Feasibility of recycled newspaper as cellulose source for regenerated cellulose membrane fabrication

An environmental friendly regenerated cellulose membrane (RCM) was successfully prepared via NaOH/urea aqueous solution system by utilizing recycled newspaper (RNP) as the cellulose source. The morphological and chemical structure of resulting membrane were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD) spectroscopy, and thermogravimetric analysis (TGA). Results from FTIR and XRD verified that the transparent RCM possesses cellulose II structure. SEM observation revealed that the transparent RCM consist of homogeneous dense symmetric membrane structure and composed of a skin layer with mean roughness parameter R_a, obtained from AFM analysis of 29.53 nm. Pure water flux, water content, water contact angle, porosity, and pore size of the resulting membrane were also measured. This study promotes the potential of the cellulose‐based membrane obtained from low cost cellulose source for application in filtration and separation system. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42684.     

Polymer‐Cationic Surfactant Interaction: 1. Surface and Physicochemical Properties of Polyvinyl Alcohol (PVA)‐S‐Alkyl Isothiouronium Bromide Surfactant Mixed Systems

Surface properties of polyvinyl alcohol (nonionic polymer) and three synthesized cationic surfactants, namely, S‐alkyl isothiouronium bromide at different mole fractions of 1:9, 3:7, 5:5, 7:3, and 9:1, were investigated. The values of the surface parameters were discussed according to the type of interaction between the cationic surfactant and type of polymer studied. The S‐alkyl isothiouronium bromide surfactant molecules are positively charged molecules, and the PVA chains contain hydroxyl groups that are partially negatively charged centers. The comparison between the surface properties of the individual cationic surfactants and their mixture with PVA polymer showed that the mixed systems have some advantages over the individual cationic surfactants.     

Mono‐, Di‐ and Tetra‐Cationic Surfactants as Carbon Steel Corrosion Inhibitors

Corrosion inhibition of three new synthesized cationic surfactants, N‐(2‐(((Z)‐4‐(pyridin‐4‐yl)but‐3‐en‐1‐yl)amino)ethyl)‐N‐(2‐((E)‐(pyridin‐4‐ylmethylene)amino)ethyl)dodecan‐1‐aminium bromide I(4N), N¹,N²‐didodecyl‐N¹‐((Z)‐4‐(pyridin‐4‐yl)but‐3‐en‐1‐yl)‐N²‐(2‐((E)‐(pyridin‐4‐ylmethylene)amino)ethyl)ethane‐1,2‐diaminium bromide II(4N) and 1‐dodecyl‐4‐((E)‐((2‐(dodecyl(2‐(dodecyl((Z)‐4‐(1‐dodecylpyridin‐1‐ium‐4‐yl)but‐3‐en‐1‐yl)ammonio)ethyl)ammonio)ethyl)imino)methyl)pyridin‐1‐ium bromide IV(4N) on carbon steel was investigated by weight loss, electrochemical impedance spectroscopy and polarization measurements. Results show that the synthesized cationic surfactants inhibit corrosion of carbon steel in 1 M HCl. The inhibitive action occurs by virtue of adsorption on the metal surface following a Langmuir adsorption isotherm model. Polarization curves reveal that the investigated cationic surfactants can be classified as mixed inhibitor types. The variations in the corrosion inhibition efficiency between three cationic surfactants are correlated with their chemical structures, with more hydrophobic surfactants yielding higher inhibition efficiency.     

Corrosion Inhibition of Mild Steel in Acidic Medium using 2-amino Thiophenoland 2-Cyanomethyl Benzothiazole

The corrosion inhibition characteristics of 2-amino thiophenol (ATP) and 2-cyanomethyl benzothiazole (CNMBT) on two types of steel in 1m HCl medium were investigated at different temperatures (25, 30, 35, 40 and 50°C). The pitting corrosion behaviour for the same system was studied using a potentiodynamic technique. The pitting corrosion resistance of steel samples increased with increase in concentration of the ATP and CNMBT. Some samples were examined by scanning electron microscopy. The effects of the inhibitors on the general corrosion of the two samples were investigated by using gravimetric and galvanostatic polarization techniques. The inhibition efficiencies increased with increase their concentration but decreased with increase in temperature. Free energies of activation, enthalpies and entropies for the inhibition processes were determined from rate constant data measured and different temperatures at different concentrations of ATP and CNMBT. Results were compared with fits obtained from the application of the Langmuir isotherm. Results were correlated to the chemical structure of the inhibitors. The inhibition efficiency of CNMBT is higher than that of ATP.     

Synthesis,Characterization, and Evaluation of Ethoxylated Lauryl-Myrisityl Alcohol Nonionic Surfactants as Wetting Agents,Anti-Foamers,and Minimum Film Forming Temperature Reducers in Emulsion Polymer Lattices

Two nonionic FAEO (fatty alcohol ethoxylated) surfactants with varying solubility were obtained by the reaction of lauryl-myrisityl alcohol (LMA) with ethylene oxide to yield lauryl-myristyl/alcohol ethoxylated with 3 and 31 mol of ethylene oxide by changing the length of polyethylene glycol segment. The prepared surfactants, designated as LMAEO-3 and LMAEO-31, were characterized for their structures using spectroscopic measurements; in addition, their surface properties were investigated. The results indicated that LMAEO-31 exhibits excellent surface activity. Evaluation of the surfactants as wetting agents, anti-foamers, and minimum film forming temperature (MFFT) reducer in emulsion polymer lattices achieved promising results indicating high performance in the mentioned industrial applications.     

