Red, Yellow and Blue Ag Nanoparticle Synthesis from AgNO3 and Chitosan Aqueous Suspension for the Eco-friendly Dyeing of Cotton Substrates

Silver nanoparticles (NPs) show diversified colour if properly treated and synthesized for the coloration of textile substrates. It is possible to apply Ag NPs easily for the dyeing of cellulosic substrates, such as cotton knit fabric, by synthesizing silver NPs. The objective of this research is to dye cotton knit fabric using silver NPs, synthesized in the presence of chitosan, which is an alternative to performing dyeing without using salt, soda and chemicals, as well as to minimize the toxicity of silver NPs. Silver NPs can be synthesized by using silver nitrate along with commercially available chitosan. Due to the surface plasmon resonance (LSPR) property of silver NPs, versatile colours are exhibited depending on the synthesizing procedures. The coloration occurs due to the electrostatic interaction between the silver NPs and chitosan-treated cotton knit fabric. The cotton dyed with silver NPs show reasonably good colour fastness to washing and colour fastness to light, which could be extremely effective for the application of silver NPs in knit fabric coloration through eco-friendly processing.