ABSTRACT
Gum Arabic is most important commercial poly-saccharine and it is probably the oldest food hydro-colloid in current use. Gum Arabic is naturally obtained from Acacia Senegal and seyal trees which are known to grow in sub Sahara region of the Sudan. Two types of Gum Arabic namely; Acacia Senegal and Seyal were used. X-ray fluorescence [XRF] and Fourier Transformation infrared spectroscopy [FTIR] were used as analytical techniques. The conductivity and dielectric of both types of Gum Arabic were measured as function of frequency. Solutions with different concentration of Gum Arabic for both types were prepared and the Ultraviolet-visible spectroscopy [UV] was used to study the optical properties of these solutions. The XRF results indicated that, Gum Arabic [Acacia Senegal and Seyal] contained Calcium [Ca], Iron [Fe], Copper [Cu], Lead [Pb], and Strontium [Sr]. The FTIR spectra of both types of Gum Arabic showed broad and strong absorption band in the range of 600 to 3000 cm-1. These absorptions were assigned to the different stretching vibrations. The conductivity was found to increase with frequency while the opposite behavior observed for the dielectric. The absorption was found to increase with the increase of concentration
ABSTRACT
Hibiscus is a genus of flowering plants in the mallow family, Malvacease. It is quite large, containing several hundred species that are native to warm-temperate and have many medical benefits, for example, hibiscus drink lowers high blood pressure. Flowering plants of hibiscus were used in this study. X-ray fluorescence [XRF] and Fourier Transformation infrared spectroscopy [FTIR] were used as analytical techniques. The XRF results indicated that, hibiscus has contained Potassium [K], Calcium [Ca], Iron [Fe], Copper [Cu], Bromine [Br], and Strontium [Sr]. The FTIR spectra of hibiscus showed a broad and strong absorption band in the range1145-2926 cm-1, and these absorptions were assigned to the different stretching vibrations. The conductivity and dielectric properties of hibiscus were measured as function of frequency. The conductivity was found to decrease with frequency while the opposite behavior was observed in case of dielectric. In order to investigate the optical properties, solutions with different concentration of hibiscus were prepared. Ultraviolet-visible spectroscopy [UV] was used to obtain the absorption for different samples with different concentration. The absorption was found to increase with the increase of concentration of hibiscus
ABSTRACT
Fractional calculus has become an important tool in the analysis of slow relaxation phenomena, such as stress-strain relationships in polymeric materials. The interaction of trilblock copolymer [Pluronics f68] with cetyltrimethylammonium bromide [CTAB]-sodium nitrate [NaNO3] wormlike micellar system in low and high salt concentration is investigated by rheological measurements. Undoped wormlike micellar solution is a viscoelastic fluid which exhibits Maxwellian behavior. Since the rheology of solutions still Maxwellian, a fractional Maxell model is applied to describe any changes. A fractional derivatives of order q and The Maxwell model consists of a spring and dashpot in series. The fractional Maxwell model relating stress to strain is used to fit several experimental results on wormlike micelles in the presence of copolymer. The comparisons between the experimental results and the theoretical predictions are found to be satisfactory
Subject(s)
Micelles , Recombinant Proteins , RheologyABSTRACT
Mesoporous silica has been synthesized by gamma-irradiation using a non-ionic surfactant as template in the cubic and hexagonal lyotropic phases. The mesopores obtained in the two phases have different diameters, cubic phase silica being with the smaller pore size of the order of 3-4 nm whereas the hexagonal phase silica is giving large mesopores of value around 15 nm. The wall size differ in the two templated phases as well, cubic phase is with a small thickness of the order of 5.0 nm while the hexagonal silica exhibits a wall thickness of 15 nm under transmission electron microscopy [TEM] approximately. Both these cubic and hexagonal phases were further characterized by small angle X-ray scattering [SAXS], polarizing microscopy and rheometry. Radiation dose and templated phase are both playing effective role in the synthesis of mesoporous silica
Subject(s)
Polyethylene Glycols , Ethers , CrystallizationABSTRACT
Phase diagrams for the ternary systems of Glucopone, Water and several hydrocarbons are reported. Four different types of hydrocarbon are used namely; heptane, octane, dodecane and tetradecane. Small angle X-ray scattering [SAXS] and polarizing microscope are used for phase identification and structure characterization. The ternary systems are shown to form different liquid crystalline phases with the Increase of concentration in the following order - cubic, hexagonal, and lamellar. An optical isotropic gel phase with strong elastic properties is found in these systems and Identified as cubic phase. The cubic phase is optically isotropic, transparent and highly viscous phase with three-dimensional structure. The cubic samples showed several diffraction peaks and can be assigned to the la3d space group. The rheological study on the cubic phase is performed. All cubic samples behave as solid-like material with storage modulus G 0.7x10[6] Pa typical of cubic lyotropic materials. The effect of oil concentration in the ultrasonic measurements for the three different liquid crystalline phases is studied. The effect of different types of oil on the ultrasonic measurements is also investigated. The ultrasonic measurements showed that the ultrasonic velocity of the cubic samples Increased as the oil concentrations increased. The ultrasonic measurements showed that the ultrasonic velocities of the lamellar phases decreased with increase in the chain lengths of the hydrocarbon, while the ultrasonic velocities were almost similar for hexagonal phases