Green Synthesis of Monodispersed Iron Oxide Nanoparticles for Leather Finishing

Abstract

Industries worldwide, including leather, have had to phase out pigments based on lead, chromium(VI), cadmium etc. due to the toxicity associated with these transition metal ions. Coupled to this phase out is also a need to enhance the functional properties of the otherwise safe pigments, with low use, so as to avoid wastage. In this direction, the use of nano-pigments is slowly coming into vogue. This paper explores the advantages of replacing an otherwise popular brown pigment – the hematite (á-Fe2O3) with nanosized oxides in leather finishing. Any synthesis methodology for nanoparticles is sustainable only when green methods are employed for their synthesis. This work takes adequate care in employing an environmentally friendly methodology based on biocompatible polysaccharide – starch as a template. The advantages of this method, such as the monodisperse character of the oxide, low particle size, ability of the carbon residue from the template to aid easy homogenization of the pigment to the finish formulation have resulted in excellent covering of surface, improved levelness, no overloading of grain, excellent physical properties and ageing resistance.