Ionic Copolymers Research Articles

Ionic copolymer-modified hexagonal carbon nitride tube as a high-performance catalyst for regioselective synthesis of hexahydroquinoline frameworks

The conventional structure of carbon nitride materials presents limitations, especially in the catalysis field, attributed to a restricted number of active sites and a low surface area. To address these challenges, we developed a unique design for a mesoporous carbon nitride tube (CNT), which was constructed by incorporating the ionic imidazole-epichlorohydrin copolymer ([IMEP][Cl]) as a template in the fabrication process. The self-assembly behavior of [IMEP][Cl] influences the formation of the melamine-cyanuric acid aggregate (as precursors) through electrostatic forces and polarity, potentially resulting in the creation of a thin-wall CNT with unique pore morphology. Synthesized three-dimensional hollow CNT demonstrated key factors of a high-performance catalyst in terms of high thermal stability (up to 550 °C), good specific surface area (108 m²/g), and significant recoverability (seven runs without a significant decrease in reaction yield). The CNT architecture was employed as a heterogeneous catalyst, and its catalytic efficiency was investigated in the regioselective synthesis of hexahydroquinoline ring systems. Based on the obtained results, CNT shows super-fast synthesis (5 min) of different pharmaceutical quinoline frameworks with exceptional yields (94–98 %) under ultrasound agitations. For the first time, an effective synthesis method is introduced for constructing hollow carbon nitride tubes, utilizing an ionic polymer (produced via chemical crosslinking rather than radical chain polymerization) as a template. This work offers a new viewpoint on improving the catalytic capability of traditional graphitic carbon nitrides through the utilization of ionic copolymers, presenting potential advancements for various technological applications.

Ionic Copolymers Including Iodide and Dihydrogen Phosphate Anions for Increased Adsorption and Anticorrosion on Copper in Sulfuric Acid

Ionic Copolymers Including Iodide and Dihydrogen Phosphate Anions for Increased Adsorption and Anticorrosion on Copper in Sulfuric Acid

Synthesis and rheological properties of water soluble ionic copolymers as modifier fluids at high temperature and saline media

AbstractPolymer flooding depicts an interesting strategy to improve the enhanced oil recovery (EOR). This work aims with the synthesis of ionic thermo‐responsive copolymers able to be used as rheological modifiers for EOR under harsh conditions (250,000 ppm of NaCl at 150°C). Copolymers composed of different molar ratio of acrylamide, N‐isopropylacrylamide and 2‐acrylamide‐2‐methyl‐1‐propanesulfonic acid were prepared in aqueous media via free radical polymerization at 50°C using 4,4′‐azobis(‐4″‐cyanopentanoic) acid (ACPA) as initiator. Nuclear magnetic resonance analyses demonstrated the structure and molar composition of synthesized copolymers. Rheological measurements performed at different concentration from 1 to 8 wt% demonstrated an increase in the viscosity from 2000 to 600,000 mPa.s. Aqueous mixtures of polymer at 5 wt% and NaCl at different concentration (5, 10, 15, 20, and 25 wt%) was analyzed. Copolymer ([PAM]/[PNIPAM] = 50/50) displayed a phase separation at 15 wt% of NaCl. Solutions of polymer at 5 and 25 wt% of NaCl were heated at 150°C for 72 h. Results revealed both thermal stability and saline tolerance of copolymers [PAM]/[PNIPAM]/[PAMPS‐Na] = 25/25/50, 35/35/30, and 50/0/50 under harsh conditions with the absence of phase separation of the brine polymer solutions.

Transient materials from hypersensitive ionic polymer fibers

Materials endowed with high strength and modulus, strong fatigue resistance and tolerance, and long service life, are always the goal we are striving for. However, in many situations, the materials are supposed to rapidly disappear unlike degradable polymers, and from this produces a series of significant changes in structure and properties, acquiring extraordinary application requirements. Herein, we develop a strategy to establish a generalized platform of transient materials via the electrospinning of ionic copolymers. The design allows these transient polymer fibers to disappear transiently with the transient efficiency in the range from 0.037 to 0.18 mg s−1. The transient fibers exhibit robust self-repairability where the repaired possesses increased tensile modulus (81 MPa) and can load a weight that is 16,000 times its own weight, transient adhesion (4-fold shear strength as much as commercial double-sided adhesive) which can realize the debonding via the ultrasound in the water, early warning (high response rates from 0.0025 s−1 to 0.025 s−1), and fiber-orientation movement (model prediction). We expect that our strategy can give access to the general and promising theory and application system of transient materials.

