Water-soluble Polyelectrolyte Research Articles

A bio-resourced phytic acid/chitosan polyelectrolyte complex for the flame retardant treatment of wool fabric

A water-soluble polyelectrolyte complex (PEC) consisting of bio-resourced phytic acid and chitosan was fabricated at pH 1.3 and used to improve the flame retardancy of wool fabric by the repeated coating technique. Citric acid was used as a solvent for chitosan and a cross-linker. The PEC coated wool fabric was treated in a pH 4 buffer solution to yield a water-insoluble coating on the fabric surface. The flame retardant efficiency and durability to washing of the PEC coating on wool fabric were discussed. The growing deposit times with the PEC caused an increase in flame retardancy of wool fabric. One coating deposition with the PEC consisting of 10% phytic acid and 2% chitosan effectively ceased the fabric burning. Five depositions could still extinguish the flame on the fabric after ten washings, indicating good washing durability of the treated wool. Both the insolubilization treatment of the PEC coating and the cross-linking action of citric acid between chitosan and wool fiber were highly beneficial to the appreciable washing durability. The morphological structure of char residues revealed a significant intumescent charring mechanism for the treated wool. This study reveals that the PEC coating by bio-resourced materials can be used to prepare flame retardant wool textiles, and exhibits less processing steps and lower cost than the layer by layer assembly.

Synthesis and scale-up of water-soluble quaternary cationic monomers in a continuous flow system

A novel, simple, power-saving and effective method for the synthesis and scale-up of cationic water-soluble polyelectrolytes represented by dimethyldiallylammonium chloride (DMDAAC) with commercially available reagents in a two-step continuous flow system has been developed.

Ultrafiltration membranes with three water-soluble polyelectrolyte copolymers to remove ciprofloxacin from aqueous systems

Water pollution is a serious problem throughout the world, and antibiotics released into the aquatic environment produce harmful effects on the ecosystem and human health. In this investigation, the elimination of ciprofloxacin (CIP) by the retention technique based on polymers in liquid phase was evaluated using three soluble polyelectrolyte copolymers with different charge ratios: poly[3-(methacryloylamino) propyl] dimethyl (3-sulfopropyl) ammonium hydroxide-co-(4-(vinylbenzyl) trimethylammonium chloride]] (CP1), poly[3-(methacryloylamino) propyl]dimethyl (3-sulfopropyl) ammonium sodium-4-styrenesulfonate] (CP2) hydroxide, and poly[3-(acryloylamino)) propyl] trimethylammonium chloride-co-sodium 4-styrenesulfonate] (CP3). The copolymers were synthesized via free radical polymerization with reaction yields of 93%, 84%, and 60% respectively. Additionally, the reactivity coefficients of the monomers were 0.40, 0.34, and 0.36 respectively. The parameters investigated included pH, ionic strength, optimal polymer concentration, and maximum retention capacity. An efficient retention of ciprofloxacin (80%) was observed with a polymer/CIP molar ratio of 20:1 at pH 5.0 for CP2 and CP3. The maximum ciprofloxacin retention capacity (MRC) was determined through the enrichment method, demonstrating that the copolymer CP3 showed the highest retention capacity and the lowest desorption with respect to the other polyelectrolyte copolymers.

Polyelectrolytes Efficiency in Grout Property Regulation

Relevance of this study is concluded in the fact that high quality cementing requires regulation of the cement grouts’ properties using various chemicals. The objective of the work is based on the study of polyelectrolytes’ application efficiency used for regulation of cement slurries’ properties. In order to conduct the research the authors used the devices meeting the API requirements. Properties of cement slurry and cement were evaluated according to GOST 1581-96. In order to study the gas show emergence mechanism during the procedure of WOC (waiting on cement), the authors used a special experimental plant. It has been found that high efficiency during the research was shown by water soluble cationic polyelectrolyte (WSC-402), belonging to the class of cationic polymers. Also the paper considers its analog – cationic polyelectrolyte (PAK) released under the trade mark Praestol. Studying the mechanism of polyelectrolyte additives’ effect on cement showed that the chemicals can slow down the hydrating reaction of С3А in cement-water suspension, and prevent from the growth of gel strength of the grout, which causes drop in hydrostatic pressure of the cement grout column, provoking gas shows.

