Conducting nylon, cotton and wool yarns by continuous vapor polymerization of pyrrole

Conductive textile yarns were prepared by a continuous vapor polymerization method; the application of polypyrrole by the continuous vapor polymerization method used is designed for the easy adaptation into industrial procedures. The resultant conductive yarns were examined by longitudinal and cross-sectional views, clearly showing the varying levels of penetration of the polymer into the yarn structure. It was found that for wool the optimum specific resistance was achieved by using the 400 TPM yarn with a FeCl3 solution concentration of 80 g/L FeCl3 to produce 1.69 Ω g/cm2. For cotton yarn, the optimum specific resistance of 1.53 Ω g/cm2 was obtained with 80 g/L of a FeCl3 solution.

Conductive wool yarns by continuous vapour phase polymerization of pyrrole

Conducting polypyrrole (PPy) coated wool yarns were prepared by a continuous vapour polymerization technique, using a speed of 1 m/min with different iron(III) chloride (FeCl₃) as the oxidant at different concentrations. The resistivities, tensile properties, longitudinal and cross-sectional views of PPy-coated wool yarns were investigated. Optimum specific electrical resistances of 2.96 Ω g/cm² at 80 g/L FeCl₃ and 1.69 Ω g/cm² at 70 g/L FeCl₃ were obtained for 500 and 400 twist per meter (TPM) yarns, respectively. PPy-coated wool yarns exhibited higher elongation than uncoated yarns. Longitudinal and cross-sectional views of the yarns indicate that PPy coating penetrated deep into the yarn cross-section and a uniform coating was obtained on the surface of the yarn surface.

Electrochromic, magnetotransport and AC transport properties of vapor phase polymerized PEDOT(VPP PEDOT)

Poly(3,4-ethylenedioxy)thiophene (PEDOT) doped with tosylate ion (PEDOT-tosylate or VPP PEDOT) was synthesized by vapor phase polymerization (VPP) technique on glass as well as on glass/ITO and the electrochromic properties were investigated. Compared with that of PEDOT-PSS spin-coated on glass/ITO, the studies showed that VPP PEDOT has a lower work function and better electrochromic properties. The magneto and AC transport properties studies were done on VPP PEDOT coated on glass substrate. The system shows 2-dimensional variable range hopping and wave function shrinkage of charge carriers.

Stable deep doping of vapor-phase polymerized poly(3,4-ethylenedioxythiophene)/ionic liquid supercapacitors

Liquid-solution polymerization and vapor-phase polymerization (VPP) have been used to manufacture a series of chloride- and tosylate-doped poly(3,4-ethylenedioxythiophene) (PEDOT) carbon paper electrodes. The electrochemistry, specific capacitance, and specific charge were determined for single electrodes in 1-ethyl-3-methylimidazolium dicyanamide (emim dca) ionic liquid electrolyte. VPP-PEDOT exhibits outstanding properties with a specific capacitance higher than 300 F g(-1) , the highest value reported for a PEDOT-based conducting polymer, and doping levels as high as 0.7 charges per monomer were achieved. Furthermore, symmetric PEDOT supercapacitor cells with the emim dca electrolyte exhibited a high specific capacitance (76.4 F g(-1) ) and high specific energy (19.8 Wh kg(-1) ). A Ragone plot shows that the VPP-PEDOT cells combine the high specific power of conventional ("pure") capacitors with the high specific energy of batteries, a highly sought-after target for energy storage.

The suitability of DEAE-Cl active groups on customized poly(GMA-co-EDMA) continuous stationary phase for fast enzyme-free isolation of plasmid DNA

The creation of a commercially viable and a large-scale purification process for plasmid DNA (pDNA) production requires a whole-systems continuous or semi-continuous purification strategy employing optimised stationary adsorption phase(s) without the use of expensive and toxic chemicals, avian/bovine-derived enzymes and several built-in unit processes, thus affecting overall plasmid recovery, processing time and economics. Continuous stationary phases are known to offer fast separation due to their large pore diameter making large molecule pDNA easily accessible with limited mass transfer resistance even at high flow rates. A monolithic stationary sorbent was synthesised via free radical liquid porogenic polymerisation of ethylene glycol dimethacrylate (EDMA) and glycidyl methacrylate (GMA) with surface and pore characteristics tailored specifically for plasmid binding, retention and elution. The polymer was functionalised with an amine active group for anion-exchange purification of pDNA from cleared lysate obtained from E. coli DH5α-pUC19 pellets in RNase/protease-free process. Characterization of the resin showed a unique porous material with 70% of the pores sizes above 300 nm. The final product isolated from anion-exchange purification in only 5 min was pure and homogenous supercoiled pDNA with no gDNA, RNA and protein contamination as confirmed with DNA electrophoresis, restriction analysis and SDS page. The resin showed a maximum binding capacity of 15.2 mg/mL and this capacity persisted after several applications of the resin. This technique is cGMP compatible and commercially viable for rapid isolation of pDNA.

