Supporting Information · protium in the solvent (CDCl 3, δ 7.26 ppm). Solid-state 13C CP/MAS NMR spectrum was recorded on a 500 MHz Bruker Avance III HD spectrometer (125 MHz) equipped

Supporting Information

Preparation of compressible polymer monoliths that contain

mesopores capable of rapid oil–water separation

Ji Ae Chae,a Yuree Oh,a Hea Ji Kim,a Go Bong Choi,a Kyoung Min Lee,a,b

Doyoung Jung,a Yoong Ahm Kim,a and Hyungwoo Kim*a

a School of Polymer Science and Engineering & Alan G. MacDiarmid Energy Research

Institute, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186, Korea b Department of Materials Science and Engineering, Seoul National University, 1 Gwanak-

ro, Gwanak-gu, Seoul 08826, Korea

*Corresponding author e-mail: [email protected]

Electronic Supplementary Material (ESI) for Polymer Chemistry.This journal is © The Royal Society of Chemistry 2019

S–1

Contents

Contents ................................................................................................................................................... S–1

General Experimental .......................................................................................................................... S–1

Instrumentation ...................................................................................................................................... S–1

Synthetic Procedures............................................................................................................................ S–3

Mechanical Properties of 9 ................................................................................................................ S–8

SEM Measurement ............................................................................................................................... S–9

Measurement of Porosity of Materials ........................................................................................... S–9

Fiber Growth Measurement ............................................................................................................. S–10

Mechanical Properties of Carbonized 3 ....................................................................................... S–11

Optical Properties of 3 ....................................................................................................................... S–12

Contact Angle Measurement ........................................................................................................... S–12

Absorption Properties of Materials ................................................................................................ S–13

References ............................................................................................................................................. S–18

NMR Spectra........................................................................................................................................ S–19

General Experimental

All reactions were performed in flame-dried glassware under a positive pressure of nitrogen

unless otherwise noted. 1,3,5-Triethynylbenzene (1) was synthesized following the

previous method.S1

Instrumentation

Proton nuclear magnetic resonance (1H NMR) spectra were recorded using Bruker 400

MHz NMR spectrometers at 25 °C. Proton chemical shift are expressed in part per million

(ppm, δ scale) and are referenced to tetramethylsilane ((CH3)4Si 0.00 ppm) or to residual

protium in the solvent (CDCl3, δ 7.26 ppm).

Solid-state 13C CP/MAS NMR spectrum was recorded on a 500 MHz Bruker

Avance III HD spectrometer (125 MHz) equipped with a CP‐MAS probe.

Nitrogen adsorption–desorption isotherms were measured at 77 K by using a

Belsorp‐Max (BEL Japan, Inc.) apparatus. Samples were degassed at 150 °C under vacuum

S–2

for at least 12 h before measurements, and ultra‐high purity grade nitrogen gas was used for

all measurements. The specific surface area was calculated by Brunauer–Emmett–Teller (BET)

method and the pore size distribution was estimated according to the nonlocal density function

theory (NLDFT) with a slit model. Total pore volumes were calculated at a relative pressure of

P/P0 = 0.990.

Uniaxial compressive tests were performed using a universal testing machine

(UTM) (MCT-2150, A&D, Japan) with a 500-N load cell at 25 °C in air. The cylindrical

samples were compressed at a rate of 10 mm min-1 and triplicated during the measurement.

Then, stress–strain curves were recorded. Young's modulus was obtained from the initial

slope of the stress-strain curve in the strain range of 0–10%.

Micromorphology of dried hydrogels was observed using a Carl Zeiss SUPRA

55VP scanning electron microscope (SEM) at an accelerating voltage of 2 kV. Before the

measurement, the sample was dried in vacuum and coated with a thin platinum layer.

Photoluminescence spectra were measured using a Shimadzu RF-5301PC

spectrofluorometer.

Attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR)

was performed using IFS66/S (Bruker) was used to observe absorption spectra of hydrogels.

Water Contact angle measurements were conducted using a SurfaceTech GSA-X

goniometer at 25 °C in air. The contact angle measurement was performed on a flat surface.

The angles were measured immediately after dripping a water droplet on the surface of

sample.

S–3

Synthetic Procedures

Synthesis of (Z)-2,3-bis(4-iodophenyl)acrylonitrile (2):

Scheme S1. Synthetic procedures for 2.

