Materials

Electroactive Polymers

Fractal Systems, Inc. has focused on the development of intrinsically conducting polymers (ICPs), examples of which are shown below, for a wide variety of applications. The materials’ properties are tailored to fit the desired application, particularly their electrical, electronic, optical and morphological properties. The materials characteristics can be fine-tuned by control of the amount of dopant (oxidizing or reducing agent) in the polymer. For example, the polymers go from transparent in the visible light to opaque as the dopant concentration is increased. Similarly, their conductivity covers a wide range from insulating through semiconducting to metallic levels with the highest conductivity values being similar to that of copper. Their morphology can also be varied to yield specific properties. Examples are shown below.

Examples of ICPs

Scanning Electron Micrographs of High Conductivity Polymers

Polypyrrole Poly(ethylenedioxythiophene)

Random (left) and Ordered (more conductive, right) Morphology

Fractal Morphology of Conductive Polymers

Ferromagnetic Materials

Fractal Systems, Inc. is in the process of developing nanoparticles of ceramic ferromagnets and organic polymers that exhibit ferromagnetism at room temperature. The ceramic nanoparticulates offer processing advantages relative to conventional materials with intrinsic properties that lead to novel application areas. The organic polymers are obtained using proprietary synthesis/processing techniques with film forming properties. The two types of material can be combined to form a nanocomposite with superior characteristics compared to either one separately. In addition, nanocomposites made of selected ICPs and ceramic ferromagnetic nanoparticles yield superior properties to those of ceramic nanoparticles alone.

Nanocomposites

ICPs are combined in a unique way with different conventional conductors such as metals, carbon and carbon nanotubes to tailor conductivity and other electronic properties with interpenetrating network (IPN) characteristics and therefore minimal concentration levels in different host polymeric materials for achieving tough and durable nanocomposites. Thin nanocomposite films are also being fabricated for electronic and electrochemical applications. Given below are the atomic force micrographs (AFM) of conducting polymer-metal oxide nanocomposite films.

AFM of Self-Assembled Polypyrrole-Metal Oxide Nanocomposite Films

AFM of Self-Assembled Polyaniline-Metal Oxide Nanocomposite Films

AFM of Self-Assembled Regioregular Poly(hexylthiophene)-Metal Oxide Nanocomposite Films