Poly(vinyl alcohol) modified by KE reactive dyes as a novel proton‐exchange membrane for potential fuel‐cell applications

A new type of proton‐exchange membrane based on poly(vinyl alcohol) (PVA) modified KE reactive dyes (KE‐4BD) was prepared and evaluated as H⁺‐conducting polymer electrolytes. The effects of the content of KE‐4BD on the membrane H⁺ conductivity and water uptake were studied with an alternating‐current impedance technique and the method of weighing, respectively. Fourier transform infrared and scanning electron microscopy were used for the chemical and structural characterization of these membranes. With all of these properties, the optimal mass ratio between PVA and KE‐4BD was 1:0.5, and the resulting membrane exhibited a high proton conductivity (0.109 S/cm) at room temperature; this afforded a power density of 83.9 mW/cm² at 210.4 mA/cm² and an open‐circuit voltage of 810.8 mV. The PVA/KE‐4BD membranes showed a high oxidative stability in Fenton's reagent (3% H₂O₂ v/v, 2 ppm FeSO₄). Thermal analysis also showed that the membranes exhibited a significant improvement in thermal stability. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43019.     

Synthesis of polypyrrole‐modified TiO2 composite adsorbent and its adsorption performance on acid Red G

The adsorption–desorption characteristics of Acid Red G (ARG) on the polypyrrole‐modified TiO₂ (PPy/TiO₂) composite as a novel adsorbent was investigated. PPy/TiO₂ was synthesized via the in‐situ polymerization of pyrrole monomer in the prepared TiO₂ sol solution. Results from X‐ray diffraction and Fourier transform infrared spectra indicated the formation of the PPy/TiO₂ composite. The adsorption experiments showed that the modification of PPy substantially improved the adsorption and regeneration abilities of PPy/TiO₂. The adsorption equilibrium was achieved in a short time of 20 min, and the adsorption kinetics followed the pseudo‐second‐order model. The Langmuir adsorption isotherm was found for PPy/TiO₂, with the maximum adsorption capacity of 179.21 mg/g. The regeneration experiments showed that PPy/TiO₂ could be successfully regenerated by simple alkali‐acid treatment. The adsorption efficiency of the regenerated PPy/TiO₂ adsorbent for ARG was still greater than 90% after regeneration for 10 times. Additionally, the adsorption efficiency of PPy/TiO₂ for the ARG effluent was still higher than 78% after adsorption–desorption for four times. It is expected that the PPy/TiO₂ composite can be considered as a stable adsorbent for the removal of dye. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Effect of the grain size of nanoparticle dye‐coated titanium dioxide on the short‐circuit current density and open‐circuit voltage of an indium tin oxide/titanium dioxide/poly(acrylonitrile)–propylene carbonate–lithium perchlorate/graphite solar cell

A dye‐sensitized indium tin oxide (ITO)/titanium dioxide (TiO₂)/polyacrylonitrile (PAN)–propylene carbonate (PC)–lithium perchlorate (LiClO₄)/graphite solar cell was fabricated, and its performance was tested in the dark and under the illumination of a 100 mW/cm² light. Three TiO₂ samples were used in the device, namely, uncoated TiO₂, a TiO₂ film coated with methyl red dye, and a TiO₂ film coated with coumarin dye. The films were deposited onto an ITO‐covered glass substrate by a controlled hydrolysis technique assisted with a spin‐coating technique. The films were characterized by scanning electron microscopy to determine their average grain size. The smallest grain size (48 nm) was obtained for the uncoated film. An electrolyte of PAN–LiClO₄ with PC plasticizer was prepared by a solution‐casting technique. A graphite electrode was prepared on a glass slide by an electron‐beam evaporation technique. The device showed rectification properties in the dark and showed a photovoltaic effect under illumination. The device with the uncoated TiO₂ film showed the highest short‐circuit current density (2.0 μA/cm²) and an open‐circuit voltage of 0.64 V because it possessed the smallest grain size. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Effects of a pretreatment with N‐methylmorpholine‐N‐oxide on the structures and properties of ramie