A solution of NaOH (49.6 mg, 1.24 mmol, 0.12 equiv) in ethanol (30 mL) was added

dropwise to the mixture of 4-iodophenylacetonitrile (2.43 g, 10 mmol, 1 equiv) and 4-

iodobenzaldehyde (2.32 g, 10 mmol, 1 equiv) in ethanol (50 mL). The reaction mixture

was stirred at rt for 1.5 h under nitrogen atmosphere. The resulting solid was filtered and

sufficiently washed with cold ethanol. The desired product 2 was obtained as a white solid

(4.08 g, 8.93 mmol, 89.3%). 1H NMR (CDCl3, 400 MHz): δ 7.39 (d, J = 8 Hz, 2 H), 7.44

(s, 1 H), 7.60 (d, J = 4 Hz, 2 H), 7.78 (d, J = 4 Hz, 2 H), 7.81 (d, J = 8 Hz, 2 H). The

spectrum (Figure S17) matched with the reported data in S2.

Synthesis of (Z)-2,3-bis(4-bromophenyl)acrylonitrile (4):


A solution of NaOH (2.45 mg, 0.061 mmol, 0.12 equiv) in ethanol (1.5 mL) was added

dropwise to the mixture of 4-bromophenylacetonitrile (100 mg, 0.51 mmol, 1 equiv) and

4-bromobenzaldehyde (94.38 mg, 0.51 mmol, 1 equiv) in ethanol (2.5 mL). The reaction

mixture was stirred at rt for 1.5 h in nitrogen atmosphere. The solid was filtered and

S–4

sufficiently washed with cold ethanol. The desired product 4 was obtained as a white solid

(100.3 mg, 0.28 mmol, 54.2%). 1H NMR (CDCl3, 400 MHz): δ 7.53 (d, J = 8 Hz, 2 H),

7.45 (s, 1 H), 7.58 (d, J = 8 Hz, 2 H), 7.60 (d, J = 8 Hz, 2 H), 7.74 (d, J = 12 Hz, 2 H). The

spectrum (Figure S18) matched with the reported data in S3.

Synthesis of 7:


Non-agitated reaction: To a solution of 1,3,5-triethynylbenzene (24.7 mg, 0.16 mmol, 1.0

equiv), (Z)-2,3-bis(4-bromophenyl)acrylonitrile (59.7 mg, 0.16 mmol, 1.0 equiv), and

bis(triphenylphosphine)palladium(II) dichloride (3.46 mg, 4.9 μmol, 0.03 equiv) in toluene

(1 mL) was added a solution of copper(I) iodide (0.94 mg, 4.9 μmol, 0.03 equiv) in

triethylamine (0.5 mL). After storing at rt for 24 h without agitation, the resulting powder

was filtered and washed with MeOH, THF, and acetone consecutively. The obtained

product was further purified by gentle stirring in MeOH for 24 h and dried under vacuum

at rt to afford 7 as a brown powder (8.52 mg, 10.1%). IR (cm-1): 2970, 2155, 2109, 1739,

1577, 1435, 1367, 1217, 1095.

Agitated reaction: To a solution of 1,3,5-triethynylbenzene (74.0 mg, 0.49 mmol, 1.0

equiv), (Z)-2,3-bis(4-bromophenyl)acrylonitrile (178.8 mg, 0.49 mmol, 1.0 equiv), and

bis(triphenylphosphine)palladium(II) dichloride (10.4 mg, 0.01 mmol, 0.03 equiv) in

toluene (3 mL) was added a solution of copper(I) iodide (2.81 mg, 0.0148 mmol, 0.03 equiv)

S–5

in triethylamine (1.5 mL). After stirring at rt for 24 h, the resulting powder was filtered and

washed with MeOH, THF, and acetone consecutively. The product was further purified by

gentle stirring in MeOH for 24 h and dried under vacuum at rt to afford 7 as a brown

powder (78.61 mg, 31.1 %).

Synthesis of 8:


1,3,5-Triethynylbenzene (49.4 mg, 0.33 mmol, 1.0 equiv), 4,4’-diiodo-trans-stilbene (0.14

g, 0.33 mmol, 1.0 equiv), and bis(triphenylphosphine)palladium(II) dichloride (6.92 mg,

0.0099 mmol, 0.03 equiv) were dissolved in 1:1 toluene–DMF (4 mL, v/v) after sonication.

To the reaction mixture was added a solution of copper(I) iodide (1.88 mg, 9.9 μmol, 0.03

equiv) in triethylamine (1 mL). After storing at 85℃ for 24 h without agitation, the

resulting product was taken out and washed with MeOH, THF, and acetone consecutively.

