An estimation of hydrophilic and hydrophobic interaction of aqueous urea, methylurea, dimethylurea and tetramethylurea from density and apparent molal volume at 30.0 degrees C

作者：Kumar Ajay^*; Singh Man; Gupta K C

来源：Physics and Chemistry of Liquids, 2010, 48(1): 1-6.

DOI：10.1080/00319100701785135

• solute-solvent interaction
• hydrophilic-hydrophobic interaction
• density

Density (rho) for 0.20-1.0 mol kg(-1) of urea, 1-methylurea, 1,3-dimethylurea and 1,1,3,3-tetramethylurea solutions have been measured at an interval of 0.2 mol kg(-1). Apparent molal volume (V-phi, cm(3) mol(-1)) is calculated from rho values. Primary data were regressed and extrapolated to zero concentration for the limiting density (rho(0)) and limiting apparent molal volume (V-phi(0)) values for solute-solvent interactions. -CH3 (methyl) groups of N- methylureas weaken hydrophilic interaction and enhance hydrophobic interaction. The value of rho(0) and V-phi(0) reflect the intermolecular forces due to electrostatic charge. The decreasing value of rho(0) and increasing value of V-phi(0) with increasing number of -CH3 groups suggest some weak hydrophilic and strong hydrophobic interactions, so that the structure-breaking effect decreases. It was also found that with increasing concentration, the hydrophilic or hydrophobic interactions become stronger.

• 出版日期2010-2