3-sulfopropyl Methacrylate Research Articles

Applying Copolymerization Kinetics to Understand and Optimize Swelling Responses in Superabsorbent Hydrogels

While acrylic acid (AA)-based superabsorbent hydrogels (SAHs) have been widely used in multiple applications, the effects of counterion condensation and the polyelectrolyte effect at suppressing the effective degree of ionization in such systems limit their superabsorbency. Herein we describe the use, and investigate the mechanism, of sulfate comonomers containing different types of polymerizable functional groups for increasing the superabsorbency of acrylic acid-based SAHs. Specifically, acrylamido-2-methylpropanesulfonic acid (AMPS), 3-sulfopropyl acrylate (SPAK), and 3-sulfopropyl methacrylate (SPMK) sulfated monomers featuring similar distances between the polymer backbone and the sulfate group but different polymerizable groups were copolymerized with acrylic acid to fabricate SAHs. Measurements of the effective homopolymerization rate constants and copolymerization ratios associated with each copolymerization enabled the prediction of the relative chain distributions of monomers in each copolymer, as quantified by the blockiness parameter (i.e., the instantaneous or average number of consecutive monomers of each type polymerized). While all sulfated comonomers significantly enhanced swelling relative to an acrylic acid control, copolymers in which longer AA blocks are produced (AA-AMPS) resulted in lower swelling than copolymers in which shorter AA blocks are produced (AA-SPAK, AA-SPMK), a result attributed to the suppressed polyelectrolyte effect in copolymers with shorter AA blocks. The formation of limited length blocks of the sulfated monomer SPMK showed additional benefits for enhancing swelling, consistent with enhanced direct charge–charge repulsion between fixed charges in such copolymer systems. We anticipate this linkage between copolymerization kinetics and swelling properties offers the potential to enable improved rational design of superabsorbent hydrogels with higher sorbency.

In situ Surface-Initiated ATRP Mediated by Gallium-Based Liquid Metal Nanodroplets.

Surface-initiated atom transfer radical polymerization (SI-ATRP) is one of the most popular methods for surface modifications with functional polymer films, which has attracted significant attention in recent years. Here, wereport a facile method of gallium-based liquid metal nanodroplets (GLM) mediated SI-ATRP to prepare polymer brushes on GLM surfaces. The ATRP initiator modified GLM nanodroplets (GLM-Br) act as a substrate for the in situ SI-ATRP and participate as a reducing agent to reduce Cu(II) deactivators to Cu(I) activators. UV-vis spectra confirm the feasibility of the in situ SI-ATRP and indicate that the thickness and density of polymer brushes play an important role in performing a successful ATRP on GLMs surfaces. Homo- and block copolymers, poly(3-sulfopropyl methacrylate potassium salt) (PSPMA) and poly((2-dimethylamino)ethyl methacrylate-b-(3-sulfopropyl methacrylate potassium salt)) P(DMAEMA-b-SPMA) are successfully grafted to the GLM nanodroplets. Polymer brushes modified GLM nanodroplets show potential applications such as friction reduction and oil-water emulsion separation. GLM nanodroplets mediated SI-ATRP provides a novel and robust approach to preparing multifunctional GLM nanodroplets for differentapplications. This article is protected by copyright. All rights reserved.

Polyelectrolyte-Functionalized NanoMOFs for Highly Efficient Aqueous Lubrication and Sustained Drug Release.

This study demonstrates the hybridization of polyelectrolyte brushes with anti-inflammatory drug-loaded nanoMOFs that can achieve highly efficient aqueous lubrication and sustained drug release for the synergistic therapy of osteoarthritis (OA). Poly(3-sulfopropyl methacrylate potassium salt) (PSPMK) brushes aregrown on the surface of the UiO-66-NH2 via one-pot grafting polymerization, which served as a general surface modification method of NH2 -MOFs to grow the polymer brushes. The growth of the PSPMK brushes greatly enhance the stability, dispersity, and swollen property of the AS-UiO-66-NH2@PSPMK in aqueous media. Using as lubricating additives, the UiO-66-NH2 @PSPMK achieves not only reductions in both coefficient of friction and wear volume over 70% and 99% but also supports high load-carrying capacity and long-term durability. The PSPMK brushes can be served as an universal interfacial modification soft layer that can significantly improve the aqueous lubricating performance of other types of NH2 -MOFs. After encapsulating the anti-inflammatory aspirin (AS), the AS-UiO-66-NH2 @PSPMK shows both sustained drug release and good biocompatibility toward the human normal chondrocytes. This work establishes anti-inflammatory drug-loaded UiO-66-NH2 @PSPMK as a potential multifunctional joint lubricant for OA treatment.

