Volume 46, Issue 4

Phase behavior of engkabang fat was determined through the construction of ternary phase diagrams using nonionic surfactants. Several phase regions appeared in the ternary phase diagrams such as isotropic, homogenous, liquid crystal, two phase and three phase regions. The increase of hydrophilic-lipophilic balance (HLB) values of the nonionic surfactants used gave larger isotropic and homogenous region in the ternary phase diagrams. The combination of engkabang fat:Solubilisant Gamma (2:1) in the ternary phases diagram gave an even larger isotropic and homogenous regions as well as the formation of liquid crystal region.

A simple, accurate and reproducible reversed-phase high performance liquid chromatography method with fluorescence detection was developed for determination of octylphenol, nonylphenol and their short-chain ethoxylates, using an octadecyl silica column. The mobile phase used for the analysis consisted of methanol, acetonitrile and water (50:15:35). The analytes were separated successfully within a reasonable time without gradient elution, which was not achieved previously. Thus, use of inexpensive fluorescence detection instead of MS detection was enabled. This chromatographic method, combined with solid-phase extraction, was highly applicable for the simultaneous determination of octyl- and nonylphenol as well as their mono- and diethoxylates in real river water samples. The limit of detection (LOD) for octylphenol and its ethoxylates was 0.05 μg · L −1 . For nonylphenol the LOD was 0.14 μg · L −1 and for its ethoxylates it was 0.15 μg · L −1 . Recovery of octylphenol and its ethoxylates was about 80%. Recovery of nonylphenol and its ethoxylates was slightly lower (from 60 to 76%).

Adsorption of brilliant blue R on activated carbon produced from the wood of Paulownia Tomentosa was investigated. Samples characterization by XRD, SEM, EDS and FTIR showed that the oxygen containing surface functional groups (carboxyls, lactones or phenols and ethers) were present on the surface which were eliminated at 800°C. Activation at 800°C, resulted in the opening of porous structure thereby increasing the adsorption capacity. Relatively high amounts of carbon with respect to oxygen were found in the samples with the rise in activation temperature. The adsorption kinetic at 10 and 45°C showed that the first order, Bangham and parabolic diffusion models are applied to the data. The rate constant increased with the rise in temperature of adsorption/activation. Thermodynamic properties (ΔE≠, ΔH≠, ΔS≠ and ΔGo) for the adsorption process were calculated. Positive values of ΔH≠ showed that the adsorption of brilliant blue R is endothermic. Negative values of ΔS≠ reflected the decrease in the disorder of the system at the solid-solution interface during adsorption. The Gibbs free energy, which is the driving force for adsorption is negative indicating spontaneous adsorption. Freundlich and Langmuir models described the equilibrium adsorption data and Thomas model was used for the column study.

In a solvent free system, hydrolytically stable nonionic surfactants, trisiloxane grafted Oligo(ethylene oxide), were synthesized by hydrosilylation of heptamethyltrisiloxane with allyl-oligo(EO) series. The structures of intermediate and products were confirmed by infrared spectroscopy and 1 H nuclear magnetic resonance spectroscopy. Surface activity, foaming property and wetting ability of the surfactants were also investigated. The results show that the prepared surfactants exhibited excellent surface activity and wetting ability.

The effect of cationic micelles of Cetyltrimethylammonium bromide (CTAB) and anionic micelles of Sodium dodecyl Sulphate (SDS) on the kinetics of oxidation of acetone by N-Bromophthalimide (NBP) was studied iodometrically at 308 K. In addition to kinetic experiments, conductivity measurements have also been done to obtain critical micelle concentration and other thermodynamic properties. The kinetic observations indicate fractional order and first order dependence, with respect to [Acetone] and [NBP] respectively. Cationic surfactant (CTAB) strongly catalysed the oxidation of acetone in aqueous acetic acid medium and typical k obs and [CTAB] profile was observed i.e. with the progressive increase in [CTAB], the reaction rate increased, at higher concentration constancy in k obs was observed, whereas anionic surfactant (SDS) was found to show no considerable effect on reaction rate. Mercuric acetate and phthalimide exhibited nil effect on the reaction rate. The presence of inorganic salts (KCl, KBr) exhibits positive effect in the reaction rate. The various activation parameters in presence of CTAB and SDS have been also evaluated. A suitable mechanism consistent with the experimental findings has been proposed. The binding constant with surfactants has been evaluated.

Two cationic surfactant intermediates were synthesized by improved method. The alkyl isocyanates, dodecyl isocyanate (1a) and tetradecyl isocyanate (1b), were synthesized by corresponding alkyl amines and bis(trichloromethyl) carbonate (BTC) in anhydrous toluene. The yield of 1a–b reached 86%, the product was colorless liquid and the purity was measured more than 98% by GC. The target products, 3-(dimethylamino)propane-1,2-di-dodecylcarbamate (2a) and 3-(dimethylamino)propane-1,2-di-tetradecylcarbamate (2b) were synthesized by 1-dimethylamino-2,3-propanediol and alkyl isocyanates with triethylamine as catalyst, the yield of 2a–b was 65%.

As our fossil raw materials are irrevocably decreasing and as the pressure on our environment is building up, the progressive changeover of chemical industry to renewable feedstocks for their raw materials emerges as an inevitable necessity i.e. it will have to proceed increasingly to the raw materials basis that prevailed before natural gas and oil out paced all other sources. Therefore, the use of renewable resources is an important component of green chemistry. Oils and fats are the most important renewable raw materials for the chemical industry. In the present study, cracking of vegetable oil was carried out to obtain olefins. Olefins are the largest volume chemical intermediates produced in the chemical industry, which is one of major raw material for surfactants manufacturing. The olefins obtained from cracking are utilized to prepare surfactant by alkylation with cumene and subsequently sulfonation and neutralization to obtained alkyl cumene sulfonates (ACS). The evaluation of surface active properties of ACS and comparison of the property with conventional surfactants was carried out and ACS exhibit excellent surface active properties.