Supporting Information

Transcription

1 Manuscript for Langmuir Supporting Information Controlling the Fluorescence Behavior of 1-Pyrenesulfonate by Cointercalation with a Surfactant in a Layered Double Hydroxide Ana L. Costa,, Ana C. Gomes, Martyn Pillinger,, * Isabel S. Gonçalves, and J. Sérgio Seixas de Melo, * Coimbra Chemistry Centre, Department of Chemistry, University of Coimbra, Rua Larga, Coimbra, Portugal Department of Chemistry, CICECO - Aveiro Institute of Materials, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal Instrumentation Microanalyses (CHNS) were performed at the University of Aveiro with a Leco TruSpec analyzer. Zn and Al contents were determined by ICP-OES at C.A.C.T.I., the University of Vigo, Spain. Powder XRD was performed with automatic data acquisition (X Pert Data Collector v4.2 software) and monochromatized Cu-K α radiation (λ = Å) using a Philips Analytical Empyrean (θ/2θ) diffractometer equipped with a PIXcel1D detector. Samples were step-scanned with.2º 2θ steps and a counting time of 5 s per step. Scanning electron microscopy (SEM) images were collected using a Hitachi SU-7 microscope operating at 15 kv. Samples were prepared by deposition on aluminum sample holders followed by carbon coating using an Emitech K 95 carbon evaporator. S1

2 Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were performed using Shimadzu TGA-5 and DSC-5 systems at a heating rate of 5 ºC min 1 under air. FT-IR spectra were obtained as KBr pellets using a FTIR Mattson-7 spectrophotometer and recorded from 4 to 3 cm 1. Raman spectra were recorded on a Bruker RFS1/S FT instrument (Nd:YAG laser, 164 nm excitation, InGaAs detector). Solid-state 13 C{ 1 H} cross-polarization (CP) magic-angle spinning (MAS) NMR spectra were recorded at 1.62 MHz on a Bruker Avance 4 spectrometer, using 3.5 µs 1 H 9º pulses, a 2 ms contact time, a spinning rate of 1 khz, and 5 s recycle delays. Chemicals shifts are quoted in ppm relative to TMS. The absorption spectra were recorded on a Cary 5 UV-Vis-NIR spectrophotometer. The solidstate photoluminescence spectra were recorded with a Horiba-Jobin-Ivon SPEX FluoroLog 3 22 spectrometer and were corrected for the instrumental response. The FluoroLog consists of a modular spectrofluorimeter with double grating excitation (range 2-95 nm, optimized in the UV and with a blazed angle at 33 nm) and emission (range 2-95 nm, optimized in the visible and with a blazed angle at 5 nm) monochromators. The bandpass for excitation and emission is 15 nm (values that are continuously adjustable using computer Datamax/32 software) and the wavelength accuracy is ±.5 nm. The excitation source consists of an ozone-free 45 W Xenon lamp and the emission detector is a Hamamatsu R928 Photomultiplier (2-95 nm range), cooled with a Products for Research thermoelectric refrigerated chamber (model PC177CE5), or a Hamamatsu R (9-14 nm range), cooled to 193 K in a liquid nitrogen chamber (Products for Research model PC176TSCE-5), and a photodiode as the reference detector. 1 The solid-state fluorescence spectra were measured either by using a Horiba-Jobin-Yvon integrating sphere or a triangular cuvette (in front-face geometry). Fluorescence decays were measured using a home-built time-correlated single photon counting (TCSPC) apparatus with an IBH NanoLED (with excitation at 282, 311 and 339 nm) as excitation source. Triangular quartz cuvettes were used and the emission, collected at the surface front at right S2

3 angle (9 ) geometry and at magic angle polarization, was detected through a double subtractive Oriel Cornerstone 26 monochromator by a Hamamatsu microchannel plate photomultiplier (R389U-5). The signal acquisition and data processing were performed employing a Becker & Hickl SPC-63 TCSPC module. The fluorescence decays and the instrumental response function (IRF) were collected using 124 channels in a 342 ps/channel scale, until 5 counts at maximum were reached. The full width at half-maximum (fwhm) of the IRF was ns for the nanoled with λ exc = 311 nm,.89 ns with λ exc = 282 nm and ns with λ exc = 339 nm, and found to be highly reproducible with identical system parameters. Deconvolution of the fluorescence decay curves was performed using the modulating function method as implemented by Striker et al. in the SAND program. 2 Additional figures Figure S1. DSC curves for HS-LDH ( ), PS-LDH (------), and PS(11.8%)/HS-LDH ( ). S3

4 Figure S2. FT-Raman spectra in the region 3-18 cm 1 of (a) NO 3 -LDH, (b) NaPS, (c) PS-LDH, (d) NaHS, (e) HS-LDH, and (f) the cointercalated sample PS(11.8%)/HS-LDH. Figure S3. TGA curves for the cointercalated samples PS(x%)/HS-LDH with x% = 1.2% ( ), 2.3% ( ), 4.7% ( ), and 11.8% ( ). S4

5 Figure S4. SEM images for the cointercalated samples PS(x%)/HS-LDH with x% = 11.8% (a), 4.7% (b), 2.3% (c) and 1.2% (d). S5

6 Figure S5. Fluorescence decays collected at the monomer (λ em = 375 nm) emission wavelength for the sample PS(1.2%)/HS-LDH (HS/PS = 82.3) in the solid state at room temperature. (Top panel) λ exc = 282 nm; (Bottom panel) λ exc = 339 nm. For a better judgment of the quality of the fits, autocorrelation functions (A.C.), weighted residuals and χ 2 values are presented. S6

