Supporting Information

Transcription

1 Supporting Information Photoinduced Postsynthetic Polymerization of a Metal Organic Framework toward a Flexible Stand-Alone Membrane** Yuanyuan Zhang, Xiao Feng,* Haiwei Li, Yifa Chen, Jingshu Zhao, Shan Wang, Lu Wang, and Bo Wang* anie_ _sm_miscellaneous_information.pdf

2 Supporting Information Contents Section A. Materials and methods Section B. Experimental section Section C. Supplementary spectra (Figure S2-S7) Section D. Supporting references

3 Section A. Materials and methods All chemicals and solvents were purchased from commercial suppliers including Alfa Aesar, Sigma-Aldrich and Beijing Chemical Reagent Company, and used without further purification. Powder X-ray diffraction (XRD) analysis was performed on a Bruker Foucus D8 diffractometer with Cu-Kα X-ray radiation (λ = nm). Particle size measurements were performed on dynamic light scattering (DLS) spectrometer (Malvern Zen MPT-2). The modified samples (UiO-66-NH-Met) were dispersed in ethanol and sonicated for several minutes before measured. The PSP-derived membrane was first soaked in CH 2 Cl 2 to remove the pure PBMA while the copolymer of PSM UiO-66-NH 2 and BMA was left, noted as PSP-derived polymer. Then the PSP-derived polymer was dispersed in ethanol. 1 H NMR spectra were recorded on a Bruker ARX-400 spectrometer. Approximately 10 mg of pristine UiO-66-NH 2, UiO-66-NH-Met, PSP-derived polymer and PBMA were degraded in 550 μl of d 6 -DMSO with 20 μl of HF, respectively. Field-emission scanning electron microscopy (FE-SEM) images were acquired from a JEOL model JSM-7500F scanning electronmicroscope. Prior to observation the membranes were sputter-coated with platinum layers to increase their conductivity. CO 2 sorption isotherms were measured at 273 K on a Quantachrome Instrument ASiQMVH002-5 after pretreatment. N 2 sorption isotherms were performed at 77 K.

4 Electrospray ionization mass spectrometry (ESI-MS) was performed using a Shimadzu LC-MS 2010 mass spectrometer. The UiO-66-NH-Met was degraded in a solution of HF and DMSO. Elemental analyses were measured by VARIO EL-III Elemental Analyzer. The concentrations of Cr (VI) solutions before and after filtration were determined by absorbance at 540 nm using a TU-1901 UV vis spectrophotometer.

5 Section B. Experimental section Preparation of UiO-66-NH 2 and modified samples. Synthesis of UiO-66-NH 2 : Samples of nanosized UiO-66-NH 2 were prepared according to the procedures reported before. [1] Briefly, ZrCl 4 (pre-dissolved in a DMF/HCl mixture v(dmf):v(hcl) = 5:1) and 2-amino-4,4 -dicarboxylic acid (pre-dissolved in DMF) at a molar ratio of 1:1.4 were mixed and heated at 80 ºC overnight. The obtained powders were isolated by centrifugation and washed with DMF (3 30 ml). Then the powders were immersed in ethanol for 3 days (the solvent was replaced with fresh ethanol each day). Finally, the product was dried under vacuum at 150 ºC overnight. Postsynthetic modification of UiO-66-NH 2 : The as-synthesized UiO-66-NH 2 was mixed with methacrylic anhydride in CH 2 Cl 2 and kept in a closed vial for 4 days. [2] The solids were washed several times with fresh CH 2 Cl 2 and then dried under vacuum at 40 ºC for 6 h. Preparation of membranes. Preparation of UiO-66-NH-Met/BMA (MMA) PSP-derived membranes: g of UiO-66-NH-Met were suspended in g of butyl methacrylate (BMA) or methyl methacrylate (MMA) and sonicated for 20 min. To the mixture, photoinitiator phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide was added (6 wt% with respect to the total weight of the two monomers) and sonicated for another 2 min. The resulting suspension was dripped into a Teflon mould and photopolymerized under a UV lamp for 20 min to obtain the PSP-derived membrane with 20 wt% loading. The distance between the mould and light was set to 20 cm. Photograph of the setup for photoinduced postsynthetic polymerization is shown in Figure S1. Membranes with different MOFs loadings were fabricated using the same

