Control of dewetting dynamics at a polymer-polymer interface by adding multiwalled carbon nanotubes

COLL 244

Jaseung Koo, jkoo@ic.sunysb.edu1, Kwanwoo Shin, kwshin@sogang.ac.kr2, Young-Soo Seo, ysseo@sejong.ac.kr3, Tadanori Koga, tkoga@notes.cc.sunysb.edu4, Seongchan Park1, Sushil K. Satija, satija@nist.gov5, Xuming Chen, xuchen@ic.sunysb.edu6, Kyunghwan Yoon, Kyunghwan.Yoon@sunysb.edu6, Benjamin S. Hsiao, bhsiao@notes.cc.sunysb.edu6, Hila Calev, acalev@optonline.net7, Jonathan Sokolov8, and Miriam Rafailovich8. (1) Department of Materials Science and Engineering, SUNY at Stony Brook, Old Engineering building, Stony Brook, NY 11794-2275, (2) Chemistry, Sogang University, Seoul, 121-742, South Korea, (3) Department of Nano Science & Technology, Sejong University, Seoul, 143747, South Korea, (4) Chemical Engineering Program, Department of Materials Science and Engineering, Stony Brook University, Stony Brook, NY 11794-2275, (5) Center for Neutron Research, NIST, 100 Bureau Dr. STOP 8562, Gaithersburg, MD 20854, (6) Department of Chemistry, State University of New York at Stony Brook, Stony Brook, NY 11794, (7) Ward Melville High School, East Setauket, NY 11733, (8) Department of Materials Science and Engineering, Stony Brook Unviersity, Stony Brook, NY 11794-2275
We have investigated an effect of the aspect ratio of the multi-walled carbon nanotubes (MWNT) on dewetting dynamics of thin polymer films on silicon substrates. The dewetting hole diameter of a polystyrene (PS) film from a poly(methyl metacrylate) (PMMA) film embedded MWNTs with a different aspect ratio, i.e. short MWNTs (s-MWNTs) and long MWNTs (l-MWNT) was measured to obtain the viscosity of the bottom layer on a basis of Brochard's model. The results showed that the films were significantly stabilized after filled with 1 wt% of the l-MWNTs and their viscosity was 20 times higher than the unfilled sample, while the s-MWNT filled samples were not effective to prevent the dewetting unstability, which exhibited a biscontinuous dewet surface on the same annealing condition. This difference is ascribed to nanotubes networks which can be effectively formed by l-MWNTs. Interestingly, however, the nanotube networks do not affect on the diffusion dynamic of the PMMA chains. This was interpreted in terms of the mesh size of the networks which is larger than the entanglement length of the PMMA, thus the motion is mostly governed by the entanglements of chains rather than the nanotube network. The results were then found to compare favorably with bulk rheological properties.
 

Fundamental Research in Colloid and Surface Chemistry
6:00 PM-8:00 PM, Monday, August 20, 2007 BCEC -- East Registration, Poster

Division of Colloid & Surface Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007