Polystyrene Sulfonate Polymer Research Articles

One-Pot Electrodeposition of a PANI:PSS/MWCNT Nanocomposite on Carbon Paper for Scalable Determination of Ascorbic Acid

In recent years, there has been growing demand for the monitoring of ascorbic acid levels, especially in underdeveloped populations where ascorbic acid deficiency affects up to 74% of individuals. To facilitate widespread ascorbic acid screening, we have developed a highly scalable conductive polymer nanocomposite with excellent ascorbic acid sensing performance. The material is based on polyaniline, which is deposited in a single step in the presence of polystyrene sulfonate and multi-walled carbon nanotubes onto carbon paper. The modified electrodes take advantage of the electrocatalytic properties of polyaniline toward ascorbic acid, which are boosted by the proton donating polystyrene sulfonate polymer and the high surface area of the multi-walled carbon nanotubes. The morphology and composition of the composite are characterized using field-emission scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy and the electrochemical characteristics are examined using cyclic voltammetry and electrochemical impedance spectroscopy. The modified electrode shows good ascorbic acid sensing characteristics, with a linear range of 1–400 μM, a sensitivity of 546 μA mM−1 cm−2, and a limit of detection of 0.11 μM. High performance and low cost results in a promising platform to support the widespread, cheap monitoring of ascorbic acid deficiency.

SERS study of cyanine dyes: Optimization of metal core and molecular label choice for plasmonic nanotags

The combined use of dyes and plasmonic nanoparticles provides new opportunities for the development of surface-enhanced Raman scattering (SERS) tags for imaging and sensing applications. Here, we report for the first time the detailed SERS study of cyanine5.5 and cyanine7.5 derivatives interaction with gold nanoparticles. SERS spectra were recorded for the solutions of nanoparticles of six different morphologies to reveal the combination of dye and plasmonic core with the highest optical response. Three compounds were tested to select the most appropriate functional derivative: cyanine5.5 amine, sulfo-cyanine5.5 amine and sulfo-cyanine5.5 NHS ester. Bare CTAB-stabilized gold nanoparticles and gold nanoparticles covered by oppositely charged polymers were used in the SERS study. The effect of chloride anions was tested for dyes adsorbed on both uncoated and coated nanoparticles. Amino derivative of non-sulfonated cyanine5.5 demonstrated the most intensive and stable SERS response which increases with the addition of chloride even when dye molecules are adsorbed on polystyrene sulfonate polymer layer. The study allows one to get acquainted with many findings that are useful for obtaining SERS and bimodal Raman-fluorescence nanotags containing dyes.

Micellar and sub-micellar chromatography with a cocamidopropyl betaine surfactant

We have coated a typical C18 column with the pH cationic charge controllable zwitterionic synthetic surfactant, cocamidopropyl betaine (CAPB), in order to generate a mixed mode reversed phase weak ion exchange column. As determined by the Thomas model, the column has an adsorbed surfactant capacity of 0.557 mmoles. The addition of 8.8 × 10–4 M CAPB to the totally aqueous mobile phase ensured stability of the surfactant on the column and permitted separation of the four component sulfonamide mixture with micellar liquid chromatography (MLC) in under 11 min. Comparatively, with a dilute H2SO4 mobile phase with no CAPB, the separation time for the sulfonamide mixture reached an excessive run time of an hour on the bare C18 chains. With CAPB in the mobile phase (no organic solvent present), a seven component sulfonamide mixture could be separated in less than 45 min. A five component short chain carboxylic acid mixture, separated in 20 min, was used to examine the ion exchange character of the column in pH environments of 2.3 and 4.6. Three phase MLC equilibrium analysis was also done in these pH environments with the sulfa drug and carboxylic acid mixtures to determine partition coefficients. Finally, a quite high molecular weight (70,000) anionic polystyrene sulfonate polymer was characterized by MLC with only CAPB and variable pH mobile phases; the optimal pH was determined to be 5.6. A totally aqueous mobile phase without CAPB was not suitable for profiling this polymer.

Phase separation in mixed suspensions of bacteria and nonadsorbing polymers.

