Solution-phase synthesis of silver nanodiscs in HPMC-matrix and simulation of UV-vis extinction spectra using DDA based method

摘要

Present investigation demonstrates a very simple seed-mediated route, using hydroxypropyl methyl cellulose (HPMC) as stabilizing agent, for the synthesis of silver nanodiscs in aqueous solution. Central to the concept of seed-mediated growth of nanoparticles is that small nanoparticle seeds serve as nucleation centres to grow nanoparticles to a desired size and shape. It is found that the additional citrate ions in the growth solution play the pivotal role in controlling the size of silver nanodiscs. Similar to the polymers in the solution, citrate ions could be likewise dynamically adsorbed on the growing silver nanoparticles and promote the two-dimensional (2D) growth of nanoparticles. Morphological, structural, and spectral changes associated with the seed-mediated growth of the nanoparticles in the presence of HPMC are characterized using UV-vis and TEM spectroscopic studies. Metal nanoparticles have received increasing attention for their peculiar capability to control local surface plasmon resonance (LSPR) when interacting with incident light waves. Extensive simulation study of the UV-vis extinction spectra of our synthesized silver nanodiscs has been carried out using discrete dipole approximation (DDA) methodology.