162
8 Nanofabrication on Reactive Block Copolymer Film …
Preparation of Thin Films. Thin polymer films were prepared by spin-coating
polymer solutions in toluene (typical concentration between 10 and 20 mg/ml) onto
silicon wafers (111) or glass (cover slide from Menzel-Glaser), which were previously cleaned by an oxygen plasma using an Elektrotech PF 340 apparatus (pressure
of O 2 : 0.5 bar; current: 30 mA). All spin-cast samples were dried at room temperature
for 24 h in vacuum before analysis. The film thickness determined by ellipsometry
(details see Chap. 5) was 100 ± 5 nm.
Solvent Treatment of Thin Films. Cyclohexane was used to enrich the surface in PS
by placing a cross-linked poly(dimethylsiloxane) (PDMS) slab previously soaked in
cyclohexane onto the polymer surface [31]. After 3 h contact treatment, the PDMS
was removed and the samples were stored overnight in vacuum.
Chemical Modification. A drop of trifluoroacetic acid (50 μl) was applied on
the solvent-treated films. The films obtained were activated by immersion in an
aqueous solution of 1-ethyl-3-(dimethylamino)-propylcarbodiimide (EDC, 1 M) and
N-hydroxysuccinimide (NHS, 0.2 M) for 30 min. The films were immersed inside
fluoresceinamine solution (100 μM, PB, pH = 7.4). Then the samples were taken
out, rinsed with PB and Milli-Q water, and dried in a stream of nitrogen. Finally,
the samples were dried inside a vacuum oven for 1 day before the fluorescence
microscopy experiments.
Atomic Force Microscopy (AFM). The contact mode AFM measurements were
carried out with a NanoScope X multimode AFM (Digital Instruments/Veeco, Santa
Barbara, CA) using a 100 μm scanner and microfabricated silicon tips/cantilevers
(Nanosensors, Wetzlar, Germany) in ambient atmosphere (ca. 30% relative humidity,
24 °C temperature). For laterally resolved pull-off force measurements, the AFM
was operated in the FV mode using a 10 μm scanner. All FV measurements were
performed in air. Arrays of 64 × 64 points
2 (4096 consecutive force–distance
measurements) were acquired on at least six different locations on each sample
using sizes of 0.5 × 0.5 μm
2 or 1.0 × 1.0 μm
2 . DPN was carried out as described
in reference.
Fluorescence Microscopy: The fluorescence microscopy data was obtained using
a Zeiss LSM 510 confocal fluorescence microscope with a BP 500-550 IR filter for
fluoresceinamine, as described in Chap. 4.
References
1. Morkved TL, Lu M, Urbas AM, Ehrichs EE, Jaeger HM, Mansky P, Russell TP (1996) Local
control of microdomain orientation in diblock copolymer thin films with electric fields. Science
273:931–933
2. Albalak RJ, Thomas EL, Capel MS (1998) Solvent swelling of roll-cast triblock copolymer
films. Polymer 39:1647–1656
3. Bodycomb J, Funaki Y, Kimishima K, Hashimoto T (1999) Single-grain lamellar microdomain
from a diblock copolymer. Macromolecules 32:2075–2077
8 Nanofabrication on Reactive Block Copolymer Film …
Preparation of Thin Films. Thin polymer films were prepared by spin-coating
polymer solutions in toluene (typical concentration between 10 and 20 mg/ml) onto
silicon wafers (111) or glass (cover slide from Menzel-Glaser), which were previously cleaned by an oxygen plasma using an Elektrotech PF 340 apparatus (pressure
of O 2 : 0.5 bar; current: 30 mA). All spin-cast samples were dried at room temperature
for 24 h in vacuum before analysis. The film thickness determined by ellipsometry
(details see Chap. 5) was 100 ± 5 nm.
Solvent Treatment of Thin Films. Cyclohexane was used to enrich the surface in PS
by placing a cross-linked poly(dimethylsiloxane) (PDMS) slab previously soaked in
cyclohexane onto the polymer surface [31]. After 3 h contact treatment, the PDMS
was removed and the samples were stored overnight in vacuum.
Chemical Modification. A drop of trifluoroacetic acid (50 μl) was applied on
the solvent-treated films. The films obtained were activated by immersion in an
aqueous solution of 1-ethyl-3-(dimethylamino)-propylcarbodiimide (EDC, 1 M) and
N-hydroxysuccinimide (NHS, 0.2 M) for 30 min. The films were immersed inside
fluoresceinamine solution (100 μM, PB, pH = 7.4). Then the samples were taken
out, rinsed with PB and Milli-Q water, and dried in a stream of nitrogen. Finally,
the samples were dried inside a vacuum oven for 1 day before the fluorescence
microscopy experiments.
Atomic Force Microscopy (AFM). The contact mode AFM measurements were
carried out with a NanoScope X multimode AFM (Digital Instruments/Veeco, Santa
Barbara, CA) using a 100 μm scanner and microfabricated silicon tips/cantilevers
(Nanosensors, Wetzlar, Germany) in ambient atmosphere (ca. 30% relative humidity,
24 °C temperature). For laterally resolved pull-off force measurements, the AFM
was operated in the FV mode using a 10 μm scanner. All FV measurements were
performed in air. Arrays of 64 × 64 points
2 (4096 consecutive force–distance
measurements) were acquired on at least six different locations on each sample
using sizes of 0.5 × 0.5 μm
2 or 1.0 × 1.0 μm
2 . DPN was carried out as described
in reference.
Fluorescence Microscopy: The fluorescence microscopy data was obtained using
a Zeiss LSM 510 confocal fluorescence microscope with a BP 500-550 IR filter for
fluoresceinamine, as described in Chap. 4.
References
1. Morkved TL, Lu M, Urbas AM, Ehrichs EE, Jaeger HM, Mansky P, Russell TP (1996) Local
control of microdomain orientation in diblock copolymer thin films with electric fields. Science
273:931–933
2. Albalak RJ, Thomas EL, Capel MS (1998) Solvent swelling of roll-cast triblock copolymer
films. Polymer 39:1647–1656
3. Bodycomb J, Funaki Y, Kimishima K, Hashimoto T (1999) Single-grain lamellar microdomain
from a diblock copolymer. Macromolecules 32:2075–2077