Supporting Information for. Intrinsically Hierarchical Nanoporous Polymers via Polymerization-Induced Microphase. Separation

Transcription

1 S1 Supporting Information for Intrinsically Hierarchical Nanoporous Polymers via Polymerization-Induced Microphase Separation Michael B. Larsen, J. David Van Horn, Fei Wu, and Marc A. Hillmyer * Department of Chemistry, University of Minnesota, Minneapolis, Minnesota Department of Chemistry, University of Missouri, Kansas City, Missouri 64110

2 S2 STP (ml g -1 ) Figure S1. Raw adsorbed volume vs. time data for nitrogen sorption kinetics experiments utilizing monoliths containing TMSS (red) and S (black) at 9.25 kpa (triangles) and 6.17 kpa (squares) initial dose pressures. Data in Figure 7 were normalized to the adsorbed volume at the final collected data point for each experiment. t (s)

3 S3 00 intensity (arb. units) time (ns) Figure S2. Sample PALS spectra of PIMS-derived styrenic monoliths containing S (black), tbus (blue), and TMSS (red). A long lifetime component that may be associated with mesoscopic voids is apparent in the nanosecond region. Conditions: ns window, in vacuo, room temperature.

4 S4 I (arb. log units) iprs CyS I (arb. log units) TMSS tbus S MeS q (nm -1 ) q (nm -1 ) Figure S3. SAXS patterns of monoliths before (dashed) and after (solid) etching of PLA. Initial reaction mixtures comprised f PLA = 0.25 (34 kda), 4:1 styrenic monomer:dvb. TMSS and CyScontaining mixtures required ca. 10 vol% dioxane for homogeneity. The monomer utilized is in blue to the left of each data pair. Data are shifted relative to the vertical axis for clarity.

5 S5 2 1 % transmittance % transmittance wavenumbers (cm -1 ) Figure S4. IR spectra of S-containing monoliths before (top) and after (bottom) etching. The disappearance of the carbonyl stretching frequency at ca cm -1 indicates full PLA removal. 2 1 % transmittance % transmittance wavenumbers (cm -1 ) Figure S5. IR spectra of CyS-containing monoliths before (top) and after (bottom) etching. The disappearance of the carbonyl stretching frequency at ca cm -1 indicates full PLA removal.

6 S6 2 1 % transmittance % transmittance wavenumbers (cm -1 ) Figure S6. IR spectra of iprs-containing monoliths before (top) and after (bottom) etching. The disappearance of the carbonyl stretching frequency at ca cm -1 indicates full PLA removal. 2 1 % transmittance % transmittance 2 1 wavenumbers (cm -1 ) Figure S7. IR spectra of MeS-containing monoliths before (top) and after (bottom) etching. The disappearance of the carbonyl stretching frequency at ca cm -1 indicates full PLA removal.

7 S7 2 1 % transmittance % transmittance wavenumbers (cm -1 ) Figure S8. IR spectra of tbus-containing monoliths before (top) and after (bottom) etching. The disappearance of the carbonyl stretching frequency at ca cm -1 indicates full PLA removal. 2 1 % transmittance % transmittance wavenumbers (cm -1 ) Figure S9. IR spectra of TMS-containing monoliths before (top) and after (bottom) etching. The disappearance of the carbonyl stretching frequency at ca cm -1 indicates full PLA removal.

8 S8 Figure S10. Additional higher magnification SEM micrographs of etched monoliths prepared via PIMS, consistent with reticulated bicontinuous structures in each case. Initial reaction mixtures comprised fpla = 0.25 (34 kda), 4:1 styrenic monomer:dvb. The styrene derivative used in each case is indicated in the top left of each micrograph; scale bar = 200 nm.

9 S STP (ml g -1 ) Figure S11. Nitrogen sorption isotherm of etched monolith containing CyS; initial reaction mixtures comprised f PLA = 0.25 (34 kda), 4:1 CyS:DVB. 300 P/P o 250 STP (ml g -1 ) P/P o Figure S12. Nitrogen sorption isotherm of etched monolith containing iprs; initial reaction mixtures comprised f PLA = 0.25 (34 kda), 4:1 iprs:dvb.

10 S STP (ml g -1 ) Figure S13. Nitrogen sorption isotherm of etched monolith containing MeS; initial reaction mixtures comprised f PLA = 0.25 (34 kda), 4:1 MeS:DVB. 350 P/P o 300 STP (ml g -1 ) P/P o Figure S14. Nitrogen sorption isotherm of etched monolith containing tbus; initial reaction mixtures comprised f PLA = 0.25 (34 kda), 4:1 tbus:dvb.

11 S STP (ml g -1 ) STP (ml g -1 ) statistical thickness (nm) statistical thickness (nm) Figure S15. Estimation of micropore surface areas by the t-plot method in tbus (left) and TMSS (right) containing monoliths. Experimental data points were plotted and fit to the carbon black thickness equation, the most appropriate model for organic adsorbents (shown as red line); nonzero intercepts in each case indicate detectable micropore (< 2 nm) volume. The micropore size distributions also likely extends into the smaller mesopore size regime (>2 nm), as evidenced by the calculated DFT pore size distributions (main text Figure 5b); thus, t-plots likely underestimate the total volume and surface area of the micropore component.

