Synthesis and characterization of functionalized polysiloxane for the stabilization of catalytically active metal nanoparticles

Potential applications of inorganic nanomaterials have generated a tremendous number of studies, whether to control the shape and size of the nanoparticle (NP) core and/or to choose the chemical structure of the stabilizing ligand shell. Polysiloxanes are inexpensive, commercially available polymers that are highly soluble in many organic solvents such as THF or toluene and in supercritical fluids, but are not soluble in water. They offer distinct advantages over other polymers when used as stabilizers (1) as they present a high degree of flexibility which allows them to interact strongly with NPs; (2) they can be used as templates to adjust the size, stability, and solubility of NPs ranging in diameter from less than 1 nm to up to 10 nm;(1) (3) NPs are primarily stabilized by steric effects, and therefore a substantial fraction of their surface is unpassivated and available to participate in surfactant exchange and catalytic reactions; (4) the silane function in poly(hydrogenomethylsiloxane) (PHMS) can act as a reducing agent, thus eliminating the need for extra reducing agents; it can also be easily functionalized(2) to control stabilization of the hybrid nanocomposite and used as handles for facilitating linking to surfaces or interactions with other molecules..