An eco‐friendly water‐soluble fluorene‐based polyelectrolyte as interfacial layer for efficient inverted polymer solar cells

A conjugated polyelectrolyte poly(9,9‐bis(3′‐[(N,N‐dimethyl)‐N‐ethylammonium]‐propyl)‐2,7‐fluorene dibromide) (PFBr) with the feature of environmental friendliness and cheapness was successfully used in polymer solar cells (PSCs) as the cathode interfacial layer (CIL). And we successfully demonstrate that the PFBr can build interfacial dipoles at the CIL/cathode interfaces, leading to reduce cathode work functions and improve open‐circuit voltages, which decrease interfacial energy loss at the cathode. It not only improves the electron transfer efficiency but also inhibits the charge carrier recombination at the contact interface. Impedance spectra revealed that the optimal device with the smallest charge transport time constant of 2.83 microseconds was achieved under the concentration of 2 mg mL−1 of PFBr, which suggests efficient electron transport on the interface between the organic active layer and the indium tin oxide cathode. Moreover, as a consequence, the power conversion efficiency of the PSCs increases to 3.83% (with PFBr as CIL) from 1.89% (without any CIL), based on the poly(3‐hexylthiophene) and [6,6]‐phenyl C61‐butyric acid methyl ester bulk heterojunction active layer. Therefore, our observation can demonstrate PFBr is a prospective candidate as CIL for constructing low‐cost, large‐area, and flexible PSCs.

Electrostatic and Hydrophobic Interactions in NaCMC Aqueous Solutions: Effect of Degree of Substitution

The rheology of water-soluble polyelectrolytes at intermediate and high concentrations is controlled by entanglement, hydrophobic, and electrostatic interactions, whose influences are difficult to isolate. We investigate the rheology of semidilute solutions of sodium carboxymethyl cellulose (NaCMC) with molecular weight Mw ≃ 2.5 × 105 g/mol and varying degree of substitution (DS) as a function of polymer concentration in various solvent media: salt-free water (long-ranged electrostatic interactions), 0.5 M aqueous NaCl (screened electrostatics), and 0.5 M aqueous NaOH (screened electrostatics, diminished hydrophobic interactions) in order to selectively examine the role played by these different interactions. Decreasing DS is found to decrease solubility and induce partial aggregation and eventual gelation. In salt-free and 0.5 M NaCl solution, NaCMC with DS ≃ 1.2 exhibits hydrophilic polyelectrolyte and neutral polymer in good solvent behavior, respectively. Decreasing DS to ≃0.7–0.8 leads to hydrophobic...

Green synthesis of antimicrobial and antitumor N,N,N-trimethyl chitosan chloride/poly (acrylic acid)/silver nanocomposites

The present study is imported to solve two critical problems we face in our daily life which are microbial pollution and colon cancer. One pot green synthesis of a water soluble polyelectrolyte complex (PEC) between cationic polysaccharide as N,N,N-trimethyl chitosan chloride (TMC) and anionic polymer as poly (acrylic acid) (PAA) in presence of silver nanoparticles to yield (TMC/PAA/Ag) nanocomposites with different Ag weight ratios. Structure of TMC, PAA and TMC/PAA (PEC) were proved via different analysis tools. TMC/PAA and its Ag nanocomposites are used as antimicrobial agents against different pathogenic bacteria and fungi to solve microbial pollution. TMC/PAA-Silver nanocomposites had the highest antimicrobial activity which increases with increasing Ag %. Cytotoxicity data confirmed also that TMC/PAA/Ag (3%) had the most cytotoxic effect (the less cell viability %) towards colon cancer. TMC/PAA (PEC) was formed through electrostatic interactions between N-quaternized (-N+R3) groups in TMC and carboxylate (-COO−) groups in PAA.

