Synthetic Leaves Based on Crystalline Olefin-Linked Covalent Organic Frameworks for Efficient CO2 Photoreduction with Water.

We report, for the first time, a new synthetic strategy for the preparation of crystalline two-dimensional olefin-linked covalent organic frameworks (COFs) based on aldol condensation between benzodifurandione and aromatic aldehydes. Olefin-linked COFs can be facilely crystallized through either a pyridine-promoted solvothermal process or a benzoic anhydride-mediated organic flux synthesis. The resultant COF leaf with high in-plane π-conjugation exhibits efficient visible-light-driven photoreduction of carbon dioxide (CO2) with water (H2O) in the absence of any photosensitizer, sacrificial agents, or cocatalysts. The production rate of carbon monoxide (CO) reaches as high as 158.1 µmol g-1 h-1 with near 100% CO selectivity, which is accompanied by the oxidation of H2O to oxygen. Both theoretical and experimental results confirm that the key lies in achieving exceptional photoinduced charge separation and low exciton binding. We anticipate that our findings will facilitate new possibilities for the development of semiconducting COFs with structural diversity and functional variability.

Mechanistic Insights into Surfactant-Modulated Electrode-Electrolyte Interface for Steering H2O2 Electrosynthesis.

Electrocatalytic reactions taking place at the electrified electrode-electrolyte interface involve processes of proton-coupled electron transfer. Interfacial protons are delivered to the electrode surface via a H2O-dominated hydrogen-bond network. Less efforts are made to regulate the interfacial proton transfer from the perspective of interfacial hydrogen-bond network. Here, we present quaternary ammonium salt cationic surfactants as electrolyte additives for enhancing the H2O2 selectivity of the oxygen reduction reaction (ORR). Through in situ vibrational spectroscopy and molecular dynamics calculation, it is revealed that the surfactants are irreversibly adsorbed on the electrode surface in response to a given bias potential range, leading to the weakening of the interfacial hydrogen-bond network. This decreases interfacial proton transfer kinetics, particularly at high bias potentials, thus suppressing the 4-electron ORR pathway and achieving a highly selective 2-electron pathway toward H2O2. These results highlight the opportunity for steering H2O-involved electrochemical reactions via modulating the interfacial hydrogen-bond network.

Ionic liquids intercalation in titanium carbide MXenes: A first-principles investigation.

Herein, we present a density functional theory with dispersion correction (DFT-D) calculations that focus on the intercalation of ionic liquids (ILs) electrolytes into the two-dimensional (2D) Ti3C2Tx MXenes. These ILs include the cation 1-ethyl-3-methylimidazolium (Emim+), accompanied by three distinct anions: bis(trifluoromethylsulfonyl)imide (TFSA-), (fluorosulfonyl)imide (FSA-) and fluorosulfonyl(trifluoromethanesulfonyl)imide (FTFSA-). By altering the surface termination elements, we explore the intricate geometries of IL intercalation in neutral, negative, and positive pore systems. Accurate estimation of charge transfer is achieved through five population analysis models, such as Hirshfeld, Hirshfeld-I, DDEC6 (density derived electrostatic and chemical), Bader, and VDD (voronoi deformation density) charges. In this work, we recommend the DDEC6 and Hirshfeld-I charge models, as they offer moderate values and exhibit reasonable trends. The investigation, aimed at visualizing non-covalent interactions, elucidates the role of cation-MXene and anion-MXene interactions in governing the intercalation phenomenon of ionic liquids within MXenes. The magnitude of this role depends on two factors: the specific arrangement of the cation, and the nature of the anionic species involved in the process.

Engineering the thermal stability of a polyphosphate kinase by ancestral sequence reconstruction to expand the temperature boundary for an industrially applicable ATP regeneration system.

