and modulus of FREP increased by 21.0 % and 14.9 %, respectively, and the Tg increased by 9.0 % compared to EP. Cone calorimeter test (CCT) data showed that compared to EP, samples of EP/HDP-5 showed a 14.5 % and 21.6 % reduction in total heat release (THR) and total smoke production (TSP), respectively, and a 13.7 % increase in coke yield (CY). EP/HDP-5 has a high limited oxygen index (32.5 %) and passes the UL-94 V-0 classification. The excellent char formation and flame retardancy was owed to the dual role of the condensed and gas phases of FREP in the combustion process.

Thermal self-initiated polymerization of divinylbenzene under refining conditions

To understand the thermal self-initiated polymerization of vinyl monomers during the divinylbenzene refining process, the differences in reaction behavior among these monomers were studied by density functional theory calculations. The calculations reveal that para-divinylbenzene (para-DVB) exhibits higher reactivity than other monomers in polymerization. Specifically, among the first step of initiation which is a Diels-Alder reaction, the reaction between para-DVB molecules shows the lowest activation energy (Ea) of 134.6 kJ/mol. Subsequently, para-DVB preferentially undergoes molecule-assisted homolysis with the products of the aforementioned Diels-Alder reaction and formatting free radicals with an Ea of 74.8 kJ/mol and a reaction rate constant (kTST) of 3.48 × 10−3 L/mol∙s. In the propagation stage, para-DVB also exhibits the highest monomer reactivity, with a kTST approximately 1.4–2.25 times greater than other monomers. The polymerization preformed under refining conditions confirms that the consumption of para-DVB is faster than that of other monomers, consistent with the DFT calculations.

Evolution Kinetics of Stabilizing Pickering Emulsion by Brush-Modified Janus Particles: DPD Simulation and Experimental Insights.

In the present study, we report the evolution of stabilizing Pickering emulsions using brush-modified Janus particles (JPs), utilizing the dissipative particle dynamics (DPD) simulation technique. Our results are subsequently corroborated with experimental findings. Each JP has one-half of the hydrophobic surface, with the other half embedded with hydrophilic polymer brushes grown via atom transfer radical polymerization (ATRP). Our generic simulation model analyzes the chemical kinetics of polymer brush growth on one-half of the initiator-embedded microparticle (MP) surface, resulting in the formation of JP. This involves evaluating monomer conversion and reaction rates. Our results exhibit a substantial influence of the number of JPs, grafted brush density, and brush length on oil-in-water emulsion stability. We studied the evolution kinetics and stability of emulsion formation by analyzing the growth of average domain size and corresponding scaling functions up to a late time limit. This study aims to clarify the connection between the size, quantity, and functionality of JPs and the stability of Pickering emulsions.

Fabrication and properties of recyclable tung oil–based polymer coatings based on dual cross-linked dynamic covalent polymer networks

The exploration of reprocessability and high-adhesion biomass polymer coatings is in line with the concept of green materials and is conducive to energy conservation and environmental protection. Here, a series of novel recyclable tung oil–based polymer coatings based on dual cross-linked dynamic covalent networks were reported. Tung oil polymerized maleic anhydride (TOA) was firstly prepared and further reacted with furfuryl alcohol. Then tung oil-polymerized maleic furanol ester (TOAFA) containing reactive conjugated double bond and carboxyl groups was prepared. FTIR and 1H NMR demonstrated the reactive monomer TOAFA was successfully synthesized. Then TOAFA was cross-linked with bismaleimide and different epoxy resins to fabricate target polymer networks based on dynamic Diels-Alder(D-A) bonds and dynamic transesterification. The shape memory, reprocessing, and mechanical and thermal stability of the copolymerized systems with different crosslinking states were investigated. The coating performances were characterized with solvent resistance, adhesion strength, hardness and glossiness tests. It was found that the dynamic D-A covalent bonds were perfectly combined with transesterification in the polymerization systems. The copolymerized systems possessed excellent thermal stability and mechanical properties. The rigid and flexible properties of the polymer networks can be controlled by adjusting the component weight ratios and the type of epoxy resin in the polymerization system. The rigid polymerization system had the highest tensile strength of 28 MPa, and its elongation at break was up to 57 % of the flexible polymerization system. Coating adhesion test showed the adhesion property reached level 1. The polymer coatings displayed excellent solvent corrosion resistance, and relative high gloss. The polymer networks also showed certain reprocessing performance and excellent shape memory effect.

A renewably sourced, circular photopolymer resin for additive manufacturing

The additive manufacturing of photopolymer resins by means of vat photopolymerization enables the rapid fabrication of bespoke 3D-printed parts. Advances in methodology have continually improved resolution and manufacturing speed, yet both the process design and resin technology have remained largely consistent since its inception in the 1980s1. Liquid resin formulations, which are composed of reactive monomers and/or oligomers containing (meth)acrylates and epoxides, rapidly photopolymerize to create crosslinked polymer networks on exposure to a light stimulus in the presence of a photoinitiator2. These resin components are mostly obtained from petroleum feedstocks, although recent progress has been made through the derivatization of renewable biomass3–6 and the introduction of hydrolytically degradable bonds7–9. However, the resulting materials are still akin to conventional crosslinked rubbers and thermosets, thus limiting the recyclability of printed parts. At present, no existing photopolymer resin can be depolymerized and directly re-used in a circular, closed-loop pathway. Here we describe a photopolymer resin platform derived entirely from renewable lipoates that can be 3D-printed into high-resolution parts, efficiently deconstructed and subsequently reprinted in a circular manner. Previous inefficiencies with methods using internal dynamic covalent bonds10–17 to recycle and reprint 3D-printed photopolymers are resolved by exchanging conventional (meth)acrylates for dynamic cyclic disulfide species in lipoates. The lipoate resin platform is highly modular, whereby the composition and network architecture can be tuned to access printed materials with varied thermal and mechanical properties that are comparable to several commercial acrylic resins.

