Dimethylamino Ethyl Acrylate Research Articles

Synthesis and Performance Study of Self-Degradable Gel Plugging Agents Suitable for Medium- and Low-Temperature Reservoirs.

Aiming at the problems of current similar hydrogel plugging agents, such as poor breaking performance, nonspontaneous degradation, and reservoir pollution which have been plaguing their application in temporary plugging operations, this study has synthesized a cross-linking agent for hydrogels with dimethylaminoethyl acrylate and dibromo-p-xylene as raw materials. With Fourier transform infrared, 1H nuclear magnetic resonance, and thermogravimetric analyses as representations of the structure and thermal stability of the cross-linking agent, a set of self-degrading hydrogel systems has been developed with the cross-linking agent as the core so as to make evaluations on the temperature resistance, plugging performance, and core damage performance of the hydrogel and conduct a study on its gelation kinetics. The research results show that the cross-linking agent shows good thermal stability. When applied in the hydrogel system, the hydrogel has shown high temperature resistance, maintaining gel strength for 5-10 days at 50-90 °C, with viscosity after complete degradation lower than 10 mPa·s. The excellent bearing strength of the hydrogel system has led to a core damage rate below 5%. The study on gelation kinetics of the hydrogel system shows that, with the increase in the concentration of the cross-linking agent, the gelation time of the hydrogel system is shortened, with the reaction order between the cross-linker concentration and the gelation time at about 0.6 under the condition of 50-90 °C.

Optimizing Biocompatibility and Gene Delivery with DMAEA and DMAEAm: A Niacin-Derived Copolymer Approach.

Gene therapy is pivotal in nanomedicine, offering a versatile approach to disease treatment. This study aims to achieve an optimal balance between biocompatibility and efficacy, which is a common challenge in the field. A copolymer library is synthesized, incorporating niacin-derived monomers 2-acrylamidoethyl nicotinate (AAEN) or 2-(acryloyloxy)ethyl nicotinate (AEN) with N,N-(dimethylamino)ethyl acrylamide (DMAEAm) or hydrolysis-labile N,N-(dimethylamino)ethyl acrylate (DMAEA). Evaluation of the polymers' cytotoxicity profiles reveals that an increase in AAEN or DMAEA molar ratios correlates with improved biocompatibility. Remarkably, an increase in AAEN in both DMAEA and DMAEAm copolymers demonstrated enhanced transfection efficiencies of plasmid DNA in HEK293T cells. Additionally, the top-performing polymers demonstrate promising gene expression in challenging-to-transfect cells (THP-1 and Jurkat cells) and show no significant effect on modulating immune response induction in ex vivo treated murine monocytes. Overall, the best performing candidates exhibit an optimal balance between biocompatibility and efficacy, showcasing potential advancements in gene therapy.

Design of an Oxygen‐Tolerant Photo‐RAFT System for Protein‐Polymer Conjugation Achieving High Bioactivity

AbstractProtein‐polymer conjugates have significant potential in pharmaceutical and biomedical applications. To enable their widespread use, robust conjugation techniques are crucial. This study introduces a photo‐initiated reversible addition‐fragmentation chain‐transfer (Photo‐RAFT) polymerization system that exhibits excellent oxygen tolerance. This system allows for the synthesis of protein‐polymer conjugates with high bioactivity under mild and aerobic conditions. Three photocatalytic systems utilizing Eosin Y (EY) as the photocatalyst with two different cocatalysts (ascorbic acid and triethanolamine) were investigated, each generating distinct reactive oxygen species (ROS) such as singlet oxygen, superoxide, hydrogen peroxide, and hydroxyl radicals. The impact of these ROS on three model proteins (lysozyme, albumin, and myoglobin) was evaluated, demonstrating varying bioactivities based on the ROS produced. The EY/TEOA system was identified as the optimal photo‐RAFT initiating system, enabling the preparation of protein‐polymer conjugates under aerobic conditions while maintaining high protein enzymatic activity. To showcase the potential of this approach, lysozyme‐poly(dimethylaminoethyl acrylate) conjugates were successfully prepared and exhibited enhanced antimicrobial property against Gram‐positive and Gram‐negative bacteria.