ATP-dependent energy-consuming enzymatic reactions are widely used in cell-free biocatalysis. However, the direct addition of large amounts of expensive ATP can greatly increase cost, and enzymatic production is often difficult to achieve as a result. Although a polyphosphate kinase (PPK)-polyphosphate-based ATP regeneration system has the potential to solve this challenge, the generally poor thermal stability of PPKs limits the widespread use of this method. In this paper, we evaluated the thermal stability of a PPK from Sulfurovum lithotrophicum (SlPPK2). After directed evolution and computation-supported design, we found that SlPPK2 is very recalcitrant and cannot acquire beneficial mutations. Inspired by the usually outstanding stability of ancestral enzymes, we reconstructed the ancestral sequence of the PPK family and used it as a guide to construct three heat-stable variants of SlPPK2, of which the L35F/T144S variant has a half-life of more than 14 h at 60°C. Molecular dynamics simulations were performed on all enzymes to analyze the reasons for the increased thermal stability. The results showed that mutations at these two positions act synergistically from the interior and surface of the protein, leading to a more compact structure. Finally, the robustness of the L35F/T144S variant was verified in the synthesis of nucleotides at high temperature. In practice, the use of this high-temperature ATP regeneration system can effectively avoid byproduct accumulation. Our work extends the temperature boundary of ATP regeneration and has great potential for industrial applications.IMPORTANCEATP regeneration is an important basic applied study in the field of cell-free biocatalysis. Polyphosphate kinase (PPK) is an enzyme tool widely used for energy regeneration during enzymatic reactions. However, the thermal stability of the PPKs reported to date that can efficiently regenerate ATP is usually poor, which greatly limits their application. In this study, the thermal stability of a difficult-to-engineer PPK from Sulfurovum lithotrophicum was improved, guided by an ancestral sequence reconstruction strategy. The optimal variant has a 4.5-fold longer half-life at 60°C than the wild-type enzyme, thus enabling the extension of the temperature boundary for ATP regeneration. The ability of this variant to regenerate ATP was well demonstrated during high-temperature enzymatic production of nucleotides.

Unraveling the Molecular Mechanisms of Alcohol-Mediated Skin Permeation Enhancement: Insights from Molecular Dynamics Simulations.

The application of alcohols as permeation enhancers in pharmaceutical and cosmetic formulations has attracted considerable attention, owing to their skin permeation-enhancing effect. Nonetheless, the elucidation of the fundamental mechanisms underlying the skin permeation-enhancing effect remains elusive. In this study, molecular dynamics (MD) simulations were employed to investigate the effect of 1,2-propanediol (1,2-PDO), 1,2-butanediol (1,2-BDO), and ethanol (EtOH) on the stratum corneum (SC) model membrane. The results showed that the effect of alcohols on the SC model membrane displayed a concentration-dependent nature. The alcohols can interact with SC lipids and exhibit a remarkable ability to selectively extract free fatty acid (FFA) molecules from the SC model membrane and make the SC looser. Meanwhile, 1,2-BDO and EtOH can penetrate into SC lipid bilayers at higher concentrations, leading to the formation of continuous hydrophilic defects in SC. The FFA extraction and the formation of continuous hydrophilic defects induced ceramide (CER) tail chains to become more disordered and fluid and also weakened the hydrogen bonding (H-bonding) network among SC lipids. Both the FFA extraction and the continuous hydrophilic defect formation endowed alcohols with the permeation-enhancing effect. The constrained simulations revealed that the free energy barriers decreased for the permeation of the hydrophilic model molecule (COL) across the SC model membranes containing alcohols, particularly for 1,2-BDO and EtOH. The possible permeation-enhancing mechanisms of alcohols were proposed correspondingly. This work not only provided a deep understanding of the transdermal permeation-enhancing behavior of alcohols at the molecular level but also provided necessary reference information for designing effective transdermal drug delivery systems in applications.

Dopant- and Surfactant-Tuned Electrode-Electrolyte Interface Enabling Efficient Alkynol Semi-Hydrogenation.

Electrochemical alkynol semi-hydrogenation has emerged as a sustainable and environmentally benign route for the production of high-value alkenols, featuring water as the hydrogen source instead of H2. It is highly challenging to design the electrode-electrolyte interface with efficient electrocatalysts and their matched electrolytes to break the selectivity-activity stereotype. Here, boron-doped Pd catalysts (PdB) and surfactant-modified interface are proposed to enable the simultaneous increase in alkenol selectivity and alkynol conversion. Typically, compared to pure Pd and commercial Pd/C catalysts, the PdB catalyst achieves both higher turnover frequency (139.8 h-1) and specific selectivity (above 90%) for the semi-hydrogenation of 2-methyl-3-butyn-2-ol (MBY). Quaternary ammonium cationic surfactants that are employed as electrolyte additives are assembled at the electrified interface in response to applied bias potential, establishing an interfacial microenvironment that can facilitate alkynol transfer and hinder water transfer suitably. Eventually the hydrogen evolution reaction is inhibited and alkynol semi-hydrogenation is promoted, without inducing the decrease of alkenol selectivity. This work offers a distinct perspective on creating a suitable electrode-electrolyte interface for electrosynthesis.

