Polymer Charge Density Research Articles

Sticky Science: Using Complex Coacervate Adhesives for Biomedical Applications.

Tissue adhesives are used for various medical applications, including wound closure, bleeding control, and bone healing. Currently available options often show weak adhesion or cause adverse effects. Recently, there has been an increasing interest in complex coacervates as medical adhesives. Complex coacervates are formed by mixing oppositely charged macromolecules that associate and undergo liquid-liquid phase separation, in which the dense bottom phase is the complex coacervate. Complex coacervates are strong and often biocompatible, and show strong underwater adhesion. The properties of the resulting materials are tunable by intrinsic factors such as polymer chemistry, molecular weight, charge density, and topology of the macromolecules, as well as extrinsic factors such as temperature, pH, and salt concentration. Therefore, complex coacervates are interesting new candidates for medical adhesives. In this review, it is described how complex coacervates form and how different factors influence their behavior. Next, an overview of recent studies on complex coacervates in the context of medical adhesives is presented. The application of complex coacervates as hemostatic or embolic agents, skin or bone repair adhesives, and soft tissue sealants is discussed. Lastly, additional possibilities for utilizing these materials in the future are discussed.

Quantifying Dielectric Material Charge Trapping and De-Trapping Ability Via Ultra-Fast Charge Self-Injection Technique.

Recently, utilizing the air breakdown effect in the charge excitation strategy proves as an efficient charge injection technique to increase the surface charge density of dielectric polymers for triboelectric nanogenerators (TENGs). However, quantitative characterization of the ability of dielectric polymers to trap reverse charges and the effect on the startup time of secondary self-charge excitation (SSCE) are essential for extensive applications. Here, an ultra-fast charge self-injection technique based on a self-charge excitation strategy is proposed, and a standard method to quantify the charge trapping and de-trapping abilities of 23 traditional tribo-materials is introduced. Further, the relationship among the distribution of dielectric intrinsic deep, shallow trap states, and transportation of trapped charges is systematically analyzed in this article. It shows that the de-trapping rate of charges directly determines the reactivation and failure of SSCE. Last, independent of TENG contact efficiency, an ultra-high charge density of 2.67 mC m-2 and an ultra-fast startup time of SSCE are obtained using a 15µm poly(vinylidene fluoride-trifluoroethylene) film, breaking the historical record for material modification. As a standard for material selection, this work quantifies the charge trapping and de-trapping ability of the triboelectric dielectric series and provides insights for understanding the charge transport in dielectrics.

A fast electron-injection strategy for enhancing triboelectric surface charge density of polymers

Surface charge density regulation has been used for diverse range of applications. As a newly emerged high-efficiency energy converter, triboelectric nanogenerator (TENG) is sensitive to the surface charge density, making triboelectric polymers with high charge density crucial for expanding the range of TENG applications. Direct charge injection is an efficient strategy to boost output performance of TENG. However, it traditionally requires a high voltage (about 10 kV) and an injection period over minutes. The fast (<1 s) and low-voltage (< 3 kV) electron-injection process in this study for a contact-separate nanogenerator yields an output charge density of 252 μC·m−2, which is twice as large as that of the pristine device. The provided strategy can be applied to various polymers, providing opportunities for investigations in multi-science fields, not just limited to TENGs.

Polyquaternium polymers cause inflammatory response and alterations of the lipidome in Danio rerio larvae

