Volumetric and Viscometric Studies on an Aqueous Urea Solution
Volumetric and Viscometric Studies on an Aqueous Urea Solution
复制标题
尿素水溶液的体积和粘度研究
DOI：
10.1080/0031910029001/0464
复制
发表时间：
2002
影响因子：
1.2
通讯作者：
E. Huque
中科院分区：
文献类型：
--
作者：
M. Motin;T. Biswas;E. Huque
最近，对尿素(变性剂)在水溶液中的行为有了新的热力学和其他研究，这些行为导致蛋白质的结构和性质的变化，包括它们的溶解性、变性、解离成亚基和酶的活性。有鉴于此，测定了在35、40、45、50和55℃下尿素水溶液的密度和粘度与浓度的函数关系。尿素的表观摩尔体积与溶质浓度呈线性关系。由摩尔体积(M)与表观摩尔体积的关系图确定了无限稀释时的表观摩尔体积(等于部分摩尔体积，V_2^o)。根据溶液和有关溶剂的粘度，利用Jones-Dole方程计算了粘度系数B和D。并用Eyring方程计算了粘性流动的活化参数：Gne，Gne，S和Hne。根据尿素在35-55℃温度范围内在水中的结构形成行为对数据进行了解释。
Of late there has been a renewed inerest in the thermodynamics and other investigations on the behaviour of urea (denaturants) in aqueous solution which induce changes in structure and properties of proteins including their solubility, denaturation, dissociation into subunits and the activity of enzymes. With this in view, density and viscosity of aqueous urea solutions were determined as a function of concentration at 35, 40, 45, 50 and 55C, respectively. The apparent molal volume $(\phi _v )$ of urea was found to be linear function of solute concentration. From the $\phi _v$ versus molality ( m ) plot the apparent molal volume at infinite dilution, $\phi _v^o$ (taken to be equal to partial molal volume, $\bar V_2^o$ ) was determined. Viscosity coefficients B and D were calculated on the basis of the viscosity of the solutions and the solvent concerned using the Jones-Dole equation. The activation parameters for viscous flow $(\Delta G^{\ne} , \,\Delta S^{\ne}\ {\rm and\ }\Delta H^{\ne} )$ were also calculated by means of the Eyring equation. The data were interpreted in terms of the structure making behaviour of urea in water at 35-55C temperature range.