Doctor Blade Tape Casting of Carbon Nanotube and Epoxy Thin Films
Open Access
- Author:
- Pawlak, Cole
- Area of Honors:
- Aerospace Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Namiko Yamamoto, Thesis Supervisor
Xin Ning, Thesis Honors Advisor - Keywords:
- CNT
Carbon Nanotubes
CFRP
OOA
Doctor Blade
Thin Film - Abstract:
- Over the past 70 years of aerospace materials advances, the industry increasingly has continued to turn to synthetic composites, and particularly carbon fiber reinforced plastics (CFRPs) for their high mass-specific properties. As requirements also increase for greater applications of these materials, improvements of CFRPs are needed. CFRPs are weak in their intralaminar regions due to higher epoxy concentrations. The intralaminar shear strength of CFRPs can be improved by integrating carbon nanotubes (CNTs) to the matrix. CNTs exhibit high performance including Young’s modulus (~1 TPa) and electrical and thermal properties that make this nanofiller ideal for aerospace applications. In this work, a consistent tape casting approach to produce thin B-staged epoxy films was developed using a doctor blade and infiltration of these films into CFRP laminates was observed. Assuming Newtonian epoxy characteristics, the thin films were tailored by adjusting epoxy curing degree, substrate temperature, blade height, and blade speed. Film thicknesses of approximately 200 µm in average thickness were achieved. B-staged thin films of ~400 µm, ~200 µm, and ~200 µm with a CNT/epoxy mixture (0.1 vol%) were used in OOA/VBO laminate consolidation. Epoxy infiltration occurred in all three laminates and was observed visually by eye and with microscope analysis. Fiber volume fraction was calculated to determine adherence to the aimed value. In future work, reducing void content, experimenting further with CNT/epoxy thin films, and producing larger CFRP laminates to use in shear testing will be necessary to continue validation and expand use cases for the doctor blading process.