Regulation on photocatalytic debromination by the reconfiguration of carbonyl groups on the covalent organic frameworks

Covalent organic frameworks (COFs) as promising organic semiconductor photocatalysts have become a research hotspot in the field of photocatalytic organic synthesis. Herein, a series of imine-linked EN-COF-x were synthesized by condensation reaction of amine monomer with triformylbenzene monomer. Then, β-ketoamine-linked KE-COF-y were obtained by the reconstruction of EN-COF-x in alkaline solution. The photocatalytic performance of COFs before and after the isomerization from enols to ketones were investigated. The characterization results and density functional theory calculations clearly demonstrated that the carbonyl groups not only make the conduction band energy level more negative, but also lead to a more inhomogeneous charge distribution in the molecule, which improved the separation efficiency of the photogenerated electrons. In addition, the increase in the number of hydroxyl groups on triformylbenzene monomer contributed to the formation of more carbonyl groups in the COF frameworks, which is beneficial to improving its photocatalytic performance. KE-COF-3 synthesized from 2,4,6-Trihydroxy-1,3,5-benzenetricarbaldehyde has more carbonyl group units and more suitable redox potential, which effectively promoted the debromination reaction with 99% yield under light irradiation. Meanwhile, it can be reused at least five times without loss of catalytic activity. This work provides insights for the rational design of functionalized β-ketoamine COFs for photocatalytic organic transformations.

Role of electron transfer between bare electrode and benzoguanamine to fabricate an electrochemical sensor for drugs: Theoretical and electrochemical approach

Herein, a poly(benzoguanamine) (BNZ) modified carbon paste electrode (CPE) was applied for the electroanalysis of paracetamol (PA) in PA tablet and human urine. Theoretical evaluation of the quantum chemical parameters of benzoguanamine (BZ) via density functional theory (DFT) calculations show that it is a reactive monomer with a tendency for back bond formation with the bare carbon paste electrode (BCPE). Scanning electron microscopy (SEM) images of BCPE and BNZ modified CPE (BNZ/CPE) show that the BNZ films were deposited on the bare electrode in layers. Results of the electrochemical characterization of these electrodes in 1 mM K4[Fe(CN)6] revealed that the BNZ/CPE has a higher electrocatalytic activity towards K4[Fe(CN)6] oxidation than BCPE. The limit of detection (LOD) of PA at the BNZ/CPE was estimated as 13.2 nM over a linear dynamic range (LDR) of 0.05–0.45 μM. Also, the proposed sensor offered PA recoveries of 99.2–100.4 % and 98.4–100.8 % in PA tablet solution and human urine sample, respectively. The BNZ/CPE showed remarkable shelf-life by retaining 97.4 % of its initial current response after 21 days of application for PA electroanalysis at 7 days interval. Notably, this study is the first attempt at the application of the BNZ/CPE for PA electroanalysis.

Controlled Enzymatic Synthesis of Polyesters Based on a Cellulose-Derived Triol Monomer: A Design of Experiment Approach.

Regioselective enzymatic polycondensation of the bio-based cellulose derived polyol, Triol-citro, and dimethyl adipate using Candida antarctica Lipase B (CaLB) was investigated. A Design of Experiment approach with MODDE® Pro 13 was used to determine important factors in the branching behavior of this polymer, and reactant ratio, temperature, reaction time and enzyme wt % were the studied factors. Multifunctional polyesters with pendant hydroxy groups were synthesized and fully characterized using 2D NMR techniques to determine degree of branching. Branching was minimal, with a maximum of 16 % observed, and monomer ratio, temperature and reaction time were all determined to be significant factors. In this work, Mn of up to 13 kDa were achieved, while maintaining degree of branching below 15 %, resulting in a linear polyester with the potential to be further functionalized.

Nanomorphogenesis of polyamide membranes by regulating activator-inhibitor diffusivity difference

The use of nanofiltration (NF) membranes featuring crumpled polyamide layers with excellent permeance and selectivity is promising for efficient water reclamation. Although diffusion-driven instability has been regarded as the key mechanism for forming crumpled polyamide structures, in-depth analyses of the morphological and structural features of these membranes are still lacking. We used ammonium carboxymethylcellulose (CMC) and glutaraldehyde (GA) to crosslink and form a pH-responsive interlayer to manipulate the interfacial polymerization (IP) process and the microstructures of interlayered thin-film composite (TFNi) membranes. Experimental observations and molecular dynamics simulations indicate a transition point in the spatial patterns from irregular to regular polyamide nanostructures by tuning the diffusivity difference between the reactant monomers in the two immiscible phases during the IP process. Compared with irregularly crumpled TFNi membranes, regularly crumpled TFNi membranes exhibited polyamide layers with higher aspect ratios (i.e., height/lateral dimension), potentially offering an increased filtration area and sufficient nanovoids. TFNi membranes exhibited a 2.5-fold increase in permeance compared to pristine polyamide membranes, along with twice the selectivity (up to 87.2) for Cl−/SO42−. Our work provides molecular insights into the tuning of morphological features and membrane performance of crumpled polyamide membranes.