TY  - JOUR
A1  - Zhong, Qi
A1  - Metwalli, Ezzeldin
A1  - Rawolle, Monika
A1  - Kaune, Gunar
A1  - Bivigou Koumba, Achille Mayelle
A1  - Laschewsky, Andre
A1  - Papadakis, Christine M.
A1  - Cubitt, Robert
A1  - Wang, Jiping
A1  - Mueller-Buschbaum, Peter
T1  - Vacuum induced dehydration of swollen poly(methoxy diethylene glycol acrylate) and polystyrene-block-poly(methoxy diethylene glycol acrylate)-block-polystyrene films probed by in-situ neutron reflectivity
JF  - Polymer : the international journal for the science and technology of polymers
N2  - The isothermal vacuum-induced dehydration of thin films made of poly(methoxy diethylene glycol acrylate) (PMDEGA), which were swollen under ambient conditions, is studied. The dehydration behavior of the homopolymer film as well as of a nanostructured film of the amphiphilic triblock copolymer polystyrene-block-poly(methoxy diethylene glycol acrylate)-block-polystyrene, abbreviated as PS-b-PMDEGA-b-PS, are probed, and compared to the thermally induced dehydration behavior of such thin thermo-responsive films when they pass through their LCST-type coil-to globule collapse transition. The dehydration kinetics is followed by in-situ neutron reflectivity measurements. Contrast results from the use of deuterated water. Water content and film thickness are significantly reduced during the process, which can be explained by Schott second order kinetics theory for both films. The water content of the dehydrated equilibrium state from this model is very close to the residual water content obtained from the final static measurements, indicating that residual water still remains in the film even after prolonged exposure to the vacuum. In the PS-b-PMDEGA-b-PS film that shows micro-phase separation, the hydrophobic PS domains modify the dehydration process by hindering the water removal, and thus retarding dehydration by about 30%. Whereas residual water remains tightly bound in the PMDEGA domains, water is completely removed from the PS domains of the block copolymer film. (C) 2017 Elsevier Ltd. All rights reserved.
KW  - Dehydration
KW  - Vacuum drying
KW  - In-situ neutron reflectivity
Y1  - 2017
U6  - https://doi.org/10.1016/j.polymer.2017.07.066
SN  - 0032-3861
SN  - 1873-2291
VL  - 124
SP  - 263
EP  - 273
PB  - Elsevier
CY  - Oxford
ER  -