Electrostatically "patchy" coatings via cooperative adsorption of charged nanoparticles.

Solutions containing oppositely charged nanoparticles (NPs) deposit "patchy" coatings of alternating charge distribution on various types of materials, including polymers, elastomers, and semiconductors. Surface adsorption of the NPs is driven by cooperative electrostatic interactions and does not require chemical ligation or layer-by-layer schemes. The composition and the quality of the coatings can be regulated by the types, the charges, and the relative concentrations of the NPs used and by the pH. Dense coatings form on flat, curvilinear, or micropatterned surfaces, are stable against common chemicals for prolonged periods of time, and can be used in applications ranging from bacterial protection to plasmonics.