Ionic Conductivity through Thermoresponsive Polymer Gel: Ordering Matters

Thermoreversible polymer gel has been prepared using PEO–PPO–PEO block copolymer (Pluronic F77) which self-assembles into different microcrystalline phases like cubic, 2D-hexagonal, and lamellar. Addition of electrolyte (LiI/I2) converts the gel into a polymer gel electrolyte (PGE) which exhibits microphase-dependent ionic conductivity. The crystalline phases have been identified by SAXS as a function of the polymer concentration. It is found that the optimum value for the ionic conductivity (≈1 × 10–3 S.cm–1) is achieved in the Im3m phase due to faster diffusion of ions through the 3D-interconnected micellar nanochannels. This fact is further supported by FTIR study, ionic transference number, and diffusion coefficient measurements

Quantification of the Dissolved Inorganic Carbon Species and of the pH of Alkaline Solutions Exposed to CO₂ under Pressure: A Novel Approach by Raman Scattering

Dissolved inorganic carbon (DIC) content of aqueous systems is a key function of the pH, of the total alkanility (TA), and of the partial pressure of CO₂. However, common analytical techniques used to determine the DIC content in water are unable to operate under high CO₂ pressure. Here, we propose to use Raman spectroscopy as a novel alternative to discriminate and quantitatively monitor the three dissolved inorganic carbon species CO₂(aq), HCO₃^–, and CO₃^2– of alkaline solutions under high CO₂ pressure (from <i>P</i> = 0 to 250 bar at <i>T</i> = 40 °C). In addition, we demonstrate that the pH values can be extracted from the molalities of CO₂(aq) and HCO₃^–. The results are in very good agreement with those obtained from direct spectrophotometric measurements using colored indicators. This novel method presents the great advantage over high pressure conventional techniques of not using breakable electrodes or reference additives and appears of great interest especially in marine biogeochemistry, in carbon capture and storage and in material engineering under high CO₂ pressure

Concentration Mediated Structural Transition of Triblock Copolymer Ultrathin Films

X-ray reflectivity, atomic force microscopy, X-ray photoelectron spectroscopy, and contact angle measurement techniques are used to study the structural changeover as a function of concentration of poly­(ethylene oxide)-poly­(propylene oxide)-poly­(ethylene oxide) (PEO-PPO-PEO) triblock copolymer diluted in toluene spin-coated as ultrathin films on hydrophilic Si substrate. A lamellar structure made of three alternating incomplete bilayers is observed until the concentration of copolymer solution attains a threshold value of about 3.6–4 g/L. Around this concentration and beyond, the entanglement of polymer chains takes place during drying and the growth of a homogeneous film made of complete bilayers on Si substrate is observed. The strong hydrophilic nature of the Si substrate dictates the growth of this amphiphilic copolymer. We evidence that the lower part of the films is made of hydrophilic PEO blocks attached to the substrate while the hydrophobic PPO blocks are directed toward air

Using Three-Dimensional 3D Grazing-Incidence Small-Angle X‑ray Scattering (GISAXS) Analysis To Probe Pore Deformation in Mesoporous Silica Films

In the past decade, remarkable progress has been made in studying nanoscale objects deposited on surfaces by grazing-incidence small-angle X-ray scattering (GISAXS). However, unravelling the structural properties of mesostructured thin films containing highly organized internal three-dimensional (3D) structures remains a challenging issue, because of the lack of efficient algorithms that allow prediction of the GISAXS intensity patterns. Previous attempts to calculate intensities have mostly been limited to cases of two-dimensional (2D) assemblies of nanoparticles at surfaces, or have been adapted to specific 3D cases. Here, we demonstrate that highly organized 3D mesoscale structures (for example, porous networks) can be modeled by the combined use of established crystallography formalism and the Distorted Wave Born Approximation (DWBA). Taking advantage of the near-zero intensity of symmetry-allowed Bragg reflections, the casual extinction or existence of certain reflections related to the anisotropy of the form factor of the pores can be used as a highly sensitive method to extract structural information. We employ this generic method to probe the slightly compressed anisotropic shape and orientation of pores in a mesoporous silica thin film having <i>P</i>6₃/<i>mmc</i> symmetry

CXDI_ESRF_Gephy_ericsonii_RCC4032_NoCorr_fig1C_uint8_126_150_143_32_5

This file contains the tomographic slice images of the coccosphere from the Gephyrocapsa ericsonii RCC4032 species. The data is obtained from 3D-coherent X-ray diffraction images at ESRF on ID10. After the reconstruction, no correction was applied. Each image has a size of 126 by 150. The intensity is coded in 8 bits (uint8). There are 143 images. The voxel size is 32.5 x 32.5 x 32.5 nm3. The data is used in the figure 1C of the article of T. Beuvier et al, Nat. Commun. (2019) (DOI: 10.1038/s41467-019-08635-x).</p

