Morphology control of conducting polypyrrole nanostructures via operational conditions in the emulsion polymerization

Polypyrrole (PPy) nanostructures with diameter smaller than 100 nm were synthesized by chemical oxidative polymerization of pyrrole in the presence of cetyl trimethylammonium bromide and sodium dodecyl sulfate as surfactants. Hydrochloric acid was used as dopant, and a solution of potassium peroxydisulfate was used as initiator. The influence of polymerization temperature, feeding strategy, and the type of surfactant on the morphology and conductivity of PPy nanostructures were investigated and well‐described. A simple route just via controlling the operational conditions in the emulsion polymerization is reported to obtain nanostructured PPy with desirable morphology and relatively good conductivity. The analysis results demonstrated that the conductivity of samples is highly affected by their morphology whereas PPy nanofibers exhibited higher conductivity respecting the other morphologies (0.66 S/cm). © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44697.     

Effect of Interfacial Activity of Eugenol and Eugenol Esters with Different Alkyl Chain Lengths on Inhibiting Sunflower Oil Oxidation

Effects of eugenol esters with different alkyl chain lengths and combinations of eugenol + eugenol esters on sunflower oil oxidation at 338, 358, and 378 K are evaluated by determining different kinetic parameters. Also, water content and reverse micelles size of sunflower oil samples are monitored during oxidation. Eugenyl acetate shows higher antioxidant activity than eugenol in sunflower oil, while eugenyl butyrate, eugenyl hexanoate, and eugenyl decanoate shows lower antioxidant activity than eugenol. Antioxidant activity of eugenol esters decreases by increasing their alkyl chain length. Eugenol shows a synergistic effect with eugenyl acetate and eugenyl butyrate on increasing the induction period and antioxidant activity values, while it shows an antagonistic effect with eugenyl hexanoate and eugenyl decanoate. Also, combinations of eugenol + eugenyl acetate, as well as, eugenol + eugenyl butyrate stabilize the reverse micelles at longer period of time (3263 min for eugenol + eugenyl acetate and 2900 min for eugenol + eugenyl butyrate) than eugenol (2750 min). In addition, eugenol + eugenyl acetate and eugenol + eugenyl butyrate decrease the magnitude of temperature-related effects on sunflower oil oxidation to the higher extent than eugenol did. Practical applications: Recent studies have suggested that the antioxidants with ability to locate at the active sites of lipid oxidation can efficiently reduce lipid oxidation in bulk oil. Despite a remarkable focus on antioxidant activity of eugenol, there is no information regarding improving its interfacial performance through esterification method. Also, there are few published data regarding the effects of esterified antioxidants on physicochemical changes during the oxidation of bulk oil. In this study, eugenol is esterified with anhydrides with different alkyl chain lengths to increase its accessibility to the active site of lipid oxidation, that is, water–oil interface of reverse micelles in sunflower oil. Effects of eugenol esters on stability of reverse micelles and critical reverse micelles concentration of lipid hydroperoxides have been investigated for the first time.     

Green synthesis of ZnO nanoparticles by Olive (Olea europaea)

Green synthesis of nanoparticles is superior to physical and chemical methods as it is environment‐friendly and cost‐effective. The present study was carried out for inducing nanoparticles synthesis by zinc nitrate in the leaves extracts of olive. Further leaves extracts were evaluated for antiradical scavenging activity by 1, 1‐diphenyl‐2‐picryl‐hydrazyl assay. Morphological and structural properties of the synthesised ZnO nanoparticles have been characterised using UV‐Vis spectrophotometer, FTIR, TEM, XRD and dynamic light scattering (DLS) analysis. Further, zinc oxide nanoparticles were evaluated for antiradical scavenging activity by capacity of total antioxidant assay. Synthesised ZnO nanoparticles were confirmed by the absorption maxima at the wavelength of 370 nm. TEM image revealed that ZnO nanoparticles were spherical with average size 41 nm. FTIR investigation suggested that the flavonoids, glycosides, proteins and phenols molecules can play an important role in the stabilisation of ZnO nanoparticles.Inspec keywords: zinc compounds, II‐VI semiconductors, wide band gap semiconductors, nanoparticles, nanofabrication, ultraviolet spectra, visible spectra, Fourier transform infrared spectra, transmission electron microscopy, X‐ray diffraction, light scatteringOther keywords: zinc oxide nanoparticles, green synthesis, physical method, chemical method, zinc nitrate, antiradical scavenging activity, 1, 1‐diphenyl‐2‐picryl‐hydrazyl assay, morphological properties, structural properties, UV‐vis spectrophotometer, FTIR, TEM, XRD, dynamic light scattering analysis, flavonoids, glycosides, proteins, phenols molecules, Olea europaea, ZnO     

Improvement of corrosion and electrical conductivity of 316L stainless steel as bipolar plate by TiN nanoparticle implantation using plasma focus