Multi-fluorous-included Counter Anions-based Ionic Copolymers: Synthesis and Enhanced Hydrophobic Adsorption Films on Copper Surface for Super Protection

Multi-fluorous-included Counter Anions-based Ionic Copolymers: Synthesis and Enhanced Hydrophobic Adsorption Films on Copper Surface for Super Protection

An Asymmetric Cross-Linked Ionic Copolymer Hybrid Solid Electrolyte with Super Stretchability for Lithium-Ion Batteries.

Composite solid electrolytes are recommended to be the most promissing strategy for solid-state batteries because they combine the advantages of inorganic ceramics and polymers. However, the huge interfacial resistance between the inorganic ceramic and polymer results in low ionic conductivity, which is still the major impediment that limits their applications. Herein, a novel highly elastic and weakly coordinated ionic copolymer hybrid electrolyte with asymmetric structure based on surface-modified Li1.5 Al0.5 Ge1.5 (PO4 )3 by "in situ" polymerization is proposed to improve ionic conductivity and mechanical properties simultaneously. The all-solid hybrids electrolytes exhibit room-temperature ionic conductivity up to 2.61 × 10-4 S cm-1 and lithium-ion transference number of 0.41. The hybrids electrolytes can be repeatedly stretching-releasing-stretching, showing a super stretchability with the elongation at break up to 496%. The Li symmetrical cells assembled with the hybrid electrolytes can continuously operate for 800h at 0.1mA cm-2 without discernable dendrites, indicating good interfacial compatibility between the hybrid electrolytes and lithium electrodes. The Li|LiFePO4 batteries assembled with the hybrid electrolytes deliver an initial discharge specific capacity of 165.5 mAh g-1 with an initial coulombic efficiency of 94.8% and 154 mAh g-1 after 100 cycles at 0.1 C, and maintain 95.4% capacity retention after 100 cycles at 0.5 C.

A New Polystyrene-Poly(vinylpyridinium) Ionic Copolymer Dopant for n-Type All-Polymer Thermoelectrics with High and Stable Conductivity Relative to the Seebeck Coefficient giving High Power Factor.

A novel n-type copolymer dopant polystyrene-poly(4-vinyl-N-hexylpyridinium fluoride) (PSpF) with fluoride anions is designed and synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. This is thought to be the first polymeric fluoride dopant. Electrical conductivity of 4.2 S cm-1 and high power factor of 67 µW m-1 K-2 are achieved for PSpF-doped polymer films, with a corresponding decrease in thermal conductivity as the PSpF concentration is increased, giving the highest ZT of 0.1. An especially high electrical conductivity of 58 S cm-1 at 88°C and outstanding thermal stability are recorded. Further, organic transistors of PSpF-doped thin films exhibit high electron mobility and Hall mobility of 0.86 and 1.70 cm2 V-1 s-1 , respectively. The results suggest that polystyrene-poly(vinylpyridinium) salt copolymers with fluoride anions are promising for high-performance n-type all-polymer thermoelectrics. This work provides a new way to realize organic thermoelectrics with high conductivity relative to the Seebeck coefficient, high power factor, thermal stability, and broad processing window.

Pd on thermo-responsive composite of silica-coated carbon nanotube and 1-vinyl-3-butylimidazolium-based ionic liquid copolymers as an efficient catalyst for hydrogenation of nitro compounds

In this work, an ionic liquid-containing thermo-responsive heterogeneous catalyst with utility for promoting hydrogenation of nitro-compounds in aqueous media is developed. To prepare the catalyst, silica-coated carbon nanotubes were synthesized and vinyl-functionalized. The resulted compound was then polymerized with 1-viny-3-butylimidazolium bromide and N-isopropylacrylamide. The obtained ionic liquid-containing thermo-responsive composite was palladated via wet-impregnation method to give the final catalyst. Study of the performance of the catalyst confirmed high catalytic activity of the catalyst at temperature above the lower critical solution temperature. Furthermore, the catalyst was highly recyclable and showed negligible Pd leaching upon recycling. Broad substrate scope and selectivity of the catalyst towards reduction of nitro functionality were also confirmed. Furthermore, hot filtration test implied the heterogeneous nature of the catalysis. The comparison of the activity of Pd/CNT-P with some control catalysts approved the importance of hybridization of P and CNT and the presence of ionic liquid for the catalytic activity.

Reversal of handedness of ionic liquid-based chiral block copolymers via self-assembly in solution and bulk phase

Polymerized ionic liquid-based block copolymer obtained by the functionalization of polystyrene-block-poly(4-vinylpyridine) with chiral auxiliaries demonstrated self-assembled helical nanofibrils with inversion of helical sense.