The product was further purified by gentle stirring in MeOH for 24 h and dried under

vacuum at rt to afford 8 as a dark brown powder (158.8 mg, 83%). IR (cm–1): 3045, 2220,

1580, 1486, 1405, 1360, 1064, 1005.

S–6

Synthesis of 9:


1,3,5-Triethynylbenzene (24.7 mg, 0.16 mmol, 1.0 equiv), 4,4’-diiodobiphenyl (66.7 mg,

0.16 mmol, 1.0 equiv), and bis(triphenylphosphine)palladium(II) dichloride (3.46 mg,

0.0049 mmol, 0.03 equiv) were dissolved in toluene (1 mL) after sonication. Then, a

solution of copper(I) iodide (0.94 mg, 4.9 μmol, 0.03 equiv) in triethylamine (0.5 mL) was

added to the reaction mixture. After storing at 75℃ for 24 h without agitation, the resulting

polymer was filtered and washed with MeOH, THF, and acetone consecutively. The

product was further purified by gentle stirring in MeOH for 24 h and dried under vacuum

at rt to afford 9 as a yellow powder (72.2 mg, 79%). IR (cm–1): 2207, 1578, 1493, 1414,

1107, 1064, 1002. The resulting material 9 was obtained as a monolith but not compressible

as shown in Figure S1.

Figure S1. Photographs of the network 9 that was obtained as a monolith (a) but destroyed after (b) loading

and (c) unloading external force.

a b c

S–7

Synthesis of 10:


Microporous polymer network 10 was prepared by following the reported procedure using

1,4-diiodobenzene instead of 2.S1 Quantities of monomers and reagents for 10: 1,3,5-

Triethynylbenzene (50 mg, 0.33 mmol, 1.0 equiv), 1,4-diiodobenzene (109.83 mg, 0.33

mmol, 1.0 equiv), bis(triphenylphosphine)palladium(II) dichloride (7.0 mg, 0.01 mmol,

0.03 equiv), and copper(I) iodide (2.0 mg, 0.01 mmol, 0.03 equiv). The product was

obtained as a compressible, yellow monolith.

S–8

Mechanical Properties of 9

0 10 20 30 40 50 60

0.0

0.1

0.2

0.3co

mp

ressiv

e s

tre

ss (

MP

a)

strain (%)

Figure S2. Compressive stress–strain curve obtained from 9. The network was destroyed over a strain of

40%.

S–9

SEM Measurement

Figure S3. SEM image of the cross section of fiber in the network 3.

Figure S4. SEM images of fibrous structure in 3 (a) before and (b) after ten consecutive loading–unloading

cycles.

Figure S5. SEM image of fibrous structure of a commercial melamine foam.

Measurement of Porosity of Materials

Table S1. Summarized specific surface areas and total pore volumes of the polymer networks.

polymer network specific surface area (m2 g–1)a total pore volume (cm3 g–1)b

3 53 0.10

7 331 0.26

8 487 0.25

9 441 0.22 a specific surface areas were calculated by the BET method from N2 adsorption isotherms at 77 K. b total pore volume were determined at P/P0 = 0.995.

200 μm 200 μm

a b

20 μm

500 nm

S–10

Fiber Growth Measurement

Figure S6. SEM images for the growth of fiber bundles during the synthesis of 3, which were monitored at

(a) 10, (b) 20, (c) 30, (d) 40, (e) 50, (f) 60, and (g) 120 min.

10 μm

10 μm 10 μm

10 μm

10 μm

10 μm

10 μm

a b

c d

e f

g

S–11

Mechanical Properties of Carbonized 3

The monolith 3 was carbonized following the conditions as follows. The material was

heated up to 800 °C at a rate of 2 °C min–1 under nitrogen atmosphere. Then, the material

was further stored at the same temperature for 1 h to complete the thermal carbonization

(char yield, 80%).

0 5 10 15 20 25

0.00

0.01

0.02

0.03

0.04

0.05

com

pre

ssiv

e s

tress (

MP

a)

strain (%)

Figure S7. Compressive stress–strain curve obtained from the carbonized 3. The network was destroyed over

a strain of 15%.

Figure S8. Photographs of the carbonized 3 that maintained the monolithic structure (a) but destroyed during

(b) loading and (c) unloading cycle.

a b c

S–12

Optical Properties of 3

Figure S9. The fluorescence emission spectrum of 3 when excited at 365 nm (yellow). The inset shows

photographs of 3 before and after 365-nm irradiation using a conventional UV hand lamp.

Contact Angle Measurement

Figure S10. Representative photographs of a water droplet on polymer network 3 (a) before and (b) after ten

consecutive loading–unloading cycles.

