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Stable latexes containing unimolecular amphiphilic core-shell star-block polymers with a triphenylphosphine(TPP)-functionalized hydrophobic core and an outer hydrophilic shell based on anionic styrenesulfonate monomers have been synthesized in a convergent three-step strategy by reversible addition-fragmentation chain-transfer (RAFT) polymerization, loaded with [RhCl(COD)]2 and applied to the aqueous biphasic hydrogenation of styrene. When the outer shell contains sodium styrenesulfonate homopolymer blocks, treatment with a toluene solution of [RhCl(COD)]2 led to undesired polymer coagulation. Investigation of the interactions of [RhCl(COD)]2 and [RhCl(COD)(PPh3)] with smaller structural models of the polymer shell functions, namely sodium p-toluenesulfonate, sodium styrenesulfonate, and a poly(sodium styrenesulfonate) homopolymer in a biphasic toluene/water medium points to the presence of equilibrated Rh-sulfonate interactions as the cause of coagulation by inter-particle cross-linking. Modification of the hydrophilic shell to a statistical copolymer of sodium styrenesulfonate and poly(ethylene oxide) methyl ether methacrylate (PEOMA) in a 20:80 ratio allowed particle loading with the generation of core-anchored [RhCl(COD)TPP] complexes. These Rh-loaded latexes efficiently catalyze the aqueous biphasic hydrogenation of neat styrene as a benchmark reaction. The catalytic phase could be recovered and recycled, although the performances in terms of catalyst leaching and activity evolution during recycles are inferior to those of equivalent nanoreactors based on neutral or polycationic outer shells. [ABSTRACT FROM AUTHOR]

In this work, poly (3,4-ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS) coated silver telluride (PCAg2Te) nanorods were prepared by a wet-chemical method using the PEDOT:PSS coated tellurium (PCTe) nanorods as the templates. Flexible PCAg2Te nanocomposite film on polyethersulfone (PES) substrate was prepared through vacuum filtration followed by mechanical pressing process. An optimal PCAg2Te nanocomposite film showed a maximum power factor of 143.3 μW/mK2 at room temperature and 221.7 μW/mK2 at 373 K. The electrical conductivity of the PCAg2Te composite film decreased by ∼ 3.3% after bending for 1000 times around a rod with a radius of 5 mm. An eight-leg thermoelectric generator assembled with the optimal PCAg2Te nanocomposite film generated a maximum output power and output density of 209.4 nW and 141.5 μW/cm2 at a temperature gradient of 30.3 K. This work provides a facile method to prepare thermoelectric materials for flexible thermoelectric generators.

Mosquito-borne viruses are a major worldwide health problem associated with high morbidity and mortality rates and significant impacts on national healthcare budgets. The development of antiviral drugs for both the treatment and prophylaxis of these diseases is thus of considerable importance. To address the need for therapeutics with antiviral activity, a library of heparan sulfate mimetic polymers was screened against dengue virus (DENV), Yellow fever virus (YFV), Zika virus (ZIKV), and Ross River virus (RRV). The polymers were prepared by RAFT polymerization of various acidic monomers with a target MW of 20 kDa (average M n ∼ 27 kDa by GPC). Among the polymers, poly(SS), a homopolymer of sodium styrenesulfonate, was identified as a broad spectrum antiviral with activity against all the tested viruses and particularly potent inhibition of YFV (IC 50 = 310 pM). Our results further uncovered that poly(SS) exhibited a robust inhibition of ZIKV infection in both mosquito and human cell lines, which points out the potential functions of poly(SS) in preventing mosquito-borne viruses associated diseases by blocking viral transmission in their mosquito vectors and mitigating viral infection in patients.

We explored the factors and mechanisms of the antiyeast and antialgal effect of zinc oxide nanoparticles (ZnONPs) coated with zinc sulfide (ZnS), silica (SiO2), poly-(sodium 4-styrenesulfonate) sodium salt (PSS), and poly-(allylamine hydrochloride) (PAH) polyelectrolytes. We examined the activity of various concentrations of bare and surface modified ZnONPs toward microalgae (C. reinhardtii) and yeast (S. cerevisiae) cells upon illumination with UV light compared with that under visible light and in dark conditions to evaluate the impact of the oxidative stress due to the reactive oxygen species (ROS). We also prepared ZnS-coated ZnONPs, SiO2-coated ZnONPs, and combinations of polyelectrolyte (PSS and PAH)-coated ZnONPs and examined their antiyeast and antialgal effects. The nanoparticles of the anionic surface (ZnONPs/ZnS, ZnONPs/SiO2, and ZnONPs/PSS) showed much lower antialgal and antiyeast activity than the ones with a cationic surface functionality (ZnONPs/PSS/PAH and bare ZnONPs). The effect of the ZnONPs surface coating was found to be much stronger than the ROS effect due to illumination with UV light. This indicates that the nanoparticles attachment to the microbial cell wall is much more important for their antimicrobial action than the ROS generation alone. This could be explained by the poor adhesion of ZnONPs/ZnS, ZnONPs/SiO2, and ZnONPs/PSS to the cells due to electrostatic repulsion. In contrast, the particle–cell electrostatic adhesion in the case of cationic ZnONPs/PSS/PAH and bare ZnONPs led to enhanced antiyeast and antialgal action. This study brings important insights about the role of the ZnONPs surface coatings on their nanotoxicity and antimicrobial action and could potentially lead to the development of better antibiofouling coatings and antiyeast formulations. [ABSTRACT FROM AUTHOR]