Cross-linked ionic copolymer solid electrolytes with loose Coordination-assisted lithium transport for lithium batteries

PEO-based solid electrolytes have attracted great attentions and made rapid development in the fields of lithium ion batteries, however its low ionic conductivity and low lithium ion transference number at ambient temperature prevent its practical applications. Herein we report a novel freestanding crosslinked ionic copolymer solid electrolytes fabricated via cross-linking polytetramethylene ether glycol with 1-vinyl-3-butylimidazole bis(trifluoromethylsulfonyl)imide ionic liquid. Polytetramethylene ether glycol is chosen to build polymer matrix owing to their loose coordination with lithium ions and vinyl imidazolium ionic liquids provide ionic species. As expected, the novel electrolytes exhibit lithium-ion transference number (tLi+) up to 0.47 at ambient temperature, good electrochemical stability up to 5.1 V and stable interface compatibility. Furthermore, the lithium ion batteries assembled with lithium anodes and LiFePO4 cathodes exhibit good cycling performance and rate performance, delivering a good discharge capacity of 154.3 mAh g−1 after 100 cycles at 0.1C and an initial discharge capacity of 137.6 mAh g−1 at 0.5C with capacity retention of 92% after 100 cycles at ambient temperature.

Spatially regulated activation of membrane fusogenic peptides with chaperone-like ionic copolymers

Controlled or targeted membrane lysis induced by cascades of assembly and activation of biomolecules on membrane surfaces is important in programmed cell death and host defense systems. In a previous study, we reported that an ionic graft copolymer with a polycation backbone and water-soluble graft chains, poly(allylamine)-graft-dextran (PAA-g-Dex) chaperoned folding and assembly of E5, a membrane-destructive peptide derived from influenza hemagglutinin, to its increase membrane-disruptive activity. In this study, we modified the copolymer with long acyl chains, which resulted in delivery of the copolymer to membrane surfaces of liposomes and living cells. The liposomes with PAA-g-Dex functionalized with stearic acid (PAA-g-Dex-SA) on their surfaces underwent vesicle-to-sheet conversion upon addition of E5, whereas control liposomes did not. E5 also induced selective lysis of cells incubated with PAA-g-Dex-SA. The spatially specific activation of E5 on target membrane surfaces driven by self-assembly of copolymer and activation of E5 should find application in lipid-based delivery devices and cell-based therapeutics.

A Molecular Dynamics Study of the Mechanical Properties of Ionic Copolymers during Tension–Recovery Deformation

AbstractPolymer electrolytes have attracted ever‐increasing attention in the field of energy storage and conversion due to their significantly improved safety features and processability compared with liquid electrolytes and inorganic solid electrolytes. The mechanical integrity of ionic copolymers is one of the most important properties that need to be considered in the development of polymer electrolytes. In this study, the uniaxial tension–recovery studies are conducted in single‐ion diblock copolymers via coarse‐grained molecular dynamics simulation, where the fraction of the charged block is varied to form spherical, cylindrical, and lamellar morphologies. It is found that the dynamic hysteresis loss and permanent displacement have strong dependence on the fraction of the charged block and charge ratio. The change in the radius of gyration greatly varies for the different morphology. Furthermore, the charged copolymers are subjected to more changes in bond orientation during tension and also preserve more changes at recovery. It is likely that the charged monomers and counterions contribute to the stronger crosslinking effect in charged copolymers, reducing chain slippage and hysteresis loss.

Fabrication of DABCO functionalized poly(ionic liquids): Vital role of ferric oxides in the formation of mesoporous structure and used as highly efficient and recyclable catalysts for multi-component reactions

The preparation of well-defined porous materials as carriers is critically fundamental for the design of heterogeneous catalysts. In this study, 1,4-Diazabicyclo[2.2.2]octane (DABCO) based hypercross-linked ionic copolymers with well-developed mesopores were fabricated, in which the alkene modified ferric oxides nanoparticles play a vital role for the formation of the mesoporous structure. The magnetic copolymers, fully characterized by N2 adsorption-desorption, scanning electron microscopy (SEM)/transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM), exhibited abundant active ionic centers, rich mesoporosity and moderate surface area. The as-prepared materials were found to be used as efficient catalysts for one-pot synthesis of indole derivatives and 3,4-fused indoles with seven-membered ring and good to excellent products yields were achieved within 10 h. The kinetic study revealed that the meso-porosity increased the catalytic efficiency in terms of reaction rate and yield, albeit with mass transfer resistance produced by mesoporous channels. Finally, the catalyst could be readily recovered using external magnetic force and recycled at least ten times without significant loss in catalytic activities, which makes it attractive for green transformation in chemical industry.

