Local heating and curing of carbon nanocomposite adhesives using radio frequencies

Abstract

The SEM imaging discussed in this thesis was performed by Aniruddh Vashisth.Materials for sample preparation, temperature and strength data for the IR lamp heating process, and additional knowledge and guidance were all provided by Tyler Auvil and Dan Sophiea, from the Dow Chemical Company.

Radio frequency heating and material processing using carbon susceptors

“…The non-contact processing with rapid heating rates can be exploited by various industries ranging from automotive to chemical synthesis to sterilization of medical devices. 23,24,45 Most of these advances have been made in the last 5-7 years and show immense potential for revolutionizing the manufacturing and processing industry. This novel method of heating using RF elds has seen substantial intellectual property development.…”

“…In this case, the efficiency of RF heating was 6 times as that of IR heating. 23 (2) Volumetric heating: bulk specimens embedded with RF susceptors can be heated inside-to-outside by RF elds; this method reduces the need for large ovens or furnaces to heat the specimens. Heating and partially/fully curing carbon ber composites is an excellent example of RF rapid volumetric heating; heating composites in conventional ovens and autoclaves takes signicant time (10-30 minutes) whereas using RF elds CF/epoxy systems can be heated as fast as 70 C s À1 to attain curing temperatures within 2 minutes of the cure-cycle.…”

“…5 Successful application of targeted RF heating has been shown in (clockwise, from top-left) additive manufacturing for improved fracture structure, bonding plastics with locally heated adhesives, plastic welding, and metal-metal bonding using adhesives. 22,23,31,57 introducing a thin layer or patterns of RF responsive materials on the plastic substrates. 57 Gerringer et al 57 showed that Laser-Induced Graphene (LIG) can be fabricated on polymer surface by using CO 2 lasers; exposure of LIG to RF elds results in the rapid heating of LIG (up to 126 C s À1 ) and welding the polymer-polymer interface.…”

“…20,21 Most of the prior work on heating carbon nanomaterials has been done using microwaves in GHz range. 14,15 Recently, researchers found that RF elds between 1-200 MHz can be used to heat carbonaceous materials including CNTs, 22 carbon black, 23 graphene, 24 and carbon bers. 25 The ability to use lower frequencies rather than microwaves for heating materials offers key benets.…”

A Suggested Vacuum Bagging Process for the Fabrication of Single-Walled Carbon Nanotube/Epoxy Composites That Maximize Electromagnetic Interference Shielding Effectiveness

“…The versatile properties and high aspect ratios of carbon nanotubes (CNTs) have attracted attention among researchers for their potential use as conductive fillers. Single-walled carbon nanotubes (SWCNTs), a type of CNTs that consist of single graphite sheets rolled into tubes, in particular, demonstrate impressive electrical conductivity at 10 6 –10 7 S/m, a level which is capable of providing electrical properties to a polymer matrix [ 1 , 2 , 3 ]. Moreover, the SWCNTs prices have fallen as production technology has improved, bringing commercialization within reach.…”