DOI: 10.5061/dryad.1vhhmgr4r
title: Photoinduced Morphology Change in Ionic Supramolecular Block Copolymer

description: Physically mixing two dissimilar polymers often results in a
 macroscopically segregated blend with poor optical clarity and mechanical
 properties. Previously, we demonstrated that chain end functionalization
 of immiscible polymer blends with oppositely paired acid and base groups
 leads to an ionic supramolecular block copolymer with electrostatically
 stabilized microdomains that suppress macroscopic phase separation. In
 this work, a functionalized polydimethylsiloxane with a photochromic
 diarylethene (DAE) end-group (PDMS-ω-DAE) is blended with a sulfonic acid
 end-functionalized polystyrene (PS-ω-SO3H), forming an ionic
 supramolecular block copolymer with tunable morphology by light. When the
 DAE is irradiated with UV light, it triggers an isomerization from the
 ring-opened (DAE–O) to the ring-closed (DAE–C) form. The light-induced
 conformational change in the chain-end group chemistry substantially
 alters the ionic junctions, leading to a phase structure difference in the
 solid-state from hexagonally packed cylinders (HEX) to lamellae (LAM).
 After UV radiation, the more localized positive charge on DAE–C led to
 stronger ionic bonds between the two dissimilar blocks, while the
 repulsion between adjacent DAE–C groups increased. The stronger
 electrostatic repulsion along the interface resulted in increased
 interfacial area per polymer chain and thus induced such phase transition.
 The light-induced phase transition of this system demonstrates that the
 ionic interactions can be tuned on-demand to create different morphologies
 from a single polymer blend.
description: Methods<br>-------------------------------------------------------------------------------------------<br>Solution-State Characterization. 1H and 13C NMR spectra were recorded on a Bruker 500 MHz NMR spectrometer using CDCl3 as the solvent. <br>Chemical shifts are reported relative to residual solvent peaks (δ 7.26 ppm for CDCl3 in 1H NMR and δ 77.05 for CDCl3 in 13C NMR).  Size-exclusion chromatography (SEC) was obtained with a Waters SEC system equipped with a refractive index detector and <br>Agilent PLgel 5 μm MiniMIX-D column at 35 °C with THF as the eluent. Molecular weight distribution was estimated by a series of polystyrene standards.  Mass spectral data was collected on the Shimadzu LCMS-9030 Q-TOF Mass Spectrometer with an electrospray ionization (ESI) source.  Matrix-assisted laser desorption ionization (MALDI-TOF) mass spectrometry. MALDI-TOF experiments were performed using a <br>Bruker Microflex MALDI-TOF mass spectrometer (Bruker Daltonics). Samples were prepared in tetrahydrofuran at 5 mg/ml. <br>Trans-2-[3-(4-tert-Butyl-phenyl)-2-methyl-2-propenylidene] malononitrile (DCTB) (10 mg/mL) and potassium trifluoroacetic acid (KTFA) (10 mg/ml)<br>were used as a matrix and cationization agent respectively. One microliter of sample, 1 µl of KTFA, and 20 µl of DCTB were mixed thoroughly. <br>About 0.5 µl of this mixture was deposited on a stainless-steel sample holder. Fourier-Transform Infrared Spectroscopy (FTIR). FTIR measurements were performed on a Thermo Nicolet iS10 spectrometer equipped with a Smart Diamond <br>attenuated total reflectance (ATR) accessory. A background spectrum was obtained every 30 minutes, and sample spectra were taken using 64 scans in absorbance mode. UV-Vis Spectroscopy and UV-Vis Kinetic Measurements. UV-Vis absorption spectra were recorded on Agilent 8453 UV-Vis spectrometer. <br>The switching kinetics of PS-ω-SO3−/ PDMS-ω-DAE-H+–O ionic blend was measured on a home-built pump-probe setup, as previously reported by our group.