纳米碳管对蠕虫状胶束流体流变特性的影响

采用流变学方法考察了纳米碳管种类、加量、矿化度及温度对CTAC NaSal蠕虫状胶束溶液流变性能的影响，并结合冷冻蚀刻电镜方法探讨了纳米碳管对黏弹性流体的改性机理。结果表明，纳米碳管与黏弹性胶束之间形成的复杂网络结构改善了体系的黏弹性。其中羟基含量高、长/径比大的多壁纳米碳管的增黏效果最好，纳米碳管的最优加量为04%，此时可使改性体系的零剪切黏度提高22倍。在低振荡频率下，纳米碳管对CTAC NaSal黏弹性胶束的增稠作用更明显，不仅松弛时间明显延长，体系的黏性和弹性也得到改善。纳米碳管还能提高CTAC NaSal黏弹性胶束的高温热稳定性，80℃下、剪切速率170 s-1时，纳米碳管改性CTAC NaSal黏弹性胶束溶液的黏度仍能保持在50 mPa·s以上。随着温度的升高，该体系的黏弹性逐渐降低，60℃以上呈黏性流体。

Effect of Carbon Nanotubes on Rheological Properties of Wormlike Micelle Solution

The rheological properties of cetyltrimethylammonium chloride (CTAC) sodium salicylata (NaSal) wormlike micelle solution with multi walled carbon nanotube (MWNT) added were studied by rheological measurements and cryo transmission electron microscopy (cryo TEM). The effects of different types of MWNT, the addition mass fraction of MWNT, total dissolved solid and temperature on the rheological properties of wormlike micelle solution were investigated. The results showed that the viscosity of the wormlike micelle solution was increased significantly because of forming a micelle MWNT pseudo crosslink network. The MWNT with high —OH mass fraction and large aspect ratio possessed better thickening efficiency. The zero shear viscosity of the solution with 04% mass fraction MWNT, which was the optimal addition amount, was about 22 times that of the base fluids. The viscoelasticity of the wormlike micelle solution was improved significantly at low frequency with the relaxation time of fluids being prolonged and the thermal stability being enhanced after addition of MWNT. The apparent viscosity of was still more than 50 mPa·s at 80℃ and 170 s-1. With the increase of temperature the viscoelasticity of the MWNT modified CTAC NaSal viscoelastic solution decreased gradually, to become a viscous fluid when the temperature exceeded 60℃.