The formation of multilamellar vesicles (MLVs) in the lyotropic lamellar phase of the system triethylene glycol mono n-decyl ether (C₁₀E₃)/water is investigated under large amplitude oscillatory shear (LAOS) using spatially resolved rheo-NMR spectroscopy and a combination of rheo-small angle light scattering (rheo-SALS) and conventional rheology. Recent advances in rheo-NMR hardware development facilitated the application of LAOS deformations in high-field NMR magnets. For the range of investigated strain amplitudes (10–50) and frequencies (1 and 2 rad s^–1), MLV formation is observed in all NMR and most SALS experiments. It is found that the MLV size depends on the applied frequency in contrast to previous steady shear experiments where the shear rate is the controlling parameter. The onset of MLV formation, however, is found to vary with the shear amplitude. The LAOS measurements bear no indication of the intermediate structures resembling aligned multilamellar cylinders observed in steady shear experiments. Lissajous curves of stress vs strain reveal a transition from a viscoelastic solid material to a pseudoplastic material.

中文翻译：

---

大振幅振荡剪切下Rheo-NMR和Rheo-SALS探测多层囊泡形成

使用空间分辨的rheo-NMR光谱和质谱分析了在大振幅振荡剪切（LAOS）下三甘醇单正癸醚（C ₁₀ E ₃）/水系统的溶致层状相中多层囊泡（MLV）的形成。流变小角度光散射（rheo-SALS）与常规流变学的结合。流变核磁共振硬件开发的最新进展促进了LAOS变形在高场核磁共振磁体中的应用。对于所研究的应变幅度（10–50）和频率（1和2 rad s ^{–1）的范围}），在所有NMR和大多数SALS实验中都观察到了MLV的形成。发现与先前的稳态剪切实验相反，MLV大小取决于所施加的频率，在先前的稳态剪切实验中，剪切速率是控制参数。然而，发现MLV形成的开始随剪切振幅而变化。LAOS测量没有迹象表明在稳定剪切实验中观察到的中间结构类似于对齐的多层圆柱体。应力与应变的李萨如曲线显示了从粘弹性固体材料到假塑性材料的过渡。