Regulating π-Conjugation in sp2 -Carbon-Linked Covalent Organic Frameworks for Efficient Metal-Free CO2 Photoreduction with H2 O.

The development of sp2 -carbon-linked covalent organic frameworks (sp2 c-COFs) as artificial photocatalysts for solar-driven conversion of CO2 into chemical feedstock has captured growing attention, but catalytic performance has been significantly limited by their intrinsic organic linkages. Here, a simple, yet efficient approach is reported to improve the CO2 photoreduction on metal-free sp2 c-COFs by rationally regulating their intrinsic π-conjugation. The incorporation of ethynyl groups into conjugated skeletons affords a significant improvement in π-conjugation and facilitates the photogenerated charge separation and transfer, thereby boosting the CO2 photoreduction in a solid-gas mode with only water vapor and CO2 . The resultant CO production rate reaches as high as 382.0 µmol g-1  h-1 , ranking at the top among all additive-free CO2 photoreduction catalysts. The simple modulation approach not only enables to achieve enhanced CO2 reduction performance but also simultaneously gives a rise to extend the understanding of structure-property relationship and offer new possibilities for the development of new π-conjugated COF-based artificial photocatalysts.

Solvent Effects on Structure and Screening in Confined Electrolytes.

Using classical density functional theory, we investigate the influence of solvent on the structure and ionic screening of electrolytes under slit confinement and in contact with a reservoir. We consider a symmetric electrolyte with implicit and explicit solvent models and find that spatially resolving solvent molecules is essential for the ion structure at confining walls, excess ion adsorption, and the pressure exerted on the walls. Despite this, we observe only moderate differences in the period of oscillations of the pressure with the slit width and virtually coinciding decay lengths as functions of the scaling variable σ_{ion}/λ_{D}, where σ_{ion} is the ion diameter and λ_{D} the Debye length. Moreover, in the electrostatic-dominated regime, this scaling behavior is practically independent of the relative permittivity and its dependence on the ion concentration. In contrast, the crossover to the hard-core-dominated regime depends sensitively on all three factors.

Construction of Core-Cross-Linked Polymer Micelles with High Biocompatibility and Stability for pH/Reduction Controllable Drug Delivery.

Polymer micelles have been studied extensively in drug delivery systems (DDS), and their stability is well known to directly affect drug delivery. In this article, a series of amphiphilic copolymers LA-PDPAn-PVPm were synthesized to prepare core-cross-linked nanoparticles (CNP) applied to controllable and targeted anticancer drug delivery. The copolymers could self-assemble in aqueous solution and form homogeneous spherical micelles with particle sizes of between 100 and 150 nm. A comparison between un-cross-linked UCNP and CNP showed that the cross-linking of LA could significantly improve the stability and responsive ability of the nanoparticles. From the in vitro-simulated drug release experiments, CNP was found to have great drug blocking ability under normal physiological conditions and could achieve rapid and efficient drug release under acidic/reducing conditions. In addition, cell experiments showed that CNP had superior biocompatibility and could target tumor cells for drug release. In conclusion, a drug carrier based on copolymer LA-PDPA-PVP realized effective controlled drug release due to the cross-linking of LA. The results will provide guidance for the design strategy of polymer micelles for drug carriers.

Prion-like Aggregation of the Heptapeptide GNNQQNY into Amyloid Nanofiber Is Governed by Configuration Entropy.

A major cause of prion infectivity is the early formation of small, fibril-like aggregates consisting of the heptapeptide GNNQQNY. The prion aggregates exhibit a unique stacking mode in which the hydrophobic tyrosine (Y) is exposed outward, forming a bilayer ß-sheet-stacking zipper structure. This stacking mode of the prion peptides, termed "Y-outward" structure for convenience, goes against the common understanding that, for other amyloid-forming peptides, the hydrophobic residues should be hidden within the peptide fibril, referred to as "Y-inward" structure. To explore the extraordinary stacking behaviors of the prion GNNQQNY peptides, two fibril models are constructed in a fashion of "Y-outward" and "Y-inward" stackings and then studied in silico to examine their thermodynamic stabilities and disaggregation pathways. The "Y-inward" structure indeed exhibits stronger thermodynamic stability than the "Y-outward" structure, according to potential energy and stacking energy calculations. To show how the peptide fibrils dissociate, we illustrated two disaggregation pathways. A dihedral-based free energy landscape was then calculated to examine the conformational degrees of freedom of the GNNQQNY chains in the "Y-outward" and "Y-inward" structures. Peptide chains lose more configurational entropy in the "Y-inward" structure than in the "Y-outward" structure, indicating that the prion peptides are prone to aggregate in a fashion of "Y-outward" stacking pattern due to its low conformational constraints. The prion-like aggregation of the GNNQQNY peptides into amyloid fibrils is primarily governed by the configuration entropy.