Electrostatic Assembly of Multiarm PEG-Based Hydrogels as Extracellular Matrix Mimics: Cell Response in the Presence and Absence of RGD Cell Adhesive Ligands.

Synthetic hydrogels have been used widely as extracellular matrix (ECM) mimics due to the ability to control and mimic physical and biochemical cues observed in natural ECM proteins such as collagen, laminin, and fibronectin. Most synthetic hydrogels are formed via covalent bonding resulting in slow gelation which is incompatible with drop-on-demand 3D bioprinting of cells and injectable hydrogels for therapeutic delivery. Herein, we developed an electrostatically crosslinked PEG-based hydrogel system for creating high-throughput 3D in vitro models using synthetic hydrogels to mimic the ECM cancer environment. A 3-arm PEG-based polymer backbone was first modified with either permanent cationic charged moieties (2-(methacryloyloxy)ethyl trimethylammonium) or permanent anionic charged moieties (3-sulfopropyl methacrylate potassium salt). The resulting charged polymers can be conjugated further with various amounts of cell adhesive RGD motifs (0, 25, 75, and 98%) to study the influences of RGD motifs on breast cancer (MCF-7) spheroid formation. Formation, stability, and mechanical properties of hydrogels were tested with, and without, RGD to evaluate the cellular response to material parameters in a 3D environment. The hydrogels can be degraded in the presence of salts at room temperature by breaking the interaction of oppositely charged polymer chains. MCF-7 cells could be released with high viability through brief exposure to NaCl solution. Flow cytometry characterization demonstrated that embedded MCF-7 cells proliferate better in a softer (60 Pa) 3D hydrogel environment compared to those that are stiffer (1160 Pa). As the stiffness increases, the RGD motif plays a role in promoting cell proliferation in the stiffer hydrogel. Flow cytometry characterization demonstrated that embedded MCF-7 cells proliferate better in a softer (60 Pa) 3D hydrogel environment compared to those that are stiffer (1160 Pa). As the stiffness increases, the RGD motif plays a role in promoting cell proliferation in the stiffer hydrogel. Additionally, cell viability was not impacted by the tested hydrogel stiffness range between 60 to 1160 Pa. Taken together, this PEG-based tuneable hydrogel system shows great promise as a 3D ECM mimic of cancer extracellular environments with controllable biophysical and biochemical properties. The ease of gelation and dissolution through salt concentration provides a way to quickly harvest cells for further analysis at any given time of interest without compromising cell viability.

Sulfonic Cryogels as Innovative Materials for Biotechnological Applications: Synthesis, Modification, and Biological Activity.

Polymeric hydrogels based on sulfo-containing comonomers are promising materials for biotechnological application, namely, for use as a system for delivering water and minerals during seed germination in conditions of an unstable moisture zone. In this work, cryogels based on 3-sulfopropyl methacrylate and 2-hydroxyethyl methacrylate copolymers were obtained by the cryotropic gelation method. The morphology, specific surface area, and swelling behaviors of cryogels are found to depend on the total concentration of monomers in the reaction system and the content of the gel fraction in cryogels. Cryogels formed in the presence of nanodiamonds are shown to exhibit high biological activity during the germination of Lepidium sativum L. variety Ajur seeds, which manifests itself by stimulating seed germination and a significant increase in the raw weight of sprouts. These results indicate that sulfonic cryogels have a high potential to improve seed germination and plant growth, proving that such cryogels can be used as environmentally friendly materials for agricultural applications.

Hydrophobically modified complex coacervates for designing aqueous pressure-sensitive adhesives.