To improve the dyeing properties of ramie, the ecofriendly organic solvent N‐methylmorpholine‐N‐oxide (NMMO) was used to substitute sodium hydroxide as a ramie‐fiber swelling solvent. Through padding and baking pretreatment, ramie fabric was modified by an NMMO aqueous solution. Ultraviolet–visible spectrophotometry, Fourier transform infrared spectroscopy, X‐ray diffraction, and differential scanning calorimetry were used to investigate the effects of NMMO pretreatment on the structure of the ramie, whereas the color strength (K/S, where K is the light absorption coefficient and S is the scattering coefficient), adsorption isotherm, and dye uptake rate curve were measured to investigate the effects of NMMO pretreatment on the dyeing properties of the ramie. The results show that the ramie fiber experienced a limited and irreversible swelling because of the partial breakage of interhydrogen and intrahydrogen bonds of cellulose molecules in the amorphous area, but the crystal and chemical structure of the ramie fiber did not change obviously under the experimental conditions. The K/S value of the NMMO‐modified ramie fabrics dyed with reactive dyes increased by about 100%, and the dye uptake increased by 27.88% compared to that of the raw sample, whereas the standard affinity and diffusion coefficient value of the reactive dyes on the NMMO‐modified ramie fabric were higher than those of the raw ramie fabric. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Antimicrobial activity of some new 4‐arylazo‐3‐methylthiophene disperse dyes on polyester fabrics

A series of novel 4‐arylazo‐3‐methylthiophenes was synthesized by the heterocyclization of 2‐arylhydrazono‐2‐acetyl thioacetanilide derivatives with a variety of α‐halogenated reagents, such as chloroacetone, phenacyl bromide, ethyl chloroacetate, and chloroacetonitrile. The structures of the synthesized thiophene derivatives were confirmed by ultraviolet–visible, IR, and ¹H‐NMR spectroscopic techniques and elemental analysis. The synthesized dyes were applied to polyester fabrics as disperse dyes, and their fastness properties were evaluated. The dyed polyester fabrics displayed antibacterial efficacy against Gram‐positive (Staphylococcus aureus) and Gram‐negative (Escherichia coli) bacteria. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Simultaneous adsorptive removal of methylene blue and copper ions from aqueous solution by ferrocene‐modified cation exchange resin

Resin was modified with ferrocene (Fc) to enhance removal of Methylene Blue (MB) and Cu²⁺ from simulated wastewater. The FTIR, N₂‐BET, and X‐ray fluorescence analysis confirmed that Fc was successfully grafted onto the surface of resin. The adsorption capacity of Fc modified cation exchange resin (FMCER) was calculated to be 392.16 mg/g Cu²⁺ and 10.01 mg/g MB. Both processes were spontaneous and exothermic, best described by Langmuir equation. Pseudo‐first‐order kinetic model satisfied the adsorption of MB, while the intraparticle‐diffusion model fitted the kinetics of Cu²⁺ adsorption best. The result revealed a multilayer adsorption of Cu²⁺ on FMCER, and the kinetics maybe controlled by intraparticle diffusion, film diffusion, and competition force. The adsorption of MB and Cu²⁺ on FMCER were physicosorptive, with activation energies of 2.09 and 1.27 kJ/mol. pH 2–7 and 4–5 are optimum for the removal of MB and Cu²⁺, and pH 4 is optimal for the simultaneous removal of MB and Cu²⁺. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41029.     

Removal of basic dyes from aqueous solutions with sulfonated phenol–formaldehyde resin

In this study, we aimed to investigate the removal of basic dyes, including Safranin T (ST), Nile Blue A (NBA), and Brilliant Cresyl Blue (BCB), from aqueous solution with a sulfonated phenol–formaldehyde resin. This sulfonated resin was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The adsorption properties of this resin were investigated under different adsorption conditions with different initial dye concentrations, contact times, and pH values. The adsorption equilibrium data were analyzed with Langmuir and Freundlich models. The adsorption behaviors of ST, NBA, and BCB onto the sulfonated resol‐type phenol–formaldehyde resin were better described by the Freundlich model. The adsorption capacities of the sulfonated resol resin for ST, NBA, and BCB decreased in the following order: NBA > BCB > ST. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Coloration properties and chemo‐rheological characterization of a dioxazine pigment‐based monodispersed masterbatch

A dioxazine‐based color pigment was added to a commercial polyamide 6 (PA6) through an extrusion process, in order to prepare monoconcentrated violet masterbatches through different production set‐up. A detailed characterization of the resulting materials was carried out in order to find the best processing parameters combination to optimize pigment dispersion and to reduce the clogging power. The preparation of masterbatches with repeated extrusions markedly reduced the filter pressure value and increased the Relative Color Strength, while filtration did not significantly influence pigment dispersion. Rheological measurements and end‐groups analysis were conducted on the same materials with the aim to evaluate their thermal degradation resistance, and the thermal stability of the compounds was retained even upon three extrusions. Therefore, it can be concluded that a proper optimization of the process parameters could lead to an important reduction of the production waste, increasing the quality of the final product. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41452.     