The shapes of bacteria can vary widely; they may, for instance, be spherical, rod-like, string-like, or curved. In general, bacilli are highly anisotropic. For research and (bio)technological purposes, it can be useful to concentrate bacteria, which is possible by adding nonadsorbing polymers. The induced phase separation originates from a polymer-mediated depletion interaction, first understood by Asakura and Oosawa. Here, it is shown that free volume theory (FVT) can semi-quantitatively describe the phase transitions observed when adding sodium polystyrene sulfonate polymers to E. coli bacteria [Schwarz-Linek et al., Soft Matter 6, 4540 (2010)] at high ionic strength. The E. coli bacteria are described as short, hard spherocylinders. FVT predicts that the phase transitions of the mixtures result from a fluid-ABC crystal solid phase coexistence of a hard spherocylinder-polymer mixture.

Development and validation of HPLC-UV method for the quantitative analysis of carcinogenic organic impurities and its isomers in the sodium polystyrene sulfonate polymer

AbstractSodium polystyrene sulfonate (SPS) powder is in use for over 50 years for the treatment of hyperkalemia. SPS powder is official in United States Pharmacopoeia, British Pharmacopoeia and European Pharmacopoeia. However, till date, no study has been published on the assessment of organic impurities for this drug. The organic impurities in bulk drug and finished product are associated with their safety, efficacy and stability. A simple, rapid, specific, precise and an accurate HPLC method has been developed for the estimation of toxic organic impurities like styrene, naphthalene, divinyl benzene (DVB) and ethylvinyl benzene (EVB) from SPS bulk drug and finished product. The developed method was validated for specificity, accuracy, precision, linearity, limit of detection (LOD), limit of quantitation (LOQ), solution stability, ruggedness and robustness. The influence of acid, alkali, oxidative stress, photolytic stress, thermal stress and humidity stress conditions on SPS bulk powder and finished product has been studied and reported. The proposed method can be successfully employed for the impurity testing of commercial batches of the bulk drug and finished products of both sodium salt and calcium salt of polystyrene sulfonate.

A novel waste paper cellulose-based Cu-MOF hybrid material threaded by PSS for lithium extraction with high adsorption capacity and selectivity

As the most abundant green and renewable resource in nature, cellulose has received the researchers’ attention because of its excellent properties. In this work, waste paper cellulose with high length-to-diameter ratio and rich hydroxyl groups was utilized as template for the preparation of Cu-MOF/PSS hybrid material (Cu-MOF: Cu3(BTC)2, BTC = 1,3,5-benzenetricarboxylate; PSS: Polymer polystyrene sulfonate), where the Cu-MOF was well-threaded by PSS polymers. Afterwards, the obtained cellulose-based Cu-MOF/PSS hybrid material (WP@PSS@Cu-MOF) was used for Li+ ion extraction in brine solution and some adsorption experiments were carried out to evaluate its adsorption behavior. The results indicated that it had an obvious selectivity and high adsorption capacity for Li+ ion. It also confirmed that the introduction of PSS into Cu-MOF matrix greatly improved the selectivity and adsorption capacity for Li+ ions due to the synergy between the size-sieving effects from Cu-MOF and special binding affinity from PSS polymer. However, it was found that an excessive PSS addition easily led to the residual Cu(OH)2 phase and negatively affected the formation of Cu-MOF crystals, causing the reduction of capturing sites for Li+ ions. As a whole, this work provided a green and simple strategy to utilize low-cost biomass as template material to fabricate some absorbents that have great potential for applications in the adsorption and separation fields.

PEDOT:PSS Microchannel‐Based Highly Sensitive Stretchable Strain Sensor

AbstractThis paper presents poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate polymer microchannel (diameter ≈175 µm) based stretchable strain sensor developed inside polydimethylsiloxane substrate. The microchannel diameter changes when subjected to various strains, leading to change in the resistance of strain sensor. The sensor exhibits about three order (ΔR/R0 ≈ 1200) increase in the resistance (R) for 10% applied strain (ΔL/L, L = length of the sensor). This leads to a gauge factor (GF Δ (ΔR/R0)/(ΔL/L) of ≈12 000, which is about ≈400 times higher than most of the reported polymer‐based strain sensors. The sensor is evaluated up to a maximum strain of 30%, which is the standard strain limit associated with human body parts such as fingers and wrists. The sensor exhibits a considerably good average degree of hysteresis (<9%). Further, the sensor is also studied for bending and twisting experiments. A response of (ΔR/R0 ≈ 250) and (ΔR/R0 ≈ 300) is recorded for 90° bending and 150° twisting, respectively. The sensor shows an electrical resolution of ≈150% per degree of free bending and ≈12k% per percentage of stretching. Finally, the potential application of presented sensor in robotics and wearable systems is demonstrated by using sensor feedback from human hand to remotely control the robotic hand movements.