Biocatalytically synthesized of water-soluble alkoxysulfonate-functionalized poly(3,4-ethylenedioxythiophene)

A photoelectric material poly(3,4-ethylenedioxythiophene)sulfonate (PEDOT-S) with better water-soluble ability was synthesized by the enzymatic-catalyzed method using sodium 4-(2,3-dihydrothieno [3,4-b] [1,4]dioxin-2-yl)-methoxybutane-1-sulfonate (EDOT-S) as monomer, horseradish peroxidase (HRP) enzyme as catalyst, and hydrogen peroxide (H2O2) as oxidant. This enzymatic-catalyzed polymerization is a “green synthesis process” for the synthesis of water-soluble conjugated PEDOT-S, which was carried out with no organic solvent, no water-soluble polyelectrolyte such as polystyrenesulfonate (PSS), no metallic catalyst and no high reaction temperature. UV-Vis spectrum of PEDOT-S changing immediately on varying the pH of the solution showed that the self-acid-doping had occurred. Thermogravimetric (TG) analyses indicated the presence of a stable form of polymer. Atomic force microscopy(AFM) images illustrated that the acid PEDOT-S aqueous solution can form excellent homogeneous and smooth films, while the basic aqueous solution induces the aggregation of polymer.

Ultrasonik Ses Dalgası Ortamında Polielektrolit Varlığında Kalsiyum Karbonat Sentezi, Karakterizasyonu ve Deneysel Tasarım

In this study, calcium carbonate (CaCO 3 ) was synthesized by means of ultrasonic irradiation process in the presence of the water-soluble polyelectrolyte Poly(Vinyl Sulfonic Acid) (PVS). Synthesized CaCO 3 crystals were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), particle size and thermal analysis (TGA-DTA). The effects of the amplitude of sonicator, polymer concentration and the application time of ultrasound on the obtained CaCO 3 with respect to particle size of final product was investigated by applying the 2 k Factorial design. The experimental design was studied at two levels. All the selected process parameters were found to be very effective on the particle size of calcium carbonate obtained in the presence of PVS.

Layer-By-Layer Self-Assembly of Polyelectrolytic Block Copolymer Worms on a Planar Substrate.

Cationic and anionic block copolymer worms are prepared by polymerization-induced self-assembly via reversible addition–fragmentation chain transfer (RAFT) aqueous dispersion copolymerization of 2-hydroxypropyl methacrylate and glycidyl methacrylate (GlyMA), using a binary mixture of a nonionic poly(ethylene oxide) macromolecular RAFT agent and either a cationic poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) or an anionic poly(potassium 3-sulfopropyl methacrylate) macromolecular RAFT agent. In each case, covalent stabilization of the worm cores was achieved via reaction of the epoxide groups on the GlyMA repeat units with 3-mercaptopropyltriethoxysilane. Aqueous electrophoresis studies indicated a pH-independent mean zeta potential of +40 mV and −39 mV for the cationic and anionic copolymer worms, respectively. These worms are expected to mimic the rigid rod behavior of water-soluble polyelectrolyte chains in the absence of added salt. The kinetics of adsorption of the cationic worms onto a planar anionic silicon wafer was examined at pH 5 and was found to be extremely fast at 1.0 w/w % copolymer concentration in the absence of added salt. Scanning electron microscopy (SEM) analysis indicated that a relatively constant worm surface coverage of 16% was achieved at 20 °C for adsorption times ranging from just 2 s up to 2 min. Furthermore, the successive layer-by-layer deposition of cationic and anionic copolymer worms onto planar surfaces was investigated using SEM, ellipsometry, and surface zeta potential measurements. These techniques confirmed that the deposition of oppositely charged worms resulted in a monotonic increase in the mean layer thickness, with a concomitant surface charge reversal occurring on addition of each new worm layer. Unexpectedly, two distinct linear regimes were observed when plotting the mean layer thickness against the total number of adsorbed worm layers, with a steeper gradient (corresponding to thicker layers) being observed after the deposition of six worm layers.

