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Query: UMLS:C1832588 (PSS)
 2,979 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The basic proteins, protamines and histones H1, are known to condense DNA in vivo. We examine here their ability to condense and solubilize in vitro linear DNA [and a synthetic polyanion, Poly(Styrene-Sulfonate) or PSS] at low ionic concentrations by varying the charge concentration ratio. Phase separation is observed in a very narrow range of ratios for short DNA and PSS; on both sides of this range, polydisperse and charged complexes are formed. A charge inversion is detected. For long DNA chains however, a different behavior is observed: the complexes are not soluble in excess of proteins.
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PMID:Solubility and charge inversion of complexes of DNA and basic proteins. 1702 7

Poly(3,4-ethylenedioxithiophene)/poly(styrene sulphonate) (PEDOT/PSS) aqueous dispersions were mixed with aqueous gold nanoparticle and aqueous silver nanoparticle colloids. PEDOT/gold nanoparticles (Au NP) and PEDOT/silver nanoparticles (Ag NP) films were obtained by solvent casting the corresponding aqueous solutions. The nanocomposite films showed the optical characteristics associated with both the surface plasmon absorption resonance of the metal nanoparticles and the excitation of the bipolaron band of the conducting polymer. As an interesting application we demonstrate the use of metal nanoparticles to tune the color of PEDOT based electrochromic films from blue to violet in the case of Au NP or green in the case of Ag NP.
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PMID:Combined electrochromic and plasmonic optical responses in conducting polymer/metal nanoparticle films. 1768 23

We present a novel fabrication method by using dip pen nanolithography with Poly (3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) for nitric oxide (NO) gas sensor in this report. PEDOT is a kind of conducting polymer which will change its conductance upon NO adsorption. Herein, we have used PEDOT with traditional thick film and DPN nanowires across electrodes. By using traditional thick film device, the lowest detection limit for NO is 3.87 ppm. The preliminary results of DPN nanowires can have aspect ratio (L/W) for up to 220 times and thus have large sensing surface area for higher sensitivity.
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PMID:Nano fabrication of conducting polymers for NO gas by Dip pen nanolithography. 1800 39

Poly(aniline-co- o-anisidine) (P(An-co- o-As)) ionomers and poly(sodium 4-styrenesulfonate) (PSS) were layer-by-layer (LbL) assembled on carboxylic acid-functionalized multiwalled carbon nanotubes (MWNTs). The multilayered polyelectrolyte greatly enhanced the dispersibility and stability of MWNTs in aqueous solutions. More importantly, the nanocomposites showed 3 orders of magnitude of conductivity increase, 4.2 S/cm, compared to that of neat ionomers, 0.004 S/cm. The deposition procedure was monitored with zeta (zeta) potential changes. Fourier transform infrared (FT-IR), ultraviolet-visible (UV-vis), and Raman spectra confirmed charge transfer from the quinoid units of the P(An-co- o-As) to MWNTs, which effectively delocalize the electrons. Further, we explored the pH response of the assembled P(An-co- o-As)/PSS/MWNTs multilayer nanocomposites. The sharp transition of the conductivity in the pH range of 2 to 6 makes the nanocomposites promising candidates for chemical-biological sensing.
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PMID:Layer-by-layer assembly of aqueous dispersible, highly conductive poly(aniline-co-o-anisidine)/poly(sodium 4-styrenesulfonate)/MWNTs core-shell nanocomposites. 1844 69

The formation of complexes with stoichiometric (1:1) as well as nonstoichiometric (2:1) and (1:2) compositions between oppositely charged synthetic polyelectrolytes carrying strong ionic groups and significantly different molecular weights is reported in this contribution. Poly(sodium styrenesulfonate) (NaPSS) was used as polyanion, and a range of copolymers with various molar ratios of the poly(methacryloxyethyltrimethylammonium) chloride, poly(METAC), and the nonionic poly(ethylene oxide) ether methacrylate, poly(PEO45MEMA), were used as polycations. Formation and stability of PECs have been investigated by dynamic and static light scattering (LS), turbidity, and electrophoretic mobility measurements as a function of polyelectrolyte solution concentration, charge density of the cationic polyelectrolyte, and mixing ratio. The data obtained demonstrate that in the absence of PEO45 side chains the 100% charged polymer (polyMETAC) formed insoluble PECs with PSS that precipitate from solution when exact stoichiometry is achieved. In nonstoichiometric complexes (1:2) and (2:1) large colloidally stable aggregates were formed. The presence of even a relatively small amount of PEO45 side chains (25%) in the cationic copolymer was sufficient for preventing precipitation of the formed stoichiometric and nonstoichiometric complexes. These PEC's are sterically stabilized by the PEO45 chains. By further increasing the PEO45 side-chain content (50 and 75%) of the cationic copolymer, small, water-soluble molecular complexes could be formed. The data suggest that PSS molecules and the charged backbone of the cationic brush form a compact core, and with sufficiently high PEO45 chain density (above 25%) molecular complexes are formed that are stable over prolonged times.
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PMID:Formation and stability of water-soluble, molecular polyelectrolyte complexes: effects of charge density, mixing ratio, and polyelectrolyte concentration. 1937 Oct 31

