Surface-initiated Polymerization Research Articles

Surface-Initiated Polymerization with an Initiator Gradient: A Monte Carlo Simulation.

Due to the difficulty of accurately characterizing properties such as the molecular weight (Mn) and grafting density (σ) of gradient brushes (GBs), these properties are traditionally assumed to be uniform in space to simplify analysis. Applying a stochastic reaction model (SRM) developed for heterogeneous polymerizations, we explored surface-initiated polymerizations (SIPs) with initiator gradients in lattice Monte Carlo simulations to examine this assumption. An initial exploration of SIPs with 'homogeneously' distributed initiators revealed that increasing σ slows down the polymerization process, resulting in polymers with lower molecular weight and larger dispersity (Đ) for a given reaction time. In SIPs with an initiator gradient, we observed that the properties of the polymers are position-dependent, with lower Mn and larger Đ in regions of higher σ, indicating the non-uniform properties of polymers in GBs. The results reveal a significant deviation in the scaling behavior of brush height with σ compared to experimental data and theoretical predictions, and this deviation is attributed to the non-uniform Mn and Đ.

Grafting Block Copolymer Nanoparticles to a Surface via Aqueous Photoinduced Polymerization-induced Self-Assembly at Room Temperature.

The creation of well-defined surface nanostructures is important for a diverse set of applications such as cell adhesion, superhydrophobic coating, and lithography. In this study, we describe a robust bottom-up method for surface functionalization that involves surface-initiated reversible deactivation radical polymerization (RDRP) and the grafting of block copolymer nanoparticles to material surfaces via aqueous photoinduced polymerization-induced self-assembly (photo-PISA) at room temperature. Using silica nanoparticles as a model substrate, colloidal mesoscale hybrid assemblies with various morphologies were successfully prepared. The morphologies can be easily tuned by changing the lengths of macromolecular chain transfer agents and parameters of the silica nanoparticles. The surface-initiated photo-PISA approach can also be employed for other large-scale substrates such as silicon wafer. Taking advantage of mild reaction conditions of this method (room temperature, aqueous medium, and visible light), enzymatic deoxygenation was introduced to develop oxygen-tolerant surface-initiated photo-PISA that can fabricate well-defined nanostructures on large-scale substrates under open-to-air conditions.

Surface Modification of Cellulose Nanocrystal Films via RAFT Polymerization for Adsorption of PFAS

Cellulose nanocrystals (CNCs) are bio-based materials able to be functionalized following different approaches, which expands their range of applications. One such approach is surface-initiated polymerization, which involves the attachment of an initiator to the CNC’s surface to initiate the growth of the polymer. This work reports the modification of CNCs using the described approach. First, a CNC-based film was prepared, on which an initiator (RAFT agent) was grafted, and then (trimethylaminoethyl methacrylate, a positively charged monomer, was polymerized using reversible addition–fragmentation chain-transfer (RAFT) polymerization. The CNC film was successfully modified and fully characterized. Different degrees of polymerization were targeted to emphasize the effect of the positively charged polymer and their chain length on the adsorption efficiency. The results showed that by increasing the chain length of the grafted polymer, up to 80% of both pollutants could be removed, with a faster adsorption of PFOS as compared to PFOA.

PEG-functionalized aliphatic polycarbonate brushes with self-polishing dynamic antifouling properties

Hydrophilic antifouling polymers provide excellent antifouling effects under usual short-term use conditions, but the long-term accumulation of contaminants causes them to lose their antifouling properties. To overcome this drawback, surface-initiated ring-opening graft polymerization (SI-ROP) was performed on the surface of the material by applying the cyclic carbide monomer 4′-(fluorosulfonyl)benzyl-5-methyl-2-oxo-1,3-dioxane-5-carboxylate (FMC), which contains a sulfonylfluoride group on the side chain, followed by a “sulfur(IV)-fluorine exchange” (SuFEx) post click modification reaction to link the hydrophilic polyethylene glycol (PEG) to the polyFMC (PFMC) brush, and a novel antifouling strategy for self-polishing dynamic antifouling surfaces was developed. The experimental results showed that the antifouling surface could effectively prevent the adsorption of proteins such as bovine serum albumin (BSA, ~96.4%), fibrinogen (Fg, ~87.8%) and lysozyme (Lyz ~69.4%) as well as the adhesion of microorganisms such as the bacteria Staphylococcus aureus (S. aureus) (~87.5%) and HeLa cells (~67.2%). Moreover, the enzymatically self-polished surface still has excellent antifouling properties. Therefore, this modification method has potential applications in the field of biosensors and novel antifouling materials.

