Advanced Dispersion Strategies of Carbon Nanofillers and their use to enhance Mechanical and Electrical Properties of Polyacrylonitrile Fibers

This study focuses on making next generation of polyacrylonitrile fibers containing carbon nanofillers, namely carbon nanotubes (CNTs) and carbon black (CB). Mechanically strong and electrically conducting poly(acrylonitrile) (PAN) fibers were obtained by incorporating up to (a) 15 wt% single wall carbon nanotubes (SWNTs) and (b) 15 wt% carbon black (CB) and 2 wt% multiwall carbon nanotubes (MWNTs). These fibers with tensile modulus of up to 32.1 GPa and electrical conductivity of 2.2 S/m rival some intrinsically electrically conducting polymer fibers without doping. Nanocomposite carbon fibers with up to (a) 25 wt% SWNTs and (b) 24 wt% carbon black and 3 wt% MWNTs were also produced, and it is shown that CNT inclusion improves tensile modulus, while the inclusion of CB can be used to lower the carbon fiber cost, while lowering the mechanical properties. Stretchable PAN fibers with up to 60 wt% CB were also produced by increasing the diameter of the CB particles. Fibers with high SWNT loading of 15 wt% were possible by wrapping the SWNTs with poly(methyl methacrylate) (PMMA). The mechanism of PMMA wrapping of SWNTs was studied experimentally and theoretically (using molecular dynamic simulation). It is shown that PMMA wrapping can be used to increase filler-matrix interaction in the polymer fiber. It is further shown that PMMA wrapping is not detrimental to the filler-matrix interaction in the resulting carbon fiber. This is despite the fact that PMMA does not have carbon yield. Effect of the carbon nanotubes and carbon black fillers on PAN solution/dispersion rheology has been studied. The effect of these fillers on fiber processability and fiber structure is also comprehensively studied. Research also includes stabilization and carbonization of the conductive CB/PAN nanocomposite fibers via Joule Heating to obtain low-cost carbon fibers.

Level thesis:degree_level

Doctoral

Department dc:contributor.department

Materials Science and Engineering

Grantor dc:publisher

Georgia Institute of Technology

Year dc:date.issued

2020

Author dc:creator

• Arias Monje, Pedro Jose

Advisor dc:contributor.advisor

• Kumar, Satish

Committee members dc:contributor.committeemember

• Jacob, Karl
• Heinz, Hendrik
• Kalaitzidou, Kyriaki
• Sitaraman, Suresh
• Thadhani, Naresh

• nanocomposite
• poly(acrylonitrile)
• carbon nanofiller
• carbon fiber
• carbon nanotubes
• carbon black
• polymer wrapping

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/1853/66035

OAI identifier oai:identifier

oai:repository.gatech.edu:1853/66035