Media.Player

Anisotropic Self-Assembly of Isotropic Nanoparticles in Polymer Nanocomposites

Summary

Lead Inventors: Sanat K. Kumar, Sc.D.; Pinar Akcora, Ph.D.Problem or Unmet Need:Composite materials can have diverse and often disparate properties, for example, being stiff yet flexible. In recent years nanocomposites have gained increasing interest for their unique electronic, chemical, and structural properties. Nanoparticles, however, are inherently difficult to assemble into the hierarchical, anisotropic (non-uniform) structures required by many applications. They cannot be manipulated with traditional manufacturing and compounding techniques. The development of a means by which to direct the assembly of nanocomposite materials is a critical technical hurdle for the growth of this industry. This invention details a novel method for the self-assembly of nanoparticles into composite structures. The particles themselves are isotropic (spherical) silica particles of ~14nm in diameter, coated with a polymer. Depending on the number and the length of the polymer chains that are grafted onto the nanoparticles, they are made to self-assemble at relatively low solid loadings into several highly anisotropic structures including one dimensional (1-D) strings, two dimensional (2-D) sheet-like structures, and three dimensional (3-D) networks and sheet aggregates. By modifying the nanoparticle surface and solution composition, assembly can be reliably controlled.

Technology Benefits

While uncoated isotropic spherical particles typically self assemble into spherical aggregates, this technology enables controlled assembly of anisotropic structures The relatively low number of nanoparticles in solution (<5%) that is required for assembly aids greatly in processing and coating as the mixture is essentially a liquid Coatings may be optically transparent and thus would not alter the appearance of the treated product Morphology, porosity, and density are all readily controlled by slight modifications to the solution composition

Technology Application

Flame retardant coatings -- By reducing gas permeability the stacked sheet-like structures serve to inhibit ignition of the coated material Electroconductive composite -- Use of a conductive nanoparticle, as opposed to silica, results in an anisotropically conductive (different conductivity depending on direction) nanocomposite Solid Oxide Fuel Cells (SOFCs) -- The assembly of oxide nanoparticles into hierarchical 3-D structures aids in manufacture of SOFCs through the tunability of gas and ion permeability of the self-assembled composite Bone or Tooth Enamel synthetic substitute -- The superior mechanical properties demonstrated by nanocomposites of this nature make it an attractive bone/tooth enamel substitute for dental and medical applications

Detailed Technology Description

This invention details a novel method for the self-assembly of nanoparticles into composite structures. The particles themselves are isotropic (spherical) silica particles of ~14nm in diameter, coated with a polymer. Depending on the number and...

*Abstract

None

*Inquiry

Beth Kauderer Columbia Technology Ventures Tel: (212) 854-8444 Email: TechTransfer@columbia.edu

*IR

M08-041

*Principal Investigator

*Publications

Akcora P, Liu H, Kumar S, et al. Anisotropic self-assembly of spherical polymer-grafted nanoparticles, Nature Materials, 8, 354 - 359 (2009)

Country/Region

USA