天然靛蓝间接电化学染色性能的研究

Indirect Electrochemical Dyeing Properties of Natural Indigo

以电能替代传统的保险粉还原靛蓝,是对靛蓝清洁染色工艺的新探索。文中分别以Fe^(3+)-TEA、Fe^(2+)-配体为阴极溶液,采用间接电化学对天然靛蓝进行还原染色工艺。发现以Fe^(3+)-TEA为阴极溶液时,优化后施加电压为13.00 V,阴极还原电位趋于-660 mV,在间接电化学反应器中仍然可以对织物进行上染,但上色不好,染色效率不高,长达7 h的还原时间,测得织物的K/S值虽有上升,仍仅为0.490 5;以Fe^(2+)-配体体系对靛蓝进行还原,得出最佳配体为葡萄糖酸钙,优化后的还原染色条件为1.500 g/L天然靛蓝、2.780 g/L FeSO_(4)·7H_(2)O、4.350 g/L葡萄糖酸钙、1.600 g/L NaOH,在10.00 V电压下电化学还原20 min后,将织物放入浸染,浸染时长为9 min,K/S值为11.204 0。

Reducing indigo with electric energy instead of traditional sodium hydrosulfite is a new exploration of indigo clean dyeing process. In this paper, Fe^(3+)-tea and Fe^(2+)-ligands are used as cathode solutions to reduce and dye natural indigo by indirect electrochemistry. It is found that when Fe^(3+)-TEA is used as the cathode solution, the applied voltage is 13.00 V after optimization, and the cathodic reduction potential is close to-660 m V. The fabric could still be dyed in the indirect electrochemical reactor, but the dyeing efficiency is not good, and the K/S value of the fabric is only 0.490 5 after 7 h reduction time. Fe^(2+)-ligand system is used to reduce indigo, and the optimal ligand is calcium gluconate. The optimized reduction staining conditions are 1.500 g/L natural indigo, 2.780 g/L FeSO_(4)·7H_(2)O, 4.350 g/L calcium gluconate, 1.600 g/L NaOH. After 20 minutes of electrochemical reduction at 10.00 V voltage, the fabric is immersed for 9 minutes and K/S value reaches at 11.204 0.