Combinatorial High-Throughput Screening of Complex Polymeric Enzyme Immobilization Supports.

Recent advances have demonstrated the promise of complex multicomponent polymeric supports to enable supra-biological enzyme performance. However, the discovery of such supports has been limited by time-consuming, low-throughput synthesis and screening. Here, we describe a novel combinatorial and high-throughput platform that enables rapid screening of complex and heterogeneous copolymer brushes as enzyme immobilization supports, named combinatorial high-throughput enzyme support screening (CHESS). Using a 384-well plate format, we synthesized arrays of three-component polymer brushes in the microwells using photoactivated surface-initiated polymerization and immobilized enzymes in situ. The utility of CHESS to identify optimal immobilization supports under thermally and chemically denaturing conditions was demonstrated usingBacillus subtilisLipase A (LipA). The identification of supports with optimal compositions was validated by immobilizing LipA on polymer-brush-modified biocatalyst particles. We further demonstrated that CHESS could be used to predict the optimal composition of polymer brushes a priori for the previously unexplored enzyme, alkaline phosphatase (AlkP). Our findings demonstrate that CHESS represents a predictable and reliable platform for dramatically accelerating the search of chemical compositions for immobilization supports and further facilitates the discovery of biocompatible and stabilizing materials.

Chiral polymer brush growth on magnetic nanoparticles under ambient conditions

Magnetic nanoparticles (MNPs) grafted with functional polymers were prepared via surface-initiated reversible addition-fragmentation chain transfer polymerization using oxygen (O2-SI-RAFT polymerization) under ambient conditions. Two types of monomers, a charged monomer and a chiral monomer, were used in this study. The successfully prepared polymer-coated MNPs could be easily separated using a bar magnet. The modified MNPs were characterized by various analytical methods, including zeta potential determination, spectroscopic analyses, magnetic hysteresis, transmission electron microscopy, and elemental composition analysis by energy-dispersive X-ray spectroscopy. Circular dichroism spectroscopy analysis showed that chiral polymers grown from the MNPs have mirror images, confirming that chiral properties can be conferred on MNPs via O2-SI-RAFT polymerization.

Growth of Double-Network Tough Hydrogel Coatings by Surface-Initiated Polymerization.

Hydrogel coatings exhibit versatile applications in biomedicine, flexible electronics, and environmental science. However, current coating methods encounter challenges in simultaneously achieving strong interfacial bonding, robust hydrogel coatings, and the ability to coat substrates with controlled thickness. This paper introduces a novel approach to grow a double-network (DN) tough hydrogel coating on various substrates. The process involves initial substrate modification using a silane coupling agent, followed by the deposition of an initiator layer on its surface. Subsequently, the substrate is immersed in a DN hydrogel precursor, where the coating grows under ultraviolet (UV) illumination. Precise control over the coating thickness is achieved by adjusting the UV illumination duration and the initiator quantity. The experimental measurement of adhesion reveals strong bonding between the DN hydrogel coating and diverse substrates, reaching up to 1012.9 J/m2 between the DN hydrogel coating and a glass substrate. The lubricity performance of the DN hydrogel coating is experimentally characterized, which is dependent on the coating thickness, applied pressure, and sliding velocity. The incorporation of 3D printing technology into the current coating method enables the creation of intricate hydrogel coating patterns on a flat substrate. Moreover, the hydrogel coating's versatility is demonstrated through its effective applications in oil-water separation and antifogging glasses, underscoring its wide-ranging potential. The robust DN hydrogel coating method presented here holds promise for advancing hydrogel applications across diverse fields.

A Versatile Approach for the Synthesis of Antimicrobial Polymer Brushes on Natural Rubber/Graphene Oxide Composite Films via Surface-Initiated Atom-Transfer Radical Polymerization.

