Kelkar Parth U, Kaboolian Matthew, Corder Ria D, Caggioni Marco, Lindberg Seth, Erk Kendra A
School of Materials Engineering, Purdue University, West Lafayette, IN, 47907, USA.
School of Mechanical Engineering, Purdue University, West Lafayette, IN, 47907, USA.
Soft Matter. 2024 Apr 17;20(15):3299-3312. doi: 10.1039/d3sm01198d.
Material relationships at low temperatures were determined for concentrated surfactant solutions using a combination of rheological experiments, cross-polarized microscopy, calorimetry, and small angle X-ray scattering. A lamellar structured 70 wt% solution of sodium laureth sulfate in water was used as a model system. At cold temperatures (5 °C and 10 °C), the formation of surfactant crystals resulted in extremely high viscosity. The bulk flow behavior of multi-lamellar vesicles (20 °C) and focal conic defects (90 °C) in the lamellar phase was similar. Shear-induced crystallization at temperatures higher than the equilibrium crystallization temperature range resulted in an unusual complex viscosity peak. The effects of processing-relevant parameters including temperature, cooling time, and applied shear were investigated. Knowledge of key low-temperature structure-property-processing relationships for concentrated feedstocks is essential for the sustainable design and manufacturing of surfactant-based consumer products for applications such as cold-water laundry.
通过流变学实验、交叉偏振显微镜、量热法和小角X射线散射相结合的方法，确定了低温下浓缩表面活性剂溶液的材料关系。以水相中70 wt%的月桂醇聚醚硫酸酯钠层状结构溶液作为模型体系。在低温（5°C和10°C）下，表面活性剂晶体的形成导致极高的粘度。层状相中多泡囊（20°C）和焦锥缺陷（90°C）的整体流动行为相似。在高于平衡结晶温度范围的温度下，剪切诱导结晶导致异常的复数粘度峰值。研究了包括温度、冷却时间和施加剪切力在内的与加工相关参数的影响。了解浓缩原料关键的低温结构-性能-加工关系对于可持续设计和制造用于冷水洗涤等应用的基于表面活性剂的消费品至关重要。