6 method. Due to the different mechanical properties of poly(butyl methacrylate) (PBMA) and poly(methyl methacrylate) (PMMA) the corresponding PSP-derived membranes exhibit quite different performances: the MOF/BMA PSP-derived membrane is elastic and flexible while the MOF/MMA PSP-derived membrane is rather brittle. Preparation of the membrane of a MOF/PBMA blend: The MOF chosen is UiO-66 and the membrane preparation was using the same method as PSP-derived membrane. Preparation of the membrane of an activated carbon/pbma blend: The activated carbon was used instead of MOF and the membrane was prepared using the same method as PSP-derived membrane. Preparation of the PBMA membrane: The membranes were fabricated using the similar method without any fillers. Figure S1. Photograph of the setup for photoinduced polymerization.

7 Cr (VI) ions removal experiment The separation capability of the PSP-derived membrane was studied for the removal of Cr (VI) ions from water. K 2 Cr 2 O 7 was dissolved in deionized water to form a solution with a concentration of 10 mg/l. 10 ml of the solution was passed through the membrane for several consecutive passes until the residual concentration remained unchanged. The residual Cr (VI) ions concentration was determined by UV vis spectrophotometer. The retention rate and separation capacity of the membrane were calculated with the following equations: Retention = C! C C! 100% (1) Capacity = (C! C) V m (2) where C 0 (mg/l) and C (mg/l) are the concentrations of Cr (VI) ions before and after filtration, respectively; V (L) is the volume of Cr (VI) solution; m (g) is the mass of dried membrane.

8 Section C. Supplementary spectra (Figure S2-S7) Figure S2. ESI-MS of digested UiO-66-NH-Met.

9 a) b) Figure S3. N 2 adsorption/desorption isotherms of a) UiO-66-NH 2 and b) UiO-66-NH-Met at 77 K.

10 Table S1. Elemental analyses data of UiO-66-NH 2 and UiO-66-NH-Met. Experimental Calculated Conv. (%) Elemental analysis C:N ratio Differences from amine Sample C wt% N wt% C:N C:N Exp. Cal. Conv. (%) UiO-66-NH 2 UiO-66-NH- Met The C:N ratio measured and calculated were used to analyze the degree of conversion from amine to amide. [3] The calculated data of modified sample was obtained by assuming all the amine functional groups in pristine sample are converted to amide groups. The conversion is estimated by comparing the C:N ratio measured with calculated values of UiO-66-NH 2 and UiO-66-NH-Met, which is in a good agreement with the result from 1 H NMR.

11 Figure S4. Particle size distribution of UiO-66-NH-Met and PSP-derived polymer analyzed by DLS measurement.

12 Figure S5. PXRD patterns of UiO-66-NH-Met, UiO-66-NH-Met/MMA PSP-derived membrane (10 wt% MOF loading) and poly(methyl methacrylate) (PMMA).

13 Figure S6. SEM image of the surface of a UiO-66-NH-Met/MMA PSP-derived membrane of 10 wt% MOF loading.

14 Figure S7. CO 2 adsorption properties of UiO-66-NH-Met, UiO-66-NH-Met/MMA PSP-derived membrane (10 wt% MOF loading) and poly(methyl methacrylate) (PMMA) measured at 0 ºC.

15 Section D. Supporting references [1] M. J. Katz, Z. J. Brown, Y. J. Colon, P. W. Siu, K. A. Scheidt, R. Q. Snurr, J. T. Hupp, O. K. Farha, Chem. Commun. 2013, 49, [2] a) S. J. Garibay, S. M. Cohen, Chem. Commun. 2010, 46, ; b) M. Kandiah, S. Usseglio, S. Svelle, U. Olsbye, K. P. Lillerud, M. Tilset, J. Mater. Chem. 2010, 20, [3] T. Ratvijitvech, R. Dawson, A. Laybourn, Y. Z. Khimyak, D. J. Adams, A. I. Cooper, Polymer 2013, 55,