Adsorption Kinetic and Thermodynamic Studies of Silk Dyed with Sodium Copper Chlorophyllin

Abstract

In this study, silk was dyed into a bright green shade with a natural dye derivative, sodium copper chlorophyllin (SCC). Kinetics and thermodynamics of SCC adsorption on silk in dye bath with and without sodium chloride at different temperatures were investigated. The pseudo second-order kinetic model fitted experimental data well. Addition of sodium chloride increased SCC adsorption at equilibrium q e , increased the diffusion coefficient D and decreased the half dyeing time t 1/2 . The Langmuir isotherm agreed well with a high correlation coefficient (R 2 > 0.99) for dyeing temperatures of 70, 80, and 90 °C with SCC concentration varying from 0.1 to 2.9 g/L. The thermodynamic parameters of SCC adsorption with and without sodium chloride showed significant difference. The adsorption affinity (−Δμ°) and enthalpy change (ΔH°) of SCC dye on silk indicated that the adsorption is a spontaneous and exothermic process. SCC could be a good candidate as a natural green dye for protein fibers.

Sodium Copper Chlorophyllin Immobilization onto Hippospongia communis Marine Demosponge Skeleton and Its Antibacterial Activity

“…After a certain time (approximately 30 min of the duration of the experiment) the value stabilizes. Our results for the efficiency of adsorption of SCC are better than others previously reported for different supports, for example, 49.75 g/kg SCC on silk fibers [1], and 5 μmol/10 mg SCC on chitosan [33]. …”

“…Further, saponification removes the methyl and phytol from the chlorophyll molecule, and may partially cleave the pentenyl ring (depending on the degree of hydrolysis [1], the cyclopentenyl ring may be cleaved with the resultant production of a third carboxyl function). This procedure leads to a complex mixture of compounds [2,3,4].…”

“…Other bioactivities are also attributed to chlorophyllin, such as immunomodulatory and antiapoptotic effects [22], antioxidant activity against oxidative stress or radiation-generated reactive oxygen species [23,24], and antibacterial effects [5,25,26,27]. SCC is used as a dietary supplement, in food, drugs and cosmetics [28], in textile dye [1,29], as an internal deodorizer [30] and as a natural wound healer [31]. …”

“…Copper chlorophyllin with hydrotalcite [34] and graphene oxide nanostructures [35] exhibits a bactericidal effect. SCC adsorbed onto silk can serve as natural dye for fibers [1]. It is also worth mentioning that copolymer of chlorophyllin sodium copper salt, acrylic acid, n-butyl acrylate, and N-isopropylacrylamide is used as light sensitive cation exchanger for lysozyme purification [36].…”

Haematoxylin sorption onto yak hair: kinetic and thermodynamic studies

“…In a certain temperature range, high temperature leads to an increase in hair fibre swelling, which can gradually intensify thermal motion . A greater number of haematoxylin molecules can diffuse into the hair from the absorbent surface, enhancing the dyeing rate markedly; thus, dye sorption at 313 K was found to be greater than dye sorption at 303 K. When the temperature exceeds a certain range, dye desorption speeds up, competing with the simultaneous increase in sorption rate and leading to a decrease in the dyeing rate; thus, dye sorption at 313 K was found to be greater than dye sorption at 323 and 333 K. This behaviour is similar to that observed for the adsorption of sodium copper chlorophyllin on silk .…”