Poly(3,4-ethylenedioxythiophene) (PEDOT) films have been electropolymerized from an aqueous micellar polyethylene glycol (PEG) based solution containing sodium poly(styrenesulfonate) (NaPSS) and lithium trifluoromethanesulfonate. On varying the NaPSS content in the electrodeposition bath, two strikingly different nanostructured morphologies were obtained for ensuing PEDOT:PSS films and these have been correlated to the electrochemical and optical performance of the films. The films grown from the formulation with EDOT:NaPSS in a 1:3 weight ratio comprise of a nanoparticulate structure with a to date scarcely reported hexagonal structure. The film surface is also characterized by some unusual floral shapes encompassing elongated grains. TEM studies reveal that in the 1:3 film two dimensional (planar) PEDOT chains are stacked on top of each other with a vertical separation of 4.63 A. On the other hand the film generated from a 1:1 solution shows a texture wherein a random segregation of PSS particles is seen and this adversely affects the electrochromic response of the film. The larger charge storage capacity (4.9 mC cm(-2)), better charge reversibility during coloration and bleaching, good electrochemical cycling stability up to 2500 cycles, higher electronic conductivity and a superior coloration efficiency of 233 cm2 C(-1) at a photopic wavelength of 550 nm under ion intercalation levels of 0.058 to 1.2 mC cm(-2) shown by 1:3 film as compared to the performance of the 1:1 film are ramifications of fast ion movement promoted by the novel microstructure and the hexagonal modification which has rarely been achieved in PEDOT:PSS films.
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PMID:Electrochromic contrast enhancement of nanostructured poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate films by composition/morphology control. 1945 69

Highly oriented polyaniline (PANI) fiber was prepared by a polymerization at higher temperature and growth in lower temperature. Poly(sodium styrenesulfonate)/polyaniline multilayer film (PSS/PANI)(n) was layer-by-layer molecular-level self-assembled by a simple technique. The morphology and structure of the oriented PANI fiber were characterized, showing an emeraldine state and ordered molecular structure. The growth process and surface topography of the (PSS/PANI)(n) multilayer film were characterized by UV-vis spectroscopy and atomic force microscopy. Absorbance plotted against the bilayers exhibited a linear dependence, indicating a progressive and uniform deposition process of the multilayer film. The (PSS/PANI)(n) multilayer film exhibited an electrical conductivity in the order of 1 S cm(-1), and when bilayer number exceeded a threshold value of 4, the conductivity of the multilayer film increased dramatically. The electrochemical properties were studied through cyclic voltammograms, and it was found that the electrochemical activity of the (PSS/PANI)(n) film increased with the increase of the bilayer number.
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PMID:Layer-by-layer self-assembly of conducting multilayer film from poly(sodium styrenesulfonate) and polyaniline. 1953 92

In this study, we fabricated polyelectrolyte multilayers (PEMs) on a polystyrene (PS) plate by a simple and novel alternate drop coating process (Acta Biomaterialia 2008, 4, 1255-1262), leading to the construction of a functional platform for improving conventional enzyme-linked immunosorbent assay (ELISA) systems. Poly(diallyldimethylammonium chloride) (PDDA) and poly(sodium 4-styrenesulfonate) (PSS) were used as cationic and anionic polyelectrolytes, and then positively or negatively charged surfaces were obtained on the PEMs. The PDDA/PSS PEMs on the PS plate had the following favorable characteristics. On the positive PEMs, the coverage of the blocking reagent (ovalbumin from egg white: OVA) was over 100% by electrostatic interaction between the protein and PEMs, hence, nonspecific adsorption from the secondary antibody was efficiently suppressed. Moreover, the positive PEMs showed higher sensitivity on the ELISA than the negative PEMs, including the PS plate. Regularly oscillating behavior for sensitivity (specific signal-to-noise ratio) was observed on 1-10-step assemblies. The calibration curves for antigen detection on the positive PEMs had wide range of concentration from 0.002 to 5 microg/mL, and largest change in signal as compared with the negative PEMs and the PS plate. In summary, we discovered that positive PEMs possessed excellent performance for ELISA systems, and PEMs could easily improve the immunoassay with a convenient process and diverse substrates.
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PMID:Polyelectrolyte multilayers-modified polystyrene plate improves conventional immunoassay: full covering of the blocking reagent. 1960 75

Even though infection followed by Intra ocular lens (IOL) implantation is a rare complication, therapeutic options are limited and it affects the vision seriously. Interestingly, IOL itself acts as substrate for the adhesion and proliferation of bacteria. An approach to facilitate antibacterial drug adsorption onto the surface of IOL through the modification of IOL surface using the concept of Layer-by-Layer (LbL) formation without sacrificing the vital optical features of the IOLs is presented here. Polyelectroylte multilayers incorporating ampicillin was fabricated on the IOLs using LbL deposition of Poly (sodium 4-styrenesulfonate) (PSS) and Poly (ethylenimine) (PEI). Altogether six layers were formed. The layer formation enabled the IOL to adsorb the drug and modulated the release in a sustained fashion. It appears that using this strategy, IOLs could be modified using a variety of degradable or non-degradable materials to precisely control the delivery of active components to protect eye and the device.
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PMID:Layer-by-Layer modification of poly (methyl methacrylate) intra ocular lens: drug delivery applications. 1977 79

The effect of Polyelectrolyte nanocoating on a cellulose electro-active paper (EAPap) was investigated to improve the actuator performance and durability of EAPap actuators. Nanocoatings of Poly(styrenesulfonate) (PSS) and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) were carried out by immersing cationized cellulose films in to aqueous solutions of PSS and PEDOT:PSS. 2,3-epoxypropyltrimethylammonium chloride was used as cationic reactant. UV-visible spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis showed the successful build up of PSS and PEDOT:PSS nanolayers over the cationized cellulose films. Results revealed that, nanocoating not only improved the durability of the actuators but it also greatly reduced (90%) the energy consumption of the actuators. Preparation, characterization and performance test of the actuators are explained.
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PMID:Effect of polyelectrolyte nanocoating on the performance and durability of cellulose electro-active paper actuator. 1990 49


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