Highly Conductive Poly(3,4-ethylenedioxythiophene) Polystyrene Sulfonate Polymer Coated Cathode for the Microbial Electrosynthesis of Acetate From Carbon Dioxide

Microbial electrosynthesis (MES) is a bioelectrochemical technology developed for the conversion of carbon dioxide and electric energy into multicarbon chemicals of interest. As with other biotechnologies, achieving high production rate is a prerequisite for scaling up. In this study, we report the development of a novel cathode for MES, which was fabricated by coating carbon cloth with conductive poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) polymer. Sporomusa ovata-driven MES reactors equipped with PEDOT:PSS-carbon cloth cathodes produced 252.5 ± 23.6 mmol d-1 acetate per m2 of electrode over a period of 14 days, which was 9.3 fold higher than the production rate observed with uncoated carbon cloth cathodes. Concomitantly, current density was increased to -3.2 ± 0.8 A m-2, which was 10.7-fold higher than the untreated cathode. The coulombic efficiency with the PEDOT: PSS-carbon cloth cathodes was 78.6 ± 5.6%. Confocal laser scanning microscopy and scanning electron microscopy showed denser bacterial population on the PEDOT:PSS-carbon cloth cathodes. This suggested that PEDOT:PSS is more suitable for colonization by S. ovata during the bioelectrochemical process. The results demonstrated that PEDOT: PSS is a promising cathode material for MES.

Effect of Concentration on the Ionic Interaction between Polystyrene Sulfonate and Cationic Surfactant in Aqueous Solution

Polystyrene sulfonate (PSS) were prepared by sulfonation method of polystyrene using sulfuric acid. Abundant amount of polystyrene waste can be reused as a coagulant, membrane for polymer fuel cell and anionic-cationic polymer interactions. The characterization of PSS was carried out by using UV-Vis, Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) spectra, molecular weight and analysis of sulfonation degree. The degree of sulfonation was obtained at 94,18%. Ionic interaction between anionic polymer PSS and cetyltrimethylammonium bromide (CTAB) as cationic compound in aqueous solution were analyzed by using dynamic light scattering (DLS), conductometry and fluorimetry. Behavior of conductivity have been calculated the critical micelle concentration (cmc). The FTIR and 1H-NMR spectra showed the ionic interaction between PSS and CTAB. This ionic interaction can be controlled by changing the polymer concentration.

Sensitive Sulfadiazine Sensor Based on Multiwalled Carbon Nanotubes Wrapped with Polystyrene Sulfonate Polymer Chain

Sensitive Sulfadiazine Sensor Based on Multiwalled Carbon Nanotubes Wrapped with Polystyrene Sulfonate Polymer Chain

Self-assembled peptide-polymer hydrogels as a 3D nanofiber substrate for biomimetic hydroxyapatite mineralization