Polyquaternium polymers are widely used in various applications, such as personal care products and wastewater treatment plants, and eventually end up in the aquatic environment. While polymers have been perceived of low toxicological concern due to their size, several studies have pointed towards water-soluble cationic polymers being toxic towards aquatic organisms – and that the toxicity largely is determined by the polymer charge density. The present study investigated the polyquaternium toxicological mechanism of action throughout lipidomic analysis and changes in immune-gene expression (qPCR) of zebrafish larvae exposed continuously to two water-soluble polymers; a high charge density polyquaternium-6 and a low charge density polyquaternium-10, for 5 and 12 days upon fertilization. The results showed that the investigated polyquaterniums cause both inflammatory responses and significant alterations of the zebrafish larvae lipidome. Depending on polyquaternium polymer and larvae development stage, the gene expression showed an inflammatory response (e.g. significant up-regulation of il8, il1β and tnfα) in the exposed zebrafish. Alterations of the lipidome were additionally observed, with severe depletion of lipids (e.g. lyso-glycerophosphocholines and ceramides) in the 12 days old larvae exposed to high charge density polymer. The findings furthermore support a hypothetical mechanism of action to be non-specific and lethality potentially to be narcosis-like driven.

Optimization on crystallization process of the magnetic core lysozyme

The continuous growth of the biomedical market highlights the significance of improvement in the efficiency of batch production for protein drug crystals. Herein, we investigated the effect of polymer-modified Fe3O4 nanoparticles on lysozyme (Lys) crystallization at different conditions, using functionalized Fe3O4 magnetic nanoparticles (Polymer C@Fe3O4) as nucleation agents. The study revealed that the surface charge density of Polymer C@Fe3O4 was highest at a modification mass ratio of Fe3O4 to Polymer C is 8:3. This ratio facilitates the augmentation of electrostatic interaction and the promotion of crystallization. By adding 15% of the PolymerC@Fe3O4 prepared from Fe3O4 with an average particle size of 150 nm, the magnetic core lysozyme (M-Lys) crystals with an average particle size of 11.08 μm, narrow size distribution, and regular morphology were obtained in a yield of 82.42% within 60 min.

Enhanced piroctone olamine retention from shampoo for superior anti-dandruff efficacy.

Dandruff is a pervasive chronic condition which negatively impacts quality of life. Effective treatment requires efficient delivery of scalp benefit agents that control commensal scalp Malassezia levels. Delivery of benefit agents from shampoos requires balancing many technical parameters to achieve the desired outcome without sacrificing secondary parameters, such as cosmetic attributes. To develop formulation technologies that increase the shampoo delivery efficiency of the scalp benefit agent piroctone olamine (PO). Increased delivery should result in increased anti-dandruff efficacy. Micellar Stability and Association parameters were quantified via dynamic surface tension and nuclear magnetic resonance (NMR) diffusion parameters, respectively. PO delivery has been assessed in vivo both on the scalp surface and follicular infindibula using extraction procedures and analytical analysis. Clinical anti-dandruff efficacy was assessed for an advanced delivery technology prototype in comparison to standard delivery technology. Shampoo prototypes have been developed that increase the delivery efficiency of PO. Both surfactant and polymer coacervate-based approaches have been developed. Decreased micellar stability results in weaker association between PO and micelles, resulting in more efficient PO retention on the scalp surface and delivery to the infundibula. Increased charge density of cationic polymers optimizes coacervation enabling improved PO delivery as well. Increased PO delivery has been shown clinically to result in higher anti-dandruff efficacy as measured by both visible flakes and underlying biomarkers. Increased efficiency PO delivery shampoos have been developed by optimization of both surfactant and coacervate parameters. The increased deposition efficiency results in significantly more products with significantly greater anti-dandruff efficacy.

Anionic Copolymers with Different Charge Densities for Regulating the Properties of Cement Pastes.

Self-compacting concrete (SCC) is an extremely flowable concrete, which increases the probability of segregation and bleeding. Viscosity-modifying admixtures (VMAs) have been developed to improve the stability of SCC. Synthetic polymer VMAs have excellent water solubility and stability, and can be easily chemically prepared and modified. In this work, a series of copolymers based on anionic 2-acrylamido-2-methyl-propanesulfonic acid (AMPS) and nonionic N, N-dimethyl acrylamide (DMAA), with similar molecular weights but different charge densities, were prepared. The effect of the charge density of the anionic polymers on the fluidity, rheological property, and adsorption behavior of the cement pastes was investigated. The action mechanism of the polymers was discussed. The results indicate that the charge density of anionic polymer VMAs is of great significance for the development of cost-effective SCCs with good rheological properties.