The rheology of complex coacervates can be elegantly tuned via the design and control of specific non-covalent hydrophobic interactions between the complexed polymer chains. The well-controlled balance between elasticity and energy dissipation makes complex coacervates perfect candidates for pressure-sensitive adhesives (PSAs). In this work, the polyanion poly(3-sulfopropyl methacrylate) (PSPMA) and the polycation quaternized poly(4-vinylpyridine) (QP4VP) were used to prepare complex coacervates in water. Progressive increase of hydrophobicity is introduced to the polyanion via partial deprotection of the protected precursor. Hence, the polymer chains in the complex coacervates can interact via both electrostatic (controlled by the amount of salt) and hydrophobic (controlled by the deprotection degree) interactions. It was observed that: (i) a rheological time-salt-hydrophobicity superposition principle is applicable, and can be used as a predictive tool for rheology, (ii) the slowdown of the stress relaxation dynamics, due to the increase of hydrophobic stickers (lower deprotection degree), can be captured by the sticky-Rouse model, and (iii) the systematic variation of hydrophobic stickers, amount of salt, and molecular weight of the polymers, enables the identification of optimizing parameters to design aqueous PSA systems. The presented results offer new pathways to control the rheology of complex coacervates and their applicability as PSAs.

Towards superior permeability and antifouling performance of sulfonated polyethersulfone ultrafiltration membranes modified with sulfopropyl methacrylate functionalized SBA-15

A non-solvent induced phase separation (NIPS) process was used to fabricate a series of sulfonated polyethersulfone (SPES) membranes blending with different concentrations of SBA-15-g-PSPA with the applications in the ultrafiltration (UF) process. SBA-15 was modified with 3-methacrylate-propyltrimethoxysilane (MPS) to form SBA-15-g-MPS. It was further modified with the charge tailorable polymer chains by reacting with 3-sulfopropyl methacrylate potassium salt. The nanoparticles were uniformly dispersed and finger-like channels were developed within the membrane. The adding of surface modified SBA-15-g-PSPA nanoparticles has significantly improved membrane water permeability, hydrophilicity, and antifouling properties. The pure water fluxes of the composite SPES membranes were significantly higher than the pristine SPES membrane. For the membrane containing 5% (mass) of SBA-15-g-PSPA (MSSPA5), the pure water flux was increased dramatically to 402.15 L∙m –2 ∙h –1 , which is ∼ 1.5 times that of MSSPA0 (268.0 L∙m –2 ∙h –1 ). The high flux rate was achieved with 3% (mass) of SBA-15 nanoparticles with retained high rejection ratio 98% for natural organic matter. The results indicate that the fashioned composite membrane comprising SBA-15-g-PSPA nanoparticles have a promising future in ultrafiltration applications.

Bioinspired simultaneous regulation in fluorescence of AIEgen-embedded hydrogels.

The development of stimuli-responsive functional fluorescent hydrogels is of great significance for the realization of artificial intelligence. In the present work, we design and synthesize a stimulus-responsive hydrogel embedded with an aggregation-induced emission (AIE) monomer, in which the fluorescence brightness and intensity can be tuned. The hydrogel embedded with tetraphenylethene-grafted-poly[3-sulfopropyl methacrylate potassium salt] (TPE-PSPMA) as the functional element is prepared by the radical polymerization method. Among them, the TPE core exhibits adaptive fluorescence ability through the AIE effect, while the PSPMA chain provides tunable hydrophilic properties under an external stimulus. The effect of different cationic surfactants with different lengths of hydrophobic tails on the fluorescence properties of TPE-PSPMA in solution is systematically investigated. With cationic surfactants, such as cetyltrimethylammonium bromide (CTAB), the fluorescence intensity is gradually tuned from 1059 to 4623. And the fluorescence intensities increase with the growth of hydrophobic tails of surfactants, which results from hydrophobicity-induced electrostatic interactions among surfactants and polymer chains. Furthermore, an obvious tunable fluorescence feature of hydrogel copolymerized TPE-PSPMA is realized, resulting from the change of brightness and the dynamic increase of fluorescence intensity (from 1031 to 3138) for the hydrogel immersed in CTAB solution with different soaking times. Such a typical fluorescence-regulated behavior can be attributed to the AIE of the TPE-PSPMA chain and the electrostatic interaction between the surfactant and the anionic polymer chain. The designed TPE-PSPMA-based hydrogel is responsive to stimuli, inspiring the development of intelligent systems such as soft robots and smart wearables.