Event Abstract Back to Event Self-assembled peptide-polymer hydrogels as a 3D nanofiber substrate for biomimetic hydroxyapatite mineralization Elham Radvar1, C Remzi Becer1 and Helena S. Azevedo1 1 Institute of Bioengineering, Queen Mary University of London, School of Engineering and Materials Science, United Kingdom Introduction: Hard tissues in vertebrates, such as bones, are produced by controlled biomineralization of an organic matrix that regulates the growth of the inorganic phase. In bone, the fundamental subunit is a collagen fibril, formed by self-assembly of single tropocollagen molecules (triple helix), where hydroxyapatite nanocrystals grow with their crystallographic c-axes aligned with the fibril long axes. Molecular self-assembly offers the possibility to recreate the same degree of nanoscale order in synthetic biomaterials and promote epitaxial mineralization mediated by an organic matrix. The self-assembly between a negatively charged polymer and a peptide amphiphile (PA) of opposite charge was shown to result in the formation of sacs and membranes[1]. Inspired by this seminal work, here we investigate the use of the negatively charged synthetic polymer polystyrene sulfonate (PSS) with a positively charged PA to form self-assembling matrices and their ability to direct hydroxyapatite mineralization. Materials and Methods: PSS (1 MDa, Fig 1-A) was commercially available from Sigma. C15H31CONH-V3A3K3-CONH2 PA (Fig 1-A) was synthesized by solid phase and purified as described elsewhere[2]. PSS/PA hydrogels were obtained by self-assembly combining aqueous solutions of PSS (2% w/v) and PA (2% w/v). Mineralization studies were performed by incubating the PSS/PA hydrogels in a simulated body fluid (SBF[3]) solution at 37°C for several days. Then, the gels were washed with distilled water and prepared for surface analysis by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Results and Discussion: Conversely to previous work reporting the self-assembly between PAs and oppositely charged polysaccharides, combining an aqueous PSS solution with a positively charged PA resulted in the formation of a self-supporting gel (Fig 1-B) exhibiting a random nanofibrilar network (Fig 1-C). PSS has been shown to direct the nucleation and growth of calcium carbonate mineral by binding to calcium ions[4]. Thus, we hypothesize that these nanofiber PSS/PA gels could be used as a 3D matrix to drive the nucleation of hydroxyapatite and create a mineralized matrix resembling the structure of natural bone. The formation of hydroxyapatite mineral on the surface of hydrogels after 14 days of incubation in SBF was confirmed by SEM (Fig 1-D, E) and EDS (Fig 1-F) analysis which show a typical morphology of hydroxyapatite crystals and the presence of calcium and phosphorus, respectively. Conclusions: While further studies are necessary to characterize the formed mineral, these self-assembled PSS/PA gels present an interesting approach to develop new biomaterials for bone regeneration considering the potential for further functionalization of the peptide segment with bioactive sequences. I would like to acknowledge the help of Dr. Daniela Ferreira and Sofia Ribeiro in peptide synthesis and SBF preparation, respectively. This work is supported by School of Engineering and Materials Science (SEMS)

Potential of Wood-Rotting Fungi to Attack Polystyrene Sulfonate and Its Depolymerisation by Gloeophyllum trabeum via Hydroquinone-Driven Fenton Chemistry.

Synthetic polymers often pose environmental hazards due to low biodegradation rates and resulting accumulation. In this study, a selection of wood-rotting fungi representing different lignocellulose decay types was screened for oxidative biodegradation of the polymer polystyrene sulfonate (PSS). Brown-rot basidiomycetes showed PSS depolymerisation of up to 50 % reduction in number-average molecular mass (Mn) within 20 days. In-depth investigations with the most efficient depolymeriser, a Gloeophyllum trabeum strain, pointed at extracellular hydroquinone-driven Fenton chemistry responsible for depolymerisation. Detection of hydroxyl radicals present in the culture supernatants showed good compliance with depolymerisation over the time course of PSS degradation. 2,5-Dimethoxy-1,4-hydroquinone (2,5-DMHQ), which was detected in supernatants of active cultures via liquid chromatography and mass spectrometry, was demonstrated to drive the Fenton processes in G. trabeum cultures. Up to 80% reduction in Mn of PSS where observed when fungal cultures were additionally supplemented with 2,5-dimethoxy benzoquinone, the oxidized from of 2,5-DMHQ. Furthermore, 2,5-DMHQ could initiate the Fenton's reagent-mediated PSS depolymerisation in cell-free systems. In contrast, white-rot fungi were unable to cause substantial depolymerising effects despite the expression of lignin-modifying exo-enzymes. Detailed investigations with laccase from Trametes versicolor revealed that only in presence of certain redox mediators limited PSS depolymerisation occurred. Our results indicate that brown-rot fungi might be suitable organisms for the biodegradation of recalcitrant synthetic polymeric pollutants.

Gallium-containing polymer brush film as efficient supported Lewis acid catalyst in a glass microreactor

Polystyrene sulfonate polymer brushes, grown on the interior of the microchannels in a microreactor, have been used for the anchoring of gallium as a Lewis acid catalyst. Initially, gallium-containing polymer brushes were grown on a flat silicon oxide surface and were characterized by FTIR, ellipsometry, and X-ray photoelectron spectroscopy (XPS). XPS revealed the presence of one gallium per 2–3 styrene sulfonate groups of the polymer brushes. The catalytic activity of the Lewis acid-functionalized brushes in a microreactor was demonstrated for the dehydration of oximes, using cinnamaldehyde oxime as a model substrate, and for the formation of oxazoles by ring closure of ortho-hydroxy oximes. The catalytic activity of the microreactor could be maintained by periodic reactivation by treatment with GaCl3.