Assessment of Cu(II) Removal from Aqueous Solutions by Modified Pomelo Peels: Experiments and Modelling.

In this study, low-cost pomelo peel wastes were used as a bio-sorbent to remove copper ions (e.g., Cu(II)) from aqueous solutions. Prior to testing its Cu(II) removal capability, the structural, physical and chemical characteristics of the sorbent were examined by scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectroscopy, and Brunauer-Emmett-Teller (BET) surface area analysis. The impacts of the initial pH, temperature, contact time and Cu(II) feed concentration on the Cu(II) biosorption using modified pomelo peels were then assessed. Thermodynamic parameters associated to the biosorption clearly demonstrate that this biosorption is thermodynamically feasible, endothermic, spontaneous and entropy driven. Furthermore, adsorption kinetic data were found to fit very well with the pseudo-second order kinetics equation, highlighting that this process is driven by a chemical adsorption. Finally, an artificial neural network with a 4:9:1 structure was then established for describing the Cu(II) adsorption using modified pomelo peels with R2 values close to 0.9999 and to 0.9988 for the training and testing sets, respectively. The results present a big potential use of the as-prepared bio-sorbent for the removal of Cu(II), as well as an efficient green technology for ecological and environmental sustainability.

The Prediction of Cu(II) Adsorption Capacity of Modified Pomelo Peels Using the PSO-ANN Model.

It is very well known that traditional artificial neural networks (ANNs) are prone to falling into local extremes when optimizing model parameters. Herein, to enhance the prediction performance of Cu(II) adsorption capacity, a particle swarm optimized artificial neural network (PSO-ANN) model was developed. Prior to predicting the Cu(II) adsorption capacity of modified pomelo peels (MPP), experimental data collected by our research group were used to build a consistent database. Then, a PSO-ANN model was established to enhance the model performance by optimizing the ANN's weights and biases. Finally, the performances of the developed ANN and PSO-ANN models were deeply evaluated. The results of this investigation revealed that the proposed hybrid method did increase both the generalization ability and the accuracy of the predicted data of the Cu(II) adsorption capacity of MPPs when compared to the conventional ANN model. This PSO-ANN model thus offers an alternative methodology for optimizing the adsorption capacity prediction of heavy metals using agricultural waste biosorbents.

One-Dimensional Covalent Organic Frameworks for the 2e- Oxygen Reduction Reaction.

Two-dimensional covalent organic frameworks (2D COFs) are often employed for electrocatalytic systems because of their structural diversity. However, the efficiency of atom utilization is still in need of improvement, because the catalytic centers are located in the basal layers and it is difficult for the electrolytes to access them. Herein, we demonstrate the use of 1D COFs for the 2e- oxygen reduction reaction (ORR). The use of different four-connectivity blocks resulted in the prepared 1D COFs displaying good crystallinity, high surface areas, and excellent chemical stability. The more exposed catalytic sites resulted in the 1D COFs showing large electrochemically active surface areas, 4.8-fold of that of a control 2D COF, and thus enabled catalysis of the ORR with a higher H2 O2 selectivity of 85.8 % and activity, with a TOF value of 0.051 s-1 at 0.2 V, than a 2D COF (72.9 % and 0.032 s-1 ). This work paves the way for the development of COFs with low dimensions for electrocatalysis.

Interlayer Structure Manipulation of Iron Oxychloride by Potassium Cation Intercalation to Steer H2O2 Activation Pathway.