<br>The UV pump source was generated by a Deep UV LED (Thorlabs M300F2, 300 nm), positioned to illuminate the sample directly without coupling into a multimode <br>optical fiber (≈1.32 mW/cm2). The probe beam was generated by a high-power MINI Deuterium Tungsten Halogen Source w/shutter 200–2000 nm (Ocean Optics DH-MINI) <br>coupled into a multimode fiber with an output collimator for the light delivery. The probe light was modulated by a shutter (Uniblitz CS25), which could be <br>controlled manually or through a digital output port (National Instruments USB-6009) using LabVIEW. Pump and probe beams overlapped using steering and focusing optics <br>at a 90° angle inside a sample holder, allowing 10×10 mm2 rectangular spectrophotometer cells to be held within or cast film samples to be held to the front using metal <br>spring clips. The solutions were continuously stirred during the measurements by a miniature stirring plate inserted into the sample holder (Starna Cells SCS 1.11). <br>Both pump and probe beams were nearly collimated inside the cell with a diameter of about 2 mm. The pump beam was blocked after passing through the sample, and the probe <br>beam was directed by a system of lenses into the detector (Ocean Optics Flame-S1-XR spectrometer), which acquired spectra of the probe light. The detector was connected <br>to a PC via a USB port. The experimentwas controlled by a National Instrument LabVIEW program, which collected the probe light spectra, determined sample optical absorption<br>spectra, controlled pump, and probe light sources. Small-angle X-ray Scattering (SAXS). Samples were loaded into aluminum washers (1 mm thickness) and sealed with Kapton tape. All experiments were performed at the National <br>Synchrotron Light Source II (NSLS-II, beamline 11-BM, Brookhaven National Laboratory), with an X-ray energy of 13.5 keV. The sample to detector distance (3m) was calibrated <br>using a silver behenate standard, and the isotropic 2D scattering patterns were reduced into 1D scattering intensity as a function of the wavevector q = 4π sin(θ/2)/λ, where θ <br>is the scattering angle and λ is the X-ray wavelength. Temperature-dependent SAXS experiments were conducted on selected ionic polymer blends, heated incrementally to 65, 85,<br>95, 105, 120, and 140 °C, followed by an equilibration time of 15 min at each temperature. Transmission Electron Microscopy (TEM). Thin sections (ca. 120 nm) for electron microscopy were obtained by cryo-microtoming at a Leica EM UC 7 at −100 °C to −80 °C and <br>collected on 200-mesh copper grids. TEM experiments were performed on Talos™ F200X G2 TEM at an acceleration voltage of 200 keV.
description: # Photoinduced morphology change in ionic supramolecular block copolymer
 [https://doi.org/10.5061/dryad.1vhhmgr4r](https://doi.org/10.5061/dryad.1vhhmgr4r) ## Description of the data and file structure Data from peer-reviewed article: Title: Photoinduced morphology change in ionic supramolecular block copolymer Journal: Polymer Chemistry Authors: Kseniia M. Karnaukh‡, Shuyi Xie‡, Kai-Chieh Yang, Komal Komal, Rachel A. Segalman* and Javier Read de Alaniz* ‡co-first author Corresponding author: Javier Read de Alaniz (javier@chem.ucsb.edu), Rachel A. Segalman (segalman@ucsb.edu) \------------------------------------------------------------------------------------------- Data files are organized into the folder: with the manuscript and supporting information. All data can be opened as a .csv file using Excel. Figures that are illustrations will not be included in the folders. This includes Fig. 1, Fig. 2a, and Figure 4a and b. File List A) Fig2b.csv B) Fig2c.csv C) Fig3a_TEMImage_HEX.png D) Fig3b_TEMImage_LAM.png E) Fig3a.csv F) Fig3b.csv G) Fig5a.csv H) Fig5b.csv I) FigS1.csv J) FigS2.csv K) FigS3.csv L) FigS4.csv M) FigS5.csv N) FigS6.csv O) FigS7a1.csv P) FigS7a2.csv Q) FigS8.csv R) FigS9a.csv S) FigS9b.csv T) FigS10.csv U) FigS11a.csv V) FigS11b.csv W) FigS12.csv X) FigS13a.csv Y) FigS13b.csv Z) FigS13c.csv FIGURE 2: UV-Vis Spectroscopy of PS-ω-SO3−/PDMS-ω-DAE-H+ blend \------------------------------------------------------------------------------------------- A) Fig2b.csv: UV-Vis Spectra before (Open) and after UV irradiation (Closed) \- Row 1: X and Y axes, corresponding to Wavelength (nm) and Absorbance (AU)/Norm. Absorbance \- Row 2: Open/Closed form \- dataset 1: Open - Wavelength (X) and Absorbance (Y) -&gt; Columns A + B \- dataset 2: Open - Wavelength (X) and