Centrifugal jet spinning of polymer nanofiber assembly : process characterization and engineering applications
Loading...
Authors
Ren, Liyun
Issue Date
2014-12
Type
Electronic thesis
Thesis
Thesis
Language
ENG
Keywords
Materials engineering
Alternative Title
Abstract
The driving mechanism behind the CJS process harnesses the centrifugal forces, the viscoelastic properties and the mass transfer characteristics of spinning solutions to promote the controlled thinning of a macro-scale polymer solution filament into desired nanofibers. Three different spinning stages, jet initiation, jet extension, and fiber formation are investigated from the role of physics involved in different spinning stages including fluid viscoelasticity, centrifugal forces and solvent mass transfer. Four different polymer solution systems with a wide range of fluid viscoelasticity properties and solvent mass transfer properties are characterized and used to fabricate polymer fibers under different rotational speeds. The correlations between spinning product morphology and spinning solution rheological properties are studied based on experimental data and observations. Dimensional analysis of the fiber formation process physics is used to adapt the experimental data into an empirical relationship describing fiber formation from spinning solution viscoelastic properties. A semi-empirical relationship is developed to predict fiber diameter as a function of spinning solution dimensionless properties without lengthy trial-error method. A 2-dimensional computational fluid mechanics model of CJS is also developed to provide the understanding of nanofiber formation with controlled air flow inside the CJS system.
Description
December 2014
School of Engineering
School of Engineering
Full Citation
Publisher
Rensselaer Polytechnic Institute, Troy, NY