Structural and Optical Characterization of Chemically Deposited PbS Thin Films

PbS thin films were deposited on glass substrates by a chemical bath deposition method. The effect of varying the film thickness on the structural and optical properties has been investigated. XRD analysis reveals the crystallinity of the deposited PbS films with (200) preferred crystal orientation. Increasing the film thickness enhances the crystallinity of the films as well as decreases the strain and dislocation density. The surface morphology features were dramatically changed from small spherical grains to bead-like shape. The absence of impurities in the deposited films was confirmed by energy dispersive x-ray spectrometry (EDX) measurements. The optical constants of the deposited films were calculated and a small decrease in the band gap energy was observed with increasing the film thickness.     

Characterization of stabilized porous magnetite core–shell nanogel composites based on crosslinked acrylamide/sodium acrylate copolymers

Stabilized and dispersed superparamagnetic porous nanogels based on sodium acrylate (AA‐Na) and acrylamide (AM) in a surfactant‐free aqueous system were synthesized via solution polymerization at room temperature. The formation of magnetite nanoparticles was confirmed and their properties characterized using Fourier transform infrared spectroscopy. Extensive characterization of the magnetic polymer particles using transmission electron microscopy (TEM), dynamic light scattering and zeta potential measurements revealed that Fe₃O₄ nanoparticles were incorporated into the shells of poly(AM/AA‐Na). The average particle size was 5–8 nm as determined from TEM. AM/AA‐Na nanoparticles with a diameter of about 11 nm were effectively assembled onto the negatively charged surface of the as‐synthesized Fe₃O₄ nanoparticles via electrostatic interaction. Crosslinked magnetite nanocomposites were prepared by in situ development of surface‐modified magnetite nanoparticles in an AM/AA‐Na hydrogel. Scanning electron microscopy was used to study the surface morphology of the prepared composites. The morphology, phase composition and crystallinity of the prepared nanocomposites were characterized. Atomic force microscopy and argon adsorption–desorption measurements of Fe₃O₄.AM/AA indicated that the architecture of the polymer network can be a hollow porous sphere or a solid phase, depending on the AA‐Na content. © 2013 Society of Chemical Industry     

Polyester condensation adducts as novel photo stabilizers for polystyrene

Polycondensation adducts formed by the reaction of maleic anhydride with some Polyalcohols, namely, phloroglucinol, glycerol, and ethylene glycol, were prepared, characterized, and investigated as photostabilizers for polystyrene. Their Photostabilizing effectiveness was evaluated by measuring the extent of weight loss (%), the amount of gel formed as well as the viscosity average molecular weight of the soluble fractions of the degraded polymer. The results indicated better stabilizing effects of these stabilizers compared with that of the UV absorber, phenyl salicylate. A synergistic effect was achieved when the investigated photostabilizers were mixed with phenyl salicylate in a weight ratio of 1 : 1, and a radical mechanism is proposed to account for the action of the polycondensation adducts as photostabilizers. J. VINYL ADDIT. TECHNOL., 19:293–301, 2013. © 2013 Society of Plastics Engineers     

UNSTEADY FLUID AND HEAT FLOW INDUCED BY A STRETCHING SHEET WITH MASS TRANSFER AND CHEMICAL REACTION

The effect of chemical reaction on the flow, heat, and mass transfer within a viscous fluid on an unsteady stretching sheet is examined. The stretching rate, temperature and concentration of the sheet, and the chemical reaction rate are assumed to vary with time. The time-dependent boundary layer equations governing the flow are reduced through a convenient similarity transformation to a set of ordinary differential equations, which are numerically solved by applying the fourth-order Runge-Kutta-Fehlberg scheme with the shooting technique. Results for the velocity, temperature, and concentration distributions as well as the wall temperature and concentration gradients are presented graphically for various values of the unsteadiness parameter A, Prandtl number Pr, Schmidt number Sc, and chemical reaction parameter γ.     

Characterization and Electrical Properties of Some Hydrochloric Acid-Doped Aniline and 2-Amino-Pyridine Homopolymers and Copolymers

The synthesis of (group I) hydrochloric acid-doped poly(aniline-co-toluidine), poly(aniline-co-thiophene), poly(aniline-co-o-phenylenediamine), and poly(aniline-co-2-aminopyridine) as well as their hydrochloric acid-doped homopolymers of polyaniline, poly-m-toluidine, poly-o-phenylene diamine, and poly-2-aminopyridine and the synthesis of (group II) hydrochloric acid-doped poly (2-aminopyridine-co-o-phenylene diamine) and its hydrochloric acid-doped homopolymers of poly 2-amino pyridine and poly-o-phenylene diamine have been carried out via a chemical oxidation process using ammonium and potassium persulphate as chemical initiators. The synthesized homo- and copolymers were characterized by ultraviolet-visible spectroscopy (UV-VIS), infrared spectroscopy (IR), and thermal analysis. The variation of the electrical conductivity (σ, S cm^?1) with the reciprocal of the absolute temperature (1000/T, K) at different frequencies (1–1000 kHz) for hydrochloric acid homopolymers and copolymers is illustrated.