Norm. Absorbance (Y) -&gt; Columns A + C \- dataset 3: Closed - Wavelength (X) and Absorbance (Y) -&gt; Columns A + D \- dataset 4: Closed - Wavelength (X) and Norm. Absorbance (Y) -&gt; Columns A + E B) Fig2c.csv: Time-dependent UV-Vis spectroscopy of PS-ω-SO3−/PDMS-ω-DAE-H+ blend in THF solution \- Column A: Time (hrs) \- Column B: Norm. Absorbance at 660 nm \------------------------------------------------------------------------------------------- FIGURE 3: TEM and SAXS of Ionic Blends before and after UV Irradiation \------------------------------------------------------------------------------------------- C) Fig3a_TEMImage_HEX.png: TEM image of the blend before UV irradiation (HEX morphology) D) Fig3b_TEMImage_LAM.png: TEM image of the blend after UV irradiation (LAM morphology) E) Fig3a.csv: SAXS of the blend before UV irradiation (HEX morphology) \- Column A: scattering vector, q \- Column B: scattering intensity, I(q) \- Column C: error bar, dI(q) F) Fig3b.csv: SAXS of the blend after UV irradiation (LAM morphology) \- Column A: scattering vector, q \- Column B: scattering intensity, I(q) \- Column C: error bar, dI(q) \------------------------------------------------------------------------------------------- FIGURE 5: Microstructure Domain Sizes as a Function of Temperature \------------------------------------------------------------------------------------------- G) Fig5a.csv: Microstructure domain sizes as a function of temperature \- Row 1: X and Y axes, corresponding to Temperature (°C) and Domain size, D (nm) \- Row 2: Type of self-assembled system with corresponding microstructure \- dataset 1: BCP (LAM) - Temperature (X) and Domain size (Y) -&gt; Columns A + B \- dataset 2: DAE–C (LAM) - Temperature (X) and Domain size (Y) -&gt; Columns A + C \- dataset 3: Imidazole (LAM) - Temperature (X) and Domain size (Y) -&gt; Columns A + D \- dataset 4: DAE–O (HEX) - Temperature (X) and Domain size (Y) -&gt; Columns A + E H) Fig5b.csv: Normalized blends domain sizes as a function of temperature \- Row 1: X and Y axes, corresponding to Temperature (°C) and Normalized Domain Size of Blends, D/D0 \- Row 2: Type of self-assembled system with corresponding microstructure \- dataset 1: DAE–C (LAM) - Temperature (X) and D/D0 (Y) -&gt; Columns A + B \- dataset 2: Imidazole (LAM) - Temperature (X) and D/D0 (Y) -&gt; Columns A + C \- dataset 3: DAE–O (HEX) - Temperature (X) and D/D0 (Y) -&gt; Columns A + D \------------------------------------------------------------------------------------------- FIGURE S1: 1H NMR spectrum of 2-(3-(4,5-bis(2-methyl-5-phenylthiophen-3-yl)-1H-imidazol-1- yl)propyl)isoindoline-1,3-dione \------------------------------------------------------------------------------------------- I) FigS1.csv \- Column 1: 1H (ppm) \- Column 2: signal/arbitrary intensity \------------------------------------------------------------------------------------------- FIGURE S2: 13C NMR spectrum of 2-(3-(4,5-bis(2-methyl-5-phenylthiophen-3-yl)-1H-imidazol-1- yl)propyl)isoindoline-1,3-dione \------------------------------------------------------------------------------------------- J) FigS2.csv \- Column 1: 1H (ppm) \- Column 2: signal/arbitrary intensity \------------------------------------------------------------------------------------------- FIGURE S3: 1H NMR spectrum of 3-(4,5-bis(2-methyl-5-phenylthiophen-3-yl)-1H-imidazol-1- yl)propan-1-amine (DAE-NH2) \------------------------------------------------------------------------------------------- K) FigS3.csv \- Column 1: 1H (ppm) \- Column 2: signal/arbitrary intensity \------------------------------------------------------------------------------------------- FIGURE S4: 13C NMR spectrum of 3-(4,5-bis(2-methyl-5-phenylthiophen-3-yl)-1H-imidazol-1- yl)propan-1-amine (DAE-NH2) \------------------------------------------------------------------------------------------- L) FigS4.csv \- Column 1: 1H (ppm) \- Column 2: signal/arbitrary intensity \------------------------------------------------------------------------------------------- FIGURE S5: 1H NMR spectrum of 