Nanostructured coating materials, methods of their production, and methods of use in a variety of applications are described. The nanostructured materials described herein include one or more 2.sup.+ and/or 3.sup.+ metal ion(s), optionally in a ternary phase, on a substrate.

A method for fabricating a film on a substrate and a method for controlling the heating rate of a plurality of nanoparticles to transform the plurality of nanoparticles into a plurality of nanorods and nano-cone structures includes the steps of providing a sol precursor, providing a substrate, depositing the sol precursor onto the substrate via a sol-gel technique, annealing the sol precursor under ambient pressure at a controlled heating rate, and cooling down the sol precursor to form a film.

The method for forming a coating of the present invention includes: a first step of applying a first solution containing a polysilazane to a surface of a metal substrate and heating the first solution to form a first coating on the surface of the metal substrate, and a second step of applying a second solution containing a polysilazane to a surface of the first coating and heating the second solution at a temperature lower than a heating temperature in the first step to form a second coating on the surface of the first coating, wherein a density of the first coating is less than 2.00 g/cm.sup.3, and a density of the second coating is 2.00 g/cm.sup.3 or more.

Provided is a method of forming a metal oxide layer may include forming a parent metal oxide layer on the substrate structure; changing the parent metal oxide layer into a cation-exchanged metal oxide layer through a cation exchange reaction between cations in the parent metal oxide layer and cations in the reaction solution by contacting the parent metal oxide layer with a reaction solution containing these latter cations; and performing a heat treatment process on the cation-exchanged metal oxide layer.

Coating compositions are provided that eject droplets of condensed fluid from a surface. The coatings include a nanostructured coating layer and in some embodiments, also include a hydrophobic layer deposited thereon. The coating materials eject droplets from the surface in the presence of non-condensing gases such as air and may be deployed under conditions of supersaturation of the condensed fluid to be ejected. A heat exchanger design utilizing the coating is described herein.