*Article* **Nanostructures and Thin Films of Poly(Ethylene Glycol)-Based Surfactants and Polystyrene Nanocolloid Particles on Mica: An Atomic Force Microscopy Study**

**John Walker 1, Andrew B. Schofield <sup>2</sup> and Vasileios Koutsos 1,\***


**Abstract:** We studied the nanostructures and ultrathin films resulting from the deposition and adsorption of polystyrene nanocolloidal particles and methoxy poly(ethylene glycol) methacrylate surfactants on mica surfaces from mixed suspensions in water. The samples were prepared by droplet evaporation and dip coating and imaged with atomic force microscopy. Topography and phase imaging revealed a significant richness in morphological features of the deposited/adsorbed films. We observed uniform ultrathin films and extended islands of the surfactant oligomers indicating their self-assembly in monolayers and multilayers, while the polystyrene nanocolloids were embedded within the surfactant structures. Droplet evaporation resulted in the migration of particles towards the edges of the droplet leaving an intricate network of imprints within the surfactant film. Dip coating induced the formation of extended nanocolloid clusters with colloidal crystalline structuring.

**Keywords:** nanocolloids; nanoparticles; nanostructures; monolayers; polymers; surfaces; thin films; mica; poly(ethylene-glycol); atomic force microscopy
