Supplementary information AWS
Supplementary information
High-Performance Multilayer Composite Membranes with Mussel-Inspired Polydopamine as a Versatile Molecular Bridge for CO2 Separation
Panyuan Li, Zhi Wang*, Wen Li, Yanni Liu, Jixiao Wang, Shichang Wang Chemical Engineering Research Center, School of Chemical Engineering and Technology, Tianjin University, Tianjin 30072, PR China Tianjin Key Laboratory of Membrane Science and Desalination Technology, State Key Laboratory of Chemical Engineering, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 30072, PR China
S-1
Synthesis of PDA, PVAm and PDA@PVAm complex (1) PDA PDA was fabricated by the oxidative self-polymerization of DOP in an open vessel at 303 K for 24 h. The solid was collected by centrifugation and then washed by deionized water for at least three times. The dark products were obtained after drying under vacuum at 333 K for 48 h. (2) PVAm N-vinylformamide (NVF) (98%, Sigma-Aldrich) was distilled under vacuum and stored at 258.15 K before polymerization. 2,2'-Azobis(2-methylpropionamidine) dihydrochloride (AIBA) (97%, Sigma-Aldrich) as initiator was recrystallized in ethanol for use. 10.0 g NVF was dissolved in 30.0 ml deionized water. A solution consisting of 0.05g of AIBA and 10.0 ml deionized water was added to the NVF solution and stirred for 20 min. The resultant solution was transferred to a 250 ml three-necked round flask equipped with a condenser and heated under nitrogen atmosphere at 323 K for 5 h. A certain amount of hydrochloric acid solution (36.5 wt%) was added, then the temperature raised to 343 K and kept for 4 h. After cooling, the reaction solution was poured into the excess ethanol, and the precipitate was washed repeatedly with fresh ethanol and dried overnight under vacuum at 303 K. The dried solid was dissolved into deionized water to obtain a homogenous solution. The solution was mixed with excess anion exchange resin and stirred for 12 h. Finally, the final product was given as white solid via precipitation and drying.
Scheme S1. Schematic procedure of PVAm synthesis. S-2
(3) PDA@PVAm complex The as-synthesized PDA deposition was added into the 0.5 wt% PVAm aqueous solution. After sonication to render PDA well-dispersed, the suspension kept at 303 K for 24 h. Then the solid was obtained via water-washing and centrifugation alternately. Last, the PDA@PVAm complex was obtained after drying under vacuum at 333 K for 48 h.
Gas permeation apparatus
Figure S1. Schematic diagram of the home-made gas permeation apparatus.
FTIR characterization of PDA and PVAm Figure S2 presents the FTIR spectrum of PDA deposition. An obvious wide absorption peak at about 3280 cm-1 is attributed to O-H and N-H stretching vibration. Moreover, the peaks at 1600 cm-1 and 1510 cm-1 assigned to C=C stretching vibration in the aromatic amine ring and N-H bending vibration, respectively. In addition, the peak corresponding to C=O stretching vibration is observed at 1720 cm-1. These results prove the existence of catechol group, amino group and quinone group in PDA. S-3
Figure S2. FTIR spectrum of PDA deposition. Figure S3 shows the FTIR spectrum of PVAm bulk. Two obvious peaks at around 3400~3200 cm-1 corresponding to N-H stretching vibration of primary amino group were observed. In addition, the peak at 1660 cm-1 is attributed to C=O stretching vibration of residual amide group during acid hydrolysis.
Figure S3. FTIR spectrum of PVAm bulk. S-4
XPS characterization of the support and membrane Figure S4(a) and S4(b) present high-resolution spectra of the N1s and O1s regions of the PDA(10)-PDMS/PSf support. The N1s region shows three peaks assigned to primary amine, secondary amine and aromatic amine, respectively. With respect to the O1s region, the peaks at 532.9 ev and 531.1 ev correspond to O-C and O=C groups, respectively, indicating the existence of quinone group and catechol group on the surface of the PDA(10)-PDMS/PSf support. The peak at 532.0 ev is attributed to Si-O group from the underlying PDMS layer.
Figure S4. High-resolution spectra of the N1s (a) and O1s (b) regions of the PDA(10)-PDMS/PSf support. Figure
S5
shows
high-resolution
spectrum
of
the
N1s
region
of
the
PVAm(0.8)/PDA(10)-PDMS/PSf membrane. Two peaks at corresponding to N-H of primary amino group and N-H of residual amide group are observed, respectively.
S-5
Figure S5. High-resolution spectrum of the N1s region of the PVAm(0.8)/PDA(10)-PDMS/PSf membrane.
Raman characterization of the supports and membrane
Figure S6. Raman spectra of the PSf, PDMS/PSf, PDA(10)-PDMS/PSf supports and PVAm(0.8)/PDA(10)-PDMS/PSf membrane.
S-6
Separation performances of the PVAm(1.0)/PSf membrane
Figure S7. Effect of feed pressure on gas transport properties of the PVAm (1.0)/PSf membrane. (a) CO2/N2 mixed gas (15/85 by volume); (b) pure N2 gas (> 99.999 vol%).