Table S2. Contact angles measured from polymer network 3.

Compound Trial 1 Trial 2 Trial 2 Avg. Std.

3 107.82 101.94 93.18 100.98 7.37

3 after compressive test

108.49 111.34 106.93 108.92 2.24

420 450 480 510 540 570 600 630 6600

15

30

45

60

PL inte

nsity (

a.u

.)

wavelength (nm)

365 nm

a b

S–13

Absorption Properties of Materials

Each dried sample was soaked in each solvent. Then the weight of samples was monitored

at each time interval.

Figure S11. (a) Expanded view of the initial region of the absorption behavior of mesoporous 3. The

absorption almost completed before 10 min. (b) Comparison of the initial absorption behavior of 3 before

(closed circles) and after compression until a strain of 80% (open circles) when immersed in n-dodecane.

Figure S12. Nitrogen adsorption–desorption isotherms of (a) the network 10 and (b) melamine foam

measured at 77 K. Open circles depict adsorption curves; closed circles, desorption curves. Pore size

distribution of large pores in the melamine foam estimated by the Barrett–Joyner–Halenda (BJH) method is

shown in the inset.

0 1 2 3 4 5 6 7 8 9 10

0

5

10

15

20

25

30

n-hexane

toluene

water

chloroform

ethanol

silicone oil

n-dodecane

absorp

tion c

apacity (

mg/m

g)

time (min)

a

0 1 2 3 4 5 6 7 8 9 10

0

3

6

9

12

absorp

tion c

apacity (

mg/m

g)

time (min)

before compression

after compression

b

0.0 0.2 0.4 0.6 0.8 1.0

0

50

100

150

200

adsorption

desorptionab

so

rbe

d N

2 a

mo

un

t (c

m3 g

-1)

relative pressure (P/P0)

0.0 0.2 0.4 0.6 0.8 1.0

0

10

20

30

absorb

ed N

2 a

mount (c

m3 g

-1)

relative pressure (P/P0)

adsorption

desorption

0 50 100 150 200

0.000

0.002

0.004

0.006

0.008

dV

p (cm

3 g

-1)

pore diameter (nm)

a b

S–14

Figure S13. (a) Absorption behavior of microporous 10 when immersed in various solvents as a function of

time. (b) Comparison of absorption capacity of 10 versus density of solvents.

Figure S14. (a) Absorption behavior of melamine foam when immersed in various solvents as a function of

time. (b) Comparison of absorption capacity of melamine foam versus density of solvents.

0 200 400 600 800 1000

0

5

10

15

20

25

30

chloroform

ethanol

silicone oil

n-dodecane

ab

so

rptio

n c

ap

acity (

mg

/mg

)

time (min)

n-hexane

toluene

water

0.6 0.8 1.0 1.2 1.4 1.60

500

1000

1500

2000

2500

3000

ab

so

rptio

n c

ap

acity(w

t%)

density(g/mL)

chloroform

ethanol

silicone oiltoluene

water

n-dodecane

n-hexane

a b

0 200 400 600 800 1000

0

30

60

90

120

150

180

n-hexane

toluene

water

absorp

tion c

apacity (

mg/m

g)

time (min)

chloroform

ethanol

silicone oil

n-dodecane

b

0.6 0.8 1.0 1.2 1.4 1.6

5000

10000

15000

20000

absorp

tion c

apacity(w

t%)

density(g/mL)

chloroform

ethanol

silicone oil

toluenewater

n-dodecane

n-hexane

a

S–15

Figure S15. Linear correlation of t/qt vs. time and obtained corresponding function for each solvent,

measured with 3: (a) n-dodecane, (b) ethanol, (c) silicone oil, (d) chloroform, (e) n-hexane, and (f) toluene.

0 500 1000 1500 2000 2500

0

50

100

150

200

250t/q

t (m

in g

g-1)

t (min)

y = 0.1024x + 0.13635

=0.9999

0 500 1000 1500 2000 2500

0

50

100

150

t/q

t (m

in g

g-1)

t (min)

y = 0.05561x + 0.60832

=0.9992

0 500 1000 1500 2000 2500

0

50

100

150

200

t/q

t (m

in g

g-1)

t (min)

y = 0.07708x + 0.58087

=0.9996

0 500 1000 1500 2000 2500

0

20

40

60

80

t/q

t (m

in g

g-1)

t (min)

y = 0.02987x + 0.33151

=0.999

0 500 1000 1500 2000 2500

0

100

200

300

400

500

600

t/q

t (m

in g

g-1)

t (min)

y = 0.2259x + 1.25212

=0.9996

0 500 1000 1500 2000 2500

0

100

200

300

400

t/q

t (m

in g

g-1)

t (min)

y = 0.15552x + 0.36509

=0.9999

a b c

d e f

S–16


measured with 10: (a) n-dodecane, (b) ethanol, (c) silicone oil, (d) chloroform, (e) n-hexane, (f) toluene, and

(g) water.