Effect of cation alkyl chain length on 3-sulfopropylmethacrylate-based draw solutes having lower critical solution temperature.

We investigated the effect of change in alkyl chain length of cation in tributylalkylphosphonium 3-sulfopropyl methacrylate ([P444#][C3S], # = 4, 6, and 8) ionic liquids (ILs) on their osmolality and recovery properties as the draw solute in the forward osmosis (FO) process. The ILs aqueous solutions exhibited a characteristic of the lower critical solution temperature (LCST)-type phase separation, which allowed for the easy recovery of the draw solute or clean water from the diluted draw solution. The LCSTs of 31, 26, 22, and 18 °C were obtained from 2.5, 5.0, 7.5, and 10.0 wt% aqueous solutions of [P4446][C3S]. When deionized water, 2000 ppm NaCl solution, and 10.0 wt% orange juice aqueous solution were used as feed solution, the water fluxes of the aqueous [P4446][C3S] solutions were approximately 4.49, 3.87, and 1.55 LMH, respectively, in the active layer facing the draw solution mode at 7.5 wt% of draw solution. This study demonstrates the applicability of a thermoresponsive ionic structure material as a draw solute for the FO process.

Influence of the Nature and Structure of Polyelectrolyte Cryogels on the Polymerization of (3,4-Ethylenedioxythiophene) and Spectroscopic Characterization of the Composites.

Conductive hydrogels are polymeric materials that are promising for bioelectronic applications. In the present study, a complex based on sulfonic cryogels and poly(3,4-ethylenedioxythiophene) (PEDOT) was investigated as an example of a conductive hydrogel. Preparation of polyacrylate cryogels of various morphologies was carried out by cryotropic gelation of 3-sulfopropyl methacrylate and sulfobetaine methacrylate in the presence of functional comonomers (2-hydroxyethyl methacrylate and vinyl acetate). Polymerization of 3,4-ethylenedioxythiophene in the presence of several of the above cryogels occurred throughout the entire volume of each polyelectrolyte cryogel because of its porous structure. Structural features of cryogel@PEDOT complexes in relation to their electrochemical properties were investigated. It was shown that poly(3,4-ethylenedioxythiophene) of a linear conformation was formed in the presence of a cryogel based on sulfobetaine methacrylate, while minimum values of charge-transfer resistance were observed in those complexes, and electrochemical properties of the complexes did not depend on diffusion processes.

Zwitterionic liquid hydrogel sustained-release strategy for high-performance nanofiltration membrane

Controlling the diffusion of amine monomers plays a crucial role in fabricating well-defined architecture and high-performance nanofiltration (NF) membranes through interfacial polymerization (IP). Herein, a sustained-release strategy was proposed to regulate the interfacial polymerization through a zwitterionic liquid hydrogel transition layer. The hydrogel (Gel) was fabricated via in-situ one-step UV photo-initiated free-radical polymerization between 1-vinyl-3-ethylimidazolium chloride ([VEIm][Cl]) and 3-sulfopropyl methacrylate potassium salt (SMP) on the polyethersulfone (PES) substrate. The polyamide (PA) layer was then formed on the Gel layer by mitigating the diffusion of amine monomers. Low-field time-domain nuclear magnetic resonance (TD NMR) analysis demonstrated that the Gel layer significantly enhanced the water-absorbing capacity of the composite membrane. Positron annihilation lifetime spectroscopy (PALS) also confirmed the Gel-PA composite membrane possessed enlarged free volumes. The obtained Gel-PA composite membrane displayed a permeance of 13.22 L m−2 h−1 bar−1, a high Na2SO4 rejection of 98.23 %, a favorable NaCl/Na2SO4 selectivity of 49.75, outstanding long-term operational stability, and membrane antifouling properties. This sustained-release strategy provides a facile and feasible approach to controlling the IP process and obtaining high-performance nanofiltration membranes.

