Electric field “Z” direction alignment of nanoparticles in polymer solutions

A method of preparing a polymer film having an oriented dispersed material, the method comprising:

• casting a multi-layer polymer solution having a top surface, the multi-layer polymer solution comprising:
• a first polymer solution layer having a first polymer, a first solvent, and a dispersed material, and
• a second polymer solution layer forming the top surface on the first polymer solution layer and having a second polymer and a second solvent,
• where the second polymer solution layer is at least partially immiscible with the first polymer solution layer,
• supplying an electric field across an electric field application zone, where the electric field is generated by a first, mesh electrode having a first charge and a second electrode having a charge opposite of the first charge,
• passing the multi-layer polymer solution through the electric field application zone being supplied with the electric field, where the top surface of the multi-layer polymer solution contacts the first electrode to form an imprinted roughness in the top surface dictated by the mesh of the first electrode and to induce orientation of the dispersed material in the first polymer solution layer,
• evaporating the first solvent and the second solvent to thereby form a multi-layer polymer film comprising respective first and second polymer layers, and
• removing the second polymer layer carrying the imprinted roughness from the first polymer layer.