Mixed Micellization of Cationic/Anionic Surfactants: Role of Matching Water Affinities between Oppositely Charged Headgroups and That between Oppositely Charged Constituent Counterions
Mixed Micellization of Cationic/Anionic Surfactants: Role of Matching Water Affinities between Oppositely Charged Headgroups and That between Oppositely Charged Constituent Counterions
复制标题
阳离子/阴离子表面活性剂的混合胶束化：带相反电荷的头基之间和带相反电荷的组成抗衡离子之间的水亲和力匹配的作用
DOI：
10.1021/acs.jpcb.9b05982
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发表时间：
2019
影响因子：
3.3
通讯作者：
Nan Yan Qing
中科院分区：
文献类型：
--
作者：
Hao Li Sheng;Xiao Kai;Hu Yan;Zhang Sha Sha;Liu Jian Xiu;Wei Yuan Yuan;Chen Yue;Nan Yan Qing
为了探讨带相反电荷的头基之间的亲水性匹配的作用，采用表面张力法和分子动力学（MD）模拟研究了十六烷基三甲基溴化铵（CTA+Br-）/十二烷酸钠（Na+L-）混合体系和CTA+Br-/十二烷基磺酸钠（Na+AS-）混合体系的胶束化.与CTA+Br-/Na+ L-体系相比，CTA+Br-/Na+ AS-体系具有更强的胶束形成能力，更小的临界胶束浓度（cmc），以及更强的协同效应，这是由于CTA+和AS-的亲水性匹配程度更高。为了探索带相反电荷的组分反离子之间的匹配的水亲和力的作用，CTA+X-/Y+ L-混合系统与各种反离子的胶束化进行了研究。反离子X-和Y+之间的水亲和力匹配程度越高，头基和反离子之间的水亲和力错配程度越高，不利于反离子对头基CTA+和L-之间静电吸引的屏蔽作用，导致胶束形成能力越强，cmc越小，反之亦然。分子动力学模拟结果还表明，对于阳离子/阴离子表面活性剂的混合胶束化，带相反电荷的头基之间的亲水亲合力比带相反电荷的组分反离子之间的亲水亲合力更重要.
To explore the role of matching water affinities between the oppositely charged headgroups, the micellization of cetyltrimethylammonium bromide (CTA+Br–)/sodium dodecanoate (Na+L–) mixed system and the CTA+Br–/sodium dodecylsulfonate (Na+AS–) mixed system has been investigated by the surface tension method and molecular dynamic (MD) simulation. In comparison with the CTA+Br–/Na+L–system, the CTA+Br–/Na+AS–system shows stronger micelle formation ability, smaller critical micelle concentration (cmc), and stronger synergistic effect arising from the higher degree of matching water affinities between the headgroups CTA+and AS–. To explore the role of matching water affinities between the oppositely charged constituent counterions, the micellization of CTA+X–/Y+L–mixed systems with various counterions has been investigated. The higher degree of matching water affinities between counterions X–and Y+and the higher degree of mismatching water affinities between headgroups and counterions are unfavorable to the screening effect of counterions on the electrostatic attraction between headgroups CTA+and L–, leading to stronger micelle formation ability and smaller cmc and vice versa. MD simulation results also indicate that, for the mixed micellization of cationic/anionic surfactants, the role of matching water affinities between oppositely charged headgroups is more important than that between oppositely charged constituent counterions.