Ionic coordination strengthening of temperature-driven gradient hydrogel actuators with rapid responsiveness

Emerging applications of stimuli-responsive hydrogels as soft actuators and robotics have attracted great attention, but they face challenges in practical applications due to their poor mechanical properties, low driving force, and low actuation speed. Herein, we presented tough hydrogel actuators composed of a copolymer of N-isopropylacrylamide (NIPAM) and 3-sulfopropyl methacrylate potassium salt (SPA) monomers, and tunicate cellulose nanocrystals (TCNCs). The negatively charged TCNCs as nanofillers were gradient arranged by a direct current electric field (DC-EF) via electrophoresis. After in situ polymerization, TCNCs gradient distributed across the thickness of hydrogel, resulting in the formation of gradient crosslinking density of networks. Hydrogel actuators with high strength were obtained via Zr4+/−SO3- ionic coordination, whose tensile strength was about 200 times of hydrogel without ionic coordination. These hydrogel actuators exhibited rapid bending velocity, excellent stability, and good cycling performance in response to temperature. Importantly, these hydrogel actuators could be designed as soft robots to lift and transport objects by changing environment temperature. This work provided a facile yet efficient strategy to fabricate soft actuators with high strength and rapid responsiveness.

Impact of hydrophobic pendant phenyl groups on transport and co-transport of methanol and acetate in PEGDA-SPMAK cation exchange membranes

CO2 reduction cells are innovative devices that reduce CO2 into valuable chemicals (i.e. methanol (MeOH) and acetate (OAcˉ)) on the cathode. A major challenge with such devices is to develop ion exchange membranes that allow ion-selective transport (i.e., protons for cation exchange membranes, CEM) and suppress the crossover of CO2 reduction products. To design such membranes, it is important to understand multi-solute transport behavior of these solutes. Previously, our group reported acetate diffusivities in co-transport with MeOH increase in sulfonated CEMs, where we speculated charge screening of the electrostatic interactions by co-diffusing MeOH has an impact. Here, crosslinked membranes fabricated by photopolymerization of poly(ethylene glycol) diacrylate (PEGDA), 3-sulfopropyl methacrylate potassium (SPMAK, SO3ˉ-containing ionomer), and a phenyl-containing comonomer either phenoxyethyl acrylate (PEA) or poly(ethylene glycol) phenyl ether acrylate (PEGPEA)) are investigated. We observe OAcˉ diffusivities to both (1) PEGDA-SPMAK and (2) PEGDA-PEGPEA increase in co-diffusion with MeOH and those to (3) PEGDA-SPMAK/PEGPEA decrease. To rationalize this emergent co-transport behavior, we speculate (1) electrostatic interactions are interfered with by co-diffusing MeOH, (2) chain mobility (segmental dynamics) increases in the presence of MeOH and (3) for films with both hydrophobic (PEGPEA) and hydrophilic (SPMAK) comonomers chain mobility (segmental dynamics) decrease due to interactions between the comonomer sidechains depressing overall solute diffusivities. While further investigations are needed, this work contributes to improving our fundamental understanding of the relationships between polymer film chemistry, solute chemistry, and emergent cotransport behavior observed and described in this work (and others) towards enabling the design of improved membrane materials.

Physical Adsorption of Graphene Oxide onto Polymer Latexes and Characterization of the Resulting Nanocomposite Particles.