Ionic poly(dimethylsiloxane)–silica nanocomposites: Dispersion and self-healing

Poly(dimethylsiloxane) (PDMS)-based nanocomposites have attracted increasing attention due to their inherent outstanding properties. Nevertheless, the realization of high levels of dispersion of nanosilicas in PDMS represents a challenge arising from the poor compatibility between the two components. Herein, we explore the use of ionic interactions located at the interface between silica and a PDMS matrix by combining anionic sulfonate-functionalized silica and cationic ammonium-functionalized PDMS. A library of ionic PDMS nanocomposites was synthesized and characterized to highlight the impact of charge location, density, and molecular weight of ionic PDMS polymers on the dispersion of nanosilicas and the resulting mechanical reinforcement. The use of reversible ionic interactions at the interface of nanoparticles–polymer matrix enables the healing of scratches applied to the surface of the nanocomposites. Molecular dynamics simulations were used to estimate the survival probability of ionic cross-links between nanoparticles and the polymer matrix, revealing a dependence on polymer charge density.Impact statementPoly(dimethylsiloxane) (PDMS) has been widely used in diverse applications due to its inherent attractive and multifunctional properties including optical transparency, high flexibility, and biocompatibility. The combination of such properties in a single polymer matrix has paved the way toward a wide range of applications in sensors, electronics, and biomedical devices. As a liquid at room temperature, the cross-linking of the PDMS turns the system into a mechanically stable elastomer for several applications. Nanofillers have served as a reinforcing agent to design PDMS nanocomposites. However, due to significant incompatibility between silica and the PDMS matrix, the dispersion of nanosilica fillers has been challenging. One of the existing strategies to improve nanoparticle dispersion consists of grafting oppositely charged ionic functional groups to the nanoparticle surface and the polymer matrix, respectively, creating nanoparticle ionic materials. Here, this approach has been explored further to improve the dispersion of nanosilicas in a PDMS matrix. The designed ionic PDMS nanocomposites exhibit self-healing properties due to the reversible nature of ionic interactions. The developed synthetic approach can be transferred to other kinds of inorganic nanoparticles dispersed in a PDMS matrix, where dispersion at the nanometer scale is a prerequisite for specific applications such as encapsulants for light-emitting diodes (LEDs).Graphical abstract

Understanding Ecotoxicological Responses of Fish Embryos and Gill Cells to Cationic Polymers.

Cationic polymers are considered by the scientific and regulatory communities as a group of greater interest amongst the polymers in commerce. As a category, relatively little hazard information is available in the public literature. Very few examples exist of published, high-quality polymer characterization and quantification of exposure. In the present study we describe a series of fish embryo toxicity (FET) and fish gill cytotoxicity assays used to establish a baseline understanding of several representative polyquaternium categories (PQ-6, PQ-10, PQ-16) in animal alternative models, accompanied by high-quality analytical characterization. Materials were chosen to encompass a range of molecular weights and charge densities to determine the influence of test material characteristics on toxicity. Both chorionated and dechorionated FET assays were generally similar to published acute fish toxicity data. Toxicity was correlated with cationic polymer charge density, and not with molecular weight, and was a combination of physical effects and likely toxicity at the site of action. Toxicity could be ameliorated by humic acid in a dose-dependent manner. Fish gill cytotoxicity results were orders of magnitude less sensitive than FET test responses. Environ Toxicol Chem 2022;41:2259-2272. © 2022 SETAC.

