关键词: 海藻酸钠, 表面活性剂, 聚合物-表面活性剂作用, 剪切粘度

Abstract: Interactions between the anionic polyelectrolyte sodium alginate (NaAlg) and the anionic surfactant sodium dodecyl sulfate (SDS), the cationic surfactant cetyltrimethylammoniumbromide (CTAB), non-ionic surfactants octylphenol polyethoxylates (TritonX-100) as well as their compounded system were investigated by viscosity measurement techniques at different pH values in dilute solution. A hydrophobic interaction was observed in NaAlg/SDS and NaAlg/TritonX-100 aqueous solutions. By increasing the surfactant concentration the zero-shear viscosity initially decreased and then remained almost unchanged. However, the strong association between NaAlg and CTAB was affected by an electrostatic attraction and also a hydrophobic interaction. In acidic solution, the zero-shear viscosity initially increased and then decreased as the CTAB concentration increased. At a TritonX-100 concentration of 0.05 mmol·L-1, the zero-shear viscosity decreased upon addition of SDS for the NaAlg/TritonX-100 system under laboratory conditions. Upon addition of CTAB, the zero shear viscosity of NaAlg/TritonX-100 system increased at pH 3.0 and 5.0 but decreased at pH 6.4.

Key words: Sodium alginate, Surfactant, Polymer-surfactant interaction, Shear viscosity