3-mercaptopropanyl-N-hydroxysuccinimide ester chain-end functionalized PDMS \------------------------------------------------------------------------------------------- M) FigS5.csv \- Column 1: 1H (ppm) \- Column 2: signal/arbitrary intensity \------------------------------------------------------------------------------------------- FIGURE S6: 1H NMR spectrum of PDMS-ω-DAE \------------------------------------------------------------------------------------------- N) FigS6.csv \- Column 1: 1H (ppm) \- Column 2: signal/arbitrary intensity \------------------------------------------------------------------------------------------- FIGURE S7: Compassion of 1H NMR spectra \------------------------------------------------------------------------------------------- O) FigS7a1.csv: 1H NMR spectra of PDMS-ω-DAE \- Column 1: 1H (ppm) \- Column 2: signal/arbitrary intensity P) FigS7a2.csv: PS-ω-SO3–/PDMS-ω-DAE-H+–O ionic copolymer \- Column 1: 1H (ppm) \- Column 2: signal/arbitrary intensity \------------------------------------------------------------------------------------------- FIGURE S8: 1H NMR spectrum of PS-b-PDMS \------------------------------------------------------------------------------------------- Q) FigS8.csv \- Column 1: 1H (ppm) \- Column 2: signal/arbitrary intensity \------------------------------------------------------------------------------------------- FIGURE S9: MALDI Spectra \------------------------------------------------------------------------------------------- R) FigS9a.csv: MALDI spectrum of PS-ω-SO3H, m/z = 3944.681 + K \- Column A: Intensity (a.u.) \- Column B: m/z S) FigS9b.csv: MALDI spectrum of PDMS-ω-DAE, m/z = 7254.838 + K \- Column A: Intensity (a.u.) \- Column B: m/z \------------------------------------------------------------------------------------------- FIGURE S10: FTIR Spectra \------------------------------------------------------------------------------------------- T) FigS10.csv: Absorbance vs. Wavelength (nm) \- Row 1: X and Y axes, corresponding to Wavelength (nm) and Absorbance \- Row 2: Type of polymer or ionic blend \- dataset 1: PDMS-w-DAE - Wavelength (X) and Absorbance (Y) -&gt; Columns A + B \- dataset 2: PDMS-w-SO3H - Wavelength (X) and Absorbance (Y) -&gt; Columns A + C \- dataset 3: Ionic Blend - Wavelength (X) and Absorbance (Y) -&gt; Columns A + D FIGURE S11: SEC Traces \------------------------------------------------------------------------------------------- U) FigS11a.csv: SEC traces of PS-w-SO3H-4.1 kDa \- Column A: Elution Time (min) \- Column B: RI Signal (a.u.) \- Column C: Normalized RI V) FigS11b.csv: SEC of PS-w-SH-3.9 kDa \- Column A: Elution Time (min) \- Column B: RI Signal (a.u.) \- Column C: Normalized RI \------------------------------------------------------------------------------------------- FIGURE S12: SEC Trace \------------------------------------------------------------------------------------------- W) FigS12.csv: SEC trace of PS-b-PDMS synthesized by thiol-ene click reaction \- Column A: Elution Time (min) \- Column B: RI Signal (a.u.) \- Column C: Normalized RI \------------------------------------------------------------------------------------------- FIGURE S13: SAXS Profiles \------------------------------------------------------------------------------------------- X) FigS13a Folder: Contains .csv files with SAXS profiles of PS-b-PDMS at different temperatures, ranging from 25°C to 140°C \- Column A: Scattering Vector, q \- Column B: Scattering Intensity, I(q) \- Column C: Error Bar, dI(q) Y) FigS13b Folder: Contains .csv files with SAXS profiles of PS-ω-SO3−/PDMS-ω-DAE-H+–O at different temperatures, ranging from 25°C to 140°C \- Column A: Scattering Vector, q \- Column B: Scattering Intensity, I(q) \- Column C: Error Bar, dI(q) Z) FigS13c Folder: Contains .csv files with SAXS profiles of PS-ω-SO3−/PDMS-ω-DAE-H+–C at different temperatures, ranging from 25°C to 140°C \- Column A: Scattering Vector, q \- Column B: Scattering Intensity, I(q) \- Column C: Error Bar, dI(q) \-------------------------------------------------------------------------------------------