Neutral and Charged 1-Butyl-3-methylimidazolium Triflate Clusters: Equilibrium Concentration in the Vapor Phase and Thermal Properties of Nanometric Droplets

Ground state energy, structure, and harmonic vibrational modes of 1-butyl-3-methylimidazolium triflate ([bmim][Tf]) clusters have been computed using an all-atom empirical potential model. Neutral and charged species have been considered up to a size (30 [bmim][Tf] pairs) well into the nanometric range. Free energy computations and thermodynamic modeling have been used to predict the equilibrium composition of the vapor phase as a function of temperature and density. The results point to a nonnegligible concentration of very small charged species at pressures (P ~ 0.01 Pa) and temperatures (T 600 K) at the boundary of the stability range of [bmim][Tf]. Thermal properties of nanometric neutral droplets have been investigated in the 0 T 700 K range. A near-continuous transition between a liquidlike phase at high T and a solidlike phase at low T takes place at T ~ 190 K in close correspondence with the bulk glass point Tg ~ 200 K. Solidification is accompanied by a transition in the dielectric properties of the droplet, giving rise to a small permanent dipole embedded into the solid cluster. The simulation results highlight the molecular precursors of several macroscopic properties and phenomena and point to the close competition of Coulomb and dispersion forces as their common origin.

High rates of oxygen reduction over a vapor phase-polymerized PEDOT electrode

The air electrode, which reduces oxygen (O₂), is a critical component in energy generation and storage applications such as fuel cells and metal/air batteries. The highest current densities are achieved with platinum (Pt), but in addition to its cost and scarcity, Pt particles in composite electrodes tend to be inactivated by contact with carbon monoxide (CO) or by agglomeration. We describe an air electrode based on a porous material coated with poly(3,4-ethylenedioxythiophene) (PEDOT), which acts as an O₂ reduction catalyst. Continuous operation for 1500 hours was demonstrated without material degradation or deterioration in performance. O₂ conversion rates were comparable with those of Pt-catalyzed electrodes of the same geometry, and the electrode was not sensitive to CO. Operation was demonstrated as an air electrode and as a dissolved O₂ electrode in aqueous solution.

Melting, ablation, and vapor phase condensation during atmospheric passage of the Bjurbole Meteorite

A detailed study of the Bjurbole fusion crust using scanning electron microscopy (SEM) and energy dispersive analysis (EDS) shows that filamentary crystals and ablation spheres may form on the meteoroid surface. Filamentary crystals, hollow spheres, and porous regions of the surface point to a period of intense vapor phase activity during atmospheric passage. Filamentary crystals can be divided into three categories on the basis of bulk composition and morphology. Two types of filamentary crystals are vapor phase condensation products formed during atmospheric entry of the meteoroid. The other type forms by the interaction of seawater with the fusion surface. The density and composition of ablation spheres varies with the flight orientation of the meteorite. The size range and composition of iron-nickel spheres on the surface of Bjurbole are similar to spheres collected in the stratosphere. A comparison of stratospheric dust collections with meteorite surfaces may provide further insight into the mechanisms of meteoroid entry into planetary atmospheres.

Electronic-structures of h2o.bf3 and related n-v addition-compounds - a combined eels-ups study in vapor-phase

The detailed electronic structure of the n-v addition compound H2O·BF3 has been investigated for the first time by a combined use of electron energy loss spectroscopy (EELS) and UV photoelectron spectroscopy (UPS) augmented by MO calculations. The calculated molecular orbital energies of H2O·BF3 agree well with the UPS results and have been used to assign the electronic transitions obtained from EELS and to construct an orbital correlation diagram. The Journal of Chemical Physics is copyrighted by The American Institute of Physics.

A novel investigation of vapor-phase charge-transfer complexes of halogens with n-donors by electron energy loss spectroscopy

Complexes of I2 with diethyl ether and triethylamine and of Br, with diethyl ether have been investigated in the vapor phase for the first time by employing electron energy loss spectroscopy. Besides the CT bands, blue-shifted vacuum-UV bands of the halogens have been assigned; the amine-I, system appears to exhibit two CT bands,associated with two different excited states of the complex.