SnSe 1–x Te x nanosheets (NSs) with lateral size of ∼500 nm were fabricated via intercalation of Li ions and exfoliation, and they were then combined with a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), to form SnSe 1–x Te x NS/PEDOT:PSS films. To evaluate the potential use of the SnSe 1–x Te x NS/PEDOT:PSS composites for thermoelectric applications, their thermoelectric properties were analyzed with the Te content and discussed for maximizing the thermoelectric power factor. The SnSe 0.97 Te 0.03 NS/PEDOT:PSS composite showed an outstanding power factor of 14.73 μW/(m·K2), with excellent durability after 1000 bending cycles. This study demonstrates that the combination of inorganic SnSe 0.97 Te 0.03 NSs with conductive PEDOT:PSS is a promising technology to develop high-performance flexible thermoelectrics. Image 1 • SnSe 1-x Te x nanosheets with a lateral size of ∼500 nm are chemically exfoliated. • Combination of SnSe 1-x Te x nanosheets and PEDOT:PSS lead to the flexible films. • Thermoelectric properties with different content of Te are examined and discussed. • Outstanding thermoelectric performance with durability of flexible film is achieved. [ABSTRACT FROM AUTHOR]

We have developed a new binder-free hybrid anode material for lithium-ion batteries, by directly coating spinel Li 4 Ti 5 O 12 particles using in-situ polymerization of styrenesulfonate (SS) to form a core-shell structure. The resulting hybrid anode has significantly improved electrochemical performance, with higher reversible capacity, rate-capability, and capacity value compared with pure Li 4 Ti 5 O 12 . Of the initial discharge capacity of 239.2 mAh g −1 , 95.6% was retained after 100 cycles at 0.1 C-rate. The high cycle performance with increased discharge capacity is attributed to the coated poly (styrenesulfonate) (PSS) shell, which takes part in lithium ion storage and prevents the growth of a solid electrolyte interface (SEI) layer. The fast electron transfer in PSS also allows high rate-capability. Moreover, we clarify the contribution of carbon conductor in the range of 0.01 V–1.0 V. [ABSTRACT FROM AUTHOR]

The search for new ways to suppress unwanted protein aggregation represents an important problem in modern biochemistry, bioengineering, and even medicine. Recently we succeeded in preventing the aggregation using synthetic polyelectrolytes. The present work describes a new approach to solubilizing pre-formed protein aggregates with sulfated or sulfonated polymers (polysulfoanions). For the first time it was shown that polysulfoanions are capable of solubilizing amorphous and amyloid protein inclusion bodies as well as thermal aggregates. Treatment of prion protein inclusion bodies with sulfonated polymers was shown to cause significant decrease in amyloid structure content, whereas in case of thermal aggregates of glyceraldehyde-3-phosphate dehydrogenase the observed solubilization was accompanied by a partial recovery of enzymatic activity. The suggested approach could be relevant in the task of extracting recombinant proteins from inclusion bodies and also useful in the development of amyloid disease therapy. [ABSTRACT FROM AUTHOR]

Abstract: Background: It is well documented that poly(sulfate) and poly(sulfonate) anions suppress protein thermal aggregation much more efficiently than poly(carboxylic) anions, but as a rule, they denature protein molecules. In this work, a polymer of different nature, i.e. poly(phosphate) anion (PP) was used to elucidate the influence of phosphate groups on stability and thermal aggregation of the model enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Methods: Isothermal titration calorimetry and differential scanning calorimetry were used for studying the protein–polyanion interactions and the influence of bound polyanions on the protein structure. The enzymatic activity of GAPDH and size of the complexes were measured. The aggregation level was determined from the turbidity. Results: Highly polymerized PP chains were able to suppress the aggregation completely, but at significantly higher concentrations as compared with poly(styrenesulfonate) (PSS) or dextran sulfate chains of the same degree of polymerization. The effect of PP on the enzyme structure and activity was much gentler as opposed to the binding of dextran sulfate or, especially, PSS that denatured GAPDH molecules with the highest efficacy caused by short PSS chains. These findings agreed well with the enhanced affinity of polysulfoanions to GAPDH. Conclusions: The revealed trends might help to illuminate the mechanism of control of proteins functionalities by insertion of charged groups of different nature through posttranslational modifications. General significance: Practical implementation of the results could be the use of PP chains as promising tools to suppress the proteins aggregation without noticeable loss in the enzymatic activity. [Copyright &y& Elsevier]

