Imaging, deposition, and self-assembly of CTAB stabilized gold nanostructures

Abstract

True picture of the nanoparticle arrangements is significant owing to their unique applications that are generally linked with their collective response within the self-assembled arrays over the underlying surface. Surfactant such as cetyltrimethylammonium bromide (CTAB) stabilized gold nanostructures on two different surfaces such as silicon dioxide and highly oriented pyrolytic graphite (SiO2, HOPG) have been investigated via using well known and widely used imaging techniques. These frequently employed substrates for the study of nanoparticles self-assembly have been used to study their images after complete evaporation of the suspension droplet. The resulting images of nanoparticle deposits via various techniques revealed contrasting topographies; some of the self-assembled features over a particular surface are highlighted in one technique whereas hidden in other technique. As CTAB molecules are not merely use to stabilizing the gold core during synthesis but these molecules also for all intents and purposes exist in suspension with the gold nanostructures. Therefore, for such multi-nano systems, evaluation of nanoparticles images by a single imaging technique is generally misleading. This work will highlight the contrasting results acquired using various imaging techniques such as high resolution scanning electron microscope, helium ion microscope, atomic force microscope, and scanning tunneling microscope.