We report here on the synthesis of nanoparticles (NPs) of sodium halide (NaX; X = F, Cl, Br, I) salts using reverse micelles (water/dioctylsodiumsulfosuccinate/toluene) with the resulting NPs having diameters of 1.5 to 2.5 nm. The initial core of reverse micelle contains a water-soluble salt. After evaporation of the volatile compounds under vacuum (water and toluene), NaX NPs are produced with an AOT surfactant cap. The NaX NPs redisperse in toluene. In contrast to previous syntheses of soluble salt NPs, Na+ ions from the surfactant are found to completely exchange with the salt in the initial core of the reverse micelles. The resulting NPs were analyzed with dynamic light scattering (DLS), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) which confirmed the exchange mechanism. Experimental results are compared and found to be in agreement with the recently published model by Bandopadhyaya and coworkers.
Sewage sludge is the promising
raw material for biosorbent preparation. In this work, we evaluated the heavy
metals adsorption characteristics of alkali treated sewage sludge (ATSS) by equilibrium
studies. The adsorption isotherms were fitted with Langmuir and Freundlich
models. Comparing with untreated sewage sludge, the total adsorption capacity (qm)
of ATSS (prepared with 0.125 mol/L NaOH) for Cd, Pb, Ni, increased by 0.51,
0.70 and 0.32 mmol/g, respectively. When the NaOH concentration for ATSS
preparation increased from 0.125 mol/L to 0.25 mol/L, the qm of ATSS for Pb decreased
from 1.05 mmol/g to 0.84 mmol/g. However, when the NaOH concentration increased
from 0.25 mol/L to 7.5 mol/L, it showed increasing trend. According to the IR
spectra data, the adsorption effect of biosorbent for heavy metals was mainly
due to the complexation of -N-H groups and -COOH groups.
The glasses of the type (30 一 x)Li2O 一 xK2O 一 10CdO 一 59B2O3 doped with 1 mol% of Fe2O3 were prepared by melt quench technique and their non-crystallinility has been established by XRD studies. The glasses were investigated for room temperature density and electrical conductivity in the temperature range 300 - 523 K and in the frequency range 102 to 105 Hz. The frequency and temperature dependence of conductivity as dielectric constant are presented.
The main advantages of biodiesel are its biodegradability, renewablity, improved nontoxic exhaust emissions and unnecessary alteration of common diesel engines. Today, biodiesel is produced by catalysis of inorganic acids, alkali and free or immobilized lipases with vegetable oil and short chain alcohols. Alkali and acidic catalysts are the most using catalysts for production of biodiesel because of their higher reaction yield and rate. In this study, we have comprised biodiesel productivity of different vegetable oils like sunflower, safflower, canola, soybean, olive, hazelnut, corn oils and waste sunflower oils by alkali catalysis. The transesterification of oils were performed by using NaOCH3 as catalyst at 25°C and at 100°C for 1 h. A defined amount of methanol as 6/1 molar ratio to oil was premixed with the metallic sodium. The amount of metallic sodium in methanol was 1.6 w% of oil mass for all of the crude oils/frying oil. Optimum reaction temperature was found as 25°C. TLC (Thin Layer Choromatography) image and GC (Gas Choromatography) results demonstrates that the dominant fatty acid in safflower, soy bean, sunflower, canola, corn and waste sunflower oil esters was linoleic acid (18:2). Besides it was oleic acid (18:1) for the olive and hazelnut oil esters. When biodiesel productivities of eight different oils were compared, similar results were obtained.
The study is carried out
to list mineralogy and texture of the basalt in Hail region. The basalt flows
belong to the Arabian Harrat volcanism. Cenozoic volcanism has produced 13,
vast, basaltic fields in western Saudi Arabia, covering a total area of about
100,000 sq. km. The volcanism starts in the late Cretaceous time and continues
periodically into the Holocene. The basaltic field presently investigated is
known as Harrat Al-Hamad (or Harrat As-Shamah) which lies in northwestern Saudi
Arabia, and continues northwards into Jordan. Mineralogical analysis of 20 rock
samples indicates that the rocks are products of continental intra-plate
magmatism; mostly as coarse-grained silica—under saturated olivine-rich alkali
basalt. Mineralogical study shows that rocks are olivine, plagioclase,
pyroxene, Nepheline and Opaque minerals. They correspond to alkali olivine basalts.
Moreover, the main well-defined texture is intergranular, vesicular and