Anionic Polymer Chains Research Articles

Single proton anti-freezing hydrogel electrolyte with enhanced ion migration number enabling high-performance supercapacitor

Compared with traditional binary ion electrolytes, single-ion electrolytes have higher ion migration number and can avoid concentration polarization. In this work, single proton hydrogel electrolytes were prepared by one-step free radical polymerization of acrylamide and 2-acrylaminoamido-2-methyl-1-propane sulfonic acid in ethylene glycol (EG)/water binary solvent. The electrolyte possesses good mechanical strength and excellent anti-freezing ability. A high conductivity of 1.28 mS cm−1 at −40 °C is achieved by adjusting monomer ratio and EG content. The proton hopping along the ion channel formed by the anionic polymer chain and the Grotthuss transport are responsible for the high conductivity. An extremely high ion migration number of 0.87 is obtained. The fixed anionic group endows the hydrogel electrolyte with good anticorrosion ability. The hydrogel electrolyte assembled supercapacitor (SC) exhibits excellent electrochemical performance in a wide temperature range from −40 °C to 60 °C and can be stored at −30 °C for 10 months without capacitance attenuation. The capacitance retention rate of the SC is as high as 92% after 15,000 cycles at both room temperature and − 40 °C. The single proton hydrogel electrolyte provides a new route for the further development of storage device based proton transport.

Simultaneous Inhibition of Zn Dendrites and Polyiodide Ions Shuttle Effect by an Anion Concentrated Electrolyte Membrane for Long Lifespan Aqueous Zinc-Iodine Batteries.

Aqueous zinc-iodine (Zn-I2) batteries have attracted extensive attention due to their merits of inherent safety, wide natural abundance, and low cost. However, their application is seriously hindered by the irreversible capacity loss resulting from both anode and cathode. Herein, an anion concentrated electrolyte (ACE) membrane is designed to manipulate the Zn2+ ion flux on the zinc anode side and restrain the shuttle effect of polyiodide ions on the I2 cathode side simultaneously to realize long-lifetime separator-free Zn-I2 batteries. The ACE membrane with abundant sulfonic acid groups possesses a multifunctional amalgamation of good mechanical strength, guided Zn2+ ion transport, and effective charge repulsion of polyiodide ions. Moreover, rich ether oxygen, carbonyl, and S-O bonds in anionic polymer chains will form hydrogen bonds with water to reduce the proportion of free water in the ACE membrane, inhibiting the water-induced interfacial side reactions of the Zn metal anode. Besides, DFT calculations and in-situ UV-vis and in situ Raman results reveal that the shuttle effect of polyiodide ions is also significantly suppressed. Therefore, the ACE membrane enables a long lifespan of Zn anodes (3700 h) and excellent cycling stability of Zn-I2 batteries (10000 cycles), thus establishing a substantial base for their practical 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.

Tuning of particle indentation by surface modification of polymer particles and substrates

We studied the influence of the chemical properties of the polymer particle and the polymer substrate on particle indentation. The polymer particles were arrayed over the polymer substrate and heat treatment (annealing) was conducted above the glass transition temperature (Tg) of bulk polymer to indent polymer particles into the polymer substrate. Surface topologies of particle-indented surfaces were observed with a field-emission scanning electron microscope (FE-SEM) and the degree of particle indentation (DI) was evaluated with a scanning probe microscope (SPM). The particle-arrayed substrate was placed upside down and then heat treatment was carried out. It was found that there was no effect of gravity on particle indentation. To prepare polymer particles with different chemical properties, surface grafting of hydrophobic, hydrophilic, cationic and anionic polymer chains was carried out by iniferter-initiated living radical polymerization. We found that the indentation of these particles was influenced by the outermost surface of the particle. Next, to investigate the effect of the substrate surface on particle indentation, sulfonation of the polystyrene (PS) substrate was carried out with concentrated sulfuric acid. We found that the surface property of the substrate also influenced particle indentation. From these results, we concluded that particle indentation would be determined by the interaction between the particle surface and the substrate surface. Finally, we intended to analyze the viscoelastic property of the substrate surface by particle indentation. We could estimate Tg values of PS and polyvinyl chloride (PVC) substrates by observing the particle indentation at the different annealing temperatures.

