Field assisted self‐assembly for preferential through thickness (“z‐direction”) alignment of particles and phases by electric, magnetic, and thermal fields using a novel roll‐to‐roll processing line

Abstract

Many functional films including heat spreaders, ultrahigh density information storage systems, capacitors, batteries, and fuel cell membranes require enhanced through thickness properties. In this paper, we describe a design and demonstration of a multipurpose novel film formation process to orient and align functional nanoparticles and polymer phases using external electric, magnetic, and thermal gradient fields. This roll‐to‐roll processing line uses a casting system that deposits liquid film of a monomer and/or polymer solution on to a flexible substrate. Substrate is carried by belt through an electric field zone that can apply DC, AC, or a biased AC to orient the phases and particles in the vertical direction while subjecting it to UV through its built in transparent conductive carrier. To orient magnetic particles, an electromagnet located along the machine may be used. The final tool that is built on this machine is the thermal alignment zone which is designed to apply a “line of heat” oriented transverse to the machine direction at nine different zones. Using this processing line, we are able to reduce the cost of manufacturing by limiting the amount of functional fillers through directional alignment while enhancing the thickness properties. POLYM. ENG. SCI., 55:34–46, 2015. © 2014 Society of Plastics Engineers