Design of oxygen-tolerant Photo-RAFT system for protein-polymer conjugation achieving high bioactivity.

Protein-polymer conjugates have significant potential in pharmaceutical and biomedical applications. To enable their widespread use, robust conjugation techniques are crucial. This study introduces a photo-initiated reversible addition-fragmentation chain-transfer (Photo-RAFT) polymerization system that exhibits excellent oxygen tolerance. This system allows for the synthesis of protein-polymer conjugates with high bioactivity under mild and aerobic conditions. Three photocatalytic systems utilizing Eosin Y (EY) as the photocatalyst with two different cocatalysts (ascorbic acid and triethanolamine) were investigated, each generating distinct reactive oxygen species (ROS) such as singlet oxygen, superoxide, hydrogen peroxide, and hydroxyl radicals. The impact of these ROS on three model proteins (lysozyme, albumin, and myoglobin) was evaluated, demonstrating varying bioactivities based on the ROS produced. The EY/TEOA system was identified as the optimal photo-RAFT initiating system, enabling the preparation of protein-polymer conjugates under aerobic conditions while maintaining high protein enzymatic activity. To showcase the potential of this approach, lysozyme-poly(dimethylaminoethyl acrylate) conjugates were successfully prepared and exhibited enhanced antimicrobial property against gram-positive and gram-negative bacteria.

A Facile Strategy to Construct Anti-Swelling, Antibacterial, and Antifogging Coatings for Protection of Medical Goggles.

During the COVID-19 (Corona Virus Disease 2019) pandemic, traditional medical goggles are not only easy to attach bacteria and viruses in long-term exposure, but easy to fogged up, which increases the risk of infection and affects productivity. Bacterial adhesion and fog can be significantly inhibited through the hydrogel coatings, owing to super hydrophilic properties. On the one hand, hydrogel coatings are easy to absorb water and swell in wet environment, resulting in reduced mechanical properties, even peeling off. On the other hand, the hydrogel coatings don't have intrinsic antibacterial properties, which still poses a potential risk of bacterial transmission. Herein, an anti-swelling and antibacterial hydrogel coating is synthesized by 2-hydroxyethyl methacrylate (HEMA), acrylamide (AM), dimethylaminoethyl acrylate bromoethane (IL-Br), and poly(sodium-p-styrenesulfonate) (PSS). Due to the self-driven entropy reduction effect of polycation and polyanion, an ion cross-linking network is formed, which endows the hydrogel coating with excellent antiswelling performance. Moreover, because of the synergistic effect of highly hydrated surfaces and the active bactericidal effect from quaternary ammonium cations, the hydrogel coating exhibits outstanding antifouling performances. This work develops a facile strategy to fabricate anti-swelling, antifouling, and antifogging hydrogel coatings for the protection of medical goggles, and also for biomedical and marine antifouling fields.

Synthesis of amphiphilic functional terpolymers towards preparation of high flux, anti-fouling, micropollutant-capturing ultrafiltration membranes

Traditional method for modification of PVC ultrafiltration membrane depends mainly on blending, but inevitably suffers from additive leakage and poor compatibility between components. Herein, we synthesized amphiphilic functional terpolymers with adjustable chemical structures through in-situ copolymerization of vinyl chloride, acrylonitrile, and dimethyl aminoethyl acrylate, subsequently prepared the terpolymer ultrafiltration membranes by non-solvent induced phase separation. The novel terpolymers endow the membranes with amphiphilic and pH-responsive performances. Compared with the blend membrane, the copolymer had the more stable covalent bonding, and then its hydrophilic segments could anchor and enrich stably to the membrane surface without diffusing into the aqueous phase. As a result, the copolymer membrane not only effectively overcame the disadvantages of blend membrane, but also showed excellent antifouling and permeable properties. Its water flux significantly increases to 469.41 L/(m2·h·bar) from 35.67 L/(m2·h·bar) of pure PVC membrane while the adsorption capacity for bovine serum proteins was reduced. Meanwhile, the copolymer membranes exhibited strong pH-dependent adsorption for anionic dyes and heavy metal ions. The maximum adsorption capacities occurred respectively at pH values of 3.5 and 6.0. In addition, the copolymer membrane can be regenerated by desorbing the adsorbed anionic dyes and heavy metal ions respectively at pH 10 and pH 3.5. This research provides a new strategy for facile preparation of amphiphilic functional ultrafiltration membranes and effective removal of micropollutants.

