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In this present study, silver (Ag) and titanium dioxide (TiO

The preparation of vegetable oil-water emulsions stabilized by soybean protein and microgel is described. The soybean protein was obtained from n-hexane-defatted soybean powder using a Soxhlet extractor. Using equal volumes of oil and water, vegetable oil-water emulsions were formed either by handshaking the mixture or homogenizing the mixture using a Lab homogenizer. The emulsion was characterized using a drop test and microscopy observation. The drop test shows that the preferred emulsion is vegetable oil-in-water (o/w). The effect of salt and emulsifier concentration on the stability and emulsion drop size was investigated. Emulsions stabilized by soybean protein without addition of salt breakdown after 3 days of preparation because of decomposition of the protein. For emulsions stabilized by microgel in the absence of salt, phase separation occurred within 1 hour. At a fixed salt concentration, it was found that increasing the emulsifier concentration has a significant effect on the stability and drop size of the emulsions stabilized by both protein and microgel. For emulsions stabilized by soybean protein, the stability of emulsions increased with increasing salt concentration without any significant influence on the drop size. The results obtained from the surface tension measurement revealed that different mechanisms of stabilization exist in emulsions stabilized by the protein and microgel.

The preparation of vegetable oil-water emulsions stabilized by soybean protein and microgel is described. The soybean protein was obtained from n-hexane-defatted soybean powder using a Soxhlet extractor. Using equal volumes of oil and water, vegetable oil-water emulsions were formed either by handshaking the mixture or homogenizing the mixture using a Lab homogenizer. The emulsion was characterized using a drop test and microscopy observation. The drop test shows that the preferred emulsion is vegetable oil-in-water (o/w). The effect of salt and emulsifier concentration on the stability and emulsion drop size was investigated. Emulsions stabilized by soybean protein without addition of salt breakdown after 3 days of preparation because of decomposition of the protein. For emulsions stabilized by microgel in the absence of salt, phase separation occurred within 1 hour. At a fixed salt concentration, it was found that increasing the emulsifier concentration has a significant effect on the stability and drop size of the emulsions stabilized by both protein and microgel. For emulsions stabilized by soybean protein, the stability of emulsions increased with increasing salt concentration without any significant influence on the drop size. The results obtained from the surface tension measurement revealed that different mechanisms of stabilization exist in emulsions stabilized by the protein and microgel.

Chemically prepared activated carbon derived from Gmelina aborea leaves (GALAC) were used as adsorbent for the removal of Rhodamine B (Rh–B) dye from aqueous solutions. The adsorptive characteristics of activated carbon (AC) prepared from Gmelina aborea leaves (GAL) were studied using SEM, FTIR, pH point of zero charge (pHpzc) and Boehm Titration (BT) techniques respectively. The effects of pH, contact time, initial dye concentration and solution temperature were also examined. Experimental data were analyzed using four different isotherm models: Langmuir, Freundlich, Temkin and Dubinin-Radushkevich. Four adsorption kinetic models: Pseudo-first-order (PFO), Pseudo-second-order (PSO), Elovich and Intraparticle diffusion models to establish the kinetics of adsorption process. The RhB dye adsorption on GALAC was best described by Langmuir isotherm model with maximum monolayer coverage of 1000 mg g−1 and R2 value of 0. 9999. The EDX analysis revealed that GALAC contained 82.81% by weight and 91.2% by atom of carbon contents which are requisites for high adsorption capacity. Adsorption kinetic data best fitted the PSO kinetic model. Thermodynamic parameters obtained for GALAC are (ΔGo ranged from -22.71 to -18.19 kJmol-1; ΔHo: 1.51 kJmol-1; and ΔSo: 0.39 kJmol-1 K−1respectively) indicating that the RhB dye removal from aqueous solutions by GALAC was spontaneous and endothermic in nature. The cost analysis established that GALAC is approximately eleven times cheaper than CAC thereby providing a saving of 351.41USD/kg. Chemically treated GAL was found to be an effective absorbent for the removal of RhB dye from aqueous solution., Biochemistry; Environmental science; Analytical chemistry; Surface Chemistry; Rhodamine B dye; kinetics; Gmelina arborea leaf; Isotherms.

The reaction was studied via pseudo-first-order kinetics using a UV-1800 Shimadzu spectrophotometer with a thermostated cell compartment and interfaced with a computer. The reaction showed first order with respect to malachite green and sugar and hydroxyl ion concentrations. However, the reaction was independent of ionic strength and showed no dependence on the salt effect, indicating an inner sphere mechanism for the reaction. There was no polymerization of the reaction mixture with acrylonitrile, indicating the absence of radicals in the course of the reaction. Michaelis-Menten plot indicated the presence of a reaction intermediate in the rate-determining step. The activation parameters of the reaction have been calculated and products were elucidated by FTIR spectroscopy. The stoichiometry of the reaction is 1:1. A mechanism consistent with the above facts has been suggested.

Bamboo supported manganese (BS-Mn) nanocomposite was prepared in a single pot system via bottom-up approach using a chemical reduction method. Langmuir surface area, BET surface area, and Single pore surface area were 349.70 m 2 /g, 218.90 m 2 /g, and 213.50 m 2 /g, respectively. The pore size (24.34 Ȧ); pore volume (0.489 cm 3 ); point of zero charge (5.8); bulk density (0.0035 gcm -3 ); specific surface area (33.00 m 2 /g) by Saer’s method and functional group of BS Mn nanocomposite determined using Fourier Transform Infrared Spectrophotometer (FTIR). Various operational parameters affecting adsorption of Cu(II) such as adsorbent dose (100 mg), pH (6), contact time (90 min), initial Cu(II) ions concentration (100 mg/L) and temperature (298 K) were determined in a batch technique. Kinetic data were best fitted to pseudo second-order model validated by sum of square error (SSE) and Chi-square test (χ 2 ). Equilibrium data were better described by Langmuir isotherm model with the monolayer adsorption capacity surpassing those previously reported for Cu(II) uptake. The thermodynamic parameters, ΔG o (- 31.773 kJ mol -1 ), ΔS o (107.30 J) and ΔH o (+202 kJmol -1 ) revealed that the adsorption process was feasible, spontaneous and endothermic in nature. The study showed that BS–Mn is a promising nanocomposite which could be utilized for industrial wastewater remediation. Keywords: BS-Mn Nanocomposite; Copper; Adsorption; Kinetics; Isotherms; Spontaneous