Abstract: In this study, monodispersed colloidal titanium dioxide (TiO2) was synthesized and applied with poly(3-octylthiophene-2,5-diyl) (P3OT), phenyl-C61-butyric acid methyl ester (PCBM), poly(3,4-ethylene dioxythiophene) (PEDOT), and poly(styrenesulfonate (PSS) to fabricate an aluminum/calcium/P3OT:PCBM:TiO2/PEDOT:PSS/indium tin oxide hybrid solar cell using spin coating and evaporation deposition. The effects of the TiO2 content and annealing temperature on cell performances were investigated. The results showed that optimization of the TiO2 content (15wt.%) and annealing temperature (150°C) effectively enhanced the performance of the hybrid solar cells. The PCBM and TiO2 absorbed more light photons in the P3OT:PCBM:TiO2 active layer. The charge transfer in the P3OT:PCBM:TiO2 active layer was more efficient, increasing the amount of photoluminescence quenching. The increased active layer surface roughness reduced the charge-transport distance and enhanced the internal light scattering and light absorption. The best values for the open circuit voltage, short-circuit current density, fill factor, and efficiency for the prepared hybrid solar cell were 0.61V, 9.50mA/cm2, 34.46%, and 2.09%, respectively. [Copyright &y& Elsevier]

Abstract: The mixture of a small amount of diluted sulfuric acid and aqueous dispersion of poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate) (PEDOT:PSS) was used in the preparation of thin films. Conductivities of around 100S/cm were obtained, which are 1400 times greater than that corresponding to pristine PEDOT:PSS films (~0.07S/cm). Absorbance, Raman and Fourier transform infrared spectroscopies suggest an increase in the doping level produced by the incorporation of bisulphate ions in the film. This doping increase is a responsible mechanism of the conductivity enhancement. As a consequence of a continuous interaction with the environment, after a few days, the formation of surface structures rich in PSS on the PEDOT:PSS films is observed. These structures are evidence that partial phase segregation of the excess of PSS is another mechanism responsible for enhancing the charge transport in the system. Additionally, for comparison we have used hydrochloric acid, another strong acid, and a large increase in the electrical conductivity was not observed. The different effects induced by these two strong acids on PEDOT:PSS films are discussed. [Copyright &y& Elsevier]

It has been shown by X-ray structure analysis that proteins have specific anion-binding sites for sulfate, citrate, and phosphate ions; however, the functional role of these anions is not always clear. Thus, it is unknown which of two phosphate anions, mono- or divalent, determines the stability of cellular proteins under stress conditions. In the present work, the influence of phosphate, sulfate, and chloride on the stability of lactate dehydrogenase (LDH) in the presence of poly(styrenesulfonate) (PSS) has been investigated by the methods of steady-state kinetics and intrinsic protein fluorescence. The study is based on the analysis of differences between the influence of phosphate and sulfate ions on the process at two pH values, 6.2 and 7.0, at which the ratio of the concentrations of mono- and bivalent phosphate forms differs, whereas sulfate remains in the bivalent form. It was shown that the differences between the influence of phosphate and sulfate ions at pH 7.0 were greater; divalent phosphate ions much more effectively stabilized LDH against destruction by a polyelectrolyte compared with sulfate and monovalent phosphate. It was concluded that, of two anion-binding sites of the LDH molecule, the intersubunit center plays the most important role in its stabilization against destruction by polyelectrolyte, and, of two forms of phosphate anions, its bivalent form HPO plays the stabilizing role. [ABSTRACT FROM AUTHOR]

