Abstract: Effective radiation shielding is required to protect crew and equipment in various fields including aerospace, defense, medicine and power generation. Light elements and in particular hydrogen are most effective at shielding against high-energy particles including galactic cosmic rays, solar energetic particles and fast neutrons. However, pure hydrogen is highly flammable, has a low neutron absorption cross-section, and cannot be made into structural components. Nanocomposites containing the light elements Boron, Nitrogen, Carbon and Hydrogen as well dispersed boron nano-particles, boron nitride nanotubes (BNNTs) and boron nitride nano-platelets, in a matrix, provide effective radiation shielding materials in various functional forms. Boron and nitrogen have large neutron absorption cross-sections and wide absorption spectra.
Type:
Application
Filed:
May 9, 2011
Publication date:
May 16, 2013
Applicants:
National Institute of Aerospace Associates, Thomas Jefferson National Accelerator Facility, and Space Administration
Inventors:
Godfrey Sauti, Cheol Park, Jin Ho Kang, Jae-Woo Kim, Joycelyn S. Harrison, Michael W. Smith, Kevin Jordan, Sharon E. Lowther, Peter T. Lillehei, Sheila A. Thibeault
Abstract: Boron nitride nanotubes (BNNTs), boron nitride nanoparticles (BNNPs), carbon nanotubes (CNTs), graphites, or combinations, are incorporated into matrices of polymer, ceramic or metals. Fibers, yarns, and woven or nonwoven mats of BNNTs are used as toughening layers in penetration resistant materials to maximize energy absorption and/or high hardness layers to rebound or deform penetrators. They can be also used as reinforcing inclusions combining with other polymer matrices to create composite layers like typical reinforcing fibers such as Kevlar®, Spectra®, ceramics and metals. Enhanced wear resistance and usage time are achieved by adding boron nitride nanomaterials, increasing hardness and toughness. Such materials can be used in high temperature environments since the oxidation temperature of BNNTs exceeds 800° C. in air.
Type:
Application
Filed:
July 26, 2011
Publication date:
July 26, 2012
Applicants:
National Institute of Aerospace Associates, Thomas Jefferson National Accelerator Facility, Space Administration
Inventors:
Jin Ho Kang, Cheol Park, Godfrey Sauti, Michael W. Smith, Kevin C. Jordan, Sharon E. Lowther, Robert George Bryant