Changes to Tensile Strength and Electromagnetic Shielding Effectiveness in Neutron Irradiated Carbon Nanocomposites
Date of Award
Master of Science
Department of Engineering Physics
John W. McClory, PhD.
Electromagnetic interference shielding effectiveness (EMI-SE) and tensile strength of nanocomposites containing multi-walled carbon nanotubes (MWNTs) are investigated following neutron irradiation. This nanocomposite material consists of two plies of MWNTs in an epoxy resin, and 4 plies of an E-glass substrate. EMI-SE measurements over the X-band frequency spectrum and monotonic tension tests to determine Young’s Modulus were performed before and after irradiation on the nanocomposite material. The nanocomposite and the MWNT plies were irradiated to a total fluence of 1.4 × 1014 1 MeV (Si-eq) n/cm2. The nanocomposites showed an average increase of 8 dB in shielding effectiveness after irradiation. However, the increase was not permanent with a return to pre-irradiation values after approximately 10 days at ambient temperature and pressure. The tensile strength and Young’s Modulus showed an 8% and 10% increase, respectively, following irradiation. This small increase is a result of the neutron induced embrittlement of the nanocomposite. Raman spectra of the MWNT plies showed a 150% increase in the D/G peak ratios after irradiation. This indicates damage in the plies due to neutron interactions in the MWNTs that does not lead to a commensurate reduction in EMI-SE or tensile strength in the nanocomposite material.
DTIC Accession Number
Shinn, James F., "Changes to Tensile Strength and Electromagnetic Shielding Effectiveness in Neutron Irradiated Carbon Nanocomposites" (2013). Theses and Dissertations. 946.