Polymer/graphene oxide (GO) nanocomposite particles were prepared via heteroflocculation between 140–220 nm cationic latex nanoparticles and anionic GO nanosheets in either acidic or basic conditions. It is demonstrated that nanocomposite particles can be formed using either poly(2-vinylpyridine)-b-poly(benzyl methacrylate) (P2VP–PBzMA) block copolymer nanoparticles prepared by reversible-addition chain-transfer (RAFT)-mediated polymerization-induced self-assembly (PISA), or poly(ethylene glycol)methacrylate (PEGMA)-stabilized P2VP latexes prepared by traditional emulsion polymerization. These two latexes are different morphologically as the P2VP–PBzMA block copolymer latexes have P2VP steric stabilizer chains in their corona, whereas the PEGMA-stabilized P2VP particles have a P2VP core and a nonionic steric stabilizer. Nevertheless, both the P2VP–PBzMA and PEGMA-stabilized P2VP latexes are cationic at low pH. Thus, the addition of GO to these latexes causes flocculation to occur immediately due to the opposite charges between the anionic GO nanosheets and cationic latexes. Control heteroflocculation experiments were conducted using anionic sterically stabilized poly(potassium 3-sulfopropyl methacrylate)-b-poly(benzyl methacrylate) (PKSPMA–PBzMA) and nonionic poly(benzyl methacrylate) (PBzMA) nanoparticles to demonstrate that polymer/GO nanocomposite particles were not formed. The degree of flocculation and the strength of electrostatic interaction between the cationic polymer latexes and GO were assessed using disc centrifuge photosedimentometry (DCP), transmission electron microscopy (TEM), and UV–visible spectrophotometry. These studies suggest that the optimal conditions for the formation of polymer/GO nanocomposite particles were GO contents between 10% and 20% w/w relative to latex, with the latexes containing P2VP in their corona having a stronger electrostatic attraction to the GO sheets.

Functionalized Ti3C2Tx-based nanocomposite coatings for anticorrosion and antifouling applications

Marine corrosion and biofouling are a major issue affecting the development of the marine industry. Traditional single-function coatings, such as those that provide either antifouling or anticorrosion, cannot meet the requirements in the current hostile conditions. In our study, block copolymer-functionalized Ti3C2Tx was successful prepared and employed to synthesize a nanocomposite coating with satisfactory antifouling and anticorrosion performances, in which the anticorrosion agent poly(2-mercaptobenzothiazole) (PMBTMA) was first grafted on the Ti3C2Tx surface, after which the antifouling agent poly(3-sulfopropyl methacrylate potassium (PSPMA) was grafted via surface-initiated atom transfer radical polymerization (SI-ATRP), to obtain the block copolymer (PMBTMA-co-PSPMA)-functionalized Ti3C2Tx (abbreviated as TMS). An appropriate corrosion protection and antifouling mechanism in the functionalized Ti3C2Tx-based epoxy nanohybrid coatings is proposed. It is noteworthy that the antibacterial activity of the proposed coating stems from the synergistic bactericidal effect of Ti3C2Tx and 2-mercaptobenzothiazole (MBT). The outstanding antibacterial properties of the TMS and the strong surface hydration of the anionic polymer brushes PSPMA, endow the as-prepared TMS-based nanocomposite coating (TMS/EP) with good antifouling performance (removal of more than 55% of bacteria and removal rate of microalgae up to 71%). More importantly, the TMS/EP has excellent corrosion resistance ability, which is due to the good synergistic anticorrosion barrier effect of Ti3C2Tx nanosheets and the on-demand release of corrosion inhibitor MBT during the corrosion process.

Dopamine-triggered one-step functionalization of hollow silica nanospheres for simultaneous lubrication and drug release

Osteoarthritis (OA) has been regarded as a lubrication deficiency related joint disease. Combination of both joint lubrication and drug intervention may provide a promising nonsurgical strategy for treatment of OA. Developing novel and simple approaches to fabricate superlubricating nanoparticles with drug release property is highly required. Herein, dopamine triggered one-step polymerization method was employed to fabricate polydopamine/poly(3-sulfopropyl methacrylate potassium salt) (PDA—PSPMA) conjugate coating on hollow silica (h-SiO2) nanosphere surfaces to engineer functional nanoparticles (h-SiO2/PDA—PSPMA). The as-prepared h-SiO2/PDA—PSPMA exhibits excellent aqueous lubrication performance on biomaterial substrates as well as natural bovine articular cartilage based on hydration effect of negatively charged PDA—PSPMA coating and “rolling” effect of h-SiO2 nanospheres. In vitro drug loading-release experiments demonstrate that PDA—PSPMA coating functionalized h-SiO2 nanospheres show high drug-loading and sustained-release capability of an anti-inflammatory drug, diclofenac sodium (DS). Such h-SiO2/PDA—PSPMA nanospheres can be potentially used as a synergistic therapy agent for OA treatment combining by simultaneous joint lubrication and drug release.

