| abstract |
A process and apparatus for producing a gradient nanovoided article, a gradient nanovoided coating, and a gradient low refractive index coating is described. The process includes providing a first solution of a polymerizable material in a solvent, and providing a first environment proximate a first region of the coating and a different second environment proximate an adjacent region of the coating. The process further includes at least partially polymerizing the polymerizable material to form a composition that includes an insoluble polymer matrix and a second solution. The insoluble polymer matrix includes a plurality of nanovoids that are filled with the second solution, and a major portion of the solvent from the second solution is removed. A first volume fraction of the plurality of nanovoids proximate the first region of the coating is less than a second volume fraction of the plurality of nanovoids proximate an adjacent of the coating. An apparatus for the process is also described, and includes a web line, a coating section, a partial polymerization section, and a solvent removal section. |