Morphology, Thickness and Composition Evolution in

Supramolecular Block Copolymers Prepared by Dip-Coating

Robert E. Prud’homme and C. Géraldine Bazuin

Département de chimieUniversité de Montréal

Two objectives:1) to obtain a Ph.D. in polymer science

2) to learn English without accent

Stein’s IUPAC lecture in Montréal in 1990

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

Morphology, Thickness and Composition Evolution in

Supramolecular Block Copolymers Prepared by Dip-Coating

Robert E. Prud’homme and C. Géraldine Bazuin

Département de chimieUniversité de Montréal

Thanks to Sébastien Roland, Alexis Laforgue, David Gaspard,

Cé Guinto Gamys and Christian Pellerin

Naphthol (NOH) Naphthoic acid (NCOOH) DHN

n m

PS block PVP blockTwo key choices:

► dip-coating method► adding a small molecule

H-bond

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, ....

AFM images TEM images

PS-b-P4VP (71.9K-30.2K) (1:1 = VP:DHN)

+ DHN(dip-coatedfrom THFsolution)

(washedwith MeOH)

– DHN

Contact angle measurements

86 o mainly PS at surface (thin layer overlaying

VP nodules)

PS: 92 o

P4VP: 62 o

60 o thin P4VP

layer overlays entire surface

1x1 mm

1x1 m

1x1 m

1x1 m

1x1 m

pore depth: ~7 nmfilm thickness: ~7 nm

stained with I2 (P4VP)

Laforgue, A.; Bazuin, C.G.; Prud’homme, R.E. Macromolecules 2006, 39, 6473.

2x2 m

AFM TEM (I2-stained)

3x3 m

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

intermediate strength

strong

NOH

a b c d e

(5 mg/mL)

(10 mg/mL)

a’ b’ c’ d’ e’

NCOOH

a* b* c* d* e*

NOH

(5 mg/mL)

a

b c

d

e

a*

b*

c*e*

a’

b’

c’d’

e’

d*

1 10 100

10

100 10 mg/mL PS-P4VP / NOH 5 mg/mL PS-P4VP / NOH 5 mg/mL PS-P4VP / NCOOH 10 mg/mL PS-P4VP 5 mg/mL PS-P4VP

Th

ickne

ss (n

m)

Dip-coating rate (mm/min)

THF solutions

0 10 20 30 40 50 60 70 80 90

0.5

1.0

10 mg/mL PS-P4VP / NOH 5 mg/mL PS-P4VP / NOH 5 mg/mL PS-P4VP / NCOOH

SM

/VP

upt

ake

ratio

Dip-coating rate (mm/min)

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.

1 10 100

10

100 10 mg/mL PS-P4VP / NOH 5 mg/mL PS-P4VP / NOH 5 mg/mL PS-P4VP / NCOOH

Thick

ness

(nm

)

Dip-coating rate (mm/min)

THF solutions, SM:VP 1:1

Dip-coated PS-P4VP (40.5k-17.5k) films

Film

thi

ckne

ss (

nm)

Faustini, M.; Louis, B.; Albouy, P.A.; Kuemmel, M.; Grosso, D. J. Phys. Chem. C 2010, 114, 7637 (Figures 1 and 3)

Sol-gel films

well-known(Landau+Levich, 1942)

new

PS-P4VP/NOH (1:1) (log-log scale)

Faustini, M.; Louis, B.; Albouy, P.A.; Kuemmel, M.; Grosso, D. J. Phys. Chem. C 2010, 114, 7637(Figure 3)

Sol-gel films

h or ho

u

1 10 100

10

100 5 mg/mL PS-P4VP / NOH

Thi

ckne

ss (nm

)

Dip-coating rate (mm/min)

a’

b’

c’d’

e’

NOH

a b c d e

(5 mg/mL)

(10 mg/mL)

a’ b’ c’ d’ e’

NCOOH

a* b* c* d* e*

NOH

(5 mg/mL)

spheres brush (wetting)layer

ǁ , ‗cyl.

