Local Heating and Curing of Carbon Nanocomposite Adhesives Using Radio Frequencies

In this thesis, the phenomenon of carbon nanoparticles producing a strong, rapid heating response in the presence of a radio-frequency electromagnetic field is explored, and this extremely selective heating property is used to cure nanocomposite thermoset adhesives without harming the surrounding plastic components. By dispersing carbon black nanoparticles into the adhesive matrix, the heat needed to cure the adhesive can be supplied by the RF-responsive nanoparticles, generating heat volumetrically inside the adhesive. Because this heat is selectively generated only in the adhesive, the substrates being bonded together can be kept at a temperature lower than the desired curing temperature of the adhesive. For example, substrate temperatures as low as 52.8°C were observed while the adhesive was curing at 85°C, in stark contrast to the higher substrate temperatures seen when curing adhesive using conventional heating methods, such as an IR lamp. The degree of cure is confirmed by mechanical tests: lap shear strengths of these RF-cured adhesive joints were 478.2 psi on average, well above the recommended green strength of 1 MPa (145 psi). These results demonstrate the viability of this technology and pave the way to expand its application toward industrial manufacturing, particularly in the automotive sector where thermoset adhesives are ubiquitous