Synthesis of CaCO3-Based Hyperdispersants and Their Application in Aqueous Coatings

As an essential pigment particle in white water-based coatings, light calcium carbonate (CaCO3) is difficult to disperse in water-based systems. The hard-to-disperse particles agglomerate, causing the viscosity of the coating to rise, which in turn affects the quality of the coating. Therefore, in order to obtain efficient dispersion, the hyperdispersant SSS–MPEGA–DMAEA (SMD) has been prepared in this study using sodium styrene sulfonate (SSS), polyethylene glycol monomethyl ether acrylate (MPEGA), and dimethylaminoethyl acrylate (DMAEA) as monomers through aqueous solution polymerization. Firstly, we utilized the central composite design method to conduct mathematical modeling of the monomer ratios so as to optimize the dispersion performance of the hyperdispersants. Secondly, the structural characteristics and molecular weight distribution of SMD were characterized by 1H NMR spectroscopy and GPC. Then, the effect of SMD on the dispersion of the CaCO3 slurry was investigated through particle size distribution and TEM measurements. Finally, we applied the SMD in aqueous white coatings and tested the surface properties of the paint film by SEM as well as the stability of the paint film. The results showed that SMD can significantly reduce the viscosity and particle size of the CaCO3 slurry. The waterborne coatings prepared by SMD had good storage stability and corrosion resistance, so the materials owned broad application prospects.

Spontaneously super-hygroscopic MOF-gel microreactors for efficient detoxification of nerve agent simulant in atmospheric environments

We design a spontaneously super-hygroscopic alkaline microreactor by photoinduced integration of Zr-MOF catalyst and alkaline poly(dimethylaminoethyl acrylate) onto LiCl-salinized poly(N-isopropylacrylamide) gel, generating a microenvironment with non-volatile polymeric base and non-bulk water for detoxification of a typical nerve agent simulant, dimethyl 4-nitrophenyl phosphate (DMNP), in atmospheric environments. The super-hygroscopic gel with directional microchannels facilitates the absorption, transport and storage of water under different humidities, and exhibits fast hygroscopic efficiency with a high moisture absorption capacity of 6.4 g g−1. The integrated microreactor achieves simultaneous water uptake and catalytic hydrolysis of DMNP in an atmospheric environment with an initial half-life of ∼1.9 h and a final conversion of 95.5%, which is attributed to the synergistic catalytic microenvironment of the exposed Zr-MOF catalyst, the polymeric base, and the water from moist air. This work provides a feasible strategy for designing spontaneously hygroscopic microreactors for detoxifying nerve agent simulants in atmospheric environments.

Evaluation of novel RAFT block copolymers as alternatives to amine collectors

This study introduced and flagged the potential of novel RAFT (reversible addition-fragmentation chain transfer) block copolymers as controllable and tunable collectors to circumvent the main drawbacks associated with amine collectors such as high foaming propensities and generating overly stable froths during froth flotation. A series of RAFT copolymers was evaluated to derive important insights into their abilities to control foamability and foam stability while maintaining high surface hydrophobization. The functional and structural design of the new RAFT copolymers included a hydrophilic block of poly dimethylaminoethyl acrylate quaternised with methyl iodide (PDMAEAI+) which induced a cationic effect, while altering the hydrophobic structure of poly n-butyl acrylate (PBA) determined the degree of surface hydrophobicity engendered on the targeted quartz surface. It was found that the specific number of the incorporated PBA functional groups largely governed the corresponding solubilities and the associated molecular interfacial activity of the copolymers relative to controlling their foaming abilities and surface hydrophobization. As a proof of concept, this study attests that these RAFT copolymers are promising in replacing amine collectors in reverse quartz flotation.