Double Pseudo-Polymeric Gold(III)-Mercury(II) Complexes [Au(S2CNR2)2]nX [R2 = (CH2)6, (CH2)4O] Containing ([HgCl3]−)n, [HgCl4]2− and [Hg2Cl6]2− Anions: Chemisorption Synthesis, Principles of Supramolecular Self-Assembly, and Thermal Behavior

Novel pseudo-polymeric complexes of gold(III)-mercury(II) with cyclic alkylene dithiocarbamate ligands: ([Au{S2CN(CH2)6}2][HgCl3])n, ([Au{S2CN(CH2)6}2]2[HgCl4]·H2O)n, and ([Au{S2CN(CH2)4O}2]2[Hg2Cl6])n have been obtained and structurally characterized. The sophisticated supramolecular structure of the obtained compounds is realized due to secondary non-valent Au⋯S interactions and includes mononuclear and binuclear cations and anions as structural units as well as cationic and anionic polymer chains. The thermal behavior of the obtained complexes has been studied by means of simultaneous thermal analysis. The products of thermal transformations of the complexes are reduced elemental gold and HgCl2.

Blending the Effectiveness of Anionic Polymerization with the Versatility of RAFT by Use of the Atom Transfer Radical Addition–Fragmentation Technique

AbstractThe efficient conversion of a living anionic polymer chain end to a macrochain transfer agent suitable for reversible addition–fragmentation chain transfer (RAFT) polymerization is reported. Conversion to the macrochain transfer agent efficiency reached as high as 97% by capping the polyanion with alcohol, coupling with α‐bromoisobutryl bromide, followed by atom‐transfer radical addition–fragmentation with bis(thiobenzyl)disulfide to add the chain transfer agent functionality. To our knowledge, this is the most efficient marriage of anionic and reversible addition–fragmentation transfer polymerization reported to date, and can be carried out under common industrial processing conditions. The combination of these polymerization methods broadens the scope of commercially accessible block copolymers by exploiting the advantages of both RAFT and anionic polymerization chemistries.

Crystal Structure of New Fluoride Complexes of Indium(III) M[Cu(H2O)4]InF6·nH2O (M = Rb, Cs, NH4; n = 0, 1)

Fluoride complexes of indium(III) with mixed monovalent M+ (M = Rb, Cs, NH4) and divalent [Cu(H2O)4]2+ cations of the composition M[Cu(H2O)4]InF6·nH2O (M = Rb, Cs, NH4; n = 0, 1) are synthesized for the first time and their crystal structures with a polymer chain character are studied. The structures of M[Cu(H2O)4]InF6·nH2O (M = Rb, Cs, NH4; n = 0, 1) are formed of monovalent Rb+, Cs+, NH4+ cations respectively, complex [Cu(H2O)4]2+ cations, slightly distorted octahedral complex [InF6]3– anions, and crystallization H2O molecules. By attaching one F atom from the neighboring InF6 groups, the [Cu(H2O)4]2+ cations form distorted octahedral Cu(H2O)4F2 groups. Via the bridging F atoms, the [Cu(H2O)4]2+ cations and [InF6]3– anions alternatively join into zigzag anionic polymer chains. A branched system of hydrogen O–H···F, O–H···Ow, and N–H···F bonds arrange the anionic chains into a threedimensional framework in whose voids the monovalent cations and crystallization H2O molecules are located. The structures of M[Cu(H2O)4]InF6·nH2O (M = Rb, Cs, NH4; n = 0, 1) are a new structure type.

Synergistic Effects of Nanoparticles and Polymers on Depletion and Structural Interactions

An experimental study was performed to investigate the synergistic effects of two different solution components on the depletion and structural forces between colloidal particles. Using silica nanoparticles and anionic poly(acrylic acid) polymer, it was found that the depletion and structural forces measured between a 30 μm diameter silica sphere and a flat silica plate (obtained using colloidal probe atomic force microscopy) were substantially greater than the sum of the forces obtained in systems containing only nanoparticles and only polymer. This result arises because the anionic polymer chains adsorb to the nanoparticles, creating a complex that is over twice as large as either component. Although the number density of depletants decreases with such complexation, the larger size results in much greater forces at longer ranges. In addition, the measured force profiles could be well described using a force model in which all components were treated as hard, charged spheres. The results clearly indicate that predicting the depletion force in systems with multiple depletant components, such as the one used here, can be much more complicated than simply adding the forces contributed from each component independently.

