Nanotechnology encompasses a broad and rapidly growing set of projects in basic research, applied research, early attempts at commercialization, and even mature technologies. A multidisciplinary team from the Massachusetts Institute of Technology Lincoln Laboratory (MIT-LL) and the U.S. Army Natick Soldier Research, Development, and Engineering Center (NSRDEC) was tasked by the Special Projects Office at the Joint Science and Technology Office for Chemical and Biological Defense (JSTO-CBD) to assess ongoing nanotechnology research efforts and commercial off-the-shelf nanotechnologies relevant to CBD, with particular emphasis on projected needs and technology gaps in the Protection, Detection, Decontamination, and Medical CBD capability areas. This broad-based assessment resulted in a list of recommended technologies to address these needs. This paper addresses the process utilized for the assessment and provides the technical detail for the recommended technologies. Early access to advanced CBD capabilities based on the unique properties of nanotechnology has high potential to provide significantly better performance than incremental improvements in current technology.

Nanocomposites made by adding nanoparticle reinforcement to polymers have been demonstrated to have significantly enhanced properties at relatively low levels of added reinforcement. The observed properties have in some cases been attributed to the shape of the reinforcing particle. Nanoparticle additives with a variety of particle morphologies and compositions have become commercially available in recent years. A study was carried out to examine the effects of varying nanoparticle morphology and composition on the mechanical and barrier properties of polymer nanocomposites made with natural rubber (NR). NR compounds were prepared containing different nanoparticles including montmorillonite layered silicate (MLS) clay, exfoliated graphite nanoparticles (EGN), carbon nanotubes (CNT) and conventional carbon black (CB). The cure behavior and mechanical properties of the prepared nanocomposites were investigated. Barrier property testing included permeation of selected organic compounds utilizing a recently developed fully flooded surface method. The relationships between these properties and nanoparticle composition and morphology are presented.

Dispersion and alignment of carbon nanotubes in thermoplastic polymers such as polycarbonate have been studied. Dispersion was accomplished by mixing in a conical twin-screw extruder and alignment was carried out using a fiber spinning apparatus. The effects of mixing time and fiber draw ratios on dispersion and alignment were investigated. Uniform dispersions were produced with relatively short residence times in the extruder. Excellent alignment of carbon nanotubes in nanocomposite filaments was obtained when the fiber draw ratio was greater than 7. The ability to closely control the dispersion and alignment of carbon nanotubes in polymers is expected to lead to the development of nanocomposites with desirable electronic and structural properties.

Nanoscale alumina powder and carbon nanotubes were mixed and hot-pressed to form dense ceramic-matrix composites. The strength and fracture toughness of hot-pressed alpha-alumina was much greater than that of conventional grain size polycrystalline alumina. The addition of carbon nanotubes to the alumina resulted in composites with even greater strength and fracture toughness. Hot pressing in a vacuum improved both of these properties over hot pressing in argon. These results suggest that lightweight composites of high strength and fracture toughness can be made from composites of nanophase alumina, or other ceramics, and carbon nanotubes.

Electrospinning is a process for making extremely fine submicron fiber by a process of charging polymer solutions to thousands of volts. This method of manufacturing man-made fibers has been known since 1934, when the first patent on electrospinning was filed by Formhals(1). Since that time, many patents and publications have been reported on electrospinning. This paper describes our latest accomplishments in the development of useful fabric membranes from electrospun fibers and describes the properties of these membranes with respect to their strength and performance as protective layers, This paper reviews the electrospinning process and its current status as a manufacturing method. New data and properties of electrospun membranes are reported, including structural effects upon moisture transport, air convection, aerosol filtration, porosity, tensile strength, and enhanced chemical activity of these membranes, demonstrating the potential of these nanofiber layers in laminates for specialty textiles.