Abstract: Mixed monolayers of surfactants were investigated by AFM and LB technique. Condensed monolayer of C₁₈H₃₇SO₃Na-C₈F₁₇COOH mixture shows two dimensional phaseseparation and crystallization. C₁₈H₃₇SO₃Na forms hexagonal domains dispersing in thecontinuous two dimensional phase of C₈F₁₇COOH; C₁₂H₂₃SO₄Na-C₁₈H₃₇N(CH₃)₃Brmixture forms a homogeneous mixed monolayer; while the mixed monolayer of C₁₈H₃₇N(CH₃)₃Br and C₈F₁₇COOH mixture shows heterogeneous in microscope. Relations between structure and state of mixed monolayer to the interactions between their hydrophilic groups and that between their hydrophobic groups have been revealed.

Key words: atomic force microscope, mixed monolayer, two dimensional phase separation and crystallization, mutual phobicity between fluorocarbon and hydrocarbon surfactants

摘要： 利用LB技术和原子力显微镜(AFM)研究表面活性剂混合不溶膜的结构。结果表明C₁₈H₃₇SO₃Na-C₈F₁₇COOH混合凝聚膜发生相分离，C₁₈H₃₇SO₃Na形成六方微畴分布在连续的C₈F₁₇COOH相中；C₁₂H₂₃SO₄Na-C₁₈H₃₇N(CH₃)₃Br形成了相当均匀完整的混合膜；C₁₈H₃₇N(CH₃)₃Br-C₈F₁₇COOH所成膜呈微不均匀状态。结果说明混合不溶膜表面状况由极性头相互作用与疏水基相互作用共同决定，并为碳氟与碳氢胶团间的互疏作用提供直观证据。

关键词: 原子力显微镜, 混合不溶膜, 二维相分离与二维结晶现象, 碳氟与碳氢基团间的互疏性