The present work reports the results of TiN-ions implantation into the SS316L samples as bipolar plates by a 4 kJ Mather type Plasma Focus (PF) device operated with nitrogen gas for 10, 20, and 30 shots in order to improve the corrosion resistance and electrical conductivity of samples. The PF can generate short lived (10–100 ns) but high temperature (0.1–2.0 keV) and high density (10¹⁸–10²⁰ cm⁻³) plasma, and the whole process of PF lasts just a few microseconds. X-ray diffraction (XRD) results reveal the formation of a nanocrystalline titanium nitride coating on the surface of substrate. The interfacial contact resistance (ICR) of samples is measured, and the results show that the conductivity of samples increase after coating because of high electrical conductivity of TiN coating. The electrochemical results show that the corrosion resistances are significantly improved when TiN films are deposited into SS316L substrate. The corrosion potential of the TiN coated samples increases compared with that of the bare SSI316L and corrosion currents decrease in TiN implanted samples. Scanning Electron Microscopy (SEM) indicates changes in surface morphology before and after potentiostatic test. The thickness of coated layer which is obtained by cross sectional SEM is about 19 μm.     

Synthesis of a fluorescent nanocomposite of methacrylate polymer via miniemulsion polymerization

Nanocomposite of poly (methacrylate) and spirobenzopyran-based fluorescent dye was synthesized via miniemulsion polymerization. In this study, hexadecane was used as a co-stabilizer. Considering the effect of dye concentration of nanocomposites, the kinetic behavior of synthesis of fluorescent nanocomposites and the rate of reactions (R _p) were investigated. The resulting nanocomposite was characterized by FTIR, TGA, DLS, TEM, SEM, and fluorescent spectroscopic techniques. Different properties of nanocomposites are discussed in comparison to the neat latex and pure dye. The results show nano-hybrid structure that provides a protective microenvironment for improving the thermo-stability of fluorescent dyes.     

Molecular dynamics simulation of a relativistic gas: Thermostatistical properties

Studying special relativistic generalizations of classical thermodynamic systems have recently attracted much attention despite its long and controversial history. Here, we propose a relativistic model of a realistic dilute gas which can easily be studied using standard molecular dynamics simulations. We briefly outline some of its thermostatistical properties which help resolve controversial issues in relativistic thermodynamics. In particular, we find that Jüttner function is the correct generalization of Maxwell–Boltzmann velocity distribution. We also conclude that relativistic temperature is best understood as a rest-frame-property, invariant under various relativistic transformations, i.e. Lorentz transformation and time reparametrization. Finally, we provide canonical non-equilibrium simulations of such systems and study the effects of a temperature gradient imposed by heat reservoirs.     

Beta casein-micelle as a nano vehicle for solubility enhancement of curcumin; food industry application

Curcumin is a potent anticancer and antioxidant natural polyphenol poorly soluble in aqueous solutions. Beta-casein (B-CN), an amphiphilic self-assembling protein that can form micellar nanostructures, could be used as a carrier system for hydrophobic therapeutic agents such as curcumin. In this study, camel B-CN was used for curcumin encapsulation. Critical micelle concentration of camel B-CN was determined at 25, 30 and 37 °C using pyrene fluorescence and the solubility of curcumin was evaluated according to the solvent-evaporation technique. Presence of camel B-CN increased the solubility of curcumin at least 2500 fold. Analysis of fluorescence emission of curcumin showed that hydrophobic interactions are predominant in its formulation with B-CN. Additionally, the cytotoxicity of curcumin to human leukemia cell line K-562 was enhanced in the presence of B-CN micelles giving inhibitory concentration (IC₅₀) values of 26.5 and 17.7 μmol/L for free and encapsulated curcumin, respectively. Antioxidant activity of curcumin encapsulated in B-CN was higher than that of both free B-CN and curcumin.     

An efficient hybrid of elephant herding optimization and cultural algorithm for optimal design of trusses

Engineering with Computers - In this article, a new hybrid algorithm is proposed which was based on the elephant herding optimization (EHO) and cultural algorithm (CA), known as elephant herding...     

Organic geochemistry of the Upper Triassic–Middle Jurassic Shemshak Group (Alborz Mountains,NE Iran)

Abstract

The organic geochemistry of shale samples of Shemshak Group at Dehmolla section in Eastern Alborz Mountains in the present study are discussed throughout the Rock-Eval pyrolysis. The results used to describe the quantity, type, maturity, and petroleum potentials of the Shemshak Group sediments. The pyrolysis data show that the total organic carbon values of the shale samples are between 0.08 and 20.98?wt% and the generation potential (S1+ S2) of the studied samples ranges from 0.02 to 9.47?mg HC/g rock revealing the organic richness of these samples varies from poor to good. The type of hydrocarbon products (S2/S3) ranging from 0.06 to 2.33 and the type of hydrocarbon determined from Tmax versus HI indicate mainly well for gas generation. Based on the HI versus OI plot diagram, the type III of kerogen is the main type of organic matter in studied samples. These data also show that most of the samples were deposited in oxic environments with low sedimentation rate and high amount of organic matter from the terrestrial source. “Tmax” values ranging from 416?°C to 602?°C in studied samples indicate that most of the samples are over mature and located in gas zone.