Optimization of thermoelectric properties of metal‐oxide‐based polymer composites

Thermoelectric modules can be used for thermal energy harvesting. Common rigid thermoelectric stacks usually contain heavy metal alloys such as Bi₂Te₃. In order to substitute conventional materials and to reduce manufacturing costs, nontoxic, inexpensive and abundant materials using low‐cost processes are first choice. This study deals with polymer composites consisting of a polysiloxane matrix filled with thermoelectric Sn_0.85Sb_0.15O₂ particles in micrometer scale. Thin composite sheets have been prepared by doctor blade technique and the Seebeck coefficient, the electrical and thermal conductivity, and the porosity were measured. Platelet‐type particles, consisting of Sn_0.85Sb_0.15O₂‐coated insulating mica substrate and globular Sn_0.85Sb_0.15O₂ particles have been varied in size, coating thickness and were mixed with each other in different ratios. The filler content was varied in order to maximize the figure of merit, ZT, to 1.9 × 10^?5 ± 4 × 10^?6. Owing to their low raw material costs and the high degree of design freedom of polymer composites, one may use these materials in thermoelectric generators for remote low‐power demanding applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 40038.     

Novel N‐ethyl‐2‐styrylquinolinium iodides as sensitizers in the photoinitiated free‐radical polymerization of trimethylolopropane triacrylate. II

Results of kinetic studies of two‐component photoinitiator systems used in the visible‐light photoinduced polymerization of 2‐ethyl‐2‐(hydroxymethyl)‐1,3‐propanediol triacrylate are presented. Nine different styrylquinolinum dyes coupled with n‐butyltriphenylborate as a coinitiator have been used as photoinitiating systems. Reactive radicals that initiate the polymerization are formed by the well‐known mechanism of photoinduced electron transfer between dye cations acting as electron acceptors and borate anions acting as electron donors. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Effect of nano‐TiO2 dispersion on PEO polymer electrolyte property

Polymer electrolyte membranes based on poly(ethylene oxide) (PEO) doped with TiO₂ nanoparticles were synthesized by simple solution cast technique. Mesoporous TiO₂ film was prepared by doctor‐blade method. The modified polymer membranes and the mesoporous films were characterized by SEM, TEM, AFM, ionic conductivity, and J‐V measurements. Dye‐sensitized solar cells (DSSC) have been fabricated in which PEO‐polymer electrolyte doped with and without nano‐TiO₂ were sandwiched between porous TiO₂ and counter electrodes. The DSSC with nano‐TiO₂ doped polymer electrolyte shows better performance (1.68%) in comparison with pristine polymer electrolyte (1.07%), which is due to improved ionic conductivity value in polymer electrolyte system by nano‐TiO₂ doping. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Preparation and properties of Styrene-Butyl Acrylate resin co-encapsulated Pigment Red 48:2 and Oxidized Polyethylene wax composite nanoparticles

In this study, the Pigment Red 48:2 (PR48:2) and oxidized polyethylene (OPE) wax were evenly dispersed in the aqueous phase by ball-milling method, and then the composite nanoparticles of styrene-butyl acrylate (P(St/BA)) resin co-encapsulated PR48:2 and OPE wax were prepared via in-situ emulsion polymerization. The morphology, size distribution, composition, thermal properties, colorimetric performance, acid–alkaline resistance, and anti UV-aging ability of the encapsulated nanoparticles were characterized by different analytical techniques. When the sodium dodecyl sulfate (SDS) concentration was 0.01 mol/L, the average size of encapsulated nanoparticles was about 120 nm, the particle dispersion index (PDI) was 0.132, and composite nanoparticles owned narrow size distribution and clear core–shell structure. Compared with original pigment, the encapsulated nanoparticles have better anti UV-aging property and acid–alkaline resistance. When the PR48:2 content was 0.5 g, the color changes of the encapsulated nanoparticles after soaking in alkaline solution for 30 days and UV light exposure for 60 days were only 1.70 and 6.59, respectively, indicating that the encapsulated nanoparticles have excellent color stability.     

