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Highly conductive nylon 6 nanofiber web was fabricated with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and dimethyl sulfoxide (DMSO) for electronic textiles. To improve electrical conductivity, repeated coating with PEDOT:PSS and multi-step treatment of DMSO was performed. The effects of these treatments on electrical conductivity, surface properties, and chemical structures were investigated. For repetitive coating cycles, pristine PEDOT:PSS dispersion was dropped onto a nylon 6 nanofiber web for between one and four times of coating. For DMSO multi-step treatment, in the one-step treatment, the nanofiber web was repeatedly treated using PEDOT:PSS doped with DMSO. In the two-step treatment, the nanofiber web was repeatedly treated with doped PEDOT:PSS at first and, then, it was immersed in a DMSO bath. As a result, the sheet resistance decreased dramatically as the number of coating cycles increased. When the two-step treatment was applied, the sheet resistance was much lower compared to that of the one-step treatment, and thereby sample PD4-D with the lowest resistance showed 6.56 Ω/sq. As a result, the surface of the nanofiber web was covered with more PEDOT:PSS as the coating cycle was repeated. The PEDOT particles became large and long shapes after the two-step treatment of DMSO. This inferred that the contact area among conducting PEDOT particles increased because insulating PSS was removed by DMSO. In addition, the presence of PEDOT:PSS and nylon 6 was confirmed. This study proved that the simultaneous treatments of repeated coating with PEDOT:PSS and multi-step treatment of DMSO can improve electrical conductivity, and it developed the highly conductive PEDOT:PSS/nylon 6 nanofiber web.

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.

The present study involves the use of dip nanocoating, one of the passive techniques by the modification of the heater surface to understand the behavior of pool boiling heat transfer characteristi...

In this study, the poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) conductive dry films were observed in terms of their thicknesses versus electrical resistances measured and related electrical resistivities calculated. The evolution of their electrical resistances was monitored in 75 days. Three groups of sensor yarns were studied also where the percolation threshold of the polymer complex poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) had a crucial role in their manufacture. More glass component in sensor yarns led to less coating thickness what is in correlation with their interface phenomena and adhesion.

We present flexible inorganic/organic composite films with high thermoelectric performance. SnSe0.97Te0.03 (Sn–Se–Te) is a promising inorganic material, with an outstanding Seebeck coefficient, and it can be successfully exfoliated from bulk ingots into nanosheets. We incorporated these Sn–Se–Te nanosheets in a conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) matrix to obtain Sn–Se–Te nanosheets(x)/PEDOT:PSS composite films (where x indicates the loading ratio in wt% of the Sn–Se–Te nanosheets). The thermoelectric properties of these composites were examined and discussed as a function of x, and their thermoelectric power factor was optimized. The maximum power factor (∼130.3 μW m−1·K−2) with outstanding durability was obtained with the Sn–Se–Te nanosheets(15)/PEDOT:PSS composite, and this was attributed to the improved Seebeck coefficient. Hence, the incorporation of Sn–Se–Te nanosheets and PEDOT:PSS is promising for flexible thermoelectric applications.

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Thermoelectric (TE) materials are important for sustainable development because they can directly convert heat into electricity. Compared with inorganic TE materials, conductive polymers have demonstrated unique benefits and their irreplaceability. But their TE properties, particularly the Seebeck coefficient, must be greatly enhanced for practical application. In this work, MXene (Ti