Aqueous size-exclusion chromatography of polyelectrolytes on reversed-phase and hydrophilic interaction chromatography columns

The size-exclusion separation of a water-soluble polyelectrolyte polymer, sodium polystyrene sulfonate (NaPSS), was demonstrated on common reversed-phase (C18, C4, phenyl, and cyano) and hydrophilic interaction chromatography (HILIC) columns. The effect of common solvents – acetonitrile (ACN), tetrahydrofuran (THF), and methanol (MeOH), used as mobile phase modifiers – on the elution of NaPSS and the effect of column temperature (within a relatively narrow range corresponding to typical chromatographic conditions, i.e., 10 °C–60 °C) on the partition coefficient, KSEC, were also investigated. Non-size-exclusion chromatography (non-SEC) effects can be minimized by the addition of an electrolyte and an organic modifier to the mobile phase, and by increasing the column temperature (e.g., to 50 °C or 60 °C). Strong solvents such as THF and ACN are more successful in the reduction of such effects than is the weaker solvent MeOH. The best performance is seen on medium polarity and polar stationary phases, such as cyanopropyl- and diol-modified silica (HILIC), where the elution of the NaPSS polyelectrolyte is by a near-ideal SEC mechanism. Hydrophobic stationary phases, such as C18, C4, and phenyl, require a higher concentration of a strong solvent modifier (THF) in the mobile phase to reduce non-SEC interactions of the solute with the stationary phase.

Biologically active polymer nanosystems.

The methods of synthesis of biologically active nanostructured systems based on functional and natural polymers are reviewed. The formation of nanosystems in the process of interaction between synthetic water-soluble polyelectrolytes and amphiphilic ionic surfactants is discussed. The influence of structure and stability of these systems on their biological activity is considered. The complexation between DNA and polycations with the formation of compacted DNA molecules, and the transport of resulting complexes into the cells are discussed. The data on nanostructuring of hemoglobin using polyfunctional crosslinkers and the data on the use of the obtained nanoparticles as oxygen-transporting blood substitutes are summarized. Using nanodisperse silver stabilized with poly(vinylpyrrolidone) as an example it was demonstrated, that transferring silver into nanodisperse state results in widening its bioactivity.

Polyelectrolyte effect on spectrophotometric determination and interaction of scandium (III) with eriochromcyanine

The influence of cationic water-soluble polyelectrolyte PSPMG on the interaction of scandium (III) with organic reagent eriochromcyanine is studied. Because the study of the possibility of obtaining new, more effective, modified reagents with a complex of better analytical characteristics is an actual analytical task. The optimal conditions of complex formation were experimentally determined: the pH range (5.5–6.5), the order of the adding of the components (1 – scandium, 2 – ECR, 3 – PSPMG, 4 – buffer solutions), the composition of the Sc-ECR-PSPMG complex (1:4:1) were experimentally determined and the molar absorption coefficient – 1.8·10 5 was calculated. A sensitive spectrophotometric method for scandium determination in solutions at the level of 10 -7 mol/L was developed. The optimal scandium sorption parameters in the form of three-component systems Sc-OR-modifier on solid-state carriers were established, scandium sorption isotherms were constructed, sorption parameters of A gran and K ads were calculated. The test systems for the identification of scandium as ternary compounds in polyurethane foam and cotton were proposed, calibration curves in the concentration range from 1·10 -6 –1·10 -5 mol/L were built and the colorimetric method of identification of scandium in solutions that accelerate analysis was proposed. It is shown that the PSPMG application is a promising direction for improvement of chemical-analytical characteristics of organic reagents (eriochromcyanine and chromazurol S) because its usage increases the sensitivity and selectivity of the spectrophotometric determination of scandium in the form of a complex Sc-OR-PSPMG.

