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The C12E8-GO mixtures were measured by small angle X-ray scattering (SAXS) at different concentrations and temperatures and a phase diagram of the different assemblies of C12E8-GO-H2O system could be determined. SAXS profiles of bulk C12E8 sample (at 40 wt%) and C12E8-GO samples (40 wt% C12E8 and 0.8 wt% GO dispersion). The sample with short lateral size GO remained in a spherical micellar phase (L1 phase) , but the sample with large GO transits in a hexagonal phase (H1 phase). In the presence of GO, the phase transitions L1-H1 and H1-V1 (cubic phase) shifted to the low concentration. The presence of water located onto the GO surface at large content, combined with the excluded volume (non-accessible volume) of GO, reduces the available free water molecules for C12E8 leading to a phase transition and reorganization of the micelles of the C12E8 in hexagonal assemblies. The mixtures were also studied by rheo-SANS (experiments carried out at J-Parc) but, interestingly, no phase changes occurred under the shear measurements even for the mixtures prepared at large concentration of GO, only an anisotropy effect of the micelles assembled in hexagonal assembly (H1 phase) was observed. Furthermore, under shear measurements, a slight shift (to low angle value) of the first Bragg reflection related to the hexagonal lattice was observed but cannot be only attributed to the impact of the shear but could more likely related to a change of the concentration of the surfactant due to an evaporation of the solvent in rheological cell during the long rheo-SANS measurements.

【研究分担者】
山田貴壽	国立研究開発法人産業技術総合研究所	材料・化学領域	研究グループ長	(Kakenデータベース)
畠山一翔	国立研究開発法人産業技術総合研究所	材料・化学領域	研究員	(Kakenデータベース)
菅原義之	早稲田大学	理工学術院	教授	(Kakenデータベース)