Structural regulation of the active centers is often pivotal in controlling the catalytic functions, especially in iron-based oxidation systems. Here, we discovered a significantly altered catalytic oxidation pathway via a simple cation intercalation into a layered iron oxychloride (FeOCl) scaffold. Upon intercalation of FeOCl with potassium iodide (KI), a new stable phase of K+-intercalated FeOCl (K-FeOCl) was formed with slided layers, distorted coordination, and formed high-spin Fe(II) species compared to the pristine FeOCl precursor. This structural manipulation steers the catalytic H2O2 activation from a traditional Fenton-like pathway on FeOCl to a nonradical ferryl (Fe(IV)═O) pathway. Consequently, the K-FeOCl catalyst can efficiently remove various organic pollutants with almost 2 orders of magnitude faster reaction kinetics than other Fe-based materials via an oxidative coupling or polymerization pathway. A reaction-filtration coupled process based on K-FeOCl was finally demonstrated and could potentially reduce the energy consumption by almost 50%, holding great promise in sustainable pollutant removal technologies.

Dynamically Formed Surfactant Assembly at the Electrified Electrode-Electrolyte Interface Boosting CO2 Electroreduction.

Electrocatalytic reactions occur in the nanoscale space at the electrified electrode-electrolyte interface. It is well known that the electrode-electrolyte interface, also called as interfacial microenvironment, is difficult to investigate due to the interference of bulk electrolytes and its dynamic evolution in response to applied bias potential. Here, we employ electrochemical co-reduction of CO2 and H2O on commercial Ag electrodes as a model system, in conjunction with quaternary ammonium cationic surfactants as electrolyte additives. We probe bias-potential-driven dynamic response of the interfacial microenvironment as well as the mechanistic origin of catalytic selectivity. By virtue of comprehensive in situ vibrational spectroscopy, electrochemical impedance spectroscopy, and molecular dynamics simulations, it is revealed that the structure of surfactants is dynamically changed from a random distribution to a nearly ordered assembly with increasing bias potential. The nearly ordered surfactant assembly regulates the interfacial water environment by repelling isolated water and suppressing water orientation into an ordered structure as well as promotes CO2 enrichment at the electrified interface. Eventually, the formed hydrophobic-aerophilic interface microenvironment reduces the activity of water dissociation and increases the selectivity of CO2 electroreduction to CO. These results highlight the importance of regulating the interfacial microenvironment by organic additives as a means of boosting the electrochemical performance in electrosynthesis and beyond.

Regulating Steric Hindrance in Redox-Active Porous Organic Frameworks Achieves Enhanced Sodium Storage Performance.

The development of novel redox-active polymers for sustainable sodium ion batteries (SIBs) has captured growing attention, but battery performance has been significantly limited by poor reversible specific capacities, where the majority of aromatic C6-benzene linkages are redox inactive. Here, a simple, yet efficient approach to improve sodium (Na) storage on these C6-benzene rings within a porous polymeric framework by rationally regulating their steric hindrance is reported. Decreasing intrinsic hindrance affords a significant improvement in redox reaction kinetics within the porous architecture, thereby facilitating the acceptance of Na ions on these functionalized benzene rings and boosting the SIB performance. As a result, the modulate porous framework exhibits an exceptional battery capacity of 376 mAh g-1 after 1000 cycles at 1.0 A g-1 , which is ≈1.5 times larger than that of the pristine framework. Furthermore, the performance can reach as high as 510 mAh g-1 at 0.1 A g-1 , comparable to that of the best-performing polymeric electrodes. The simple modulation approach not only enables Na storage modulation on functionalized C6-benzene rings, but also simultaneously provides a means to extend the understanding of the structure-property relationship and facilitate new possibilities for organic SIBs.

Microscopic Model for Cyclic Voltammetry of Porous Electrodes.

Cyclic voltammetry (CV) is a widespread experimental technique for characterizing electrochemical devices such as supercapacitors. Despite its wide use, a quantitative relation between CV and microscopic properties of supercapacitors is still lacking. In this Letter, we use both the microscopic "stack-electrode" model and its equivalent circuit for predicting the cyclic voltammetry of electric double-layer formation in porous electrodes. We find that the dimensionless combination ωτ_{n}, with ω the scan frequency of the time-dependent potential and τ_{n} the relaxation timescale of the stack-electrode model, governs the CV curves and capacitance: the capacitance is scan-rate independent for ωτ_{n}≪1 and scan-rate dependent for ωτ_{n}≫1. With a single fit parameter and all other model parameters dictated by experiments, our model reproduces experimental CV curves over a wide range of ω. Meanwhile, the influence of the pore size distribution on the charging dynamics is investigated to explain the experimental data.

Indocyanine Green Performance Enhanced System for Potent Photothermal Treatment of Bacterial Infection.