Polycomplexes of Bovine Serum Albumin with Poly[2-Methacryloyloxy) Ethyl]Trimethyl Ammonium Chloride

Complex formation between bovine serum albumin and water-soluble synthetic cationic polyelectrolyte poly[2-methacryloyloxy)ethyl]trimethyl ammonium chloride has been studied in aqueous solutions by turbidimetric and viscometric methods. It was found that the structure of polycomplex is compact and its stability strongly depends on the environment. Formation of insoluble polycomplexes is observed in solutions with low ionic strength and pH, higher than 5.0. This pH value corresponds to the isoelectric point of the protein, so at lower pH the biopolymer macromolecules gain the positive charge and not able to be bound by the positively charged macromolecules of poly[2-methacryloyloxy)ethyl]trimethyl ammonium chloride. An increase of pH within 5.0-11.0 leads to further stabilization of polycomplex because of appearance of additional negative charges on biomacromolecules, caused by ionization of acidic groups. It was found that the main forces, which are responsible for the complexation, are electrostatic interactions.<br />The intensity of the complexation is dependent on the solution concentration, pH and ionic strength. In solutions with high ionic strength (I=0.2, 1.0) the mixing of the reagents does not lead to the formation of insoluble polycomplexes. The observed dependence is connected with the screening of electrostatic interactions between macromolecules of the biopolymer and synthetic polyelectrolyte by small ions present in solution.

Probing Co-Assembly of Supramolecular Photocatalysts and Polyelectrolytes Using Isothermal Titration Calorimetry.

The creation of renewable fuels to replace dwindling fossil energy resources is one of the greatest challenges facing the scientific community. Generating H2 fuel from water is a carbon-neutral strategy that demonstrates great promise. Photocatalysts of the molecular architecture [{(TL)2Ru(BL)}2RhX2]5+ (BL = bridging ligand, TL = terminal ligand, X = halide) catalyze the formation of H2 in deoxygenated organic solvents but are limited by poor performance in air-saturated aqueous solutions. Addition of the water-soluble polyelectrolyte poly(sodium 4-styrenesulfonate) (PSS) was recently shown as being a promising new strategy to increase efficiency and stability of H2 evolving photocatalysts in air-saturated aqueous solutions. Herein we investigate intermolecular interactions between Ru,Rh,Ru photocatalysts and water-soluble polyelectrolytes using isothermal titration calorimetry (ITC). ITC studies provide insight into the thermodynamic forces that drive assembly of PSS-photocatalyst aggregates and give new evidence for the intermolecular forces that lead to increased photocatalytic efficiency.

Sewage cleaning from copper ions with the method of complex formation and ultrafiltration

The paper presents the results of the studies on determination of optimal conditions for application of the complexation / ultrafiltration method for sewage cleaning from the heavy metal of copper with the use of potassium ferrocyanides and a water-soluble polyelectrolyte. The effectiveness of this method is proved experimentally.

Thermally Reversible Physically Cross-Linked Hybrid Network Hydrogels Formed by Thermosensitive Hairy Nanoparticles.

This Article reports on thermally induced reversible formation of physically cross-linked, three-dimensional network hydrogels from aqueous dispersions of thermosensitive diblock copolymer brush-grafted silica nanoparticles (hairy NPs). The hairy NPs consisted of a silica core, a water-soluble polyelectrolyte inner block of poly(2-(methacryloyloxy)ethyltrimethylammonium iodide), and a thermosensitive poly(methoxydi(ethylene glycol) methacrylate) (PDEGMMA) outer block synthesized by sequential surface-initiated atom transfer radical polymerizations and postpolymerization quaternization of tertiary amine moieties. Moderately concentrated dispersions of these hairy nanoparticles in water underwent thermally induced reversible transitions between flowing liquids to self-supporting gels upon heating. The gelation was driven by the lower critical solution temperature (LCST) transition of the PDEGMMA outer block, which upon heating self-associated into hydrophobic domains acting as physical cross-linking points for the gel network. Rheological studies showed that the sol-gel transition temperature decreased with increasing hairy NP concentration, and the gelation was achieved at concentrations as low as 3 wt %.