A simple strategy was adopted for the preparation of an antimicrobial natural rubber/graphene oxide (NR/GO) composite film modified through the use of zwitterionic polymer brushes. An NR/GO composite film with antibacterial properties was prepared using a water-based solution-casting method. The composited GO was dispersed uniformly in the NR matrix and compensated for mechanical loss in the process of modification. Based on the high bromination activity of α-H in the structure of cis-polyisoprene, the composite films were brominated on the surface through the use of N-bromosuccinimide (NBS) under the irradiation of a 40 W tungsten lamp. Polymerization was carried out on the brominated films using sulfobetaine methacrylate (SBMA) as a monomer via surface-initiated atom transfer radical polymerization (SI-ATRP). The NR/GO composite films modified using polymer brushes (PSBMAs) exhibited 99.99% antimicrobial activity for resistance to Escherichia coli and Staphylococcus aureus. A novel polymer modification strategy for NR composite materials was established effectively, and the enhanced antimicrobial properties expand the application prospects in the medical field.

Thermo-responsive poly(di(ethylene glycol) methyl ether methacrylate) brushes as substrate-independent release coatings for cell culture and selective cell separation and purification

Abstract A systematic study on the surface-initiated polymerization of di(ethylene glycol) methyl ether methacrylate (DEGMA) by atom transfer radical polymerization (ATRP) from glass, silicon, titanium as well as tissue culture polystyrene (TCPS) is reported in an attempt to expand the known thermoresponsive poly(di(ethylene glycol) methyl ether methacrylate) (PDEGMA) cell release layers on gold to other substrates. The use of these substrate materials requires an altered immobilization chemistry to couple a bromide containing ATRP initiator to the surfaces. Using aminosilanes or polydopamine as coupling layers for the attachment of α-bromoisobutyryl bromide (BiBB) and the direct functionalization of surface hydroxyl groups with trichlorosilane-functionalized ATRP initiators all surfaces studied were shown to facilitate the growth of PDEGMA brushes using the same conditions that were reported previously for polymerization on gold. The brush layers obtained were characterized systematically using wetting, ellipsometry, X-ray photoelectron spectroscopy (XPS) as well as atomic force microscopy (AFM) analyses. Selective cell release and separation of PaTu 8988t and NIH 3T3 cells, which are known to exhibit different behavior after temperature drop-induced brush swelling, was observed for all substrates, albeit for different brush thicknesses, implying variations in initiator and also PDEGMA grafting density. The successful modification of biomedically relevant materials (Ti and TCPS) implies that the previously reported stem cell purification and selective cell release of various cell types, which is facilitated by PDEGMA brushes, can be realized and consequently scaled up in the future.

Anti-biofilm super-hydrophilic gel sensor for saliva glucose monitoring

Accurate detection of saliva glucose levels is crucail for diagnosing diabetes and oral diseases. However, the complex bacterial environment in the oral cavity presents challenges, particularly in reducing sensor sensitivity due to bacterial adhesion. The excellent self-cleaning capabilities of super-hydrophilic materials make them one of the top choices. To surpass the limitations of traditional super-hydrophilic materials, a Spin coating-Plasma treatment-Coprecipitation treatment (SPC) strategy was implemented to develop a super-hydrophilic gel saliva glucose sensor. Surface-initiated polymerization was used to form phenylboric acid hydrogels for glucose binding. A spin-coated transition layer protects the hydrogel, while plasma treatment and co-precipitation methods create a super-hydrophilic surface, providing antibacterial properties. The sensor demonstrated a remarkable ability to reduced bacterial adhesion of the five oral pathogenic bacteria by over 95 %, and significantly inhibited biofilm formation of Streptococcus pneumoniae and Streptococcus mitis by 95.7 % and 96.7 %, respectively. Its detection limit of 3.04 mg/L meets the requirements for saliva glucose detection. Overall, the development of this super-hydrophilic gel sensor holds great promise for wearable oral monitoring devices, offering new opportunities in healthcare managing and monitoring.

Pyroelectric Polyelectrolyte Brushes.

Piezo- and pyroelectric materials are of interest, for example, for energy harvesting applications, for the development of tactile sensors, as well as neuromorphic computing. This study reports the observation of pyro- and piezoelectricity in thin surface-attached polymer brushes containing zwitterionic and electrolytic side groups that are prepared via surface-initiated polymerization. The pyro- and piezoelectric properties of the surface-grafted polyelectrolyte brushes are found to sensitively depend on and can be tuned by variation of the counterion. The observed piezo- and pyroelectric properties reflect the structural complexity of polymer brushes, and are attributed to a complex interplay of the non-uniform segment density within these films, together with a non-uniform distribution of counterions and specific ion effects. The fabrication of thin pyroelectric films by surface-initiated polymerization is an important addition to the existing strategies toward such materials. Surface-initiated polymerization, in particular, allows for facile grafting of polar thin polymer films from a wide range of substrates via a straightforward two-step protocol that obviates the need for multistep laborious synthetic procedures or thin film deposition protocols. The ability to produce polymer brushes with piezo- and pyroelectric properties opens up new avenues of application of these materials, for example, in energy harvesting or biosensing.

