Phase diagrams and microstructure of aggregates in mixed ionic surfactant/foam booster systems.
Phase diagrams and microstructure of aggregates in mixed ionic surfactant/foam booster systems.
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DOI：
10.1016/j.jcis.2003.09.022
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发表时间：
2004-02
影响因子：
9.9
通讯作者：
C. Rodríguez;T. Sakai;R. Fujiyama;H. Kunieda
中科院分区：
文献类型：
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作者：
C. Rodríguez;T. Sakai;R. Fujiyama;H. Kunieda
采用相分析和小角X射线散射研究了含新型烷醇酰胺类泡沫促进剂十二烷酰基N-甲基乙醇酰胺（NMEA-12）的表面活性剂体系的相行为和微观结构。与其它类似的烷醇酰胺不同，NMEA-12具有较低的熔点，在室温下形成溶致液晶相（Lα相）。这归因于连接的甲基基团，其增加了分子的流动性。在SDS/NMEA-12/水体系中，在极低的表面活性剂浓度下得到六方和层状（Lα）液晶相。当用非离子表面活性剂（C12 EO 8）代替SDS时，这些相的稳定性降低。然而，对于离子型和非离子型表面活性剂，在加入NMEA-12后，界面处每个表面活性剂分子的有效面积缩小，表明表面活性剂层变得更加致密。这些结果对NMEA-12作为泡沫稳定剂的潜在应用的可能影响进行了讨论。
The phase behavior and microstructure of surfactant systems containing a new alkanolamide-type foam booster, dodecanoyl N-methyl ethanolamide (NMEA-12), were investigated by means of phase study and small angle X-ray scattering. Different from other similar alkanolamides, NMEA-12 possesses a low melting point and forms a lyotropic liquid-crystalline phase (Lαphase) at room temperature. This is attributed to the attached methyl group, which increases the fluidity of the molecule. In the SDS/NMEA-12/water system, hexagonal and lamellar (Lα) liquid-crystalline phases are obtained at significantly low surfactant concentrations. The stability of these phases decreases when SDS is replaced with a nonionic surfactant (C12EO8). However, for both ionic and nonionic surfactants, the effective area per surfactant molecule at the interface shrinks upon addition of NMEA-12, indicating that the surfactant layer is getting more compact. The possible implications of these results on the potential applications of NMEA-12 as foam stabilizer are discussed.