LETTER TO THE EDITOR A New Cationic Gemini Surfmer: Synthesis and Surface Activities Xin Su • Biqing Wang • Zhiyong Lu • Limin Wei • Yujun Feng Received: 27 March 2010 / Accepted: 21 April 2010 / Published online: 23 May 2010 Ó AOCS 2010 Abstract A new cationic gemini surfmer (polymerizable surfactant or surface-active monomer) with an acrylic reactive group in its spacer group was synthesized and characterized, and its surface activity properties were examined in comparison with its intermediate surfactant 12-3OH-122Cl - , a previously-reported gemini surfmer 12 0 -2-12 0 2Br - , as well as monomeric surfactant dodecyl trimethylammonium bromide. It was found that neither the incorporation of a double bond onto the gemini surfactant nor the change of location of the double bond will affect surface activities of the gemini surfactant. Keywords Gemini surfactant  Surfmer  Cationic surfactant  Surface activity Introduction Gemini surfactants are a novel family of amphiphilic compounds made up of two amphiphilic moieties con- nected at the level of, or very close to the head groups by a spacer group [1], normally referred to as m-s-m2X - , where m, s are the carbon numbers in each alkyl chain and spacer, X - represents the counterion. These surfactants usually have superior surface-active behavior over their corresponding monomeric counterparts. Because of their unique properties [2, 3], gemini surfactants find many potential applications, such as catalysis and adsorption applications [4], new synthetic vectors for gene transfec- tion [5], analytical separations [6], solubilization processes [7], biotechnology [8], enhanced oil recovery [9] and paint additives [10], etc. Polymerizable surfactants or surface-active monomers (surfmers) are a class of vinyl amphiphilic compounds, which can function both as surfactants and monomers [11]. So surfmers could offer potential for developing hybrid nanometer-sized reaction and templating media [11], and have been used in a variety of applications including cap- turing the structure of spherical micelles and as a stabilizer in emulsion polymerization, miniemulsion polymerization, and microemulsion polymerization [12–14]. Nevertheless, few reports have focused on surfactants with both gemini architecture and a polymerizable group. To the best of our knowledge, only Abe et al. [15] have reported a cationic gemini surfmer 12 0 -2-12 0 2Br - with the molecular structure [CH 2 = C(CH 3 )COO(CH 2 ) 11 N ? (CH 3 ) 2 CH 2 ] 2 2Br - . It was found its surface activity is compara- ble to its corresponding conventional gemini surfactant 12-2-122Br - which does not have a reactive double bond. Unlike 12 0 -2-12 0 2Br - whose double bonds are located at the terminal of the hydrophobic tails, a new cationic gemini surfmer with a polymerizable group in the spacer is first reported in this work. As shown in Scheme 1, the preparation of gemini surfmer 12-3AG-122Cl - (AG denotes an acryloyl group) was followed a two-step procedure: In a three-necked flask, 41.2 g N,N-dimethyldodecan-1-amine was mixed with 10 ml hydrochloride (15%, v/v) for at least 0.5 h, and 5 g epoxy chloropropane was then added dropwise. The reaction solution was stirred continuously at 60 °C. After 12 h of reaction, the intermediate gemini surfactant X. Su  B. Wang  Z. Lu  L. Wei  Y. Feng (&) Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, People’s Republic of China e-mail: yjfeng@cioc.ac.cn X. Su Graduate School of the Chinese Academy of Sciences, Beijing 100049, People’s Republic of China 123 J Surfact Deterg (2011) 14:73–76 DOI 10.1007/s11743-010-1211-x