12 S TMSS surface area (m 2 g -1 ) MeS tbus S iprs CyS A value (kcal/mol) Figure S16. Correlation of A value of substituent in 4-position of styrenic monomer with BET surface area as measured by nitrogen sorption. Data points are an average of three independently synthesized samples, with error bars indicating range. 300 TMSS tbus surface area (m 2 /g) CyS iprs S MeS styrenic homopolymer T g ( C) Figure S17. Effect of synthesis temperature on BET surface area as measured by nitrogen sorption; black = 120 C, red = 140 C. Data points are an average of three independently synthesized samples, with error bars indicating range.

13 S13 Extended PALS Discussion Polymer distributions of void size, the communication between free volume and void structures, and the migration of the Ps species at nano-, micro- and mesoscales complicates the analysis of PALS data for materials with complex void structures. Initially, the present PAL spectra were modeled as having four lifetime components, typical for polymers expected to have void structures in addition to free volume. The four components are associated with: para-ps annihilation (τ 1 ), free positron annihilation (τ 2 ), and two components associated with ortho-ps pick-off annihilation in the polymer free volume and in larger void structures, here τ FV and τ meso, respectively (numerically, τ 3 and τ 4 ). Analysis proceeded with the first two lifetimes either fixed or free in the fitting, and focused on addressing the identification of free volume and larger void volumes. This approach yields appropriate lifetime values for annihilation processes in the polymer free volume (2 3 ns) and in mesoscopic voids (70 80 ns) (Table S1). In these data, the lifetime (and radius) associated with free volume increased in the sterically demanding styrenic monomers, and an increase in fractional free volume (FFV) was also observed (Table S2). Also of note is a decrease in the lifetime associated with the mesoscopic voids in the monoliths from ca. 78 ns in S, to ca. 72 ns in tbus and TMSS-containing monoliths. The lifetime differences between the parent and sterically demanding polymers, a larger variance in fitting, and the BET data suggested that an additional lifetime component due to the presence of microscopic voids could result in better overall analysis and interpretation of the PALS data. Thus, a five-component analysis, including a lifetime component for microporous voids, τ micro, was completed (see main text). PAL spectra for the parent styrenic, mesoporous monolith fit better in the fourcomponent analysis, while the PALS data for the monoliths with sterically demanding monomer fit better with a five component analysis, consistent with the expected difference in hierarchical structures. In the five component analysis, the parent styrenic monolith is consistent with having free volume and mesoporous structures, but may possess a small amount of incidental void volume at the microscale. Notwithstanding, in the five-component analysis, the intensity associated with micropores in the parent may be considered less significant.

14 S14 Table S1. Positronium lifetimes [τ] and intensities [I] for PIMS-derived parent and modified styrenic monoliths using a four-positronium lifetime component analysis. Conditions: ns window, in vacuo, room temperature ( counts collected for each exp. in spectral region). In parentheses are the calculated errors, corresponding to the last place(s) of the reported value. τ 1 τ 2 τ 3 sample file var. (ns) (ns) (ns) (ns) (%) (%) (%) (%) S DV097a 0.015(3) 0.406(4) 2.212(11) 78 (1) 39.3(2) 31.4(2) 22.3(1) 6.93(5) 18 tbus DV097b 0.022(2) 0.397(4) 2.698(10) 73 (2) 41.9(2) 28.8(2) 25.3(1) 3.84(4) TMSS DV097c 0.248(2) 8(4) 2.843(22) 71 (2) 61.6(5) 11.7(3) 23.5(3) 3.03(4) τ 4 I 1 I 2 I 3 I 4

15 S15 Table S2. Estimated free volume, fractional free volume and micro- and meso-pore radii for PIMS-derived parent and modified styrenic monoliths using a four-positronium lifetime component analysis. Conditions: ns window, in vacuo, room temperature. In parentheses are the calculated errors, corresponding to the last place(s) of the reported value. sample file τ 3 I 3 R fv ffv (ns) (%) (Å) (Å 3 model a τ 4 I 4 R ) (%) (ns) (%) (Å) model a S DV097a 2.212(11) 22.3(1) 3.053(7) 119 (1) 4.79(6) MTE 78 (1) 6.93(5) 20.07(1) MCM tbus DV097b 2.698(10) 25.3(1) 3.442(5) 170 (1) 7.79(7) MTE 73 (2) 3.84(4) 18.98(2) MCM TMSS DV097c 2.843(22) 23.5(3) 3.548(11) 187 (2) 7.91(19) MTE 71 (2) 3.03(4) 18.64(2) MCM a MTE = modified Tao-Eldrup. MCM = modified classical model; a large pore model derived from: Wada, K.; Hyodo, T. A simple shape-free model for pore-size estimation with positron annihilation lifetime spectroscopy. J. Phys. Conf. Ser. 2013, 443, 0120.