Surface Modification Method for Adhesion of Gels

Abstract We successfully realized the adhesion of cationic gels in aqueous solution by a method of surface modification with an anionic polymer chain. The adhesion force of the gel, which originates in the electrostatic interaction between the cationic gel surface and anionic polymer chain, is controlled by the solution pH because poly(acrylic acid) with –COO− and poly(N,N′-dimethylaminopropylacrylamide) gel with –NH+(CH3)2 were used. With the proposed method, we can select the electric charge of each gel surface to adhere to anionic or cationic gels.

Effect of Polacrilin Potassium as Disintegrant on Bioavailability of Diclofenac Potassium in Tablets : a Technical Note

Polacrilin potassium is an ion exchange resin used in oral pharmaceutical formulations as a tablet disintegrant. It is a weakly acidic cation exchange resin. Chemically, it is a partial potassium salt of a copolymer of methacrylic acid with divinyl benzene. It ionizes to an anionic polymer chain and potassium cations. It was hypothesized that polacrilin potassium may be able to improve the permeability of anionic drugs according to the Donnan membrane phenomenon. The effect of polacrilin potassium on the permeability of diclofenac potassium, used as a model anionic drug, was tested in vitro using diffusion cells and in vivo by monitoring serum levels in rats. The amount of drug permeated across a dialysis membrane in vitro was significantly more in the presence of polacrilin potassium. Significant improvement was found in the extent of drug absorption in vivo. It could be concluded that polacrilin potassium may be used as a high-functionality excipient for improving the bioavailability of anionic drugs having poor gastrointestinal permeability.

Easy-dispersible poly(glycidyl phenyl ether)-functionalized graphene sheets obtained by reaction of “living” anionic polymer chains

Excellent dispersion of functionalized graphene (FG) sheets in polystyrene was achieved relying on the reaction of "living" poly(glycidyl phenyl ether) chains onto graphene sheets. The physical aging of polystyrene was substantially accelerated by the presence of FG sheets at low filler content, retaining film transparency and increasing the electrical conductivity.

Kinetics of Living Anionic Polymerization of Polystyrenyl Lithium in Cyclohexane

Living anionic polymer chains polymerized with organolithium initiators usually form aggregates through their Li ends in nonpolar solvents. This aggregation structure strongly affects the anionic polymerization (propagation) kinetics. In the conventional molecular picture, the aggregates are assumed to be chemically inert and the propagation occurs only though the dissociated unimers, which leads to single-exponential decay of the residual monomer fraction φ(t) with time t. This picture was tested by 1H NMR measurements for protonated polystyrenyl lithium (hPSLi) polymerized in a nonpolar solvent, deuterated cyclohexane (dCH). The measurements were made mostly at 34.5 °C, the theta condition for neutral (non-anionic) high-M hPS. An oligomeric, deuterated styrenyl lithium (oSLi) was utilized as an initiator so that the NMR data exclusively detected the propagation kinetics (no contamination of the initiation process). For hPSLi with the molecular weight ranging from 4.2×103 to 276×103, φ(t) was found to exhibit almost single-exponential decay at short t (where φ(t)>10–20%) but the decay slowed at longer t (for smaller φ(t)). Furthermore, φ(t) decayed more slowly when the polymerization batch contained neutral, deuterated dPS (not affecting the hPSLi chemistry) at a concentration in the semi-dilute regime. These results indicated the failure of the conventional molecular picture assuming the chemical inertness of the aggregates. Consequently, some (unstable) aggregates appeared to contribute to the propagation, and the osmotic interaction among the aggregates as well as with the coexisting dPS seemed to reduce this contribution at long t thereby giving the non-single-exponential decay of φ(t). A simple kinetic model considering this osmotic effect consistently described the behavior of φ(t) in the absence/presence of dPS for the polymerization of hPS in a range of 10−3M=11–73, although deviations were noted for the polymerization of lower- and higher-M hPS.