The instability in solution and aggregation-induced self-quenching of indocyanine green (ICG) have weakened its fluorescence and photothermal properties, thus inhibiting its application in practice. In this study, the cationic and anionic liposomes containing ICG were prepared based on 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) and 1,2-dipalmitoyl-sn-glycero-3-phospho-rac-glycerol (DPPG), respectively. Molecular dynamics (MD) simulations demonstrate that ICG molecules are better distributed in the membranes of cationic DOTAP-based liposomes, leading to a superior fluorescence and photothermal performance. The liposomal ICG also shows the physical and photothermal stability during irradiation and long-term storage. On this basis, the prepared DOTAP-based liposomal ICG was encapsulated in the self-healing hydrogel formed by guar gum through the borate/diol interaction. The proposed liposomal ICG-loaded hydrogel can not only convert near-infrared (NIR) light into heat effectively but also repair itself without external assistance, which will realize potent photothermal therapy (PTT) against bacterial infection and provide the possibility for meeting the rapidly growing needs of modern medicine.

Study on the Liquid-Liquid and Liquid-Solid Interfacial Behavior of Functionalized Graphene Oxide.

With the rise of carbon neutrality, the applications of carbon-based materials are gaining considerable attention. Graphene oxide (GO) is a two-dimensional sheet with epoxy and hydroxyl groups on the basal plane and carboxyl groups at the edge. In order to change the oil/water (o/w) interfacial activity, GO was controlled and modified by dodecylamine to get two kinds of functionalized GOs (fGOs), named as basal plane-functionalized GO (bGO) and edge-functionalized GO (eGO), respectively. The interfacial tension measurement showed that fGOs could reduce more interfacial tension at the poly-α-olefin/water interface than those at synthetic esters or aromatic compounds/water interfaces. Besides, eGO can reduce more poly-α-olefin-4/water interfacial tension compared to bGO. The interfacial dilatational rheology of eGO and fatty alcohol polyoxyethylene ether-4 (MOA4) showed that MOA4 gradually replaced eGO at the interface with the increase of MOA4, until the interface was completely occupied. eGO and MOA4 complex emulsion exhibited the best friction-reducing performance at 250 rpm. The coefficient of friction (COF) curves of the emulsions with eGO showed two platforms, with the COF reduced by 37.42% at the most. The rheological results of emulsions showed that the addition of eGO increased the elasticity of the emulsion. Emulsions showed shear-thinning and friction-thickening properties, which make it easier for the emulsion to form a lubricating film on the metal surface. Our research results suggested that the functionalization on the edge of GO will change the interfacial properties significantly, which have widespread applications in the encapsulation of active materials, surface protection, adsorption, and separation of pollutants.

Multiple strategies to control the hydrophilic-hydrophobic balance of P(DMA-co-DMAEMA-co-QDMAEMA) coatings.

The regulation of the hydrophilic-hydrophobic balance of polymers has an important influence not only on their aggregation behavior in aqueous solution, but also on their adhesion properties on the surface of substrates and the applications of the modified surfaces. Based on this, a random copolymer poly(dopamine methacrylamide-co-2-(dimethylamino)ethyl methacrylate) (P(DMA-co-DMAEMA)) was synthesized as a starting polymer to generate P(DMA-co-DMAEMA-co-QDMAEMA) (PDDQ) derivatives by a programmable quaternization of the DMAEMA precursor. By adjusting the pH or temperature, both the aggregation behavior in aqueous solutions and the surface adhesive behavior on the substrate surfaces of PDDQ copolymers were regulated due to the hydrophilic-hydrophobic balance. Specifically, the surface adsorption of PDDQ copolymers on surfaces was enhanced by the increased hydrophobicity of PDDQ. Stainless steel meshes (SSM) modified with the PDDQ0 copolymer without quaternization showed a superoleophobicity in acidic aqueous media, which endowed it with improved oil-water separation performance. In addition, the hydrophilic-hydrophobic balance of PDDQs and their coatings could also be tuned by changing the ratio of DMAEMA to QDMAEMA in the copolymer. From PDDQ0 to PDDQ100, by increasing the hydrophilic QDMAEMA component of PDDQ copolymers, anti-protein properties and oil/water separation efficiency of the modified surfaces were also enhanced gradually. The results provided a reference for designing P(DMA-co-DMAEMA-co-QDMAEMA) coatings in different application environments.