Nonconductive commercial viscose yarns have been coated with a commercial conducting poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) layer providing electrical conductivity which allowed a second coating of the electroactive conducting polymer polypyrrole through electropolymerization to develop textile yarns actuators. To simplify the PEDOT coating process and at the same time make this process more suitable for application in industry, a new coating method is developed and the properties of the PEDOT-PSS conducting layer is optimized, paying attention on its effect on the actuation performance. The effect of the concentration of an additive such as dimethylsulfoxide (DMSO) on actuation, and of PEDOT:PSS layers, is investigated. Results show that on improving this conducting layer, better performance than previously developed yarn-actuators is obtained, with strains up to 0.6%. This study provides a simple and efficient fabrication method toward soft, textile-based actuators for wearables and assistive devices with improved features. Funding agencies: The authors acknowledge the Erling-Persson Family Foundation,Promobilia Foundation (F17603), Union’s Horizon 2020 research andinnovation program under grant agreement no. 825232 “WEAFING”for their nancial support. E.W.H.J. acknowledges nancial support fromthe Swedish Government Strategic Research Area in Materials Science onFunctional Materials at Linköping University (Faculty Grant SFO Mat LiUNo. 2009 00971). F.E-T. acknowledges Universidad Tecnica de Ambato(UTA-FCIAL-UODIDE-2018-0047-M) for the financial support.

We report the adsorption characteristics and mechanisms of a strong polyanion, poly(styrenesulfonate), PSS, onto α-Al2O3 with large size (L-Al2O3) and small size (S-Al2O3) in this paper. Some effective conditions to the adsorption of PSS onto L-Al2O3 and S-Al2O3 such as adsorption time, pH, mass ratio of PSS to α-Al2O3, and ionic strength were systematically studied. Maximum adsorption capacities of PSS onto both L-Al2O3 and S-Al2O3 were achieved with adsorption time 120 min, mass ratio of PSS to α-Al2O3 20 mg/g, and ionic strength 50 mM NaCl. The PSS adsorption onto S-Al2O3 significantly decreased with increasing pH from 4 to 9 while PSS adsorption onto L-Al2O3 decreased insignificantly in the pH range 4–9. Adsorption of PSS onto both L-Al2O3 and S-Al2O3 increased with increasing salt from 0 to 50 mM NaCl, indicating that electrostatic and none-lectrostatic interactions controlled adsorption at low ionic strength. However, adsorption of PSS was independent on the ionic strength at salt concentration higher than 50 mM. The changes in surface charge after PSS adsorption onto L-Al2O3 and S-Al2O3 were determined by zeta potential while the differences of surface functional groups before and after PSS adsorption were characterized by Fourier-transform infrared spectroscopy (FT-IR). The zeta potential as a function of the mass ratio of PSS to L-Al2O3 and S-Al2O3 agreed well with the adsorption capacity against the mass ratio. Adsorption mechanisms of PSS onto L-Al2O3 and S-Al2O3 were also discussed based on the changes in zeta potential, the differences of surface functional groups, and adsorbed amount as a function of the mass ratio of PSS to α-Al2O3.

Sensor devices using different poly(3,4-ethylene dioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) based active layers were fabricated with all solution processes. It was found the devices of pristine PEDOT:PSS presented high response to humidity change, but little response to ammonia (NH3). In contrast, the DMSO doped PEDOT:PSS devices were nearly insensitive to humidity change, and exhibited significantly improved responsivity to NH3. Incorporation of AgNWs into the DMSO doped PEDOT:PSS film further enhanced the responsivity to NH3, while maintaining insensitivity to humidity changes. The mechanisms for such different sensing properties were revealed. Finally, the fabricated NH3 and humidity sensors using different PEDOT:PSS based films were integrated with a near field communication (NFC) chip to realize a flexible system, which was able to be attached on the packaging film for monitoring the meat freshness, with the sensing data being read out wirelessly by a smart phone.

A modified Hummers method was used to synthesize graphene oxide (GO) with different degrees of oxidation. Single-factor and orthogonal experiments were designed to analyze the influence of the oxid...