Asymmetric and mikto-arm stars with a C60 core by grafting of macro-radicals or anionic polymer chains

Asymmetric and mikto-arm stars were synthesized by the stepwise addition of macro-radicals or of anionic polymer chains onto C60. Pure di-adducts (PSa)2C60 were obtained by atom transfer radical addition of a Br-terminated polystyrene (PSaBr). Tetra-adducts (PSa)2C60(PSb)2 and (PSa)2C60(PI)2 were prepared by grafting, respectively, two additional PSbBr or PIBr onto (PSa)2C60. The addition of ‘living’ polystyryllithium onto C60 can be stoichiometrically controlled. For example, the reaction of four PSaLi with one C60 led to the formation of (PSa)4C604−(Li+)4. The additional grafting of polystyryllithium (PSbLi) or polyisoprenyllithium (PILi) provided, respectively, (PSa)4C60(PSb)2 and (PSa)4C60(PI)2. All the stars were characterized using multiple detectors size exclusion chromatography (SEC).

Novel heterometallic Cu/Cd complex containing a unique polymeric ladder-like anion [Cd 2(O 2CMe) 6] 2−n derived from elemental copper and cadmium oxide

Copper powder reacts with cadmium oxide and ammonia acetate in methanol solution of ethylenediamine affording {[Cu(en) 2][Cd 2(O 2CMe) 6]} n in which seven-coordinated cadmium atoms are ligated by three bonding modes of acetate groups forming ladder-like anions [Cd 2(O 2CMe) 6] 2− n . The cations [Cu(en) 2] 2+ are located in the lattice and serve as bridges to connect separate anionic polymer chains into a two- dimensional network via hydrogen bonds.

Coil-Ring-Coil Block Copolymers as Building Blocks for Supramolecular Hollow Cylindrical Brushes.

Solvent-induced self-assembly of oligomer-substituted shape-persistent macrocycles leads to the formation of cylindrical aggregates, which have been fully characterized in solution. These aggregates, bound by nonspecific interactions, can be described as supramolecular hollow polymer brushes.

Recent Advances in Anionic Synthesis of Functionalized Polymers

Abstract There has been growing interest and research on new synthetic methods for the preparation of well-defined polymers with in-chain and chain-end functional groups. These functional groups in polymers can participate in (a) reversible ionic association; (b) chain extension, branching or crosslinking reactions with polyfunctional reagents; (c) coupling and linking with reactive groups on other oligomer or polymer chains; and (d) initiation of polymerization of other monomers. It is noteworthy that the use of end-functionalized polybutadienes formed by reaction of poly(butadienyl)lithium with 4,4′-bis(diethylamino)-benzophenone has been reported to provide marked improvements in the wear and traction properties of tires. In order to exploit the unique potential of functionalized polymers, it is important to consider the scope and limitations of current functionalization methodology using anionic polymerization. Anionic polymerization approaches the goal of synthesizing polymers with predictable, well-defined structures in certain systems such as diene, styrene, methacrylate, and heterocyclic monomers, which proceed in the absence of chain termination and chain transfer reactions. These living polymerizations generate stable, anionic polymer chain ends when all of the monomer has been consumed. In principle, these anionic chain ends can react with a variety of electrophilic species to generate a diverse array of functional groups. Unfortunately, many of the reported functionalization reactions have not been well characterized. Another limitation of the use of specific electrophilic functionalization reactions is the necessity of developing, optimizing, and characterizing new procedures for each different functional group. Variables such as chain-end structure, solvent, temperature, concentration, stoichiometry, mode of addition of reagents, and polar additives can have dramatic effects on yield and product distributions. This review will first provide a critical overview of some recent developments in the use of specific functionalization reactions to prepare polymers labeled with carboxyl, hydroxyl, amino, and sulfonate end groups via alkyllithium-initiated polymerization methods. In addition, a recently developed methodology will be described which utilizes the addition reactions of organolithium compounds to substituted 1,1-diphenylethylenes as a general, quantitative functionalization reaction, independent of the specific functional group.