Effect of low‐temperature plasma and chitosan treatment on wool dyeing with Acid Red 27

This study examines in detail the influence of low‐temperature plasma and biopolymer chitosan treatments on wool dyeability. Wool knitted fabrics were treated and characterized by whiteness and shrink‐resistance measurements. Surface modification was assessed by contact‐angle measurements of human hair fibers, which were used as a model to study the wetting properties of the treated wool knitted fabrics. The dyeing behavior was assessed from the diffusion mechanism point of view. The dyeing kinetics were measured at two different pHs (4.2 and 6.5) and three different temperatures (60, 85, and 100°C) to gain information about the contribution of the surface modification treatment to the dyeing mechanism. The exhaustion and reflectance data were compared, and the apparent diffusion coefficients were calculated. On the basis of the obtained results, a model for the dyeing mechanism of the chitosan treated wool was proposed. When treated with chitosan, the polymer sheath spread on the surface of the fibers acted as a predominant dyeing site in very short dyeing times, thus interacting with the dye and in later stages imparting the dye to the wool fiber. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2204–2214, 2005     

Colloidal properties of copolymer‐encapsulated and surface‐modified pigment dispersion and its application in inkjet printing inks

A styrene–maleic acid copolymer (PSMA)‐encapsulated 2‐[(2‐methoxy‐4‐nitrophenyl) azo]‐N‐(2‐methoxyphenyl)‐3‐oxobutyramide (PY74) dispersion was prepared by the phase‐separation technique. A surface‐modified PY74 dispersion was prepared with PSMA sodium as a dispersant by the milling method. Furthermore, the two dispersions were applied to formulate pigment inks. The colloidal properties of these two dispersions were compared. The printing and color performance of the prepared inks were also investigated. The results show that the PSMA‐encapsulated PY74 dispersion with a small particle size had higher stabilities of NaCl concentration, pH value, and temperature than the surface‐modified PY74 dispersion. The apparent viscosity of the PSMA‐encapsulated PY74 dispersion changed little, while it changed greatly in the surface‐modified PY74 dispersion with an increase of the shear rate from 10 to 100 s⁻¹. The ink printing and color performance of printed Fabrics indicated that the PSMA‐encapsulated PY74 dispersion was more suitable for the preparation of inkjet printing ink than the surface‐modified PY74 dispersion. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Single‐pack,self‐curable,aqueous‐based polyurethane dispersion containing a disperse dye

An organic‐solvent‐soluble disperse dye was introduced into an aqueous phase by a reaction with a self‐emulsified, aqueous‐based polyurethane (PU), and this resulted in the formation of a homogeneous, aqueous polymeric dye dispersion. This aqueous polymeric dye was stable in a water phase with excellent color extension upon application. It was formulated with a latent curing agent, polyaziridine (e.g., TMPTA‐AZ), as a single‐component, self‐curable, aqueous polymeric dye. The curing reaction took place between PU carboxylic acid and the latent curing agent upon drying. A self‐cured polymeric dye was obtained with excellent color extension and fastness and resistance to organic solvents and water after drying. This single‐component, self‐curable, aqueous‐based PU system containing a dye has potential for printing, writing, and dyeing applications. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 2006 © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3741–3747, 2006     

Effect of nano‐TiO2 surface modification on polarization characteristics and corona aging performance of polyimide nano‐composites

Using coupling agent isocyanatopropyltriethoxysilane (ICTOS) to modified nano‐TiO_2, the polyimide (PI) with different titanium dioxide (TiO₂) contents (0, 1, 2, 3, 4, and 5 wt %) doped nano‐composites were prepared by sol–gel method (PI/TiO_{2 ICTOS} composites). The effect of ICTOS modification on polarization and time‐to‐breakdown properties of composites were investigated by thermally stimulated depolarization current (TSDC) method, dielectric, and Corona aging measurements. The TSDC spectra show that ICTOS modification enhanced α‐peak intensity and make β‐peak disappear in composites. Relevant trap parameters were calculated by an approximate model, and the results indicate that introduction of ICTOS is effective for the charge carrier traps, activation energy distribution in composites. Corona aging measurement show corona resistance was also sufficient improved in PI/TiO_{2 ICTOS} composites. The changes of activation energy and intensity of traps in composites may be responsible for the corona resistance. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45101.     

