摘要
分别用溶解度参数和介电常数表征超临界流体的溶剂特性，并计算了不同压力下二氧化碳的溶解度参数和介电常数。测定了不同压力下脂肪酶催化月桂酸和正丁醇酯化反应的最大反应速率和米氏常数，研究了溶解度参数δ和介电常数ε对最大反应速率Ｖｍ的影响，并比较好地进行了关联：ｌｎ［Ｖｍａｘ／（ｍｍｏｌｈ－１ｇ－１）］＝４．４６５－０．１５３（δ／ＭＰａ０．５），ｌｎ［Ｖｍａｘ／（ｍｍｏｌｈ－１ｇ－１）］＝４．１８７－８．３１８（ε－１）／（ε＋１）．从而通过溶剂特性将压力这一操作条件直接与反应动力学相联系。
The solvent properties of supercritical fluids are charicterized by the Hildebrand solubility parameter and dielectric constant. The Hildebrand solubility parameter and dielectric constant of carbon dioxide are calculated. Based on the lipase catalyzed esterification of lauric acid and n butanol, the maximum reaction rate and the Michaelis Menten constant are measured. The effects of the Hildebrand solubility paramter δ and dielectric constant ε on the maximum reaction rate V max are studied, which are well correlated as follow: ln [V max /(mmol·h -1 ·g -1 )]=4.465-0.153[σ/ MPa 0.5 ], ln [V max /(mmol·h -1 ·g -1 )]= 4.187-8.318(ε-1)/(ε+1) . Therefore effects of pressure on the lipase catalyzed esterification can be correlated with reaction process through the solvent properties.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
1999年第6期31-34,共4页
Journal of Tsinghua University(Science and Technology)
基金
国家自然科学基金
关键词
超临界二氧化碳
酶催化反应
脂肪酶
酯化反应
supercritical carbon dioxide
enzyme catalysed esterification
solubility parameter
dielectric constant