Tertiary sulfonium/quaternary ammonium-containing silsesquioxane nanoparticles with lithium salts as potential hybrid electrolytes

Solid and semisolid electrolytes consisted of ionic liquids, that can be used in lithium batteries to enhance their safety and performance, have attracted increasing attention, owing to the heavy demand for clean energy and a sustainable society. In this paper, we report the design, synthesis, and study of the chemical–physical properties of tertiary sulfonium/quaternary ammonium-based silsesquioxane nanoparticles (SQ-NPs) with lithium salt additives. Hydrolytic condensation of sulfide-containing triethoxysilane prepared from 3-(methylthio)propyl acrylate (MTPA) and (3-aminopropyl)triethoxysilane yielded MTPA-containing SQ-NP. The cationization of MTPA-containing SQ-NP and subsequent anion exchange reaction with lithium salts (lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and lithium bis(fluorosulfonyl)imide (LiFSI)) produced viscous MTPA(S+)-SQ[TFSI−] and MTPA(S+)-SQ[FSI−], respectively. Adopting the same procedure, 2-(dimethylamino)ethyl acrylate (DMAEA) was used as a tertiary amine-containing starting material to prepare DMAEA(N+)-SQ[TFSI−] and DMAEA(N+)-SQ[FSI−]. Among the four SQ-NPs, MTPA(S+)-SQ[FSI−] exhibited the highest ionic conductivity (3.32 × 10−4 S cm−1 at 55 °C), and the lowest Tg (−24.8 °C) and viscosity (2.75 × 103 Pa∙S), while maintaining high thermal stability (Td5 = 217 °C). The maximum ionic conductivities of 2.24 × 10−5 and 3.48 × 10−3 S cm−1 at 25 and 90 °C, respectively, were observed in MTPA(S+)-SQ[FSI−] mixed with 30 wt% Li salt (LiTFSI). These results reveal the potential of the tertiary sulfonium/quaternary ammonium-based hybrids, showing the synergistic effects of combining the sulfonium/ammonium-based ionic liquids and multifunctional SQ-NPs (<5 nm), as semisolid-state electrolytes for the future development of lithium ion batteries and related applications.

Dextrin‐graft‐poly(2‐dimethylamino ethyl acrylate‐co‐2‐acrylamido‐2‐methyl propane sulfonic acid) polymer: A potential adsorbent for the fast removal of nitrophenols from aqueous medium

AbstractA graft copolymer is synthesized by grafting a mixture of 2‐(dimethylamino) ethyl acrylate (DMAEA) and 2‐acrylamido‐2‐methyl propane sulfonic acid (AMPS) monomers onto the dextrin, polysaccharide backbone via free radical polymerization process using potassium peroxydisulfate (KPS) as radical initiator in aqueous phase. Various characterization techniques like 1H and 13C NMR, FT‐IR, SEM, EDAX, and XRD analysis are used to characterize the copolymer. The polymer is used as an adsorbent for the removal of nitrophenols namely ortho‐nitrophenol (ONP), para‐nitrophenol (PNP), and 2,4‐ dinitrophenol (DNP) from their water solutions. Adsorption dynamics, kinetics, isotherms, and thermodynamics are studied. The maximum nitrophenol adsorption occurs at time 80 min, temperature 45°C, pH 3.5 (DNP), and 4.5 (ONP and PNP), polymer dose 30 mg/L. The nitrophenol adsorption data are well‐fitted with the Langmuir isotherm model with maximum adsorption capacity () 215.26 mg g−1 for ONP, 223.60 mg g−1 for PNP, and 288.24 mg g−1 for DNP. The equilibrium kinetics follow pseudo‐second‐order kinetic model. Thermodynamic values unfold that the following nitrophenol adsorption onto the polymer surface is spontaneous and endothermic in nature. The value of Gibb's free energy for the nitrophenol adsorption is in the range of −6.5 to −9.5 kJ mol−1. The preferential nitrophenol adsorption by the copolymer is followed in the order ONP&lt;PNP&lt;DNP.

