Synthesis,Surface Properties,and Inhibiting Action of Novel Nonionic Surfactants on Carbon Steel Corrosion in 1 M Hydrochloric Acid Solution

In the present study novel nonionic surfactants were synthesized, characterized, and tested as corrosion inhibitors for carbon steel in 1 M HCl solution. The inhibiting performances of these surfactants were studied by weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). The adsorption of these inhibitors was well described by Langmuir adsorption isotherm, and the kinetic parameters were calculated and discussed. The inhibition efficiency (IE) was found to rise with increasing the concentration of these inhibitors. Polarization measurements revealed that the inhibitors acted as mixed-type inhibitors. The efficiencies obtained from the impedance measurements were in good agreement with those obtained from the weight loss and potentiodynamic polarization techniques which prove the validity of these tools in the measurements of the tested inhibitors. The surface parameters of the synthesized nonionic surfactants were investigated and the results showed that these surfactants have lower values of surface tension and are effective as wetting and emulsifying agents.     

Optimization of Pheromone Lure and Trap Characteristics for Currant Clearwing, <Emphasis Type="Italic">Synanthedon tipuliformis</Emphasis>

Currant clearwing Synanthedon tipuliformis (Sesiidae) has been a pioneering and successful target of mating disruption in New Zealand, with virtually universal black currant industry adoption since c. 1990. Recent unexplained control failures using mating disruption lead to questions about pheromone efficacy. In this study, we have investigated the possible reasons for reduced control from mating disruption, and report improvements in trap catch based on pheromone loading and trap color. No differences were found in electrophysiological responses to pheromone components from two New Zealand populations. Male moth catches in traps baited with synthetic lures were disrupted in the presence of mating disruption dispensers (> 99.99%) indicating no apparent barrier to efficacy from the pheromone formulation. Field behavioral observations confirmed this result. Male attraction to yellow delta traps was equivalent to green delta traps, but was greater than to red, black, blue, or white traps. Solid yellow delta traps were more attractive than black traps with yellow stripes, the latter designed to mimic the color pattern of the insect. Solid yellow funnel traps were less attractive than a composite of green, yellow, and white funnel traps. Trap catch increased as a function of pheromone loading and trap color. In another experiment conducted in Tasmania, there was no difference in catch with single component [(E,Z)-2,13-octadecadienyl acetate] or two component lures [97% (E,Z)-2,13-octadecadienyl acetate:3% (E,Z)-3,13-octadecadienyl acetate], refuting the suggestion of a different pheromone strain there.     

Attraction of New Zealand Flower Thrips, <Emphasis Type="Italic">Thrips obscuratus</Emphasis>, to <Emphasis Type="Italic">cis</Emphasis>-Jasmone,a Volatile Identified from Japanese Honeysuckle Flowers

This work was undertaken to identify floral compound(s) produced by honeysuckle flowers, Lonicera japonica (Thunberg), that mediate the attraction of New Zealand flower thrips Thrips obscuratus (Crawford). Volatiles were collected during the day and night and analyzed by gas chromatography–mass spectrometry (GC-MS) to determine their emission over these two periods. Nine compounds were identified in the headspace; the main compound was linalool, and the other compounds were germacrene D, E,E-alpha-farnesene, nerolidol, cis-jasmone, cis-3-hexenyl acetate, hexyl acetate, cis-hexenyl tiglate, and indole. There was a quantitative difference between day and night volatiles, with cis-3-hexenyl acetate, hexyl acetate, cis-hexenyl tiglate, and cis-jasmone emitted in higher amounts during the day compared to the night. When the compounds were tested individually in field trapping experiments, only cis-jasmone attracted New Zealand flower thrips in a significant number. In another field trapping experiment, cis-jasmone caught similar numbers of New Zealand flower thrips compared to a floral blend formulated to mimic the ratios of the compounds emitted during the day, while catch with the night-emitted floral blend was not significantly different from the control. Subsequently, two field trapping experiments were conducted to determine the optimal attraction dose for cis-jasmone, a range of 1–100 mg loaded onto a red rubber stopper was tested, and the highest catches were in traps baited with 100 mg loading. A higher range of 100–1000 mg loaded into polyethylene vials was tested, and the highest catch was in traps baited with 500 mg. In another experiment aimed at comparing the attraction efficacy of cis-jasmone with the two other known thrips attractants (ethyl nicotinate and p-anisaldehyde), ethyl nicotinate showed the highest trap catch followed by cis-jasmone. A smaller number of Thrips tabaci (Lindeman) was attracted to traps baited with cis-jasmone. These results suggest that cis-jasmone might act as a kairomone that mediates the attraction of New Zealand flower thrips to the flowers of the Japanese honeysuckle.     