Water‐soluble,antiyellowing polymeric fluorescence brighteners

In this study, a type of polymeric fluorescence brightener (PFB) with a triazine–stilbene structure was synthesized through a three‐step condensation reaction, and the performance of this PFB on antiyellowing was also investigated by the whiteness of paper coated with the as‐prepared PFB. Fourier transform infrared spectra revealed that the chlorine atom (·Cl) was substituted by a poly(vinyl alcohol) (PVA) group ([CH₂CHOH]_n). According to the UV aging experiment, the PFB not only enhanced the whiteness of the paper but also improved the anti‐UV aging properties [compared to those of VBL 4′‐double‐(6‐diethanolamine‐4‐sulfanilic acid‐1,3,5‐triazine‐2‐amino)‐stilbene‐2,2′‐disulfonic acid sodium, a type of commonly used fluorescent whitening agent as a light stabilizer and fluorescent brightening agent]. Moreover, the results of UV–visible spectra indicated that the substitution of PVA suppressed the isomerization of trans conformers to cis conformers under UV light irradiation; this was attributed to the big space steric hindrance of PVA in the as‐prepared samples being restricted the isomerization reaction. Meanwhile, the solubility of the as‐prepared sample was also improved because more hydroxyl groups were introduced into the PFB with the substitution of PVA. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45536.     

Production of Narrow‐Size‐Distribution Polymer‐Pigment‐Nanoparticle Composites via Electrohydrodynamic Atomization

Near‐monodisperse, size‐controllable, poly(methyl methacrylate)‐pigment nanoparticle composites were produced using electrohydrodynamic atomization (EHDA). The geometric mean diameters of the composite particles were in the 0.91 to 1.90 µm‐diameter range with geometric standard deviations of approximately 1.05 to 1.12. Increasing the polymer volume fraction and liquid flow‐rate resulted in an increase in the diameter of the composite particles, which agreed well with droplet scaling relations for EHDA. The results here demonstrate that EHDA can be used for polymer‐nanoparticle‐composite production and as an alternative to conventional inkjet printing.

     

Surface‐confined electropolymerization of pyronin Y in the graphene composite paper structure for the amperometric determination of dopamine

Surface‐confined electropolymerization allowed us to easily prepare homogeneous polymer composite paper structures. The fabrication of freestanding graphene (Gr)‐based composite electrodes is very important for many modular approaches in electrochemical applications, such as fuel cells, supercapacitors, and sensors. A Gr composite paper electrode doped with polymeric films of pyronin Y was fabricated by two repetitive simple applications: vacuum filtration and surface‐confined electropolymerization. The characterization of this composite paper was done with scanning tunneling microscopy, scanning electron microscopy, X‐ray photoelectron spectroscopy, powder X‐ray diffraction spectroscopy, Raman spectroscopy, UV–visible absorption spectroscopy, four‐point probe conductivity measurement, cyclic voltammetry, and electrochemical impedance spectroscopy. The freestanding composite paper demonstrated good electrocatalytic activity for the electrooxidation of dopamine; this indicated that this composite paper could be used for the amperometric quantification of dopamine in real samples. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45139.     

Partially crosslinked P(SMA‐DMA‐St) copolymer in situ modified RGB tricolor pigment particles for chromatic electrophoretic display

RGB tricolor organic pigments were in situ modified by stearyl methacrylate‐2‐(dimethylamino)ethyl methacrylate‐styrene random copolymer [P(SMA‐DMA‐St)] through solution polymerization. The modified particles were charged in tetrachloroethylene (TCE) with the aid of suitable charge control agent. The structure and electrophoretic property of ink particles were characterized by FTIR, TEM, PALS, et al. P(SMA‐DMA‐St) modification decreased the particles size and enhanced the suspending stability of the pigments in tetrachloroethylene due to the repulsive forces among the treated pigment particles resulting from the extending polyacrylate chain in the media. Partial crosslinking the P(SMA‐DMA‐St) on the pigment surface with ethylene glycol dimethacrylate (EGDMA) helped to increase the Zeta potential and electrophoresis mobility of RGB electrophoretic particles. The maximum values of the Zeta potential for red, green, and blue electrophoretic particles reached ?36.2, ?57.7, and ?42.7 mV, respectively. The obtained RGB electrophoretic particles could be applied in the color/white dual‐particle electronic ink together with charged TiO₂ to show vivid color and white images under a DC electric field. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013