Studies on volumetric properties of some saccharides in aqueous potassium chloride solutions over temperature range (288.15 to 318.15)K

Modulation in physico-chemical characteristics of some polyhydroxy solutes in presence of l-glycine: Volumetric and NMR spectroscopic approach

“…The V 2° values of solutes studied in water are in good agreement with the literature (Table 3) values [4,6,11,13,[18][19][20][21][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44]. The standard partial molar volumes of transfer at infinite-dilution,  tr V 2 º of each solute from water to aqueous L-glycine solutions were calculated as:…”

“…This difference in V AB values may be due to the fact that the methyl glycopyranosides disturb on average more water molecules in comparison to deoxy-derivatives of hexoses. The substitution of -CH 2 OH group with hydrophobic, -OCH 3 group introduces a hydrophobic hydration, hence manifesting significantly weaker hydration in methyl glycopyranosides[4,27]. This is the reason that in Me α-Glc, the V AB coefficients are negative and V ABB coefficients are positive.…”

Effect of sodium acetate on the volumetric behaviour of some mono-, di-, and tri-saccharides in aqueous solutions over temperature range (288.15 to 318.15)K

“…Thermodynamic studies on saccharides in organic salt solutions are missing in the literature and therefore it will also be interesting to study the hydration characteristics of saccharides in aqueous sodium acetate solutions. In continuation of our previous studies [7,[10][11][12]19], we report in the present work the apparent molar volumes, V 2,/ for various mono-, di-, and tri-saccharides in water and in (0.5, 1.0, 2.0, and 3.0) mol Á kg À1 aqueous sodium acetate (co-solute) solutions at temperatures T = (288.15, 298.15, 308.15, and 318.15) K. Molalities, m of the various saccharides studied range from (0.03 to 0.12) mol Á kg À1 . The standard partial molar volumes of transfer, D t V 2 at infinite dilution from water to aqueous sodium acetate (co-solute) solutions have been determined.…”

“…In some plants and animals such as mushroom, yeast, fungi and brine shrimps, intracellular a,a-trehalose contributes throughout its vitrification to their survival abilities against severe conditions like freezing and desiccation. Disaccharides (particularly trehalose and sucrose) can stabilize labile biomolecules in aqueous solutions by a combination of kinetic and specific effects [6,7]. The presence of salts modifies important properties of aqueous saccharide systems related to their protective role such as viscosity, water sorption, crystallization rate, and glass transition temperature [2,8].…”

Estudio hidrofóbico de soluciones acuosas diluidas de isómeros de pentanodiol a varias temperaturas a partir de datos volumétricos

“…El signo positivo se atribuye a que el soluto tiene un efecto formador sobre la estructura del agua y el signo negativo a que el soluto tiene un efecto disruptor. 13 Siguiendo este orden de ideas un ajuste funcional del con la temperatura mediante la ecuación cuadrática es presentado en la ecuación (3) y sus constantes de ajuste en la Tabla 4; de acuerdo con la interpretación antes dada, podemos decir que en la región diluida los isómeros de pentanodiol ejercen un efecto formador sobre la estructura del agua, ratificando de esta forma lo obtenido con la pendiente límite, por cuantola segunda derivada del volumen molar parcial a dilución infinita con respecto a la temperatura es positiva, además esta se hace Tabla 4. Constantes de ajuste para la dependencia cuadrática del con temperatura para soluciones acuosas diluidas de más pequeña en el orden 1,2 PD> 1,5PD >1,4PD > 2,4PD, reflejando así que este efecto cambia con la posición de los grupos hidroxilos.…”