Inverse gas chromatography as a tool for screening materials: The relation between Lewis acid–base constants and triboelectric charge density of polymers

Since Saint-Flour and Papirer first introduced Gutmann's acceptor number and donor number parameters into the inverse gas chromatography (IGC) field in 1982, IGC has become an important technology for the measurement of surface Lewis acid–base properties of solid materials. However, introducing new roles of Lewis acid–base parameters, especially using them to predict material properties rather than just explain material properties, is an important aspect in developing IGC technology. In this paper, we first introduce the Schultz and Abraham methods for measurement of acid–base properties and discuss the traditional role of acid–base parameters. Then, we present a relation between the ratio of acid–base constants, Ka/Kb, and triboelectric charge density of some polymers to prove the possible new application field of IGC.

Significance of polymer elasticity on drag reduction performance in dispersed oil-in-water pipe flow

Mechanisms proposed for the drag reduction by high molecular weight polymers range from stress anisotropy, elasticity and the formation of intermolecular associations. This experimental study tests the role of elasticity as indicated by the measurement of normal force, from which Weissenberg number can be calculated. Cationic drag reducing polyacrylamides were injected in a dispersed oil-in-water flow through 30.6-mm pipe. Four polymers were used to investigate the effect of polymer molecular weight and charge density. Three polymers with different molecular weights and 10% charge density were investigated along with a polymer with 45% charge density. The flow in the test section was set at 0.3 oil fraction and mixture velocities of 0.8, 1.0, 1.2 and 1.5 m/s (Reynolds number above 34,400) with polymer concentrations from 10 to 40 ppm. Generally, the maximum drag reduction was obtained for polymer concentrations in the test section higher than 20 ppm. It increased with flow velocity and polymer molecular weight. The rheological measurements indicated that the elasticity of the polymers increase with the increase in molecular weight and change density. Similarly, the maximum drag reduction increased with the increase in molecular weight and charge density, which indicates a correlation between the efficiency of the drag reducing polymer and its elasticity. Drag reduction increased also with the increase in mixture velocity (or Reynolds number). On the other hand, drag reduction was generally independent of the hydrodynamic volume of the polymer above intrinsic viscosity of 4700 cm3/g.

The effect of erythrosine-B on the structuration of poloxamer 407 and cellulose derivative blends: In silico modelling supporting experimental studies

Erythrosine is a dye approved for medical use that has shown promising photodynamic activity, allowing for the inactivation of microorganisms and activity against malignant cells. Despite the great photodynamic potential, erythrosine exhibits hydrophilicity, negatively impacting its action in biological membranes. Therefore, the incorporation of erythrosine in micellar polymeric systems, such as poloxamers, may overcome this limitation. Moreover, using bioadhesive and thermoresponsive polymers to combine in situ gelation and bioadhesion may enhance retention of this topically applied drug. In this work, mucoadhesive and thermoresponsive micellar systems were prepared containing erythrosine in two states: the native form (ERI) and the disodium salt (ERIs). The systems were evaluated based on the effect of ERI/ERIs on the micellar structure of the binary polymer mixtures. Optimised combinations of poloxamer 407 (polox407) and mucoadhesive sodium carboxymethylcellulose (NaCMC) or hydroxypropyl methylcellulose (HPMC) were used as micellar systems for ERI or ERIs delivery. The systems were studied with respect to theoretical interactions, qualitative composition, morphology, and micellar properties. In silico modelling indicated a higher interaction of the drug with poly(ethylene oxide) (PEO) than poly(propylene oxide) (PPO) fragments of polox407. Systems containing NaCMC displayed a repulsive effect in the presence of erythrosine, due to the polymer's charge density. Both systems could convert the photosensitizer in its monomeric form, ensuring photodynamic activity. In these mixtures, crystallinity, critical micellar temperature and enthalpy of polox407 micellisation were reduced, and micellar size, evaluated by transmission electron microscopy (TEM), showed low impact of ERI/ERIs in HPMC preparations. Aiming toward photodynamic applications, the findings showed how ERI or ERIs can affect the micellar formation of gels composed of 17.5% (w/w) polox407 and 3% (w/w) HPMC or 1% (w/w) NaCMC, important for understating their behaviour and future utilisation as erythrosine delivery systems.