Demulsification Performance and Mechanism of Tertiary Amine Polymer-Grafted Magnetic Nanoparticles in Surfactant-Free Oil-in-Water Emulsion.

Numerous cationic magnetic nanoparticles (MNPs) have previously been developed for demulsifying oil-in-water (O/W) emulsion, and results showed that the cationic MNPs could effectively flocculate and remove the negatively charged oil droplets via charge attraction; however, to the best of our knowledge, there are no research reports regarding the synergetic influence of both the positive charge density and interfacial activity of MNPs on the demulsification performance. In this study, three tertiary amine polymer-grafted MNPs, namely, poly(2-dimethylaminoethyl acrylate)-grafted MNPs (M-PDMAEA), poly(2-dimethylamino)ethyl methacrylate)-grafted MNPs (M-PDMAEMA), and poly(2-diethylaminoethyl methacrylate)-grafted MNPs (M-PDEAEMA), were synthesized and evaluated for their demulsification performance. Results demonstrated that a high positive charge density and superior interfacial activity of MNPs could cause partial oil droplet re-dispersion when excessive MNPs were introduced, leading to a lower magnetic separation efficiency and narrower demulsification window. Herein, a demulsification window is defined as a range of nanoparticle dosages in which the MNPs can effectively demulsify the O/W emulsion under certain conditions. For highly positively charged MNPs, their good interfacial activity could aggravate the formation of a narrower demulsification window. When tertiary amine polymer-grafted MNPs carried a lower positive charge density or weak interfacial activity, that is, M-PDMAEA at pH 4.0, M-PDMAEMA at pH 5.0-9.0, and M-PDEAEMA at pH 9.0-10.0, wide demulsification windows were observed. Additionally, a recycling experiment suggested that MNPs could maintain high demulsification efficiency up to at least five cycles, indicating their satisfactory recyclability. The three tertiary amine polymer-grafted MNPs can be potentially used for efficient demulsification from surfactant-free O/W emulsion in various pH ranges.

Adjustable Thermo-Responsive, Cell-Adhesive Tissue Engineering Scaffolds for Cell Stimulation through Periodic Changes in Culture Temperature.

A three-dimensional (3D) scaffold ideally provides hierarchical complexity and imitates the chemistry and mechanical properties of the natural cell environment. Here, we report on a stimuli-responsive photo-cross-linkable resin formulation for the fabrication of scaffolds by continuous digital light processing (cDLP), which allows for the mechano-stimulation of adherent cells. The resin comprises a network-forming trifunctional acrylate ester monomer (trimethylolpropane triacrylate, or TMPTA), N-isopropyl acrylamide (NiPAAm), cationic dimethylaminoethyl acrylate (DMAEA) for enhanced cell interaction, and 4-acryloyl morpholine (AMO) to adjust the phase transition temperature (Ttrans) of the equilibrium swollen cross-polymerized scaffold. With glycofurol as a biocompatible solvent, controlled three-dimensional structures were fabricated and the transition temperatures were adjusted by resin composition. The effects of the thermally induced mechano-stimulation were investigated with mouse fibroblasts (L929) and myoblasts (C2C12) on printed constructs. Periodic changes in the culture temperature stimulated the myoblast proliferation.

The Impact of Polymer Architecture on Polyion Complex (PIC) Micelles: When Topology Matters (and When It Doesn't)

AbstractThe influence of homopolymer architecture on the properties of polyion complex micelles is reported. Using a combination of dynamic and static light scattering, the authors show how the architecture is only relevant in kinetically trapped states of micelles formed by the electrostatic assembly of poly(N‐isopropyl acrylamide‐block‐styrene sulfonate) (p(NIPAM‐b‐SS) and linear, 4‐arm, 8‐arm star quaternized poly(dimethyl amino ethyl acrylate) (PDMAEA) homopolymers or poly(amidoamine) (PAMAM) dendrimers. Interestingly, the micellar size and the aggregation number in these kinetically arrested states follow a clear trend with the number of arms but differ in the case of dendrimers possibly due to the distinct chemical nature of the monomers. The authors show that if the micelles are prepared in a weak polyelectrolyte pairing regime (i.e., high ionic strength), they all converge into similar structures. The presented findings represent a new way of controlling the properties of polyion complex micelles through kinetically trapped states.