Grafting photochromic spiropyran polymer brushes on graphene oxide surfaces via surface-initiated ring-opening metathesis polymerization.

A practical "grafting-from" strategy is described to grow photochromic polymer brushes bearing spiropyran (SP) functional groups on graphene oxide (GO) surfaces via surface-initiated ring-opening metathesis polymerization (SI-ROMP). The Grubbs II catalyst was fixed on the GO surface, and the norbornene derivatives functionalized using spiropyran were synthesized from this active site via the ROMP method. The results indicated that the spiropyran-modified polymer brushes were obtained on the GO surface in the form of thin films. The solubility of GO modified by spiropyran polymers (GO-SPs) in organic solvents was significantly improved. The GO-SPs exhibited excellent photochromic properties, including fast coloration/decoloration. The modified GO with an isomeric structure was colored in 90 s under ultraviolet irradiation and decolored in 360 s under white light. The fading kinetic rate in the dark was slow and the kinetic attenuation curve followed bi-exponential decay. The GO-SP composite materials took more than 2 h to return to thermodynamically stable forms. The reversible change in the water contact angle reached 8° after continuous cycling with ultraviolet and visible light. GO-SP maintained its photochromic performance and possessed excellent fatigue resistance after more than six successive UV/light cycles. This work describes a practical strategy for the preparation of photochromic polymer brush modified GO composite materials and extends the applications of GO in photochromic materials.

Solvent effects on surface-grafted and solution-born poly[N-(2-hydroxypropyl)methacrylamide] during surface-initiated RAFT polymerization

Solvent effects influence grafting density and cause discrepancy between molar mass of surface-grafted and solution-born poly[N-(2-hydroxypropyl) methacrylamide] during surface-initiated RAFT polymerization.

Comparison study of surface-initiated hydrogel coatings with distinct side-chains for improving biocompatibility of polymeric heart valves.

Polymeric heart valves (PHVs) present a promising alternative for treating valvular heart diseases with satisfactory hydrodynamics and durability against structural degeneration. However, the cascaded coagulation, inflammatory responses, and calcification in the dynamic blood environment pose significant challenges to the surface design of current PHVs. In this study, we employed a surface-initiated polymerization method to modify polystyrene-block-isobutylene-block-styrene (SIBS) by creating three hydrogel coatings: poly(2-methacryloyloxy ethyl phosphorylcholine) (pMPC), poly(2-acrylamido-2-methylpropanesulfonic acid) (pAMPS), and poly(2-hydroxyethyl methacrylate) (pHEMA). These hydrogel coatings dramatically promoted SIBS's hydrophilicity and blood compatibility at the initial state. Notably, the pMPC and pAMPS coatings maintained a considerable platelet resistance performance after 12 h of sonication and 10 000 cycles of stretching and bending. However, the sonication process induced visible damage to the pHEMA coating and attenuated the anti-coagulation property. Furthermore, the in vivo subcutaneous implantation studies demonstrated that the amphiphilic pMPC coating showed superior anti-inflammatory and anti-calcification properties. Considering the remarkable stability and optimal biocompatibility, the amphiphilic pMPC coating constructed by surface-initiated polymerization holds promising potential for modifying PHVs.