Abstract LB023: Drug loaded nanoparticle targeting of pancreatic cancer using tumor treating fields (TTFields)

Abstract Tumor Treating Fields (TTFields) have been clinically proven as safe, effective, and non-invasive approach for cancer treatment. Specifically, TTFields in conjunction with Gemcitabine/nab-Paclitaxel have shown promising results in Phase II pancreatic cancer (PC) PANOVA study. It is imperative to understand here that while TTFields are very safe, concurrent use of anticancer drugs will continue to elicit non-site-specific adverse effects resulting in overall low patient compliance. To overcome this drawback, we have developed an innovative strategy called ‘Tumor Treating Fields Triggered Targeting of Nanoparticles in Cancer (TTFields-TTONIC)'. For this, self-assembling cationic-anionic polymer nanoparticles (S-CAP NPs) encapsulating Gemcitabine as a model anticancer drug were developed. The hypothesis involves combination of NPs and TTFields wherein the developed NPs will be preferentially taken up by the tumor owing to leaky vasculature. Further, only under the applied TTFields, the NPs will be destabilized due to high charge density of cationic and anionic polymers leading to targeted release of encapsulated drug at the tumor site (reduction in non-site-specific side effects). For this, multiple batches of two types of S-CAP NPs [chitosan- bovine serum albumin (Chitosan-BSA) and polyethylenimine- bovine serum albumin (PEI-BSA)] were developed. The formulations were optimized using mathematical modelling and Design Expert® software to achieve low particle size and optimum encapsulation efficiency. Based on the results, 2 formulations from each type i.e., chitosan- BSA S-CAP NPs [Batch C4 - particle size: 210.54 ± 38.96 nm, PDI: 0.194, encapsulation efficiency: 61.26 ± 5.11%, zeta potential: (+) 7.38 ± 3.11; Batch C7 - particle size: 215.67 ± 32.55 nm, PDI: 0.201, encapsulation efficiency: 65.31 ± 5.84 %, zeta potential: (+) 3.22 ± 1.28] and PEI-BSA S-CAP NPs [Batch P5 - particle size: 198.29 ± 41.05 nm, PDI: 0.227, encapsulation efficiency: 58.83 ± 3.33%, zeta potential: (+) 8.17 ± 2.63; Batch P8 - particle size: 209.92 ± 31.33 nm, PDI: 0.196, encapsulation efficiency: 64.31 ± 5.13%, zeta potential: (+) 11.49 ± 2.99] were shortlisted that exhibited particle size ~ 200 nm and encapsulation efficiency in range of 55-65 %. All the formulations exhibited sustained drug release profile over a period of 60 h wherein chitosan- BSA S-CAP NPs showed slower drug release compared to PEI-BSA S-CAP NPs (P&amp;lt;0.05). All formulations were subjected to stability studies as per the ICH guidelines wherein the formulations were observed to be stable. Further, the conventional MTS inhibitory assay and colony formation assay against the PC cell lines (Panc-1 and Mia Paca-2) showed significant efficacy with the PEI-BSA S-CAP NPs (P&amp;lt;0.01) compared to chitosan-BSA S-CAP NPs. In the next phase, efficacy of S-CAP NPs against the PC cell lines in presence of TTFields will be analyzed followed by in vivo safety studies. The success of this strategy will not only enhance the safety of combination treatment involving TTFields-anticancer drugs but will also establish a newer application of TTFields as a targeting modality. The work is funded by AACR-Novocure tumor treating fields research fellowship (2019-2021). Citation Format: Preshita Prafulla Desai, Sunil Prabhu. Drug loaded nanoparticle targeting of pancreatic cancer using tumor treating fields (TTFields) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB023.

