Rakesh Kumar Bhardwaj

Excess molar volumes and viscosities of binary mixtures of 1,2-diethoxyethane with chloroalkanes at 298.15 K

Excess molar volumes (VmE) and viscosities (η) of the binary mixtures of 1,2-diethoxyethane with di-, tri- and tetrachloromethane have been measured at 298-15 K and atmospheric pressure over the entire mole fraction range. The deviations in viscosities (δlnη) and excess energies of activation (δG*E) for viscous flow have been calculated from the experimental data. The Prigogine-Flory-Patterson (PFP) model has been used to calculateVmE, and the results have been compared with experimental data. The Bloomfield and Dewan model has been used to calculate viscosity coefficients and these have also been compared with experimental data for the three mixtures. The results have been discussed in terms of dipole-dipole interactions between 1,2-diethoxyethane and chloroalkanes and their magnitudes decreasing with the dipole character of the molecules. A short comparative study with results for mixtures with polyethers and chloroalkanes is also described.

Excess molar volumes and viscosities of binary mixtures of diethylene glycol diethyl ether with chloroalkanes at 298.15 K

Abstract Excess molar volumes (V m E ) and dynamic viscosities (η) at 298.15 K and atmospheric pressure for mixtures of diethylene glycol diethyl ether + dichloromethane, + trichloromethane, and + tetrachloromethane were determined as a function of composition. The excess molar volumes are all negative over the whole composition range. The deviations in viscosity (Δlnη) and excess energies of activation (ΔG ∗E ) for viscous flow have been calculated from the experimental data. The rseults have been discussed in terms of dipole-dipole interactions between diethylene glycol diethyl ether and chloroalkanes. The magnitude of the strength of interaction decreases with the dipole character of the molecule. Furthermore, the viscosity data have been correlated by the methods of Kendall and Monroe, Grunberg and Nissan, Tamura and Kurata, Hind, Katti and Chaudhry and of McAllister. A short comparative study with results for mixtures and polyethers and chloroalkanes is also discussed.

Evaluation of plant extracts as antifungal agents against wood rotting fungi Coriolus versicolor (L.: Fr.) Quelet

Aqueous extracts from 20 plants were tested for their antifungal activity against Coriolus versicolor inciting wood rot in trees. Test results showed a differential activity of the plant extracts against the mycelium growth. The combined seed extracts of Azadirachta indica and rhizome extracts of Curcuma domestica in general showed a strong enhancement in activities over the individual seed extracts of A. indica and rhizome extracts of C. domestica against the mycelium growth. The seed extracts of Albizia stipulata and seed extracts of Acacia arabicae showed strong inhibitory effect against the test fungi. The leaf extracts of Adhatoda vasika, leaf extracts of Aegle marmelos, whole plant extracts of Cuscuta reflexa, leaf extracts of Clerodendron inerme and root extracts of Acacia catechu showed appreciable good inhibitory effect against the test fungi.