Recycling of supported nanocomposites for hazardous industrial wastewater treatment via Solar photocatalytic process

Study of the photocatalytic activity of the synthesized polyvinylidene fluoride/multi-walled carbon nanotubes/titanium dioxide (PVDF/x%(MWCNTs/8%TiO2) nanocomposites using a simple modified solvent casting technique in decontamination of hazardous industrial wastewater and Reactive Yellow 145 dye as an industrial organic pollutant (local textile dye) were evaluated. Also, different MWCNTs/8%TiO₂ weight percentages in PVDF/x%(MWCNTs/8%TiO₂) nanocomposites were prepared and evaluated. The surface morphology and the structures of the synthesized samples were characterized using SEM, ATR-FTIR, DRS, XRD, and BET. The evaluated bandgap values for MWCNTs/xTiO₂ nanocomposites are from 2.38 to 2.69 based on the weight ratios (2%, 5%, and 8%). The results of the surface area of samples and the best optical behavior obtained at MWCNTs/8%TiO₂ are reported and its photodegradation rate raised to 10.22x10^?3S^?1. The photodegradation process of Reactive Yellow 145 dye by PVDF/x%(MWCNTs/8%TiO₂) nanocomposites was monitoring using chemical oxygen demand (COD). Also, the observed PL intensity for PVDF/MWCNTs/8%TiO₂ has high photonic efficiency and photocatalytic activity. The solar photocatalytic process efficiency for an Egyptian dying factory by repeating it 10 times using PVDF/10%(MWCNTs/8%TiO₂) nanocomposites as a supported photocatalyst for the industrial wastewater treatment was evaluated by the COD method and still under Egyptian environmental law allowed COD limit (1000 ppm).     

Treatment of oil–water emulsions by adsorption onto activated carbon,bentonite and deposited carbon

Emulsified oil in waste water constitutes is a severe problem in the different treatment stages before disposed off in a manner that does not violate environmental criteria. One commonly used technique for remediation of petroleum contaminated water is adsorption. The main objective of this study is to examine the removal of oil from oil–water emulsions by adsorption on bentonite, powdered activated carbon (PAC) and deposited carbon (DC). The results gave evidence of the ability of the adsorbents to adsorb oil and that the adsorptive property of the three adsorbents (bentonite, PAC, and DC) has been influenced by different factors. The effects of contact time, the weight of adsorbents and the concentration of adsorbate on the oil adsorption have been studied. Oil removal percentages increase with increasing contact time and the weight of adsorbents, and decrease with increasing the concentration of adsorbate. Equilibrium studies show that the Freunlich isotherm was the best fit isotherm for oil removal by bentonite, PAC, and DC. The data show higher adsorptive capacities by DC and bentonite compared to the PAC.     

Reactions with 2-Oxo-4-thioxo-1,2,3,4-tetrahydrobenzo[f]isoquinoline and 1,2,3,4-tetrahydro-benzo[f]-isoquinoline-2,4-dione

Alkylation of 2-oxo-4-thioxo-1,2,3,4-tetrahydro-benzo[f]isoquinoline 2 gave at first the S-alkyl derivatives, then the S- and O-dialkyl derivatives were formed. Compound 2 and its alkyl derivatives coupled with aryldiazonium salts. The S-methyl derivatives of 2 , on acid hydrolysis, gave 1,2,3,4-tetrahydro-benzo[f]isoquinoline-2,4-dione 10 , which coupled with diazonium salts. 10 gave a monochloro and a monobromo derivative. 10 reacted also with p-nitrosodimethylaniline and the product was hydrolysed to the triketo compound 14 , which condensed with o-phenylenediamine to give the quinoxaline derivative 15 .