Designing tubular composite membranes of polyelectrolyte multilayer on ceramic supports with nanofiltration and reverse osmosis transport properties

Ceramic membranes are relevant for applications, which require mechanical robustness and chemical stability. The preparation of purely ceramic membranes for nanofiltration (NF) and reverse osmosis (RO) is a demanding process. Composite membranes comprise a mechanically stable ceramic support and a functional polymeric separation layer, combining the advantages of both worlds. In this work, we present a molecular strategy to fabricate polyelectrolyte multilayer membranes (PEMM) ranging from dense nanofiltration into the region of reverse osmosis deposited on tubular ceramic supports. A dynamic coating of PAH/PSS on a α-Al2O3 support membrane with pore sizes of 150 nm (MF) and 50 nm (UF) leads to a dense separation layer on the lumen side, with NaCl rejections above 90%. Coating solutions with increased ionic strength, as well as a subsequent covalent crosslinking of the amine groups of the PAH improve long term stability. The substitution of the polyanion PSS by PVSA, having a higher charge density, results in a remarkably low MWCO of 115 Da. This work indicates that balancing the charge density of polymers with the ionic matrix can result in reverse osmosis type selective layers on ceramic support with pore size even as large as 150 nm.

Generation and Use of Lignin-g-AMPS in Extended DLVO Theory for Evaluating the Flocculation of Colloidal Particles.

In this work, Kraft lignin (KL) was polymerized with 2-acrylamido-2-methylpropane sulfonic acid (AMPS) to generate an anionic water-soluble KL-g-AMPS polymer. The effects of reaction conditions on the charge density of polymers were evaluated to induce lignin-based polymers with the highest anionic charge density. The optimal process conditions were 2.5 mol/mol AMPS/lignin, 0.6 g/g solid/water ratio, 2.0 initiator/lignin weight ratio, 80 °C, 120 min, and pH 1.5, which yielded KL-g-AMPS with the anionic charge density of 4.28 mequiv/g and the grafting ratio of 285%. The chemical structure and compositions of the polymers were confirmed by 1H NMR and elemental analysis. The flocculation performance of the polymer was evaluated in an aluminum oxide suspension, and its performance was compared with that of a homopolymer of AMPS produced under the same conditions. In addition, the extended Derjaguin–Landau–Verwey–Overbeek (XDLVO) theory was applied to study the flocculation mechanism of the polymers and alumina particles. The results revealed that electrostatic interaction was found to be the dominant force in this flocculation process.

Surface Diffusion of Dendronized Polymers Correlates with Their Transfection Potential.

Successful intracellular delivery of therapeutics requires interactions at several liquid-solid interfaces, including cell surface, endosomal membranes, and-depending on the therapeutic-the nuclear membrane. Understanding the dynamics of polymer kinetics at the liquid-solid interface is fundamental for the design of polymers for such biomedical delivery applications. However, the effect of polymer architecture and charge density on polymer kinetics is not readily investigated using routine techniques, and the role of such parameters in the context of gene delivery remains unknown. We adopted a synthetic strategy which enabled the systematic manipulation of charge density, flexibility, and molecular weight using a dendronized linear polymeric architecture. High-speed atomic force microscopy (HS-AFM) was used as a label-free method to directly observe the polymers' dynamic properties, such as velocity, displacement, and diffusion, in physiologically relevant conditions. Importantly, we found that the physical parameters measured by HS-AFM relate to the transfection potential of the individual polymers and may be a valuable tool in screening structural polymer variants.

