Counteranion-Mediated Intrinsic Healing of Poly(Ionic Liquid) Copolymers

Transcription

1 Supporting Information Counteranion-Mediated Intrinsic Healing of Poly(Ionic Liquid) Copolymers Panlong Guo, Houyu Zhang, Xiaokong Liu and Junqi Sun* State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun , P. R. China * S-1

2 Figure S1. (a) Schematic illustration of the synthesis of the IL/Br monomer (i.e., 1-(2-ethoxyethyl)-3-vinylimidazolium bromide) and its 1 H NMR (D 2 O, 500 MHz) spectrum. (b) 1 H NMR (D 2 O, 600 MHz) spectra of the PIL/Br-co-PEA copolymers at the feed IL/EA monomer ratios of 1:2, 1:1 and 2:1. According to the chemical structure of the PIL/Br-co-PEA copolymer (Figure S1b), the IL/EA monomer ratios in the copolymers equal to the ratios between the -CH 2 - groups at position a (or the -CH 2 - groups at position b ) and the -CH 2 - groups at position c. The NMR peaks corresponding to the -CH 2 - groups at position a, b and c are labelled as peak a, b and c, respectively, in Figure S1b. It can be found that peak b is well separated from peaks a and c, while peaks a and c are overlapped. Nevertheless, the amount of -CH 2 - groups at position a is exactly the same as that of the -CH 2 - groups at position b. Therefore, The IL/EA molar ratios in the copolymers can be calculated by the following equation: S b /(S a +S c -S b ), where S a, S b and S c represent the relative areas of peak a, b and c, respectively. Accordingly, the IL/EA unit ratios in the PIL/Br-co-PEA copolymers prepared from IL/EA feed ratios of 2:1, 1:1, and 1:2 are calculated to be 2:1.2, 1:1.1 and 1:2.2, respectively. S-2

3 Figure S2. (a) Schematic sketch of the molecular structure of the PIL 1 /X-co-PEA 1 copolymers and their 1 H NMR (DMSO-d6, 500 MHz) spectra when X is TFSI, FSI, Tf and Br. (b) FTIR spectra of the PIL 1 /X-co-PEA 1 copolymers when X is TFSI, FSI, Tf and Br. The 1 H-NMR spectra of the copolymers shown in Figure S2a indicate that the C2-proton peak of the imidazolium cation associated with Br shifts to a lower chemical shift when Br is replaced with Tf, FSI, or TFSI, verifying the successful substitution of Br with Tf, FSI, or TFSI after the ion-exchange process. 1 Figure S2b shows the FT-IR spectra of the PIL 1 /X-co-PEA 1 copolymers when X is Br, Tf, FSI and TFSI. In all the spectra of the copolymers, the IR adsorption bands located at 1550 cm -1 and those situated between 2800 cm -1 and 3300 cm -1 are attributed to the imidazolium cations. 2 After replacing Br with Tf, FSI or TFSI in the PIL/X-co-PEA copolymers, the disappearance of the aromatic C H stretching bands of C H Br at 3055 cm -1 was observed with the appearance of the characteristic IR adsorption bands attributed to Tf (1257, 1161, 1030 and 755 cm -1 ), FSI (1378, 1360, 1178, 1105 and 830 cm -1 ) or TFSI (1351, 1194, 1057 and 570 cm -1 ). 3 The IR adsorption bands at 1730 cm -1 are attributed to the carbonyl groups from the PEA side chains. 4 S-3

4 Table S1. Summary of the molecular weights (M w ) and polydispersity indices of the various PIL copolymers. [a] M w was determined by GPC calibrated with polystyrene standards using DMF as eluents in which lithium salts containing the same anions as the ionic liquid units are added. Polymer M w, GPC [a] PDI ( M w /M n [a] ) PIL 2 /Br-co-PEA PIL 1 /Br-co-PEA PIL 1 /Br-co-PEA PIL 1 / Tf-co-PEA PIL 1 /FSI-co-PEA PIL 1 /TFSI-co-PEA Figure S3. (a) Schematic sketch of the molecular structure of the PVI-co-PEA copolymer and its 1 H NMR spectrum. (b) DSC spectrum of the PVI-co-PEA copolymer. (c) A series of photos exhibiting that the PVI-co-PEA copolymer cuboid after cut cannot be healed at 130 ºC for 7.5 h. S-4

5 Figure S4. (a, b) FTIR spectra of the PIL 1 /Br-co-PEA 1 (a) and PIL 1 /TFSI-co-PEA 1 (b) copolymers measured at varied temperatures. To verify whether there are hydrogen-bonding interactions between the C2 protons of the imidazolium ring and the carbonyl groups of the EA moieties in/between the PIL-co-PEA copolymers, FTIR analysis on the PIL 1 /Br-co-PEA 1 and PIL 1 /TFSI-co-PEA 1 copolymers at varied temperatures was conducted. The characteristic adsorption bands attributed to the carbonyl groups of the copolymers do not shift with temperature, suggesting that there are minimal hydrogen-bonding interactions in/between the copolymers. 5,6 Figure S5. (a) A series of photos exhibiting that the PIL/TFSI homopolymer cuboid after cut can be well healed at 150 C for 7.5 h. (b) A series of photos exhibiting that no healing performance is observed for the PIL/Br homopolymer after being incubated at 200 C for 7.5 h. S-5

6 Reference: (1) Wulf, A.; Fumino, K.; Ludwig, R. Spectroscopic Evidence for an Enhanced Anion-Cation Interaction from Hydrogen Bonding in Pure Imidazolium Ionic Liquids. Angew. Chem. Int. Ed. 2010, 49, (2) Yin, K.; Zhang, Z.; Li, X.; Yang, L.; Tachibana, K.; Hirano, S.-i. Polymer Electrolytes Based on Dicationic Polymeric Ionic Liquids: Application in Lithium Metal Batteries. J. Mater. Chem. A 2015, 3, (3) Ye, Y.; Elabd, Y. A. Anion Exchanged Polymerized Ionic Liquids: High Free Volume Single Ion Conductors. Polymer 2011, 52, (4) Zhang, H.; Li, L.; Feng, W.; Zhou, Z.; Nie, J. Polymeric Ionic Liquids Based on Ether Functionalized Ammoniums and Perfluorinated Sulfonimides. Polymer 2014, 55, (5) Bai, B.; Wang, H.; Xin, H.; Zhang, F.; Long, B.; Zhang, X.; Qu, S.; Li, M. Hydrazide-Based Organogels and Liquid Crystals with Columnar Order. New J. Chem. 2007, 31, 401. (6) Zhang, P.; Wang, H.; Liu, H.; Li, M. Fluorescence-Enhanced Organogels and mesomorphic superstructure based on hydrazine derivatives. Langmuir. 2010, 26, S-6