Cellulose has been the extracted from rice husk by chemical treatment with aqueous solution of sodium hydroxide. The physical properties of derived cellulose (water uptake and swelling behavior) has been investigated with view of different applications. The morphology and chemical structure were investigated by Infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM) and Thermogravimet...

Using density functional theory we investigate whether intrinsic defects in ice surface segregate. We predict that hydronium, hydroxide, and the Bjerrum L- and D-defects are all more stable at the surface. However, the energetic cost to create a D-defect at the surface and migrate it into the bulk crystal is smaller than its bulk formation energy. Absolute and relative segregation energies are ...

A new interatomic potential for dissociative water was developed for use in molecular dynamics simulations. The simulations use a multibody potential, with both pair and three-body terms, and the Wolf summation method for the long-range Coulomb interactions. A major feature in the potential is the change in the short-range O-H repulsive interaction as a function of temperature and/or pressure i...

Water maintains a pH value of 7 owing to a balance between dissociation into hydronium (H3O+) and hydroxide (OH−) ions and their recombination. An examination is made of the effect of applying voltages from 0.1 to 0.82V on these ions between metal electrodes which act as blocking electrodes. The movement of hydronium ions away from and hydroxide ions towards the anode is followed. This movement...

The hydronium salt (H3O)2[Cu(N7–acv)2(H2O)2(SO4)2]·2H2O (1, acv = acyclovir) has been synthesized and characterized by single-crystal X-ray diffraction and spectral methods. Solvated Cu(OH)2 is a by-product of the synthesis. In the all-trans centrosymmetric complex anion, (a) the Cu(II) atom exhibits an elongated octahedral coordination; (b) the metal-binding pattern of acyclovir (acv) consists...

4-(Dimethylamino)benzaldehyde is alkylated at the N atom by dialkyl sulfates, MeI, or Me3O BF4. In contrast, ethylation by Et3O BF4 occurs selectively at the O atom yielding a quinoid iminium ion. 4-(Diethylamino)benzaldehyde is alkylated only at O by either Et or Me oxonium reagent. The iminium salts are prone to hydrolysis giving the corresponding hydrotetrafluoroborates. Five crystal structu...

Using Vorbrüggen's protocol, reaction of persilylated uracil with xylofuranose derivatives having 3beta-oxy-3alpha-alkyl substitution produced both alpha- and beta-nucleosides. Only the beta-nucleosides were formed from substrates having the reverse stereochemistry at C-3 or lacking the 3-alkyl substituent. Participation of the 3beta-oxy substituent in stabilizing the incipient C-1 carbonium io...