CHARACTERISTICS OF FLOCCULES OF CLAY-SALT SLUDGE FORMED BY POLYACRYLAMIDE AND ITS COPOLYMERS

The main characteristics of aggregates formed during the flocculation of clay-salt slurry using polyacrylamide-based polymers with various types of charge and molecular weights were studied using a laser analyzer of particle size Lasentec D600L of the FBRM system. The effect of the polymer type on the size of the floccules formed and their density was shown. It has been established that when using non-ionic polyacrylamide and its anionic copolymers floccules with a size of 500-600 mm are formed, and when flocculated with a cationic reagent, the floccules do not exceed 300 mm It was shown that an increase in the molecular weight of the cationic polymer does not contribute to an increase in the size of the aggregates of the clay slurry particles. It has been proven that with the use of non-ionic polyacrylamide and its anionic copolymers, the density of floccules significantly decreases with increasing their size, which is an important property of fractal aggregates. If the charge density of anionic polymers increases, the aggregates density decreases, due to electrostatic repulsion between the negatively charged polymer and the negatively charged surface of the sludge. Analysis of the kinetics of the clay sludge flocculation process showed that when using non-ionic and anionic polymers, fast flocculation occurs, and the number of primary particles in the aggregate does not exceed several units. When using a cationic polymer, the filling of the intraflouclear volume with primary particles occurs due to the displacement of the liquid phase, which contributes to the formation of dense and compact floccules. The results obtained can be used for the selection of flocculant in order to improve the process of thickening clay-salt sludge in the production of potash fertilizers.

Comparison of Single-Ion Conducting Polymer Gel Electrolytes for Sodium, Potassium, and Calcium Batteries: Influence of Polymer Chemistry, Cation Identity, Charge Density, and Solvent on Conductivity

From the standpoint of material diversification and sustainability, the development of so-called “beyond lithium-ion” battery chemistries is important for the future of energy storage. Na, K, and Ca are promising as the basis for battery chemistries in that these elements are highly abundant. Here, a series of single-ion conducting polymer electrolytes (SIPEs) for Na, K, and Ca batteries are synthesized and investigated. The two classes of metal cation neutralized SIPEs compared are crosslinked poly(ethylene glycol) dimethacrylate-x-styrene sulfonate (PEGDMA-SS) and poly(tetrahydrofuran) diacrylate-x-4-styrenesulfonyl (trifluoromethylsulfonyl)imide (PTHFDA-STFSI); three cation types, three charge densities, and four swelling states are examined. The impact on conductivity of all of these parameters is studied, and in conjunction with small angle X-ray scattering (SAXS), it is found that promoting ion dissociation and preventing the formation of dense ionic aggregates facilitates ion transport. These results indicate many of the lessons learned from the Li SIPE literature can be translated to beyond Li chemistries. At 25 °C, the best performing Na/K and Ca exchanged polymers yield active cation conductivity on the order of 10−4 S/cm and 10−6 S/cm, respectively, for ethylene carbonate:propylene carbonate gelled SIPEs, and 10−5 S/cm and 10−7 S/cm, respectively, for glyme gelled SIPEs.

Surfactant-Modulation of the Cationic-Polymer-Induced Aggregation of Anionic Particulate Dispersions

Commodity formulations contain many chemically distinct components and their mutual interactions define the beneficial characteristics of the formulation. Mixing oppositely charged polymers and surfactants invariably induces macroscopic phase separation, to a degree dependent on the prevailing polymer and surface charge densities, and the interaction can be modulated by added ionic surfactants. Here, it is shown that a general universality exists between the charge present on a series of cationic-modified cellulose polymers—the charge being controlled either by the degree of cationic modification of the polymer itself or through the subsequent level of anionic surfactant binding—and its capacity to remove anionic colloidal material from solution, be that silica particles or polystyrene-butadiene lattices. Particulate material not removed from solution bears no adsorbed polymer, i.e., the particle surface is bare. Addition of nonionic surfactant does not negate this universality, implying that the nonionic surfactant is largely a spectator molecule or structure (micelle) in these systems, and that the dominant force is an electrostatic one.

Manipulating the triboelectric surface charge density of polymers by low-energy helium ion irradiation/implantation

Modification of polymers by ion irradiation improves their effective charge density due to the generation of electron-donating groups.