Study on the Preparation and Anti-CO2 Corrosion Performance of Soap-Free Latex for Oil Well Cement.

To improve the resistance to CO2 corrosion of oil well cement, soap-free emulsion polymerization was used to prepare a soap-free latex (PSAC) with sodium styrene sulfonate (SSS) and nano-SiO2 (SSS/SiO2) as the ionic copolymer emulsifier. The effects of SSS/SiO2 on the performance, thermal stability, and latex particle morphology of the PSAC were investigated through zeta potential, TGA, and TEM measurements, respectively. The carbonation resistance properties of cement with PSAC were evaluated, and the anticorrosion mechanism of the PSAC cement was determined by SEM, EDS, XRD, and 29Si NMR analyses. The results showed that the PSAC particle size was uniform, the particles were monodispersed, and they had a typical core–shell structure and good heat resistance. The carbonation resistance test results showed that after 60 days of corrosion, the corrosion depth of the cement with 12.0% PSAC content was only 2.16 mm, the permeability was 0.0018 mD, and the decrease in the compressive strength was 6.65%. The porosity in the cement was reduced significantly, and the pore volume (>50 nm) of the cement was reduced by 0.24 times. The PSAC film formation decreased the contact between hydration products and CO2. In addition, the nano-SiO2 in the PSAC reacted with Ca(OH)2 to reduce the free Ca(OH)2 content in the cement and generate C–S–H gel with a low Ca/Si ratio and high polymerization, which did not react as readily with CO2.

Direct surface modification of nanodiamonds with ionic copolymers for fast adsorptive removal of copper ions with high efficiency

In this study, we developed a rapid microwave-assisted Diels-Alder reaction to prepare hydroxylated ND; then the ionic copolymers functionalized ND composites were obtained through direct surface-initiated Ce(IV)/HNO3 redox polymerization by utilization of the hydroxyl groups and the resultant ND based composites were utilized for adsorptive removal of copper ions. The results demonstrated the Pseudo-second-order model can well describe the adsorption kinetic of ND-poly(AA-co-MPC) and it has been confirmed that the adsorption behavior is initiative and endothermic and related thermodynamic parameters (△G, △H, △S). The Langmuir isotherm model is better to describe the adsorption isotherms and the temperature experiment results show the best pH environment is pH 7–9. The results above demonstrated the ND-poly(AA-co-MPC) prepared by Ce(IV)/HNO3 redox polymerization shows great potential in environmental treatment and remediation and the easy, mild, hydrous polymerization strategy can be exampled in the field of material surface modification.

Asymmetric Reactions in Water Catalyzed by L-Proline Tethered on Thermoresponsive Ionic Copolymers

L-Proline was covalently tethered on thermoresponsive ionic block copolymers that formed micelles in aqueous solutions. The block copolymers consisted of a poly(N-isopropylacrylamide) (PNIPAAm) segment and an anionic or cationic polymer segment. These copolymers exhibited lower critical solution temperature (LCST) behavior at ca. 35-40°C, and achieved thermal stimuli-induced formation and dissociation of micelles. The copolymer generated micelles in aqueous solution at a higher temperature, where a catalytic aldol reaction proceeded with high diastereo- and enantioselectivities. The micelles dissociated at lower temperature to form a clear solution such that the products could be efficiently extracted from the aqueous reaction mixture. Extraction of the aldol product with an organic solvent from the aqueous solution of the anionic copolymer was more efficient than from the nonionic copolymer solution.

Exploring the Possibility of Using Ionic Copolymer Poly (Ethylene-co-Methacrylic) Acid as Modifier and Self-Healing Agent in Asphalt Binder and Mixture

It is well-accepted that the ionic copolymer poly (ethylene-co-methacrylic) acid (also named EMAA) is one type of self-healing material. This particular capability has great potential for extending the service life of infrastructures. In order to improve the rheological, mechanical, and self-healing properties of asphalt binder and asphalt mixtures, EMAA and styrene butadiene rubber (SBR) were selected as the additives. In this study, the effects of EMAA and SBR on the performance of bitumen and asphalt mixtures were examined and characterized using various parameters including rheological indices, Glover–Rowe parameter, ductility self-healing rate, fluorescence microscopy, and scanning electron microscope (SEM) test on binders, and different testing methods such as complex modulus, thermal stress-restrained specimen test (TSRST), disk-shaped compact tension (DCT), and fatigue–healing–fatigue test on the mixtures. The results showed that EMAA can significantly improve the stiffness and self-healing capacity of virgin and SBR modified binders and mixtures. Moreover, the cracking resistance of EMAA/SBR compound modified binder and mixture showed a significant improvement. However, EMAA is not recommended to be added as a modifier to virgin binders and mixtures due to its poor cracking resistance. Some novel tests and parameters mentioned in this paper are recommended for characterizing binders and mixtures in the future.

