黄芩甙在蚕丝上的染色热力学研究

Dyeing thermodynamics of baicalin on silk

为了探讨天然染料黄芩在蚕丝纤维上的染色机制,提高其对上染过程控制、染色效果预测及染色工艺优化的指导价值,对蚕丝纤维先用铝离子预媒染后用黄芩提取物黄芩甙进行染色平衡实验。运用3种理论吸附模型即Langmuir、Freundlich和Nernst对30、45、60℃下的实验数据进行模拟,计算黄芩甙在蚕丝纤维上的热力学参数。结果表明,黄芩甙在蚕丝上的吸附最符合Langmuir吸附模型,并用拟合系数和正规偏差验证了吸附模型,该过程是吸热过程,染色热为2.303 4 kJ/mol,染色熵为6 J/mol,染色亲和力和饱和吸附量随温度的升高而增加。

For investigating the dyeing mechanism of the natural dye-Scutellaria baicalensis Georgi on silk fiber and improving the dye up-taking control, dyeing result prediction and dyeing process optimization, the absorption equilibrium experiments of silk fiber were carried out by pre-chelating with aluminium ions, then dyed with Scutellaria baicalensis Georgi＇s extract-baicalin, and three theoretic adsorption models, i.e., Langmuir, Freundlich and Nernst isotherm were used to simulate the experimental data at the temperature of 30,45,60 ℃Some dyeing thermodynamics parameters of baicalin on silk were studied. The results indicated that the kind of adsorption belonged to Langmuir model proximally, and the adsorption model was validated by the simulation coefficients and normalized deviations. The process was endothermic with the dyeing heat AH =2.303 4 kJ/mol, and the dyeing entropy AS = 6 J/mol. In addition, the dyeing affinity and saturation absorption capacity increased as the temperature increased.