Institute of Colloid and Interface Chemistry, College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou, Fujian 350108, PR China.
J Colloid Interface Sci. 2010 Nov 15;351(2):457-65. doi: 10.1016/j.jcis.2010.07.076. Epub 2010 Aug 4.
The adsorption and aggregation of 2-hydroxyl-propanediyl-α,ω-bis(dimethyldodecyl ammonium bromide) (abbreviated as 12-3(OH)-12) in aqueous solution have been investigated by equilibrium and dynamic surface tension, surface dilational rheology, conductivity, fluorescence probing, viscosity, zeta potential and dynamic light scattering measurements. The results measured by dynamic surface tension, molar and differential conductivities strongly suggested the formation of dimolecular moieties in dilute systems prior to their adsorption and aggregation, which was attributed to intermolecular hydrogen-bonding between the hydroxyl substituted spacers. This increased the hydrophobicity of the molecular moieties and greatly promoted their adsorption at the air/water interface and association in solution. The intermolecular hydrogen-bonding between the molecules adsorbed at the air/water interface made their arrangement tighter and thus produced lower γ(cmc) compared with unsubstituted 12-3-12. Moreover, the effect of intermolecular hydrogen bonding promotes growth of 12-3(OH)-12 micelles and leads to dissociation of the counterions on the aggregate surfaces.
2-羟基丙二基-α,ω-双（二甲基十二烷基溴化铵）（简称 12-3(OH)-12）在水溶液中的吸附和聚集已通过平衡和动态表面张力、表面扩张流变学、电导率、荧光探针、粘度、ζ 电位和动态光散射测量进行了研究。通过动态表面张力、摩尔和微分电导率测量得到的结果强烈表明，在其吸附和聚集之前，在稀溶液中形成了双分子基团，这归因于羟基取代间隔物之间的分子间氢键。这增加了分子基团的疏水性，并极大地促进了它们在空气/水界面上的吸附和在溶液中的缔合。吸附在空气/水界面上的分子之间的分子间氢键使它们的排列更加紧密，因此与未取代的 12-3-12 相比，产生更低的 γ(cmc)。此外，分子间氢键的作用促进了 12-3(OH)-12 胶束的生长，并导致聚集表面上反离子的解离。