Drug-eluting stents (DESs) are widely used in the palliative treatment of many kinds of cancers. However, the covered polymers used in DESs are usually associated with stent migration and acute cholecystitis. Therefore, developing noncovered drug-loading layers on metal stents is of great importance. In this work, Ni-Ti layered double hydroxide (Ni-Ti LDH) films were prepared on the surface of nitinol via hydrothermal treatment, and the LDH films were further modified by poly(styrenesulfonate) (PSS). The anticancer drug doxorubicin could be effectively loaded onto the modified films, and drug release could be smartly controlled by the pH. Besides, the drug absorption amounts of cancer cells cultured on the films could be effectively improved. These results indicate that the PSS-modified LDH film may become a promising drug-loading platform that can be used in the design of DESs.

In this work, the posttreatment of an organic polymer is performed using an inorganic acid, nitric acid (HNO3). We picked poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as the base material and improved its electrical conductivity by acid treatment with different concentrations of HNO3. The acid treatment was able to achieve the optimum electrical conductivity of 197 S/cm, which is 115.5 times higher than the base material when treated with an aqueous solution containing 65% of HNO3. Moreover, the films showed higher transparency in the visible range while conducting Fourier transform infrared analysis. In addition, the treated films showed improved stability against outdoor operating conditions in terms of sheet resistance compared with untreated PEDOT:PSS films. We tried to develop a hypothesis to describe the reason behind the electrical conductivity enhancement by studying the thicknesses of all the samples at different acid concentration levels. The results from atomic force microscopy, the Hall effect, and the trend of film thickness suggest that the conformational change, the removal of excess PSS from the polymer, and the increase in carrier concentration are the reasons behind the improvement in electrical conductivity.

Organic-inorganic halide perovskite materials have been touted for their excellent light-absorbing properties, implying great potential for low-cost fabrication of high-performance solar cells. Nevertheless, numerous studies revealed that choice of materials and optimization of device architecture is crucial for realizing high efficiency photovoltaics consisting perovskite photoactive materials. PEDOT:PSS, poly (3,4-ethylenedioxythiophene):poly (styrenesulfonate), has been widely selected as a hole transport material, for its high transparency, which allows enough light to the photoactive layer. However, perovskite solar cells with PEDOT:PSS hole transport layer often suffers low stability, due to the high acidity compared to the other devices. In this research, we introduce various effective solutions for controlling electrical and chemical properties of PEDOT:PSS, for realization of high efficiency and stability of perovskite solar cells. Introducing inorganic copper-based chalcogenide, (such as copper sulfide, Cu2-xS) nanoparticles [1] and organic nanosheets [2] (covalent organic nanosheets, CONs) to PEDOT:PSS hole transport layer resulted in improved charge dynamics factors and device performance. The incorporation of the CuS nanoparticles induced interaction between PEDOT molecules and the particles, which resulted in structural transition of PEDOT:PSS and its higher hole mobility. Interestingly, UV-selective absorbing properties of CuS particles reduced photo-induced damage on perovskite materials, by filtering UV light from the sunlight which enhanced the devices’ stability significantly. On the other hand, the additional organic interlayer between PEDOT:PSS and hole-selective electrode facilitates formation of even film morphology, which contributed to the higher crystallinity of perovskite layers and enhanced charge separation, which resulted in higher performance compared to the pristine device. Suppressing acidity of PEDOT:PSS layer has been another target for enhancing stability of perovskite solar cells. Acidity modification by incorporation of imidazole [3] not only prevented unintentional degradation of device structure, and the PEDOT:PSS with modified pH brought about higher performance which originated from tuned surface properties and molecular rearrangement, which resulted in better crystallization of perovskite coated onto the PEDOT:PSS layers, and efficient charge transport. Also, tailoring ratio of amount of PEDOT to PSS molecules by inducing solution reaction between neutral and acid PEDOT:PSS [4] revealed encouraging electric properties and stability of PEDOT:PSS hole transport layer. This work provides solutions for effective tailoring of electrical and chemical properties of PEDOT:PSS, which will shed light on the low-cost and reliable fabrication of perovskite photovoltaics. [1] Kim, B. G., Jang, W., Choa, Y. H., and Wang, D. H., ACS Sustain. Chem. Eng., 2020, 8, 20, 7617–7627. [2] Park, S., Kim, M. S., Jang, W., Park, J. K., and Wang, D. H. Nanoscale, 2018, 10, 4708-4717. [3] Yi, M., Jang, W., and Wang, D. H. (2019). ACS Sustain. Chem. Eng., 2019, 7, 8245–8254. [4] Kim, M., Yi, M., Jang, W., Kim, J. K., and Wang, D. H. Polymers, 2020, 12, 129.

