Covalently cross-linked nanogels were prepared via irradiation of inverse micelles that had been preparedfrom radiation crosslinkable polymer, water, oil and surfactant. A mixture of polymer, water, heptane andsodium dioctyl sulfosuccinate (AOT) at certain compositions forms inverse micelles with the size rangingfrom 2 to 8 nm. The hydrophilic head of the surfactant facilitates encapsulation of water soluble polymer.If the entrapped polymer is radiation crosslinkable, it is expected that upon irradiation, polymerizationshall take place in such small and confined space, leading to formation of nano-sized polymeric gel.Meanwhile, emulsion at 2 nm size was chosen for gamma irradiation process. The formation of thenano-sized discreet gel using irradiation of inverse micelles technique was proven at a dose as low as 5kGy to obtain nanogel sized ~ 95 nm.
Analyses of tocols (tocopherols and tocotrienols) in palm oil have been extensively reported in the past. However, due to the scarcity of individual tocotrienol standards, calibrations have mostly been carried out using only α-tocopherol as standard. Moreover, even if the individual tocotrienols are being used, their reliability is often questioned, because tocotrienols are highly susceptible to oxidation and deterioration. This paper reports on the study of the deterioration rate of individual tocotrienol standards upon storage as well as different calibration methods for the tocols in palm oil.
Evaporation of vaporize organic liquid has ecological consequences when the compounds are introduced into both freshwater and marine environments through industrial effluents, or introduced directly into the air from industrial unit processes such as bioreactors and cooling towers. In such cases, a rapid and simple method are needed to measure physicochemical properties of the organic liquids. The Reversed-Flow Gas Chromatography (RF-GC) sampling technique is an easy, fast and accurate procedure. It was used to measure the diffusion coefficients of vapors from liquid into a carrier gas and at the same time to determine the rate coefficients for the evaporation of the respective liquid. The mathematical expression describing the elution curves of the samples peaks was derived and used to calculate the respective parameters for the selected liquid pollutants selected such as methanol, ethanol, 1-propanol, 1-butanol, n-pentane, n-hexane, n-heptane and n-hexadecane, evaporating into the carrier gas of nitrogen. The values of diffusion coefficients found were compared
with those calculated theoretically or reported in the literature. The values of evaporation rate were used to determine the activation energy of respective samples using Arrhenius equation. An interesting finding of this work is by using an alternative mathematical analysis based on equilibrium at the liquid-gas interphase, the comparison leads to profound
agreement between theoretical values of diffusion coefficients and experimental evidence.
Liquid-liquid iron(III) extraction was investigated using benzyl fatty hydroxamic acids (BFHAs) and methyl fatty hydroxamic acids (MFHAs) as chelating agents through the formation of iron(III) methyl fatty hydroxamate (Fe-MFHs) or iron(III) benzyl fatty hydroxamate (Fe-BFHs) in the organic phase. The results obtained under optimized conditions, showed that the chelating agents in hexane extract iron(III) at pH 1.9 were realized effectively with a high percentage of extraction (97.2% and 98.1% for MFHAs and BFHAs, respectively). The presence of a large amount of Mg(II), Ni(II), Al(III), Mn(II) and Co(II) ions did affect the iron(III) extraction. Finally stripping studies for recovering iron(III) from organic phase (Fe-MFHs or Fe-BFHs dissolved in hexane) were carried out at various concentrations of HCl, HNO(3) and H(2)SO(4). The results showed that the desired acid for recovery of iron(III) was 5 M HCl and quantitative recovery of iron(III) was achieved from Fe(III)-MFHs and Fe(III)-BFHs solutions in hexane containing 5 mg/L of Fe(III).