The number of hydrophilic and hydrophobic groups of a surfactant has a great influence on its property. Two Gemini surfactants, N,N″‘‐didodecyl‐N,N',N″,N″‘‐tetrapropionate triethylenetetramine and N,N'‐didodecyl‐N,N'‐dipropionate ethylenediamine (referred as DTPTT and DDPED), were prepared by Michael addition reaction of the didodecyl secondary amines with methyl acrylate. The didodecyl secondary amines were synthesized by nucleophilic substitution reaction of triethylenetetramine or ethylenediamine with bromododecane. The DTPTT and DDPED surfactants were characterized by mass spectrometry and proton nuclear magnetic resonance spectrometry. The surface activities of the DTPTT and DDPED aqueous solutions were studied by surface tension measurements. The surface tension and critical micelle concentration (cmc) of DDPED is smaller than that of DTPTT. The DDPED can reduce the surface tension of water to approximate 34 mN m⁻¹ at concentration levels of 10⁻⁵ mol L⁻¹. The aggregation behavior of the DTPTT and DDPED aqueous solution were studied by dynamic light scattering and transmission electron microscopy. Both surfactants can form spherical vesicles at a solution of about 3–5 times cmc of the Gemini surfactants. The foam property was determined by nitrogen blowing method. The DTPTT has relatively good foaming ability and DDPED has excellent foam stability. The foam volume of DDPED barely change within 1000s. The emulsion stability of the Gemini surfactants was determined by separation time of water from the emulsion. The emulsion stability of DDPED is equivalent to Tween 80. The DDPED Gemini surfactant with two hydrophilic carboxylic groups has better surface activity, foam stability, and can be used as an O/W emulsifier.

中文翻译：

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两种氨基羧酸双子表面活性剂的合成及性能

表面活性剂的亲水和疏水基团的数量对其性能有很大的影响。两种Gemini表面活性剂分别为N，N'''-双十二烷基-N，N'，N''，N'''-四丙酸酯三亚乙基四胺和N，N'-十二烷基-N，N'-二丙酸酯乙二胺（称为DTPTT和DDPED）。通过十二烷基仲胺与丙烯酸甲酯的迈克尔加成反应制备。十二烷基仲胺是通过三亚乙基四胺或乙二胺与溴代十二烷的亲核取代反应合成的。通过质谱和质子核磁共振光谱对DTPTT和DDPED表面活性剂进行了表征。通过表面张力测量研究了DTPTT和DDPED水溶液的表面活性。表面张力和临界胶束浓度（cmcDDPED的）小于DTPTT的）。所述DDPED可以降低水的表面张力，以近似为34mN米^-1以10浓度水平^-5摩尔大号^-1。通过动态光散射和透射电子显微镜研究了DTPTT和DDPED水溶液的聚集行为。两种表面活性剂都可以在大约3-5倍cmc的溶液中形成球形囊泡双子表面活性剂。泡沫性质通过吹氮法测定。DTPTT具有相对良好的发泡能力，DDPED具有出色的泡沫稳定性。DDPED的泡沫体积在1000s内几乎没有变化。Gemini表面活性剂的乳液稳定性通过水从乳液中的分离时间来确定。DDPED的乳液稳定性相当于Tween80。具有两个亲水性羧基的DDPED Gemini表面活性剂具有更好的表面活性，泡沫稳定性，并且可用作O / W乳化剂。