TY - JOUR
T1 - A Direct Quantitative Measure of Surface Mobility in a Glassy Polymer
AU - Chai, Y.
AU - Salez, T.
AU - McGraw, J. D.
AU - Benzaquen, M.
AU - Dalnoki-Veress, K.
AU - Raphaël, E.
AU - Forrest, J. A.
PY - 2014/2/28
Y1 - 2014/2/28
N2 - Thin polymer films have striking dynamical properties that differ from their bulk counterparts. With the simple geometry of a stepped polymer film on a substrate, we probe mobility above and below the glass transition temperature Tg. Above Tg the entire film flows, whereas below Tg only the near-surface region responds to the excess interfacial energy. An analytical thin-film model for flow limited to the free surface region shows excellent agreement with sub-Tg data. The system transitions from whole-film flow to surface localized flow over a narrow temperature region near the bulk Tg. The experiments and model provide a measure of surface mobility in a simple geometry where confinement and substrate effects are negligible. This fine control of the glassy rheology is of key interest to nanolithography among numerous other applications.
AB - Thin polymer films have striking dynamical properties that differ from their bulk counterparts. With the simple geometry of a stepped polymer film on a substrate, we probe mobility above and below the glass transition temperature Tg. Above Tg the entire film flows, whereas below Tg only the near-surface region responds to the excess interfacial energy. An analytical thin-film model for flow limited to the free surface region shows excellent agreement with sub-Tg data. The system transitions from whole-film flow to surface localized flow over a narrow temperature region near the bulk Tg. The experiments and model provide a measure of surface mobility in a simple geometry where confinement and substrate effects are negligible. This fine control of the glassy rheology is of key interest to nanolithography among numerous other applications.
UR - http://www.scopus.com/inward/record.url?scp=84896728448&partnerID=8YFLogxK
UR - https://www.scopus.com/record/pubmetrics.uri?eid=2-s2.0-84896728448&origin=recordpage
U2 - 10.1126/science.1244845
DO - 10.1126/science.1244845
M3 - RGC 21 - Publication in refereed journal
SN - 0036-8075
VL - 343
SP - 994
EP - 999
JO - Science
JF - Science
IS - 6174
ER -