Removal of anionic and cationic dyes from aqueous solution using thermo- and pH-responsive amphiphilic copolymers

Amphiphilic copolymers exhibiting thermally induced phase segregation in water hold great potential as smart flocculants for water purification. Herein, we report the preparation of thermo- and pH-responsive copolymers based on oligo(ethylene glycol) methacrylate (OEGMA), dimethylaminoethyl acrylate (DMAEA) and pentafluorostyrene (PFS), and their use as thermally induced adsorbents for the removal of anionic and cationic dyes from water. The copolymer self-assembly behaviour in water was first studied as a function of concentration and pH. Then, the potential to remove thiazole yellow G (TYG) and rhodamine B (RhB) was investigated as a function of pH and dye concentration, highlighting that dye removal is mediated by hydrophobic and electrostatic interactions. As regards TYG, at pH 4 a removal capacity (RC) of about 80 mg/g, corresponding to a 97 % dye removal efficiency, was achieved at 800 mg/L TYG. In the case of RhB, a maximum RC value of 32 mg/g was obtained at pH 10. The results reported herein show that these copolymers represent a versatile platform to remove water-soluble organic dyes depending on pollutant concentration and pH conditions.

Single‐Step Expeditious Synthesis of Diblock Copolymers with Different Morphologies by Lewis Pair Polymerization‐Induced Self‐Assembly

AbstractLewis pair polymerization has demonstrated its unique advantages and powerful capability in polymer synthesis. Here we employ strong nucleophilicN‐heterocyclic olefin (NHO) and bulky organoaluminum to construct a frustrated Lewis pair, which can realize the compounded sequence control (CSC) copolymerization and self‐assembly the mixture of dimethylaminoethyl acrylate and fluoride‐functionalized methacrylate into diblock copolymers (di‐BCPs) nano‐assemblies through polymerization‐induced self‐assembly in one‐pot, single‐step manner within minutes. These di‐BCPs were characterized by1H and13C NMR, GPC, DSC, and TEM. By utilizing appropriate solvophilic block and solvophobic block, such Lewis pair polymerization‐induced self‐assembly strategy enables the expeditious, room‐temperature synthesis of di‐BCP nanoparticles with different morphologies, including spheres, worms, vesicles, and even fibers, thus suggesting the great application potential of such method in the future.

Solenis buys acrylic monomer firm SCL

The specialty chemical producer Solenis has acquired SCL, a German company that makes dimethylaminoethyl acrylate, an acrylic monomer used to produce the water treatment chemical polyacrylamide. Based in Ludwigshafen, Germany, SCL was spun out of BASF in 2009. “The acquisition of this business provides Solenis with the backward integration that supports our polyacrylamide growth plan,” Solenis CEO John Panichella says in a press release.

Integration of a Hydrophilic Hyperbranched Polymer and a Quaternary Ammonium Compound to Mitigate Membrane Biofouling

Membrane biofouling, adhesion of microorganisms on the surface and the subsequent formation of a biofilm, remains a persistent and inevitable issue, which results in a dramatic reduction of permeability and lifespan. Constructing a membrane with active bacteria-killing and passive anti-adhesion properties is still a challenge to mitigate membrane biofouling. Herein, an active–passive anti-biofouling membrane was originally fabricated by integration of hydrophilic hyperbranched poly(N-acryloylmorpholine) (HPA) and the dimethylaminoethyl acrylate–dodecylammonium bromide (DD) quaternary ammonium compound. Inspired by modern dopamine biomimetic adhesion chemistry, thiolated HPA was first immobilized on the polydopamine (PD)-modified poly(vinylidene fluoride) membrane surface through Michael addition, followed by conjugation of DD via a thiol–ene click reaction. The membrane surface changes of the chemical structure, hydrophilicity, and zeta potential proved that bacteria-killing DD and the anti-adhesion HPA layer were successively conjugated. The initial contact angle of the M-PD/HPA/DD membrane was reduced from 120.5° for the pure membrane to 52.3°. Furthermore, the water flux of the M-PD/HPA/DD membrane increased from 318.9 L m–2 h–1 (0.02 MPa) for the pure membrane to 854.4 L m–2 h–1. In addition, the M-PD/HPA/DD membrane exhibited excellent active bacteria-killing property with inhibition rates of ∼90% for Escherichia coli and ∼95% for Staphylococcus aureus, respectively. Meanwhile, in the filtration of artificial bacteria wastewater, the M-PD/HPA/DD membrane showed a higher water flux recovery rate of 86.9% than 43.3% for the pure membrane, indicating an excellent anti-biofouling property. Therefore, this molecular-level design approach for the modification of the membrane surface could significantly enhance permeability and mitigate membrane biofouling, which provides a promising dimension for the preparation of the anti-biofouling membrane.