Nanocomposites of ionic copolymer integrating Gd-containing polyoxometalate as a multiple platform for enhanced MRI and pH-response chemotherapy.

This article describes the fabrication of nanosized paramagnetic drug carriers via the assembly of a pH-responsive hydrophilic block copolymer poly(polyethylene glycol methyl ether methacrylate)-b-poly(methacrylic acid-co-trimethyl ammonium bromide propyl methacrylate) (PPMT) and polyoxometalate K13[Gd(β2-SiW11O39)2] (GdSiW11) through electrostatic interaction. Owing to the hydrophilicity, large molecular weight, and high content of the GdSiW11 cluster bearing in the nanocomposites, the organic-inorganic nanocomposite exhibited an impressive longitudinal relaxivity as a contrast agent for magnetic resonance imaging (MRI). The surplus negative charges from the polyoxometalate cluster in the polymer nanocomposites facilitated the capture of the anti-tumor drug doxorubicin (DOX). The DOX-loaded nanocomposites were stable under the physiological environment, whereas a responsive release of DOX was achieved at pH values similar to the tumor microenvironment due to the regulation of the polyoxometalate and carboxyl groups. The DOX-loaded PPMT2-GdSiW11 nanocomposites were observed to enrich effectively at tumor sites through MRI after intravenous injection. Furthermore, the DOX-loaded composites manifested enhanced in vivo anti-tumor therapeutic efficacy and sustainable circulation time of more than 5 h, which were favourable for imaging measurement. With the advantages of the designed composite system, the present experiments propose a strategy for developing a new multiple imaging-drug delivery-local therapy platform for synergistic diagnosis and therapy.

Highly efficient cycloaddition of diluted and waste CO2 into cyclic carbonates catalyzed by porous ionic copolymers

It is believed that porous heterogeneous materials with excellent properties are promising candidates for efficient fixation of diluted and waste CO2. Herein, a family of mesoporous porous ionic copolymers (PIPs) was designed and prepared from the copolymerization of divinylbenzene (DVB) with vinyl-functionalized ionic liquids monomers through free radical copolymerization process. It was demonstrated that the heterogeneous PIP poly(divinylbenzene-1-allyl-tetramethylguanidinium bromide) PDVB-[AlTMG]Br-0.2 showed excellent activities in facile cycloaddition of CO2 into cyclic carbonates without using any external co-catalysts or metal additives. The results of characterizations and quantum mechanical calculations further showed that the specic hierarchical meso-macroporous structure of PDVB-[AlTMG]Br-0.2 offered the strongest binding interaction with SO and besides had a relatively good CO2 affinity, which results to the best cataltic activity for cycloaddition of CO2. Moreover, PDVB-[AlTMG]Br-0.2 exhibited high activities and good reusability in cycloaddition of 15 % diluted CO2 with various epoxides. It is believed that our work would have a great potential in energy-effective fixation of industrial combustion CO2 into high-value organic carbonates.

Orderly self-assembly of new ionic copolymers for efficiently protecting copper in aggressive sulfuric acid solution

In this study, new ionic polymers (IPs) based on the copolymerization of rigid aromatic phenylmethyl-linked bisimidazole and dibromide derivatives are presented. The prepared IPs display orderly self-assembly in 0.5 mol/L aqueous sulfuric acid solution. Furthermore, the formed IPs aggregates with regular elliptic or circular-like shape exhibit the strong adsorption capability on the studied copper surface in aggressive acid medium, which occurs mainly via the chemical chelation bonding with cuprous ions demonstrated by the FT-IR spectroscopy, Raman spectroscopy together with XPS spectroscopy. In addition, the polarization tests at the different temperatures indicate the physisorption of the IPs aggregates on Cu surface can be presence. The electrochemical measurements show that the formed robust IPs-assemblies layers can protect the studied copper specimens efficiently with the maximal corrosion inhibition efficiency of 97.8% (IP1) and 96.8% (IP2) in aqueous sulfuric acid solution. The results are further understood by the molecular modeling and molecule dynamic simulation, and the electronic density distribution of the surveyed IPs and the optimal equilibrium configurations on Cu slab are revealed and analyzed. The results presented in this study could act as the models for guiding us to develop new organic corrosion inhibitors for metal in aggressive media.