TY - GEN
T1 - Neutral wetting brush layers for block copolymer thin films using homopolymer blends
AU - Antonioli, Diego
AU - Sparnacci, Katia
AU - Laus, Michele
AU - Lupi, Federico Ferrarese
AU - Giammaria, Tommaso Jacopo
AU - Seguini, Gabriele
AU - Ceresoli, Monica
AU - Perego, Michele
AU - Gianotti, Valentina
N1 - Publisher Copyright:
© 2016 Author(s).
PY - 2016/5/18
Y1 - 2016/5/18
N2 - Binary homopolymer blends of two hydroxyl-terminated polystyrene (PS-OH) and polymethylmethacrylate (PMMA-OH) homopolymers (Mn ∼ 16000 g mol-1) were grafted on SiO2 substrates by high-temperature (T > 150 °C), short-time (t < 600 s) thermal treatments. The resulting brush layer was tested to screen preferential interactions of the SiO2 substrate with the different symmetric and asymmetric PS-b-PMMA block copolymers deposited on top of the grafted molecules. By properly adjusting the blend composition and the processing parameters, an efficient surface neutralization path was identified, enabling the formation, in the block copolymer film, of homogeneous textures of lamellae or cylinders perpendicularly oriented with respect to the substrate. A critical interplay between the phase segregation of the homopolymer blends and their grafting process on the SiO2 was observed. In fact, the polar SiO2 is preferential for the PMMA-rich phase that forms a homogeneous layer on the substrate, while the PS-rich phase is located at the polymer-air interface. During the thermal treatment, phase segregation and grafting proceed simultaneously. Complete wetting of the PS rich phase on the PMMA rich phase leads to the formation of a PS/PMMA bilayer. In this case, the progressive diffusion of PS chains toward the polymer-SiO2 interface during the thermal treatment allows tuning of the brush layer composition.
AB - Binary homopolymer blends of two hydroxyl-terminated polystyrene (PS-OH) and polymethylmethacrylate (PMMA-OH) homopolymers (Mn ∼ 16000 g mol-1) were grafted on SiO2 substrates by high-temperature (T > 150 °C), short-time (t < 600 s) thermal treatments. The resulting brush layer was tested to screen preferential interactions of the SiO2 substrate with the different symmetric and asymmetric PS-b-PMMA block copolymers deposited on top of the grafted molecules. By properly adjusting the blend composition and the processing parameters, an efficient surface neutralization path was identified, enabling the formation, in the block copolymer film, of homogeneous textures of lamellae or cylinders perpendicularly oriented with respect to the substrate. A critical interplay between the phase segregation of the homopolymer blends and their grafting process on the SiO2 was observed. In fact, the polar SiO2 is preferential for the PMMA-rich phase that forms a homogeneous layer on the substrate, while the PS-rich phase is located at the polymer-air interface. During the thermal treatment, phase segregation and grafting proceed simultaneously. Complete wetting of the PS rich phase on the PMMA rich phase leads to the formation of a PS/PMMA bilayer. In this case, the progressive diffusion of PS chains toward the polymer-SiO2 interface during the thermal treatment allows tuning of the brush layer composition.
KW - PMMA
KW - PS
KW - PS-b-PMMA
KW - Surface neutralization
KW - Thermogravimetry-Gas Chromatography-Mass spectrometry; Composition Determination; Ultra-thin Films Analysis; Polymer Brushes
UR - https://www.scopus.com/pages/publications/84984540675
U2 - 10.1063/1.4949744
DO - 10.1063/1.4949744
M3 - Conference contribution
AN - SCOPUS:84984540675
T3 - AIP Conference Proceedings
BT - VIII International Conference on "Times of Polymers and Composites"
A2 - D'Amore, Alberto
A2 - Grassia, Luigi
A2 - Acierno, Domenico
PB - American Institute of Physics Inc.
T2 - 8th International Conference on Times of Polymers and Composites: From Aerospace to Nanotechnology
Y2 - 19 June 2016 through 23 June 2016
ER -