Although dual redox mediators (RMs) largely promote the discharge capacity and decreases the charge overpotential in Li-O2 batteries, the shuttle effect leads to a RM degradation and a serious deterioration of Li metal, which results in a poor sustainability. Here, a poly (3,4-ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS) -decorated separator has been firstly introduced into a dual mixture RMs-involved Li-O2 system, which restrains the shuttle effect via coulombic interactions. Benefiting from the advantages of as-prepared separator, a cell exhibits an enhanced cycling stability and a good reversibility associated with the Li2O2 formation and decomposition during cell cycling. These results represent a promising progress in the development of an easy-to-operate modified separator for a highly efficient Li-O2 battery.

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.

We report a broad photoluminescence (PL) band of poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) ranging from 1.2 to 3.0 eV over the full range of the visible region. Comparison with the PL of related materials reveals that the origin of the observed PL of PEDOT/PSS is PSS. This study indicates that the removal of excess PSS improves the optical properties of PEDOT/PSS for application as transparent electrodes.

We describe a simple method to increase the conductivity of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) film by exposure to ultraviolet (UV) light in vacuum. Up to four order of conductivity improvement (from 10−3 to 50 S/cm) is achieved by irradiating PEDOT:PSS film with 254 nm ultraviolet (UV) light. Increased conductivity in UV treated PEDOT:PSS film is stable under ambient exposure. The mechanism for conductivity improvement is investigated by current-voltage measurement, atomic force microscopy, and absorption spectrum. Photo-cross-linking of PSS chains is determined as the reason for conductivity improvement. Our result demonstrates that UV treatment is capable of modifying the conductivity of PEDOT:PSS film independent of the process of film formation.

Free-standing nanocomposite films of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)/Fe3O4 were successfully prepared by mechanically blending magnetic Fe3O4 nanoparticles with poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) solution and casting the mixed solution on polypropylene film substrates. The characterization of nanocomposite films was investigated by scanning electron microscopy and Fourier transform infrared spectra. The result indicated that the Fe3O4 nanoparticles were composited together well with poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate). It was found that the content of Fe3O4 has a significant effect on the electrical conductivity of the nanocomposite film. The maximum electrical conductivity could be up to 218 S/cm, at optical weight ratio (25 wt% Fe3O4). Simultaneously, the Seebeck coefficient fluctuated smoothly in a tiny range (13.1–15.8 µV/K), and the power factor was calculated to be 5.26 μW/mK2.

Poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate)/silver nanoparticles composite inks have been prepared through in situ synthesis and ultrasonic dispersion. The developed inks were proved to be suitable for various inkjet printing trials to deposit the thin films which were subsequently characterized to assess their electric and optical properties. The results have indicated that the dedoping of PSS from PEDOT during the in situ synthesis can be detrimental to the conductivity of the deposited composite films. However, the addition of silver nanoparticles to pristine PEDOT:PSS has significantly enhanced the conductivity of the thin films, with an inevitable loss in transparency. The various factors that can influence the properties of the thin films have also been analyzed and discussed. This study provides an insight into the effect of silver nanoparticles on PEDOT:PSS thin films deposited using inkjet printing process, and their properties due to the methods of ink formulation.

