1 research outputs found
Assembly of Mid-Nanometer-Sized Gold Particles Capped with Mixed Alkanethiolate SAMs into High-Coverage Colloidal Films
We investigated the influence of
the mixed <i>n</i>-alkanethiolate
self-assembled monolayer (SAM) formed on gold nanoparticles (AuNPs:
50.0 ± 3.2 nm in diameter) on their assembly into colloidal films.
Dodecanethiol and octadecanethiol were selected as the short- and
long-chain alkanethiols, respectively. The mixed SAMs were formed
by immersing AuNPs in a mixed alkanethiol solution at different molar
ratios. Au colloidal films were fabricated on indium tin oxide substrates
by our previously reported hybrid method. The composition of the two
alkanethiolates in the SAM was deduced from the intensity ratio of
two Raman bands at 1080 and 1105 cm<sup>–1</sup>. The surface
coverage of the colloidal films increased by forming equimolar or
dodecanethiolate-dominant mixed SAMs on AuNPs instead of a pure dodecanethiolate
or octadecanethiolate SAM. The highest coverage exceeded 80%. This
improvement is attributed to the high dispersion stability of AuNPs
covered with equimolar or dodecanethiolate-dominant mixed SAMs