Cationic Gemini surfactant at the air/water interface

Network structure of collagen layers absorbed on LB film

“…Therefore, it could be concluded that although the monolayer is compressed to a high surface pressure, different from the chains of conventional amphiphilic molecules in close-packed "solid" films, the chain orientation of 18-3-18 is not likely completely vertical but is partially tilting or with some inhomogeneous structure. This is in agreement with the result of p-xylyl-bis(dimethyloctadecylammonium bromide), a cationic Gemini surfactant with a rigid spacer, in our previous work [27].…”

“…2 presents a nearly homogeneous layer with holes embraced by the interconnected terraces. The analogous results were observed by Banaszak Holl and co-workers [28] and in our previous work [27]. Banaszak Holl and co-workers [28] studied the n-octylsilane monolayer pattern formed on Au(111) and found that n-octylsilane monolayer appears an interwoven pattern of elevated sinuous ridges that frequently combine to form loop or knotted feature.…”

“…This resembles the variation of p-xylyl-bis(dimethyloctadecylammonium bromide) with the increasing surface pressure [27]. As a result, the contact angle slightly increases with the increasing surface pressures.…”

“…Banaszak Holl and co-workers [28] studied the n-octylsilane monolayer pattern formed on Au(111) and found that n-octylsilane monolayer appears an interwoven pattern of elevated sinuous ridges that frequently combine to form loop or knotted feature. In our previous work, [27] the properties of p-xylyl-bis(dimethyloctadecylammonium bromide) at the air/water interface and its monolayer transferred on mica and quartz slides were investigated, the similar topographical image was acquired at zero surface pressure, which was the network-like labyrinthine interconnected ridges. During the evaporation process of the spreading solution at the air/water interface, the amount of solvent molecules decreases rapidly with time.…”

Dynamic adsorption of a gemini surfactant at the air/water interface

“…In comparison with conventional surfactants, gemini surfactants have a number advantages, including high capability, lower critical micelle concentrations (CMC) and low Kraft temperatures [2][3][4]. Amongst the gemini surfactants, the bisquaternary ammonium bromide surfactants, [CmH2m+1N(CH3)2-(CH2)s-N(CH3) 2CmH2m+1]Br2, are the most popular due to their simple synthesis [5,6].…”