Sulfonated polyimide as a thermally stable template for water processable conductive polymers

Herein, sulfonated polyimides are utilized as a template for the polymerization of pyrrole (Py), aniline (ANi) and 3,4-ethylenedioxythiophene (EDOT) in order to produce their corresponding conductive polymers as stable processable aqueous dispersions. With polyimides having high thermal stabilities, the use of sulfonated polyimides (SPI) as templates imparts higher thermal stabilities on their water processable conductive polymers in comparison to their counterparts using polystyrenesulfonate (PSS) templates allowing for annealing temperatures approaching 300°C. This factor is of importance; in that it is comparable to processing temperatures of conventional polymers when these conductive polymers should be used in conductive composite materials, and for advancing developments in further increasing the electrical conductivities of these materials by studying the effects of annealing and the use of additives in a higher temperature regime.The PEDOT–SPI polymer exhibited superior conductivities (10–1000 fold) than the PEDOT–PSS polymer after processing at room temperature (RT) and after annealing at elevated temperatures (180°C, 300°C). The PEDOT–SPI system also showed 20 fold, 50 fold and 6 fold increases in conductivity after RT, 180°C and 300°C processing respectively, relative to the conducting polymers PEDOT–SPAA and PEDOT–SPI (from thermal treatment of SPAA) derived from the corresponding sulfonated polyamic acid (SPAA) and EDOT. The PANi–SPI polymer displayed the highest room temperature conductivity but lost considerable conductivity after high annealing temperatures of 180°C and 300°C. The PPy–SPI polymer systems revealed better conductivities after room temperature processing and elevated annealing temperatures, 180°C and 300°C (40×, 10×, 50×, respectively), than the PEDOT–SPI system. Secondary dopants (such as DMF), when used at 0.1wt.% DMF and annealed at 180°C/10min, affected a 100 fold improvement in conductivity (5.94×10−1S/cm versus 4.0×10−3S/cm of PEDOT–SPI). Furthermore, PANi–SPI doped with 0.1wt.% DMF showed the highest conductivity (2.51S/cm).

Simultaneous determination of ascorbic acid, dopamine and uric acid using polystyrene sulfonate wrapped multiwalled carbon nanotubes bound to graphite electrode through layer-by-layer technique

A promising electrochemical system is fabricated using layer-by-layer (LBL) technique on graphite electrode, by positively charged poly(diallyldimethylammonium chloride) (PDDA) and negatively charged multiwalled carbon nanotubes (MWCNTs) wrapped with polystyrene sulfonate (PSS) through electrostatic interaction, for the simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). Solubility of MWCNTs in water was increased by using linear polymer PSS. The PSS wrapped MWCNTs modified electrodes were characterized by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV) and chronoamperometric techniques. The modified electrode exhibits superior electrocatalytic activity towards AA, DA and UA than the bare graphite electrode. The three separated anodic peaks were obtained at 192, 123 and 315 mV between AA–DA, DA–UA and AA–UA respectively in CV and corresponding separated anodic peaks were 210, 119 and 329 mV in DPV respectively. No electrode fouling was observed during all the experiments and good stability and reproducibility was obtained for simultaneous determination of AA, DA and UA.

In-situ Polymerization vs direct Polymer Incorporation for the Nanocomposite PSS/LDH

AbstractInterleaved polystyrene sulfonate polymer between a layered double hydroxide of composition Zn2Al(OH)6Cl. nH2O are prepared either by direct exchange or by in-situ polymerization of the monomer. The latter is confirmed by 13C CP-MAS solid state NMR spectroscopy. This technique provides also clear evidence of the strong interaction between the incorporated monomer and the LDH inorganic framework. A shielding of the aromatic carbon attached to the sulfonate group is observed, this is transmitted through the carbonaceous skeleton to the vinylic carbon. The 2D structure is stabilized with the presence of organic moieties, and even more through the in-situ polymerization process, as exemplified with the conversion from Oh to Td aluminium cations environment. However the difference is diminished with the heating process. The exfoliation/restacking process is found to be here unappropriate, giving rise to ill-defined materials.

Multilayered supermolecular structures self-assembled from polyelectrolytes and cyclodextrin host–guest complexes

Supermolecular multilayers with high levels of compositional and structural complexities have been fabricated with an example that involves formation of stable host–guest complexes from bolaamphiphiles and cyclodextrins, followed by sequential build-up of multilayered films by these complexes in combination with anionic polystyrene sulfonate polymer chains.