Photonic polymer-blend structures and method for making

Abstract

The present invention comprises the formation of photonic polymer-blend structures having tunable optical and mechanical properties. The photonic polymer-blend structures comprise monomer units of spherical microparticles of a polymer-blend material wherein the spherical microparticles have surfaces partially merged with one another in a robust inter-particle bond having a tunable inter-particle separation or bond length sequentially attached in a desired and programmable architecture. The photonic polymer-blend structures of the present invention can be linked by several hundred individual particles sequentially linked to form complex three-dimensional structures or highly ordered two-dimensional arrays of 3D columns with 2D spacing.

What is claimed is:  
     
         1 . A method for making photonic polmer-blend structures having tunable optical and mechanical properties comprising the steps of: 
 a) providing an aqueous polymer-blend solution comprising a relative mass fraction of polyethylene glycol and polyvinyl alcohol wherein said solution having a sufficient water and polymer blend ratio to form polymer-blend spherical microparticles having specific properties and morphology to enable said microparticles to partially merge in a sequential attachment with one another to form an inter-particle bond having an inter-particle separation wherein said specific properties and morphology of said microparticles tune said inter-particle separation and wherein said specific properties and morphology of said spherical microparticles produce a desired photonic polymer-blend structure having a desired architecture;    b) injecting said aqueous polymer-blend solution into a particle focusing device at a sufficient rate so to form individual droplets of solution;    c) controlling said parameters of said particle focusing device to allow said droplets to be spatially focused and guided through said particle focusing device to form spherical microparticles partially merged in a sequential attachment in an inter-particle bond with one another and having a tuned inter-particle separation; and    d) depositing said spherical microparticles in a precise placement on a collection device forming a desired architecture of said photonic polymer-blend structure.    
     
     
         2 . The method of  claim 1  wherein said polyethylene glycol and said polyvinyl alcohol is in a 4:1 mass ratio.  
     
     
         3 . The method of  claim 1  wherein homogeneous polymer-blend spherical microparticles are formed having diameters ranging from 1-10 μm.  
     
     
         4 . The method of  claim 1  wherein said inter-particle separation is tuned by adjusting said relative mass fraction of said polymer-blend material.  
     
     
         5 . The method of  claim 1  wherein said aqueous polymer-blend solution further comprises an ionic species.  
     
     
         6 . The method of  claim 1  wherein said particle focusing device is an electric quadrupole.