Defect Site Functionalization:  An Approach for Promoting Adhesion in Carbon Nanoparticle/Epoxy Nanocomposites

Eun Su Park, Mickey Richardson, Jaehyun Kim, Charles Guttman, Nandika D’Souza, and Gale A. Holmes

Polymers Division, MSEL, NIST

Adhesion has often been altered in polymer nanocomposites composed of nanotubes by treating the nanotubes with acid solutions that completely disrupts the nanotubes’ p-p bonding structure, thereby greatly reducing their electrical conductivity and possibly their mechanical strength.  It has recently been demonstrated that specific sites on C₆₀ fullerenes and the defect sites on carbon nanotubes can be selectively functionalized, without significantly altering the p-p bonding structure of the carbon nanotubes.  Although this approach will only generate a fraction of the possible adhesion sites, Holmes et al. in 2003 demonstrated that 80 % of the maximum adhesion at the fiber matrix interface in conventional composites can be obtained by having only 33 % of the fiber surface containing groups capable of promoting covalent bonding.  Therefore, this research seeks expand on the Holmes et al. research results by quantifying the impact that this new functionalization approach has on the mechanical performance of nanocomposites composed of carbon nanoparticles embedded in epoxy resins as the adhesion strength at the nanoparticle-matix interface is altered.  Recent research by Kinloch et al. indicates an increase in fracture energy due to debonding of the nanoparticles and subsequent plastic void growth for anhydride cured epoxy nanocomposites composed of well dispersed silica nanoparticles.

Author information:

Eun Su Park

Guest Researcher

Mentor: Gale A. Holmes

Polymers Division

Materials science and Engineering Laboratory

National Institute of Standards and Technology

100 Bureau Drive, MS 8541

Gaithersburg, MD 20899-8541, USA

Building 224, Room B330

Tel: (301) 975-6790

Fax: (301) 975-3928

Email: espark@nist.gov

Non-Member

Category: Materials