0 200 400 600 800 1000

0

15

30

45

60

75

t/q

t (m

in g

g-1)

t (min)

0 200 400 600 800 1000

0

10

20

30

40

50

60

t/q

t (m

in g

g-1)

t (min)

0 200 400 600 800 1000

0

10

20

30

40

50

60

t/q

t (m

in g

g-1)

t (min)

a b c

d e f

y = 0.0616x + 0.09872

=0.9995

y = 0.06216x + 0.02434

=0.9999

0 200 400 600 800 1000

0

10

20

30

40

50

60

t/q

t (m

in g

g-1)

t (min)

y = 0.05836x + 0.07847

=0.9999

0 200 400 600 800 1000

0

10

20

30

40

t/q

t (m

in g

g-1)

t (min)

y = 0.03551x + 0.0243

=0.9999

y = 0.07431x + 0.05509

=0.9999

0 200 400 600 800 1000

0

10

20

30

40

50

60

70

t/q

t (m

in g

g-1)

t (min)

y = 0.0671x + 0.0278

=0.9999

g

0 200 400 600 800 1000

0

50

100

150

200

250

300

t/q

t (m

in g

g-1)

t (min)

y = 0.27168x + 2.52588

=0.9980

S–17


measured with melamine foam: (a) n-dodecane, (b) ethanol, (c) silicone oil, (d) chloroform, (e) n-hexane, (f)

toluene, and (g) water.

a b c

d e f

g

0 200 400 600 800 1000

0

2

4

6

8

t/q

t (m

in g

g-1)

t (min)

y = 0.0078x + 0.15064

=0.9960

0 200 400 600 800 10000

2

4

6

8

10

12

t/q

t (m

in g

g-1)

t (min)

y = 0.0106x + 0.00582

=0.9999

0 200 400 600 800 1000

0

2

4

6

8

10

12

t/q

t (m

in g

g-1)

t (min)

y = 0.01283x + 0.00873

=0.9999

0 200 400 600 800 1000

0

2

4

6

8

10

t/q

t (m

in g

g-1)

t (min)

y = 0.00928x + 0.00349 =0.9999

0 200 400 600 800 1000

0

2

4

6

8

10

12

t/q

t (m

in g

g-1)

t (min)

y = 0.01102x + 0.00111

=0.9999

0 200 400 600 800 1000

0

2

4

6

8

t/q

t (m

in g

g-1)

t (min)

y = 0.00797x + 0.00274

=0.9999

0 200 400 600 800 1000

0

1

2

3

4

5

6

t/q

t (m

in g

g-1)

t (min)

y = 0.00571x + 0.00221

=0.9999

S–18

References

S1. Lee, K. M.; Kim, H. J.; Kang, C.-S.; Tojo, T.; Chae, J. A.; Oh, Y.; Cha, M. C.;

Yang, K. S.; Kim, Y. A.; Kim, H. Preparation of carbon-containing, compressible,

microporous, polymeric monoliths that regulate macroscopic conductivity. Polym.

Chem. 2019, 10, 852–859.

S2. Chen, C.-H.; Lee, S.-L.; Lim, T.-S.; Chen, C.-h.; Luh, T.-Y. Influence of polymer

conformations on the aggregation behaviour of alternating dialkylsilylene-[4,4′-

divinyl(cyanostilbene)] copolymers. Polym. Chem. 2011, 2, 2850–2856.

S3. Upamali, K. A. N.; Estrada, L. A.; De, P. K.; Cai, X.; Krause, J. A.; Neckers, D. C.

Carbazole-Based Cyano-Stilbene Highly Fluorescent Microcrystals. Langmuir

2011, 27, 1573–1580.

S–19

NMR Spectra

Figure S18. 1H NMR spectrum of 2.

Figure S19. 1H NMR spectrum of 4.

Documents

Supporting Information · protium in the solvent (CDCl 3, δ 7.26 ppm). Solid-state 13C CP/MAS NMR spectrum was recorded on a 500 MHz Bruker Avance III HD spectrometer (125 MHz) equipped