7 12 τ (ns) Fluorescence contribution, C (%) 8 4 C 1 Figure S6. (From left to the right) Decay times and, pre-exponential and factors, and fluorescence contribution obtained with λ exc = 282 nm and emission at 375 nm for different HS/PS τ i (ns) τ A 13. Fluorescence contribution (%) C 1 C 3 Figure S7. (From left to the right) Decay times, and τ 3, pre-exponential, and A 13 factors, and fluorescence contribution obtained with λ exc = 282 nm and emission at 48 nm for different HS/PS S7

8 τ i (ns) τ A 13. Fluorescence contribution (%) C 1 C 3 Figure S8. (From left to the right) Decay times, and τ 3, pre-exponential, and A 13 factors, and fluorescence contribution obtained with λ exc = 282 nm and emission at 52 nm for different HS/PS τ i (ns) τ A 13. Fluorescence contribution (%) C 1 C 3 Figure S9. (From left to the right) Decay times, and τ 3, pre-exponential, and A 13 factors, and fluorescence contribution obtained with λ exc = 311 nm and emission at 48 nm for different HS/PS S8

9 τ i (ns) τ A 13 C Figure S1. (From left to the right) Decay times, and τ 3, pre-exponential, and A 13 factors, and fluorescence contribution obtained with λ exc = 311 nm and emission at 52 nm for different HS/PS Fluorescence contribution (%) C 3 12 τ (ns) Fluorescence contribution, C (%) 8 4 C 1 Figure S11. (From left to the right) Decay times and, pre-exponential and factors, and fluorescence contribution obtained with λ exc = 339 nm and emission at 375 nm for different HS/PS S9

10 τ i (ns) τ A 13. Fluorescence contribution (%) C1 C 3 Figure S12. (From left to the right) Decay times, and τ 3, pre-exponential, and A 13 factors, and fluorescence contribution obtained with λ exc = 339 nm and emission at 48 nm for different HS/PS τ i (ns) τ Fluorescence contribution (%) 1 8 A 13 C C 3 Figure S13. (From left to the right) Decay times, and τ 3, pre-exponential, and A 13 factors, and fluorescence contribution obtained with λ exc = 339 nm and emission at 52 nm for different HS/PS S1

11 Analysis of the Decays with Single Exponential and Dispersive Kinetic Laws Figure S14. Fluorescence decays collected at λ em = 48 and 52 nm for the sample PS(11.8%)/HS- LDH analyzed with a single exponential (top) and double exponential fit. S11

12 Additional analysis with (i) first order (single exponential) and (ii) dispersive kinetics (i) I(t) = A1*exp(-t/t1) + y, with t1=τ (ii) I(t)=I (t)*exp(-k*t)^β), with k=1/τ and <β<1 are presented in Table S1 and Figures S15 and S16 covering the whole range of samples with different HS/PS ratios and in the PS (solid sate) and only with PS in the LDH. Table S1- Lifetimes and beta values recovered from a Dispersive kinetic analysis and a single exponential analysis (with no deconvolution) of the decays for the different PS(x%)/HS-LDH samples obtained with λ exc = 311 nm and λ em = 375 and 48 nm. Dispersive Kinetics Single Exponential β τ(ns) τ (ns) PS(x%)/HS-LDH λ em = 375 nm HS (98.8%) + PS (1.2%) λ em = 48 nm HS (98.8%) + PS (1.2%) HS (97.7%) + PS (2.3%) HS (95.3%) + PS (4.7%) HS (88.2%) + PS (11.8%) LDH + PS PS solid state In the case of the single exponential analysis in figure S15 the poor adjustment of the overall decay is clear, whereas in the case of dispersive kinetic analysis only in the first part of the decay (~1 ns) can the fit be considered reasonable. S12

13 5 4 Experimental Single Exponential decay fit Dispersive kinetics fit Counts HS (97.7%) + PS (2.3%) Time (ns) Figure S15- Fluorescence decays and analysis resulting from a dispersive kinetic analysis (red line) and single exponential analysis (blue line) for the PS(2.3%)/HS-LDH sample obtained with λ exc = 311 nm and λ em = 48 nm. The single exponential analysis in Table S1 (made with the fitting of the decays after time zero (that is, without deconvolution of the decays) leads to significant differences of the major component of the decays when compared with the sum of exponentials. For example in the HS (88.2%) + PS (11.8%) mixture the 36 ns component only represents 37% of the decay, whereas in Table S1 the 31.7 ns component is the major one in the single exponential fit. For example in the HS (88.2%) + PS (11.8%) mixture the 36 ns component only represents 37% of the decay, whereas in Table S1 the 31.7 ns is the major component in the single exponential fit. In the case of the analysis in the 375 nm emission wavelength (figure S16) the lack of a good fit is evident in the first part of the decay (shorter times). S13

14 Counts Experimental Dispersive Kinetics fit Single Exponential fit HS (98.8%) + PS (1.2%) time (ns) Figure S16- Fluorescence decays and analysis resulting from a dispersive kinetic analysis (red line) and single exponential analysis (blue line) for the PS(1.2%)/HS-LDH sample obtained with λ εxc = 311 nm and λ em = 375 nm. References (1) Seixas de Melo, J.; Costa, T.; Francisco, A.; Macanita, A. L.; Gago, S.; Goncalves, I. S. Dynamics of Short as Compared with Long Poly(acrylic acid) Chains Hydrophobically Modified with Pyrene, as Followed by Fluorescence Techniques. Phys. Chem. Chem. Phys. 27, 9, (2) Striker, G.; Subramaniam, V.; Seidel, C. A. M.; Volkmer, A. Photochromicity and Fluorescence Lifetimes of Green Fluorescent Protein. J. Phys. Chem. B 1999, 13, S14