This paper presents layer-by-layer (LbL) self-assembly of single-walled carbon nanotube (SWNT)/polymer membranes with a well-dispersed wide-range tunable volume fraction of functionalized SWNTs. The surface morphology of the SWNT/polymer membranes shows a high strength, dense and random network structures. The quartz crystal microbalance (QCM) characterization illustrates that the deposition thickness and the SWNT loading fraction in SWNT nanocomposites can be controlled in a large range based on LbL sequential deposition process. The Young's modulus of the self-assembled SWNT/polymer composite membranes is characterized by a combinative approach of piezoelectric excitation and laser vibrometer measurement. The Young's modulus of SWNT/polymer nanocomposites is tunable from hundreds to tens of GPa, as a function of the SWNT volume fraction. Such significant enhancement of LbL self-assembled SWNTs offers a way in which the embedded SWNTs can realize the true potential to strengthen SWNT/polymer nanocomposites. Conventional mixture models such as rule-of-mixture model and Halpin-Tsai model fail to explain the structure-property regime in nanoscale at a high SWNT fraction ratio. This observed tunability can serve as a benchmark to tailor the design of nanocomposite thin films for potential applications to MEMS and NEMS devices.
Bibliographical noteFunding Information:
This work was partially supported by the Minnesota Partnership Program and the Fundamental Research Funds for the Central Universities of China (No. 12CX04065A). We also acknowledge the Characterization at the University of Minnesota. In particular, we thank Dr. Peng Li and Bo Zhang for the valuable discussion and help on the characterization of SWNT/polymer using SEM.
Copyright 2012 Elsevier B.V., All rights reserved.
- Layer-by-layer (LbL) self-assembly
- Mechanical characterization
- Nanocomposite film
- Single-walled carbon nanotube (SWNT)