Constructing novel nanofibrous polyacrylonitrile (PAN)-based anion exchange membrane adsorber for protein separation

Purification of biopharmaceutical streams is essential for producing high quality therapeutic bioproducts. This work developed a novel polyacrylonitrile (PAN)-based nanofibrous membrane with strong anion exchange functionality via electrospinning. The key material functionality was obtained via RAFT copolymerization of acrylonitrile and dimethylaminoethyl acrylate (pAD), followed by quaternization to form quaternary amine (QA) ligands, namely pAQ, a series of nanofibrous PAN-pAQ membranes were electrospun by blending the pAQ copolymer with PAN homopolymer at varying ratios. The chemistry of the respective pAQ copolymer and resulting membranes was confirmed by NMR and FTIR, evidencing successful functionalization. As compared to the reference pure membrane PAN4 that was negatively charged, the resulting composite membranes showed a positive surface charge. The investigation on surface morphology revealed that the nanofiber diameter increased from 300 nm to 1 μm with an increasing blend ratio from 1:4 to 1:7 for the PAN-pAQ membranes. Such trend in surface micro/nano morphology changes strongly influenced other surface properties such as increased pore size, reduced specific surface area and increased hydrophobicity. The static binding of model protein BSA of PAN-pAQ membranes firstly increased with blend ratio from 1:4 to 1:5, and then decreased at 1:7, which was attributed to the complex trade-off relationship between surface micro/nano-structure and hence distribution/density of quaternary functional groups. The PAN-pAQ membranes showed about a 10-fold increase in static binding capacity compared to PAN4, up to 310–320 mg·g−1 at a blend ratio of 1:5. Thus through this study, we were able to demonstrate a facile route to incorporate pre-functionalized copolymers into conventional polymers to form chromatographic membranes, with many possibilities to tailor membrane functionality for a wide range of applications.

Polymer-Grafted Nanoparticles (PGNs) with Adjustable Graft-Density and Interparticle Hydrogen Bonding Interaction.

Polymer-grafted nanoparticles (PGNs) receive great attention because they possess the advantages of both the grafted polymer and inorganic cores, and thus demonstrate superior optical, electronic, and mechanical properties. Thus, PGNs with tailorable interparticle interactions are indispensable for the formation of a superlattice with a defined and ordered structure. In this work, the synthesis of PGNs is reported which can form interparticle hydrogen-bonding to enhance the formation of well-defined 2D nanoparticle arrays. Various polymers, including poly(4-vinyl pyridine) (P4VP), poly(dimethyl aminoethyl acrylate) (PDMAEMA), and poly(4-acetoxy styrene) (PAcS), are attached to silica cores by a "grafting from" in a mini emulsion-like synthesis approach. SiO2 -PAcS brushes are deprotected by hydrazinolysis and converted into poly(4-vinyl phenol) (PVP), containing hydroxyl groups as potential hydrogen-bonding donor sites. Understanding and controlling interparticle interactions by varying grafting density in the range of 10-2 -10-3 chain nm-2 , and the formation of interparticle hydrogen bonding relevant for self-assembly of PGNs and potential formation of PGN superlattice structures are the motivations for this study.