S-7
High-Performance Multilayer Composite Membranes with Mussel-Inspired Polydopamine as a Versatile Molecular Bridge for CO2 Separation
Panyuan Li, Zhi Wang*, Wen Li, Yanni Liu, Jixiao Wang, Shichang Wang Chemical Engineering Research Center, School of Chemical Engineering and Technology, Tianjin University, Tianjin 30072, PR China Tianjin Key Laboratory of Membrane Science and Desalination Technology, State Key Laboratory of Chemical Engineering, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 30072, PR China
S-1
Synthesis of PDA, PVAm and PDA@PVAm complex (1) PDA PDA was fabricated by the oxidative self-polymerization of DOP in an open vessel at 303 K for 24 h. The solid was collected by centrifugation and then washed by deionized water for at least three times. The dark products were obtained after drying under vacuum at 333 K for 48 h. (2) PVAm N-vinylformamide (NVF) (98%, Sigma-Aldrich) was distilled under vacuum and stored at 258.15 K before polymerization. 2,2'-Azobis(2-methylpropionamidine) dihydrochloride (AIBA) (97%, Sigma-Aldrich) as initiator was recrystallized in ethanol for use. 10.0 g NVF was dissolved in 30.0 ml deionized water. A solution consisting of 0.05g of AIBA and 10.0 ml deionized water was added to the NVF solution and stirred for 20 min. The resultant solution was transferred to a 250 ml three-necked round flask equipped with a condenser and heated under nitrogen atmosphere at 323 K for 5 h. A certain amount of hydrochloric acid solution (36.5 wt%) was added, then the temperature raised to 343 K and kept for 4 h. After cooling, the reaction solution was poured into the excess ethanol, and the precipitate was washed repeatedly with fresh ethanol and dried overnight under vacuum at 303 K. The dried solid was dissolved into deionized water to obtain a homogenous solution. The solution was mixed with excess anion exchange resin and stirred for 12 h. Finally, the final product was given as white solid via precipitation and drying.
Scheme S1. Schematic procedure of PVAm synthesis. S-2
(3) PDA@PVAm complex The as-synthesized PDA deposition was added into the 0.5 wt% PVAm aqueous solution. After sonication to render PDA well-dispersed, the suspension kept at 303 K for 24 h. Then the solid was obtained via water-washing and centrifugation alternately. Last, the PDA@PVAm complex was obtained after drying under vacuum at 333 K for 48 h.
Gas permeation apparatus
Figure S1. Schematic diagram of the home-made gas permeation apparatus.
FTIR characterization of PDA and PVAm Figure S2 presents the FTIR spectrum of PDA deposition. An obvious wide absorption peak at about 3280 cm-1 is attributed to O-H and N-H stretching vibration. Moreover, the peaks at 1600 cm-1 and 1510 cm-1 assigned to C=C stretching vibration in the aromatic amine ring and N-H bending vibration, respectively. In addition, the peak corresponding to C=O stretching vibration is observed at 1720 cm-1. These results prove the existence of catechol group, amino group and quinone group in PDA. S-3
Figure S2. FTIR spectrum of PDA deposition. Figure S3 shows the FTIR spectrum of PVAm bulk. Two obvious peaks at around 3400~3200 cm-1 corresponding to N-H stretching vibration of primary amino group were observed. In addition, the peak at 1660 cm-1 is attributed to C=O stretching vibration of residual amide group during acid hydrolysis.
Figure S3. FTIR spectrum of PVAm bulk. S-4
XPS characterization of the support and membrane Figure S4(a) and S4(b) present high-resolution spectra of the N1s and O1s regions of the PDA(10)-PDMS/PSf support. The N1s region shows three peaks assigned to primary amine, secondary amine and aromatic amine, respectively. With respect to the O1s region, the peaks at 532.9 ev and 531.1 ev correspond to O-C and O=C groups, respectively, indicating the existence of quinone group and catechol group on the surface of the PDA(10)-PDMS/PSf support. The peak at 532.0 ev is attributed to Si-O group from the underlying PDMS layer.
Figure S4. High-resolution spectra of the N1s (a) and O1s (b) regions of the PDA(10)-PDMS/PSf support. Figure
S5
shows
high-resolution
spectrum
of
the
N1s
region
of
the
PVAm(0.8)/PDA(10)-PDMS/PSf membrane. Two peaks at corresponding to N-H of primary amino group and N-H of residual amide group are observed, respectively.
S-5
Figure S5. High-resolution spectrum of the N1s region of the PVAm(0.8)/PDA(10)-PDMS/PSf membrane.
Raman characterization of the supports and membrane
Figure S6. Raman spectra of the PSf, PDMS/PSf, PDA(10)-PDMS/PSf supports and PVAm(0.8)/PDA(10)-PDMS/PSf membrane.
S-6
Separation performances of the PVAm(1.0)/PSf membrane
Figure S7. Effect of feed pressure on gas transport properties of the PVAm (1.0)/PSf membrane. (a) CO2/N2 mixed gas (15/85 by volume); (b) pure N2 gas (> 99.999 vol%).
S-7
