A New Appraoch For Dyeing And Functional Finishing Of Cotton Fabric Using Henna Extract And Reactive Dyes Combined With TiO₂ Nano-sol

Incorporation of functional finishes in the dyeing process saves energy and reduce water consumption, which is important both in economical and ecological point of view.Embedding dyestuffs into inorganic matrix （metal oxide nanoparticles） is a novel approach for obtaining dyeing with functional finishing on cotton fabric i.e., Antibacterial activity and UV-protection.In this current study cotton fabrics were cationized with 3-chloro-2-hydroxy propyl trimethylammonium chloride to obtain eco-friendly dyeing having multifunctional properties by means of dyeing of cotton fabrics without addition of salt.TiO₂ nano-sols were prepared by sol-gel method using tetraisopropyl orthotitanate. Reactive dyes （CI Reactive Yellow 176, CI Reactive Red 120 and CI Reactive Yellow 145） and natural dye （Henna extract） were used in the dyeing processes.TiO₂ nano-sols were integrated with reactive dyes and Henna extract using diverse routes. Different dyeing processes and finishing formulations were applied, summarized as follows:1. Two types of reactive dyes （CI Reactive Red 120 and CI Reactive Yellow 145） were doped with different amounts （0.035mol,0.053mol and 0.07mol） of TiO₂ nano-sol by sol-gel method and applied on cationized cotton fabric using pad-dry-steam method without addition of salt.ATR-FTIR spectra and XRD pattern revealed peaks ascribed to TiO₂ nanoparticles of the samples dyed with titanium dyeing solutions. Moreover, the SEM images showed a clear dispersion of TiO₂ nanoparticles on the surface of the dyed samples. Samples dyed with titanium dyeing solutions exhibited better dyeing and fastness properties as well as antibacterial efficacy, and durable UV protection even after 10 laundering cycles, with slight reduction in tensile strength compared to the samples dyed with commercial reactive dves.2. Cotton fabrics were cationized with different amounts of 3-chloro-2-hydroxypropyl trimethylammonium chloride. TiO₂ nano-sol was prepared by sol-gel technique and applied on cationized cotton fabrics with different quantities using the same finishing formulation and treatment sequence. Treated fabrics were then dyed with various concentrations of Reactive Yellow 176. FT-IR test revealed that the O-Ti-O peak appears on treated sample as well as on treated, dyed samples and that proves the existence of TiO₂ nanoparticles even after dyeing process. The XRD pattern of treated and treated, dyed samples showed a peak of TiO₂ nano-particles at （20=20.8）. Moreover, the SEM revealed a clear dispersion of TiO₂ nanoparticles on the surface of the treated and treated, dyed samples. The UPF of the treated dyed samples was higher than that of untreated dyed samples. This treatment showed better UV protection with slight reduction in color depth （K/S） and tensile strength.3. In this part cationic agent （3-chloro-2-hydroxy propyl, trimethylammonium chloride） was used to substitute metallic mordants （heavy-metal salts） in pre-treating cotton fabric. This eventually will prevent heavy metal pollution as well as obtain dyeing without addition of salt.3.1 TiO₂ nano-sol was prepared by sol-gel method using different amounts of tetraisopropyl orthotitanate （TTIP） and applied on cationized cotton fabrics using the same finishing formulation and treatment sequence. Treated fabrics were then dyed with Henna extract at different dyeing temperatures （60℃, 80℃ and 90℃） in absence of salt. Samples treated with TiO₂ nano-sol and dyed with Henna extract exhibited outstanding enhancement in both the UV protection and antibacterial efficacy with minimal impact on color depth and tensile strength.3.2 Cationized cotton fabrics were dyed with Henna extract at different dyeing temperatures （40℃,60℃,80℃ and 90℃） for different dyeing times （40min, 60min and 80min） in absence of salt. Cationized fabric dyed with Henna extract exhibited outstanding enhancement in the UV protection with minimal impact on tensile strength.