A Conjugated Polyelectrolyte-Based New Strategy. for In Situ Detection of Carbon Dioxide

Transcription

1 Supporting Information A Conjugated Polyelectrolyte-Based New Strategy for In Situ Detection of Carbon Dioxide Yibing Fan, Chengfen Xing, *, Hongbo Yuan, Ran Chai, Linfei Zhao, and Yong Zhan Key Laboratory of Hebei Province for Molecular Biophysics, Institute of Biophysics, Hebei University of Technology. Tianjin , P.R. China. School of Materials Science and Engineering, Hebei University of Technology. Tianjin , P.R. China. xingc@hebut.edu.cn. S-1

2 Experimental Section Materials and Measurements: The chemicals were purchased from Acros, Aladdin or Alfa Aesar and used as received if not specially stated. All organic solvents were purchased from Tianjin Guangfu Ltd. CO 2 was obtained from Tianjin Lianbo Ltd with a purity of 99.99%. All solutions were prepared with Milli-Q water. The fluorescence spectra were taken on a Hitachi F-4600 fluorimeter equipped with a Xenon lamp excitation source. Dynamic light scattering (DLS) experiments and ζ Potentials were carried out on Nano-S90 (Malvern Instruments, UK). AFM images were taken by CSPM 5000 scanning probe microscope in tapping mode and SEM images were observed by a NOVA NANOSEM 450 (FEI, USA) field-emission scanning electron microscope. Photographs were taken with a Canon EOS-600D digital camera. Synthesis of PFBT: A mixture of the monomer 1 (100 mg, mmol), monomer 2 (2.06 mg, mmol) and 1,4-bis(5,5-dimethyl-1,3,2-dioxaborinan-2-yl)benzene (40.77 mg, mmol) in 3 ml of toluene and 2 ml of 2.0 M Na 2 CO 3 was degassed and Pd(dppf)Cl 2 (10 mg) was subsequently added in nitrogen stream. The resulted mixture was vigorously stirred at 85 C for 2 days. After cooling to room temperature, the resulting solution was poured into acetone to get the precipitate, and then redissolved in methanol and a solution of NaOH (0.3 g, 7.5 mmol) in 3 ml of water was added, stirring at 50 C for 12 h. After cooling to room temperature, methanol was removed. The mixture was dialyzed against water using a membrane with a molecular weight cut-off of 3500 for three days to yield 58.8 mg of PFBT (67.13%). 1 H NMR (400 MHz, D 2 O/Na 2 CO 3 ): δ (br, 8H), 3.51 (br, 2H), (br, 13H), (br, 8H), (br, 18H), 1.0 (br,4h), 0.90 (br,4h). FT-IR (KBr cm -1 ):3410, 3036, 2918, 1586, 1468, 1357, 1177, 1004, 806, 594. S-2

3 Preparation of CO 2 Saturated ddh 2 O: To ml of pre-cooling ddh 2 O were bubbled CO 2 (99.99% purity) at a constant flow rate of 1.0 ml/min for no less than 60 minutes, storing the solution on ice. According to the Lange's Handbook of Chemistry. 1 the concentration of CO 2 contained in the CO 2 saturated ddh 2 O is mm at 0 ºC. Detection of CO 2 in Water: To a series of CO 2 solutions (500 µl) with various concentrations were added 10.0 µg/ml of PFBT respectively. After 5.0 min of incubation, the fluorescence spectra were measured in 300 µl quartz cuvettes at 4ºC. The scan speed was 2400 nm/min. The solutions with different concentrations of CO 2 were prepared by mixing various volumes of CO 2 saturated solutions with pre-cooling ddh 2 O. Detection of gaseous CO 2 : To a series of mixed gas with different volumes of CO 2 were bubbled into 10.0 µg/ml of PFBT solutions (500 µl) directly at a constant flow rate of 1.0 ml/min for different times, and the fluorescence spectra were measured in 300 µl quartz cuvettes at 4 ºC with the scan speed of 2400 nm/min by the Hitachi F-4600 fluorimeter combining with a recirculating chiller F-305 (BÜCHI) to control the temperature. Detection of CO 2 by composite film: 10.0 µg/ml of PFBT was sprayed onto a substrate of the cellulose ester film. After 5.0 min of exposure to a CO 2 atmosphere, the images were taken under UV light (λ = 365 nm). Detection of CO 2 in photosynthesis in situ: 10.0 µg/ml of PFBT solution (500 µl) was put in the greenhouse which was closed the windows and shut down the ventilation system, and the fluorescence spectra were measured in 300 µl quartz cuvettes after 5 min of incubation. The samples were measured at different times in the greenhouse from 21:00 to 10:00 upon cycling day and night in situ. S-3

4 Morphology study of PFBT in the absence and presence of CO 2 : To a CO 2 saturated solution was added 10.0 µg/ml of PFBT. After the mixture was incubated for 5.0 min at room temperature, 3.0 µl of the sample was placed on a mica wafer for 15 min and then dried at room temperature overnight for AFM studies (5500 atomic force microscope, Agilent, USA, operated in the tapping mode). The blank experiment was carried out in the absence of CO 2 under the same conditions. SEM images were taken on a NOVA NANOSEM 450 (FEI, USA) emission scanning electron microscope. Scheme S1. Charge changes of PFBT upon bubbling with CO 2 Scheme S2. Schematic Preparation of PFBT S-4

5 Table S1. ζ Potentials of PFBT in ddh 2 O and saturated carbon dioxide solution. [PFBT] = 10 µg/ml at 4.0 C ζ Potentials (mv) PFBT ± 0.41 PFBT+CO ± 1.06 Figure S1. The thermal gravimetric analysis (TGA) curve of PFBT. S-5

6 Figure S2. UV-vis absorption and emission spectra of PFBT in ddh 2 O. The excitation wavelength is 380nm. Figure S3. Dynamaic light scattering analysis of PFBT in aqueous solution in the absence and presence of CO 2 at a) 4 ºC, and b) 25 ºC. [PFBT] = 10 µg/ml. S-6

7 Figure S4. SEM images of PFBT in the a) absence and b) presence of CO2 at room temperature. [PFBT] = 5.0 µg/ml Figure S5. SEM images of composite film in the a) absence and b) presence of CO2 at room temperature. [PFBT] = 10 µg/ml References (1) J. A. Dean, Lange's Handbook of Chemistry, 10th ed, McGraw-Hill, U.S S-7