Ultrasensitive aptamer biosensor for malathion detection based on cationic polymer and gold nanoparticles

In this work, we have demonstrated a novel sensing strategy for an organophosphorus pesticide namely, malathion, employing unmodified gold nanoparticles, aptamer and a positively charged, water-soluble polyelectrolyte Polydiallyldimethylammonium chloride (PDDA). The PDDA when associated with the aptamer prevents the aggregation of the gold-nanoparticles while no such inhibition is observed when the aptamer specific pesticide is added to the solution, thereby changing the color of the solution from red to blue. This type of biosensor is quite simple and straightforward and can be completed in a few minutes without the need of any expensive equipment or trained personnel. The proposed method was linear in the concentration range of 0.5–1000pM with 0.06pM as the limit of detection. Moreover, the proposed assay selectively recognized malathion in the presence of other interfering substances and thus, can be applied to real samples for the rapid screening of malathion.

Synthesis, photophysical studies and 1O2 generation of ruthenium phthalocyanine dendrimers

A series of ruthenium phthalocyanine centered dendrimers has been prepared with up to 32 ethyl ester end groups. The photophysical properties have been assessed in THF to reveal a correlation between the degree of dendritic environment and the ability to generate singlet oxygen. In the attempt to prepare the correponding highly water-soluble polyelectrolyte dendrimers upon saponification we observed the cleavage of the central esters moieties adjacent to the pyridine unit in all cases. However, despite the lack of shielding by a growing branched shell surrounding the photoactive center, the obtained tetracarboxylate-terminated ruthenium phthalocyanine derivative was still able to generate singlet oxygen in aqueous medium.

Surface - Active and Complexforming Copolymers of Sodium 2-acrylamido-2-methylpropanesulfonate with Ethyleneglycol Vinyl Ether

<p>A new water-soluble polyelectrolyte - the copolymer of sodium 2-acrylamido-2-methylpropanesulfonate and ethylene glycol vinyl ether has been synthesized by free-radical copolymerization in aqueous medium. Synthesis of the linear structure water-soluble copolymer of sodium 2-acrylamido-2-methylpropanesulfonate (Na-AMPS) and ethylene glycol vinyl ether (EGVE) has been confirmed by IR spectroscopy method, potentiometric titration and viscometer. The concentration behavior of the reduced viscosity of copolymer solutions that is typical for polyelectrolytes has been revealed. The reactivity ratios for the copolymerization of the monomers estimated by the Mayo–Lewis method have indicated lower reactivity of ethylenglycol vinyl ether in comparison with sodium 2-acrylamido-2-methylpropanesulfonate. Also it was shown the decrease of reaction’s relative rate with an increase of molar fraction of EGVE in the initial mixture of monomers. Adsorption at the air-water solution interface was studied by measure of surface tension (σ) in order to determine the surface properties of new copolymers of ethyleneglycol vinyl ethers – sodium 2-acrylamido-2-methylpropanesulfonate. It was shown that copolymers of sodium 2-acrylamido-2-methylpropanesulfonate and ethylenglycol vinyl ether have higher surface activity compared to sodium 2-acrylamido-2-methylpropanesulfonate homopolymer. The isotherm of copolymer’s surface tension based on equilibrium value of σ was constructed together with the isotherm of surface tension water solution poly- Na-AMPS. Based on isotherms the surface activity on Rebinder (G<sub>Re</sub>) for poly- Na-AMPS and copolymer Na-AMPS-EGVE was determined. The values of polymer’s standard free energy of adsorption (Δ<sub>ads</sub>G<sup>0</sup><sub>298</sub>) were calculated in order to identify the causes and mechanism of change in surface activity and adsorption. Results show that the gain in standard free energy adsorption in the transition from homopolymer to copolymer Na-AMPS-EGVE is about 4 kJ/base-mole. Interpolymer reaction of the Na-AMS–EGVE copolymer with poly- <em>N,N</em>-dimethyl-<em>N,N</em>-diallylammonium chloride (PMAAC) has been studied. Higher surface activity of mixtures of copolymer and PMAAC than of individual polyelectrolytes was discovered. This effect testified to the formation of interpolymer complex of the Na-AMS–EGVE copolymer with polycations due to electrostatic interactions.</p>