C_(12)-3-C_(12)·2Br及C_(12)-3(OH)-C_(12)·2Br水溶液的胶团聚集数及流变特征

Micelle Aggregation Numbers and Rheological Characterization of C_(12)-3-C_(12)·2Br and C_(12)-3(OH)-C_(12)·2Br in Aqueous Solution

采用荧光探针法测定了C12-3-C12·2Br及C12-3(OH)-C12·2Br Gemini表面活性剂胶团聚集数,结果表明,浓度极大影响其胶团聚集数,当浓度为各自临界胶团浓度的5.5倍时,由于联结链中羟基的作用,C12-3(OH)-C12·2Br的胶团聚集数为44.7,远大于C12-3-C12·2Br的33.2;C12-3-C12·2Br浓度直至64 mmol/L,C12-3(OH)-C12·2Br浓度直至54 mmol/L,剪切速度γ在0～1 875 s-1范围内,流变行为表现出牛顿体特征;在其后浓度的范围,临界剪切速度γ*以上时,为非牛顿体特征。黏度随浓度增大而增大并有一上升拐点;在联结链上引入羟基,对流变行为影响不大,但在相同条件下,黏度略微增大。

The micelle aggregation numbers of C12-3-C12·2Br and C12-3（OH）-C12·2Br were measured by the technique of fluorescence probe.It was found that the concentration of the Gemini surfactants had great influences on their micelle aggregation number,owing to the presence of hydroxyl group in spacer.When the concentrations were set as 5.5cmc,the aggregation number of C12-3（OH）-C12·2Br was 44.7 and was much greater than that of C12-3-C12·Br（33.2）.The two surfactants followed the Newtonian flow with their shear rates γ in the range of 0~1 875 s-1 for the concentrations of C12-3-C12·2Br and C12-3（OH）-C12·2Br up to 64 mmol/L and 54 mmol/L,respectively.Beyond these,the shear rates are higher than their critical values（γ＊） and then the flow transformed from Newtonian to non-Newtonian modes.In addition,the viscosity η increased with the increase of concentration accompanied with a sharp increase.It was found that the introduction of —OH into the spaces has barely effect on their flow behaviors but cause a slight increase of η.