The functional state of three proteins of different molecular weight (urease, lactate dehydrogenase, and hemoglobin) in the presence of the linear polyelectrolytes poly(allylamine hydrochloride) (PAA) and sodium poly(styrenesulfonate) (PSS) in the dissolved state and of the same polyelectrolytes bound to the surface of microspheres has been investigated. Microspheres were prepared by consecutive absorption of oppositely charged polyelectrolytes so that the outer layer of the shell was PAA for the acidic protein urease, and PSS for the alkaline proteins LDH and hemoglobin. It was shown that the dissolved polyelectrolyte completely inactivates all three proteins within one minute with a slight difference in the time constant. (By Hb inactivation are conventionally meant changes in the heme environment observed from the spectrum in the Soret band.) In the presence of microspheres, the proteins were adsorbed on their surface; in this case, more than 95% of the activity was retained within two hours. The proportion of the protein adsorbed on microspheres accounted for about 98% for urease, 72% for Hb, and 35% for LDH, as determined from the tryptophan fluorescence data. The interaction of hemoglobin with another type of charged colloidal particles, phospholipid vesicles, leads to the destruction of the tertiary structure of the protein, which made itself evident in the optical absorption spectra in the Soret band, as well as the spectra of tryptophan fluorescence and circular dichroism. In this case, according to circular dichroism, the percentage of α-helical structure of Hb was maintained. The differences in the physical and chemical mechanisms of interaction of proteins with these two types of charged colloidal particles that leads to differences in the degree of denaturing effects are discussed. [ABSTRACT FROM AUTHOR]

The temperature stability of the cytoplasmic enzyme of glycolysis, lactate dehydrogenase from pig muscle (isoenzyme M4) in complex with anionic polyelectrolyte poly(styrenesulfonate) has been investigated by the methods of adiabatic differential scanning microcalorimetry, own protein fluorescence, and circular dichroism. Calorimetric investigations of the complex of lactate dehydrogenase with poly(styrenesulfonate) in 50 mM phosphate buffer at pH 7.0 have shown that the temperature of the transition and enthalpy of lactate dehydrogenase thermal denaturation sharply decreases with growing weight ratio poly(styrenesulfonate)/lactate dehydrogenase, though at 20°C the enzyme activity of lactate dehydrogenase remains unchanged for several hours irrespective of the addition of poly(styrenesulfonate). The addition of phosphate ions to the solution enhances the resistance of lactate dehydrogenase to both thermal denaturation and inactivation by polyelectrolyte. The data obtained are interpreted from the viewpoint of a special role of two anion-binding centers in intersubunits contacts of lactate dehydrogenase, which enhance its resistance to both thermal denaturation and destruction by polyelectrolyte. [ABSTRACT FROM AUTHOR]

Abstract: Mesoporous silica/polymer sulfonate composite materials were prepared by simply mixing hexadecyltrimethylammonium bromide, polymer sulfonates and TEOS (tetraethoxysilane) in alkaline aqueous solution. Nafion and poly(sodium 4-styrenesulfonate) were employed as polymer sulfonates. XRD patterns and nitrogen adsorption–desorption isotherms showed that the precipitates obtained had mesostructure similar to MCM-41. Especially, the crystallinity of hexagonal structure of composite materials synthesized with Nafion was high. From all the results obtained here, it is concluded that the polymer sulfonate resins might be incorporated in the wall framework of mesoporous silica matrix. However, when the excess amount of Nafion was mixed, the acid sites of Nafion were significantly lost in the obtained materials. These composite materials present new classes of organically modified mesoporous silicas, where organic polymers are incorporated in the framework of mesoporous silica. They were used as catalysts for α-methylstyrene dimerization and Friedel–Crafts alkylation reaction of aromatics. [Copyright &y& Elsevier]

Abstract: Styrenesulfonate was photopolymerized in the presence of the anionic dye Eosine Y. The study of the reactions of the excited- and ground states of the species involved in the photoinitiation process showed that the monomer aggregates forming hydrotropic domains in aqueous solution at concentrations above 0.1M. Although the dye is distributed between these domains and the bulk of the solution, the main initiating pathway involves excited dyes outside the clusters. These results are opposite to those obtained using the cationic dye Safranine, which starts photopolymerization from the dye molecules incorporated in the monomer clusters. [Copyright &y& Elsevier]

A poly(styrenesulfonate) lithium salt was tested as a single-ion conductor in a poly(ethylene oxide)/poly(ethylene glycol) dimethyl ether matrix. Impedance spectroscopy and voltage step polarization were used to characterize the composite electrolytes. A specific conductivity of about 7×10−8 S cm−1 was evaluated at 70 °C. The very low conductivity was attributed to the poor solubility of Li+ in the polymer matrix. AlCl3 was added to the polymer electrolyte to increase the salt dissolution. The addition of the Lewis acid strongly increases the conductivity and a specific conductivity of about 4×10−6 S cm−1 was measured at 20 °C. For temperature lower than 60 °C, the specific conductivity dependence with increasing temperature follows an Arrhenius-type behavior. An activation energy of about 55.6 kJ mol−1 was calculated. A very similar activation energy (60.3 kJ mol−1) was found for the charge transfer resistance. The transport properties of the polymer electrolyte were tested by applying a d.c. voltage step to a symmetrical lithium cell. The current at the applied voltage decreased with time. The decrease was related to an increase in the cell resistance due to the continuous growth of a passivation layer on the lithium surface. [Copyright &y& Elsevier]