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Accession Number:
ADA582343
Title:
Changes to Tensile Strength and Electromagnetic Shielding Effectiveness in Neutron Irradiated Carbon Nanocomposites
Descriptive Note:
Master's thesis
Corporate Author:
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
Report Date:
2013-03-01
Pagination or Media Count:
91.0
Abstract:
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 Youngs 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 x 1014 1 MeV Si-eq ncm2. 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 Youngs 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 DG 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.
Distribution Statement:
APPROVED FOR PUBLIC RELEASE