Linear, Y- and Ψ-shaped poly(2-(dimethylamino)ethyl methacrylate) and poly(methyl methacrylate) brushes prepared by surface-initiated polymerization from a homologous series of ATRP initiators

A series of 3 homologous surface-anchored initiators for atom transfer radical polymerization has been used to graft linear, Y- and Ψ-shaped poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and poly(methyl methacrylate) (PMMA) brushes from silicon surfaces. The film thicknesses of these architecturally different polymer brushes could be tuned both by controlling the polymerization time, as well as (as was shown for the polymerization of 2-(dimethylamino)ethyl methacrylate) by changing the monomer concentration. The library of linear, Y- and Ψ-shaped PDMAEMA and PMMA brushes was used to investigate the possible impact of polymer architecture on the swelling properties as well as the degrafting behavior of these surface-grown polymer films. The swelling of the PDMAEMA and PMMA brushes in PBS, respectively, acetone as a solvent was studied by ellipsometry. These experiments revealed a smaller swelling ratio for Y-shaped polymer brushes, as compared to linear analogues of comparable dry film thickness. Degrafting experiments were conducted with linear, Y- and Ψ-shaped PDMAEMA brushes in PBS. These experiments revealed a 2-fold, respectively, 3-fold increase in the initial rate constant of degrafting for the Y- and Ψ-shaped PDMAEMA brushes as compared to the linear analogues.

Synthesis of PEDOT:PSS Brushes Grafted from Gold Using ATRP for Increased Electrochemical and Mechanical Stability.

We report PEDOT:PSS brushes grafted from gold using surface-initiated atom-transfer radical polymerization (SI-ATRP) which demonstrate significantly enhanced mechanical stability against sonication and electrochemical cycling compared to spin-coated analogues as well as lower impedances than bare gold at frequencies from 0.1 to 105 Hz. These results suggest SI-ATRP PEDOT:PSS to be a promising candidate for use in microelectrodes for neural activity recording. Spin-coated, electrodeposited, and drop-cast PEDOT:PSS have already been shown to reduce impedance and improve biocompatibility of microelectrodes, but the lack of strong chemical bonds of the physisorbed polymer film to the metal leads to disintegration under required operational stresses including cyclic mechanical loads, abrasion, and electrochemical cycling. Rather than modifying the metal electrode or introducing cross-linkers or other additives to improve the stability of the polymer film, this work chemically tethers the polymer to the surface, offering a simple, scalable solution for functional bioelectronic interfaces.

Two birds with one stone: A magneto-optical dual-stimuli-responsive intelligent Pickering emulsion for efficient conversion of glucose to 5-hydroxymethylfurfural

The efficient conversion of glucose to 5-hydroxymethylfurfural (HMF) is a critical process for maximizing the value of lignocellulosic biomass. However, the existing systems of binary solvent and ionic liquids (ILs) commonly employed for this conversion often encounter significant interphase mass transfer resistance and exhibit lower utilization efficiency of ILs. Herein, the study presents the precise fabrication of a novel Pickering interfacial catalyst, P(0.8[CL8]-[ILs]2-[SP])@SiO2@Fe3O4 with immobilized magneto-optical bi-sensitizer and Brønsted&di-superimposed-Lewis acid functionalized ILs (B-L-ILs), realized through surface-initiated reversible addition-fragmentation chain transfer polymerization. The construction of an intelligent Pickering emulsion with dual-stimuli-responsive properties was effectively accomplished by accurate manipulation under Vis-light radiation, utilizing P(0.8[CL8]-[ILs]2-[SP])@SiO2@Fe3O4. The presence of this emulsion significantly enhances interphase mass transfer in a binary solvent system, while the incorporation of B-L-ILs at interphase interfaces in Pickering emulsion greatly facilitates the efficient conversion of glucose to HMF. The Pickering interfacial catalyst demonstrates exceptional and unprecedented performance, as evidenced by its ability to achieve a glucose conversion rate of 96.3% and HMF yield of 86.7%. Various characterizations, experimental analyses, and kinetic studies synergistically confirm the efficient conversion of glucose to HMF in the Pickering emulsion. The effective control of Pickering demulsification can be intelligently achieved by simultaneously applying magnetic stimulation and UV-light irradiation, while its catalytic activity remains unaltered even after undergoing five consecutive cycles. This study presents a novel approach to enhance the efficiency of HMF production by combining a cutting-edge Pickering emulsion with B-L-ILs, thereby accomplishing two objectives simultaneously.