CXDI_ESRF_Emili_huxleyi_RCC1212_NoCorr_fig1CS7B_uint8_244_320_288_32_5

This file contains the tomographic slice images of the coccosphere from the Emiliania huxleyi RCC1212 species. The data is obtained from 3D Coherent X-ray Diffraction Imaging (3D-CXDI) at ESRF on ID10. After the reconstruction, no correction (no Gaussian subtraction) was applied. Each image has a size of 244 by 320. The intensity is coded in 8 bits (uint8). There are 288 images. The voxel size is 32.5 x 32.5 x 32.5 nm3. The data is used in the figures 1C and S7 of the article of T. Beuvier et al, Nat. Commun. (2019) (DOI: 10.1038/s41467-019-08635-x).</p

CXDI_ESRF_Gephy_oceanica_RCC1314_NoCorr_fig1A_uint8_304_304_304_32_5

This file contains the tomographic slice images of the coccosphere from the Gephyrocapsa oceanica RCC1314 species. The data is obtained from 3D-coherent X-ray diffraction images at ESRF on ID10. After the reconstruction, no correction was applied. Each image has a size of 304 by 304. The intensity is coded in 8 bits (uint8). There are 304 images. The voxel size is 32.5 x 32.5 x 32.5 nm3. The data is used in the figure 1A of the article of T. Beuvier et al, Nat. Commun. (2019) (DOI: 10.1038/s41467-019-08635-x)

Anisotropic One-Dimensional Aqueous Polymer Gel Electrolyte for Photoelectrochemical Devices: Improvement in Hydrophobic TiO₂–Dye/Electrolyte Interface

Aqueous photoelectrochemical devices have emerged recently as promising area because of their economic and ecological friendliness. In the present work, we have expedited surface active amphiphilic quasi-solid aqueous polymer gel electrolyte (PGE) with hydrophobic sensitizer SK3 in water-based dye sensitized solar cell (DSSC). PGE was prepared from amphiphilic block copolymer (PEO)–(PPO)–(PEO) with iodide–triiodide couple in pure aqueous media without any organic solvent. This block copolymer, with iodide-triiodide salt exhibits 1D-lamellar microcrystalline phase which shows stability in the temperature range of 25–50 °C. Parallel (||^al) and perpendicular (⊥^ar) alignment of anisotropic lamellar microcrystalline phase pertaining by PGE were characterized and applied in quasi-solid DSSC. Temperature dependency of ionic conductivity, triiodide diffusion, differential scanning calorimetry, viscosity, and 1-D lamellar anisotropic behavior were studied. Surface active effect of PGE at the hydrophobic dye sensitized photoanode was investigated and compared with liquid water based electrolyte. Because of the amphiphilic nature and thermoreversible sol–gel transition of PGE at a lower temperature (0 to −2 °C) allowing PGE to penetrate efficiently inside the hydrophobic surface of dye–TiO₂ and resulted in a fused contact between dye–TiO₂/PGE interface. This aqueous PGE successfully enhances the performance of DSSCs over liquid water based devices by improving their <i>V</i>_oc and stability. Under 0.5 sun illumination, DSSC with 1-D lamellar perpendicularly align PGE shows an efficiency of 2.8% and stability up to 1000 h at 50 °C

CXDI_ESRF_Emili_huxleyi_P41_NoCorr_fig1C_uint8_193_218_206_28_8

This file contains the tomographic slice images of the coccosphere from the Emiliania huxleyi P41 species. The data is obtained from 3D Coherent X-ray Diffraction Imaging (3D-CXDI) at ESRF on ID10. After the reconstruction, no correction (no Gaussian subtraction) was applied. Each image has a size of 193 by 218. The intensity is coded in 8 bits (uint8). There are 206 images. The voxel size is 28.8 x 28.8 x 28.8 nm3. The data is used in the figure 1C of the article of T. Beuvier et al, Nat. Commun. (2019) (DOI: 10.1038/s41467-019-08635-x)

CXDI_ESRF_Gephy_muellerae_RCC3370_NoCorr_fig1C_uint8_240_240_240_32_5

This file contains the tomographic slice images of the coccosphere from the Gephyrocapsa muellerae RCC3370 species. The data is obtained from 3D-coherent X-ray diffraction images at ESRF on ID10. After the reconstruction, no correction was applied. Each image has a size of 240 by 240. The intensity is coded in 8 bits (uint8). There are 240 images. The voxel size is 32.5 x 32.5 x 32.5 nm3. The data is used in the figure 1C of the article of T. Beuvier et al, Nat. Commun. (2019) (DOI: 10.1038/s41467-019-08635-x)