Acquiring Sustainable Coloration and Antimicrobial Properties to Natural Fabrics via Spirulina Algae/Silver Nanocomposite

This study investigates the solid-state synthesis of silver nanoparticles (AgNPs) using Spirulina platensis, an environmentally friendly algal source, as both a reducing and stabilizing agent. The solid-state synthesis method was employed to produce AgNPs without solvents or intermediates, enhancing cost-effectiveness and sustainability. Spirulina, when activated with NaOH, successfully reduced silver ions (Ag⁺) to silver nanoparticles, as confirmed by a characteristic color change of the mixture and UV–Vis spectroscopy. The optimal concentration of AgNO₃ for maximum AgNP formation was determined to be 0.25 g per gram of Spirulina, yielding nanoparticles with a size of 19.9 nm and excellent homogeneity (PdI = 0.2). The AgNPs were further characterized using TEM, which revealed uniform and small nanoparticle formation at lower precursor concentrations. FTIR and SEM analyses confirmed the interaction between Spirulina and the AgNPs, where Spirulina effectively stabilized the nanoparticles. Furthermore, the synthesized AgNPs, when used as a colorant in printing pastes for wool and cotton fabrics, exhibited promising results for textile applications. The printing process, which involved a conventional screen-printing method, produced durable, vibrant prints with improved stability, highlighting the potential of Spirulina-mediated AgNPs as an innovative, eco-friendly dye alternative in the textile industry. This method presents a novel, green approach to nanoparticle synthesis, offering a sustainable solution to textile dyeing and printing, with reduced environmental impact.

Graphical Abstract

Graphical Abstract of solid-state synthesis of silver nanoparticles mediated by Spirulina and application in textile printing.