Forryan Claire L, Klymenko Oleksiy V, Wilkins Shelley J, Brennan Colin M, Compton Richard G
Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
J Phys Chem B. 2005 Nov 10;109(44):20786-93. doi: 10.1021/jp058197a.
In this paper we present a mathematical model for the surface-controlled dissolution of cylindrical solid particles. This is employed to interpret experimental data published previously for the dissolution of potassium bicarbonate in dimethylformamide at elevated temperatures. Significant kinetic differences in assuming cylindrical rather than spherical shapes are reported with the former representing a closer approximation to the true shape of the particles as revealed by scanning electron microscopy. From the fits of experimental data to the cylindrical model for the surface-controlled dissolution, the dissolution rate constant, k, for the dissolution of KHCO(3) in DMF was found to be (9.6 +/- 1.6) x 10(-9) mol cm(-2) s(-1) at 100 degrees C, and the activation energy for the dissolution was 34.5 kJ mol(-1) over the temperature range of 60-100 degrees C. Comparison between cylindrical and spherical dissolution theory highlights the importance of considering the particle shapes for realistic modeling of surface-controlled dissolution kinetics.
在本文中，我们提出了一个用于圆柱形固体颗粒表面控制溶解的数学模型。该模型用于解释先前发表的关于碳酸氢钾在高温下于二甲基甲酰胺中溶解的实验数据。据报道，假设颗粒为圆柱形而非球形时存在显著的动力学差异，扫描电子显微镜显示前者更接近颗粒的真实形状。通过将实验数据拟合到表面控制溶解的圆柱形模型，发现KHCO₃在DMF中于100℃时的溶解速率常数k为(9.6±1.6)×10⁻⁹ mol cm⁻² s⁻¹，在60 - 100℃的温度范围内，溶解的活化能为34.5 kJ mol⁻¹。圆柱形和球形溶解理论之间的比较突出了在表面控制溶解动力学的实际建模中考虑颗粒形状的重要性。