‗ cyl.

a*

b*

c*e*

a’

b’

c’d’

e’

d*

1 10 100

10

100 5 mg/mL PS-P4VP / NOH 5 mg/mL PS-P4VP / NCOOH

Thi

ckne

ss (nm

)

Dip-coating rate (mm/min)

a’

sph. brushlayer

ǁ cyl. lamellar(face-down)

a b c

d e f

g h i

T0

T1

T1

T1

T2

S

A

SS

S SS

SSS

A

A AA

A A A

A

TEM micrographs of cross-sectional slices of I2-stained 41.5-17.5 PS-P4VP/NCOOH

1 mm/min

dots (AFM) ® spheres

(micellar solutions)

(visible wetting layer)

scale bar: 100 nm

a b c

d e f

g h i

T0

T1

T1

T1

T2

S

A

SS

S SS

SSS

A

A AA

A A A

A

TEM micrographs of cross-sectional slices of I2-stained 41.5-17.5 PS-P4VP/NCOOH

2 mm/min

stripes (AFM) horizontal cylinders

(visible wetting layer)

scale bar: 100 nm

z : 12 nm2 x 2 µm²3 mm/min

z : 12 nm2 x 2 µm²7 mm/min

z : 10 nm2 x 2 µm²20 mm/min

z : 12 nm2 x 2 µm²40 mm/min

10 mg/mL5 mg/mL

z : 12 nm2 x 2 µm²2 mm/min

z : 12 nm2 x 2 µm²4 mm/min

z : 10 nm2 x 2 µm²20 mm/min

z : 12 nm2 x 2 µm²40 mm/min

PS-P4VP (SM-free)

1 10 100

10

100 10 mg/mL PS-P4VP / NOH 5 mg/mL PS-P4VP / NOH 5 mg/mL PS-P4VP / NCOOH 10 mg/mL PS-P4VP 5 mg/mL PS-P4VP

Thick

ness

(nm

)

Dip-coating rate (mm/min)

z : 12 nm2 x 2 µm²3 mm/min

z : 12 nm2 x 2 µm²7 mm/min

z : 10 nm2 x 2 µm²20 mm/min

z : 12 nm2 x 2 µm²40 mm/min

10 mg/mL5 mg/mL

z : 12 nm2 x 2 µm²2 mm/min

z : 12 nm2 x 2 µm²4 mm/min

z : 10 nm2 x 2 µm²20 mm/min

z : 12 nm2 x 2 µm²40 mm/min

PS-P4VP (SM-free)

SM-free PS-P4VP

dots (spheres) only

0 10 20 30 40 50 60 70 80 90

0.5

1.0

10 mg/mL PS-P4VP / NOH 5 mg/mL PS-P4VP / NOH 5 mg/mL PS-P4VP / NCOOH

S

M/V

P u

ptak

e ra

tio

Dip-coating rate (mm/min)

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

a

b c

d

e

a*

b*

c*e*

a’

b’

c’d’

e’

d*

1 10 100

10

100 10 mg/mL PS-P4VP / NOH 5 mg/mL PS-P4VP / NOH 5 mg/mL PS-P4VP / NCOOH 10 mg/mL PS-P4VP 5 mg/mL PS-P4VP

Th

ickne

ss (n

m)

Dip-coating rate (mm/min)

NOH

a b c d e

(5 mg/mL)

(10 mg/mL)

a’ b’ c’ d’ e’

NCOOH

a* b* c* d* e*

NOH

(5 mg/mL)

NOH: spheres horizontal cylinders vertical cylindersNCOOH: spheres horizontal cylinders face-down lamellae

0.1 1 10 100

20

40

60

80

100

120

Dioxane Toluene THF CHCl

3

Film

thic

knes

s (n

m)

Dip-coating rate (mm/min)

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.

  Vapor

pressur

e

(kPa)

Viscosity

η

(mN.s.m-

2)

Surfac

e

tensio

n, γ

(mN.m-

1)

Densit

y,

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

Chlorofor

m

26.2 0.537 26.67 1.479 0.050

0.1 1 10 100

20

40

60

80

100

120

Dioxane Toluene THF CHCl

3

Film

thic

knes

s (n

m)

Dip-coating rate (mm/min)

capillarity regime(dip-coating rate slower

than evaporation rate):evaporation ratedominates film thickness

drainingregime

film thickness related to D (at a given dip-coating rate):

dioxane > toluene > THF > CHCl3

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, …)

Thanks, Prof. Stein, for your mentoring and your

friendship