1. Morphology, Thickness and Composition Evolution in Supramolecular Block Copolymers Prepared by Dip-Coating
Robert E. Prud’homme and C. Géraldine Bazuin
Département de chimie
Université de Montréal

2. Two objectives: 1) to obtain a Ph.D. in polymer science
Stein’s IUPAC lecture
in Montréal in 1990
2) to learn English without accent

3. 1973 picture. On the first row, from right to left, Richard Stein, Do Yoon and Robert Prud’homme.
In the second row, Judy Stein.

4. Morphology, Thickness and Composition Evolution in Supramolecular Block Copolymers Prepared by Dip-Coating
Robert E. Prud’homme and C. Géraldine Bazuin
Département de chimie
Université de Montréal
Thanks to Sébastien Roland, Alexis Laforgue, David Gaspard,
Cé Guinto Gamys and Christian Pellerin

5. Two key choices: ► dip-coating method ► adding a small molecule
PS block
PVP block
Two key choices:
► dip-coating method
► adding a small molecule n m
H-bond
Naphthol (NOH)
Naphthoic acid (NCOOH)
DHN

6. Block copolymer (BC) self-assembly
In the bulk (melt)
Important parameters: fA, fB ,  and N
In thin films (ex. spin-coating + annealing, dip-coating)
Additional parameters: surface/interface energetics (air, substrate) – preferential wetting, domain orientation -, and confinement effects
solvent evaporation rate, other kinetic effects
Supramolecular block copolymers
addition of a block selective (H-bonding) small molecule, SM
 modifies block fractions, interfacial energies, ....

7. PS-b-P4VP (71.9K-30.2K) (1:1 = VP:DHN)
Contact angle
measurements
86 o 
mainly PS
at surface
(thin layer
overlaying
VP nodules)
PS: o
P4VP: 62 o
60 o 
thin P4VP
layer overlays
entire surface
AFM images
TEM images
1x1 mm
1x1 m
+ DHN
(dip-coated
from THF
solution)
stained with I2 (P4VP)
(washed
with MeOH)
– DHN
pore depth: ~7 nm
film thickness: ~7 nm
Laforgue, A.; Bazuin, C.G.; Prud’homme, R.E. Macromolecules 2006, 39, 6473.

8. PS-b-P4VP (71.9k-30.2k), 5 mg/mL THF solutions (micellar),
SM:VP 1:1, dip-coating rate 2 mm/min, silicon substrates
H-bonded to P4VP
AFM
TEM (I2-stained)
2x2 m
intermediate strength
3x3 m
strong

9. a b c d e a* b* c* e* a’ b’ c’ d’ e’ d*
THF solutions
Sébastien Roland, R.E. Prud'homme, C.G. Bazuin, ACS Macro Letters 2012, 1, 973.
Sébastien Roland, David Gaspard, R.E. Prud'homme, C.G. Bazuin, Macromolecules 2012, 45, 5463.

10. Dip-coated PS-P4VP (40.5k-17.5k) films
THF solutions, SM:VP 1:1
Film thickness (nm)

11. Sol-gel films new well-known
(Landau+Levich,
1942)
Faustini, M.; Louis, B.; Albouy, P.A.; Kuemmel, M.; Grosso, D. J. Phys. Chem. C 2010, 114, 7637 (Figures 1 and 3)

12. Sol-gel films PS-P4VP/NOH (1:1) h or ho u
(log-log scale)
h or ho u
Faustini, M.; Louis, B.; Albouy, P.A.; Kuemmel, M.; Grosso, D. J. Phys. Chem. C 2010, 114, 7637
(Figure 3)

13. spheres
brush (wetting) layer
ǁ , ‗
cyl.
‗ cyl. e’ a’ d’ c’ b’

14. sph. ǁ cyl. brush layer lamellar (face-down) e’ a* a’ a’ b* d’ e* c’

15. spheres (micellar solutions)
TEM micrographs of cross-sectional slices of I2-stained PS-P4VP/NCOOH
1 mm/min
dots (AFM)
spheres (micellar solutions)
(visible wetting layer)
scale bar: 100 nm

16.  horizontal cylinders (visible wetting layer)
TEM micrographs of cross-sectional slices of I2-stained PS-P4VP/NCOOH
2 mm/min
stripes (AFM)
 horizontal cylinders
(visible wetting layer)
scale bar: 100 nm

17. SM-free PS-P4VP
dots (spheres) only

18. S. Roland, C. Pellerin, C.G. Bazuin, R.E. Prud’homme,
Macromolecules, 2012, 45, 7964.

19. NOH: spheres  horizontal cylinders  vertical cylinders b c b* d’ e* c’ c* b’ d*
NOH: spheres  horizontal cylinders  vertical cylinders
NCOOH: spheres  horizontal cylinders  face-down lamellae

20. Other Dip-coating Solvents
(10 mg/mL PS-P4VP solution concentration, 1:1 NCOOH:VP)
S. Roland, C.G. Gamys, J. Grosrenaud, S. Boissé, C. Pellerin, R.E. Prud’homme,
C.G. Bazuin, Macromolecules 2015, 48, 4823.

21. film thickness related to D
Vapor pressure
(kPa)
Viscosity η
(mN.s.m-2)
Surface tension, γ
(mN.m-1)
Density, ρ (g.cm-3)
D (x 106)
p-Dioxane
4.95
1.177
32.75
1.034
0.116
Toluene
3.79
0.560
27.93
0.862
0.087
THF
21.6
0.456
26.5
0.883
0.074
Chloroform
26.2
0.537
26.67
1.479
0.050
draining
regime
film thickness related to D
(at a given dip-coating rate):
dioxane > toluene
> THF > CHCl3
capillarity regime (dip-coating rate slower than evaporation rate):
evaporation rate
dominates film
thickness

22. Conclusions
V-shaped dependence of dip-coated film thickness with dip- coating rate (capillarity vs. draining regimes)
Films obtained in the capillary regime depend on solvent characteristics (insensitive in the draining regime)
Morphologies depend on SM uptake ratio and solution/solvent characteristics (micellar or not, “tightness” of micelles, …)

23. Thanks, Prof. Stein, for your mentoring and your friendship