Carbon nanotubes (CNTs) have a remarkable combination of electrical, thermal and mechanical properties. In order to realize these properties in applications, CNTs need to be processed into scalable materials such as fibers, coatings, and transparent films. Fluid-phase self-assembly is one of the most promising ways to process CNTs. Strong acids including chlorosulfonic acid (CSA) have shown to be a true solvent for CNTs. CNTs, similar to the other rigid rod molecules, form liquid crystalline phase at high concentrations. Low concentration solutions are used for making transparent films, while high concentration solutions can be spun into multifunctional fibers. Successful assembly of CNTs needs a better understanding of the phase behavior and the flow process. My research aims to study the phase behavior of CNTs in solution and the microstructural alignment of them in the processing flow.