A fabrication method of ester-functionalized palladium nanoparticle monolayers on amino-terminated silicone surfaces

This paper describes a new strategy for maximizing the density limit of Pd nanoparticle (∼4 nm) monolayers (∼1.6 × 1012 particles/cm2). These were obtained on a flat silicone substrate by means of the spin-coating electrostatic self-assembly method. The density limit probably originated from electrostatic repulsion among identically charged nanoparticles in solution and on the substrate. The ester-modified Pd nanoparticles (NPs) (D ≈ 4 nm) spin-coated on amino-functionalized silicon are directly immobilized on the substrate through hydrogen bonding during acidic hydrolysis. Using this method, the particle density increased more than three times, to 4.69 × 1012 particles/cm2, compared with previous results that were obtained by using electrostatic attraction.