Polyelectrolyte gels are useful as carriers of proteins and other biomacromolecules in, e.g., drug delivery. The rational design of such systems requires knowledge about how the binding and release are affected by electrostatic and hydrophobic interactions between the components. To this end we have investigated the uptake of lysozyme by weakly crosslinked spherical poly(styrenesulfonate) (PSS) microgels and macrogels by means of micromanipulator assisted light microscopy and small angle X-ray scattering (SAXS) in an aqueous environment. The results show that the binding process is an order of magnitude slower than for cytochrome c and for lysozyme binding to sodium polyacrylate gels under the same conditions. This is attributed to the formation of very dense protein-rich shells in the outer layers of the microgels with low permeability to the protein. The shells in macrogels contain 60 wt % water and nearly charge stoichiometric amounts of lysozyme and PSS in the form of dense complexes of radius 8 nm comprising 30–60 lysozyme molecules. With support from kinetic modelling results we propose that the rate of protein binding and the relaxation rate of the microgel are controlled by the protein mass transport through the shell, which is strongly affected by hydrophobic and electrostatic interactions. The mechanism explains, in turn, an observed dependence of the diffusion rate on the apparent degree of crosslinking of the networks.

Direct Observation of an Isolated Cyclic Sodium Poly(styrenesulfonate) Molecule by Atomic Force Microscopy

To provide an in-depth understanding of the complexation mechanism of protein and polyelectrolyte, a heating-cooling-reheating protocol was employed to study the unfolding and refolding behaviors of a model protein, lysozyme, in the presence of a negatively charged polyelectrolyte, sodium poly(styrenesulfonate) (PSS). It was found that, with elevated PSS concentration, a new state (state I) was first formed via a "two-state" conversion process and this state could further convert to a completely unfolded state (state II) via a "non-two-state" conversion. This non-two-state conversion process occurs without the coexistence of states I and II but involves the formation of various intermediate unfolded protein structures. Different from the pure lysozyme that exhibited refolding upon cooling from its heat-denatured state, lysozyme in state I could undergo unfolding upon heating but no refolding upon cooling, while lysozyme in state II did not undergo unfolding or refolding upon thermal treatments. In addition, the effects of ionic strength and molecular weight of polyelectrolyte on the unfolding and refolding behaviors of lysozyme were also investigated. The present work provides a better understanding of the principles governing protein-polyelectrolyte interactions and may have implications for the fabrication of biocolloids and biofilms.

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 0.1 M. 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.

We present experimental results on the dynamic surface properties of aqueous solutions of sodium poly(styrenesulfonate). The dynamic surface elasticity at frequencies from 0.01 up to 500 Hz and at concentrations exceeding 0.1 wt % proved to be significantly higher than the corresponding data for solutions of nonionic polymers. Another peculiarity consisted in extremely slow changes of the surface properties with time. The addition of salt did not lead to significant changes of the surface elasticity, which was in disagreement with the expectation from the SCF theory. The obtained results can be explained if one assumes aggregate formation in the surface layer.

Ionic amphiphilic diblock copolymers, such as polystyrene-b-poly(styrenesulfonate), show non-surface activity when some requirements are satisfied. The main origin of this unique property has been ...

Electron spin resonance (ESR) study was performed on organic layered films of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/pentacene that were fabricated with different depos...

Addition of Ca2+ ions increases the electrocatalytic response towards NADH at poly(aniline)–poly(vinylsulfonate) and poly(aniline)–poly(styrenesulfonate) modified electrodes by up to 12 and 25 times, respectively. This enhancement effect is reproducible and reversible. Measurement of the amount of charge passed through the polymer film in the presence of Ca2+ indicates a correlation between the total amount of Ca2+ incorporated within the polymer film and the magnitude of the enhancement of the electrocatalytic current for NADH oxidation at the polymer film. In addition, 31P-NMR studies show that the amount of NADH bound within the poly(aniline) film is increased significantly when Ca2+ is present. These results suggest that the enhancement of the NADH oxidation current at poly(aniline) modified electrodes caused by Ca2+ is due to an increase in the partition of NADH into the polymer film and/or an increase in the binding affinity of the polymer for NADH.