Tubular structures at the nano size level exist naturally based on pure elements (carbon nanotubes) and minerals (halloysite). These tubules are of interest because of their mechanical properties, electrical properties, thermal properties and their potential to act as templates for other materials such as metals that are not normally formed in tubular shapes. Because of their extremely small size (from 10 to 100 nm in diameter, from 100 to 100nm in length) they have potential to absorb and adsorb species and allow their controlled elution into the environment, allowing controlled release of a variety of materials including elements such as hydrogen, pharmaceuticals, pesticides, oligomers (to allow self-healing polymers) and a variety of other applications.

Dr. Alan Russell and his colleagues at University of Pittsburgh McGowan Institute for Regenerative Medicine developed a simple chemical process for the manufacture of well-defined and uniform diacetylene nanotubes by molecular self-assembly. Using basic benchtop techniques and reagents, we can manipulate the properties of these nanotubes, and can even create sheets of self-assembled mono-disperse “nanocarpets”. Exposing the structured diacetylene nanotubes to ultraviolet light causes stabilization via cross-links between adjacent molecules, which enables the tubes to be used in water, strong acids and alkali, and a variety of polar and non-polar organic fluids. The UV induced cross-linking process also turns the nanotubes from colorless to deep blue, and perturbation to the surface of blue cross-linked nanotubes changes the color to red. In addition to some of the properties listed above for other tube structures, they have potential to be used as indicators, sacrificial templates, and biocides and their structural properties have the potential to be altered by electric fields or ionic species to allow the formation of mutable materials, or “muterials”, with significant military and commercial potential.

Applications to be developed include:

• Sensors: responsive materials exhibiting modified optical and physical properties in the presence of chemicals or biologically active agents.
• Biocidal Materials: coatings and surfaces that demonstrate antimicrobial responses to viral or bacterial stimuli
• Templating: creation of nanowires by templating metal, semiconductor or ceramic material on bioactive nanotube arrays or singletons that may encapsulate the polymer or have the polymer removed during processing

The intermediate and nascent portfolio includes:

• Unpublished utility patent application covering the basic nanotube production and applications.
• Unpublished provisional patent application covering flexible membranes incorporating self-assembled nanotubes
• Unpublished provisional patent application covering textiles and porous materials with stably embedded nanoparticles
• Disclosures on interpenetrating polymer networks for immobilizing nanomaterials on surfaces