Fabrication of carboxylic functionalized poly(methacrylic acid 2-(tert-butylamino)ethyl ester)-coated mesoporous silica nanoparticles and their application for removing ionic dyes from polluted water

The removal of dyes from wastewater that are released during industrial processes has become a significant concern in the environmental science in recent years. To tackle this issue, researchers are exploring the use of nanomaterials for designing new adsorbents. Another promising approach is to grow polymer brushes with high density functional groups via surface-initiated atom transfer radical polymerization (SI-ATRP), which can significantly enhance their ability to absorb dyes. The presence of carboxylic acid groups on the adsorbent material significantly contributes to its efficacy in dye removal by enhancing adsorption capacity, enabling selective adsorption, pH-dependent behavior, chelation, or complexation, and providing stability for repeated usage. In this work, a nanomaterial of carboxylic functionalized poly (methacrylic acid 2-(tert-butylamino)ethyl ester)-coated mesoporous silica nanoparticles (MSNPs–PMATBAE–COOH) was synthesized by the growth of PTBAEMA via surface-initiated atom-transfer radical polymerization, then reacted with succinic anhydride reaction. The chemical structure of MSNPs–PMATBAE–COOH was confirmed using multiple methods, including FT-IR and DLS, and the core-brush morphology was observed clearly using TEM. MSNPs–PMATBAE–COOH were subsequently employed to adsorb hazardous dyes efficiently. The anionic polymer brushes enabled the adsorption of methylene blue (MB) and tetraethylrhodamine (TER) at optimum pH value of 3. The results also indicated that MSNPs–PMATBAE–COOH possessed significant adsorption capacity (263.4 and 212.9 mg g−1 for MB and TER, respectively) and fast adsorption rate (within 15 min), which can be explained by the abundance of adsorptive polymer brushes and the small size of the nanoparticles. Overall, the findings indicate that MSNPs-PMATBAE-COOH is a highly effective adsorbent material for eliminating dye pollutants from wastewater.

Low-Fouling and Antibacterial Polymer Brushes via Surface-Initiated Polymerization of a Mixed Zwitterionic and Cationic Monomer.

The use of surface-grafted polymer brushes with combined low-fouling and antibacterial functionality is an attractive strategy to fight biofilm formation. This report describes a new styrene derivative combining a quaternary ammonium group with a sulfobetaine group in one monomer. Surface-initiated polymerization of this monomer on titanium and a polyethylene (PE) base material gave bifunctional polymer brush layers. Grafting was achieved via surface-initiated atom transfer radical polymerization from titanium or heat-induced free-radical polymerization from plasma-activated PE. Both techniques gave charged polymer layers with a thickness of over 750 nm, as confirmed by ToF-SIMS-SPM measurements. The chemical composition of the brush polymers was confirmed by XPS and FT-IR analysis. The surface charge, characterized by the ζ potential, was positive at different pH values, and the number of solvent-accessible excess ammonium groups was found to be ∼1016 N+/cm2. This led to strong antibacterial activity against Gram-positive and Gram-negative bacteria that was superior to a structurally related contact-active polymeric quaternary ammonium brush. In addition to this antibacterial activity, good low-fouling properties of the dual-function polymer brushes against Gram-positive and Gram-negative bacteria were found. This dual functionality is most likely due to the combination of antibacterial quaternary ammonium groups with antifouling sulfobetaines. The combination of both groups in one monomer allows the preparation of bifunctional brush polymers with operationally simple polymerization techniques.

Continuous Ultrathin Zwitterionic Covalent Organic Framework Membrane Via Surface-Initiated Polymerization Toward Superior Water Retention.

Efficient construction of proton transport channels in proton exchange membranes maintaining conductivity under varied humidity is critical for the development of fuel cells. Covalent organic frameworks (COFs) hold great potential in providing precise and fast ion transport channels. However, the preparation of continuous free-standing COF membranes retaining their inherent structural advantages to realize excellent proton conduction performance is a major challenge. Herein, a zwitterionic COF material bearing positive ammonium ions and negative sulphonic acid ions is developed. Free-standing COF membrane with adjustable thickness is constructed via surface-initiated polymerization of COF monomers. The porosity, continuity, and stability of the membranes are demonstrated via the transmission electron microscopy (TEM), atomic force microscopy (AFM), and scanning electron microscopy (SEM) characterization. The rigidity of the COF structure avoids swelling in aqueous solution, which improves the chemical stability of the proton exchange membranes and improves the performance stability. In the higher humidity range (50-90%), the prepared zwitterionic COF membrane exhibits superior capability in retaining the conductivity compared to COF membrane merely bearing sulphonic acid group. The established strategy shows the potential for the application of zwitterionic COF in the proton exchange membrane fuel cells.