Repeatedly Regenerating Mechanically Robust Polymer Brushes from Persistent Initiator Coating (PIC).

In this study, a novel surface initiated polymerization (SIP) method was developed from organic-inorganic hybrid persistent initiator coating (PIC) that embeds initiator molecules into inorganic silica sol-gel layer. Comparing with traditional silane initiator surface that prepared by chemical vapor deposition (CVD) method, the PIC can effectively improve the mechanical stability of initiator that was able to endure ten-thousand times of friction cycles. Besides, it allows polymer grafting from sub-surface and so the grafted brushes, poly 3-sulfopropyl methacrylate potassium salt (pSPMA) on the PIC were also much more wear-resisting than those prepared by the traditional ways. More importantly, the PIC could still trigger new polymerization reaction when the grafted brushes were worn off. In addition, the PIC is universal and can be covered on different substrates including glass, metals and plastics, etc. to realize functionalization of these materials. The approach may pave technological way for the application of surface grafted polymer brushes.

Preparation and properties of cryogels based on poly(sulfopropyl methacrylate) or poly(sulfobetaine methacrylate) with controlled swelling

Preparation and properties of cryogels based on poly(sulfopropyl methacrylate) or poly(sulfobetaine methacrylate) with controlled swelling

Antifouling PVDF membranes fabricated via progressive potassium ion-π assembly of dopamine

Mussel-inspired surface modification draws a lot of attention for improving membrane antifouling property. However, it remains a serious challenge to fabricate a strong hydrophilic layer on the rough surface, preventing the pollutants to adhere to them during the filtration process. Here, a progressive cation-π assembly of polydopamine (PDA) was introduced to boost the antifouling property of the rough polyvinylidene fluoride (PVDF) membrane, which was fabricated by the non-solvent induced phase separation (NIPS) method using alcohol as the non-solvent. Afterward, dopamine and 3-sulfopropyl methacrylate potassium salt (SMPS) were co-deposited on the rough membranes via K+-π interactions, leading to >20% increment in graft yield compared with DA layer at the same deposition time. In addition, spin–spin relaxation time (T2) of water of DS modified membrane characterized by relaxation NMR decreased 484.9 ms, revealing strong hydration capability on the membrane surface and excellent water hydrophilicity. Benefited by the hydration capability, improved antifouling performance was obtained against natural organic polymers and crude oil, and good oil-in-water emulsions separation property without pressure. The K+-π interactions assistance dopamine assembly indicated a convenient technique for improving the antifouling performance of the rough membrane with a thick and strong hydrophilic layer.

Mitigating Early Phase Separation of Aliphatic Random Ionomers by the Hydrophobic H-Bond Acceptor Addition

This study reports a new phenomenon whereby the ionic content of a random ionomer was increased by the introduction of a hydrophobic modifier. In the current study, the ionomer synthesized from the solution polymerization of the three vinyl monomers, which are polar hydrophobic monomers acrylonitrile (AN), glycidyl methacrylate (GMA), and ionic monomer potassium 3-sulfopropyl methacrylate (SPM), encountered an early phase separation problem when the ionic content exceeded a certain threshold value. However, the addition of a strongly hydrophobic monomer, 2,2,3,3-tetrafluoropropyl methacrylate (TFPM), during the copolymerization is able to restrain this phase separation trend, consequently allowing 50% more of SPM units to be incorporated and uniformly distributed in the ionomer and achieving a random copolymer chain. The ionic clustering of the SPM units, which is the cause for the phase separation, was reduced as a result. The resulting random ionomer was demonstrated to be a superior proton conducting material over its ternary originator. This is due to the fact that TFPM possesses acidic protons, which brings about an association of TFPM with SPM and GMA via hydrogen bonding. This study could impact the synthesis of random ionomers by free radical polymerization since monitoring ionic content and improving ionic unit distribution in ionomers are issues encountered in several industries (e.g., the healthcare industry).