Green Chemical Synthesis of Silver Nanowires and Microfibers Using Starch

In recent years considerable efforts have been focused on the synthesis of silver nanostructures in view of their manifold application potentials in various fields such as catalytic processes,1 optics,2 surface-enhanced Raman spectroscopy,3 etc. The majority of the methods used for the fabrication of nanometerand micrometer-sized silver materials generally employ organic solvents, synthetic macromolecules, and other chemical compounds that hardly satisfy the requirements of green chemistry. Thus to reduce or minimize the risk of environmental hazards there is much emphasis on and consistent demand for eco-friendly chemicals for synthesizing the desired products. In combination with suitable environment-friendly compounds, biopolymers are being increasingly exploited as resource materials for nanofabrication. Biomacromolecules such as peptides are utilized for the biomimetic synthesis and pattern formation of silver nanomaterials.4 However, besides proteins, biopolymers have rarely been utilized for the controllable synthesis of silver crystals having desired morphological modifications. Limin Qi et al.5 obtained silver microcrystals of various morphologies by controlled crystallization using dextran. Qian et al.6 reported hydrothermal synthesis of silver nanowires by the interaction of AgNO3 and glucose in presence of poly(vinyl alcohol) (PVA). The authors also prepared silver nanowires by interacting freshly