Surface-Tension Properties of Novel Phosphocholine-Based Fluorinated Surfactants

Phase behavior and surface tensions of amphiphilic fluorinated random copolymer aqueous solutions

“…The copolymer solution was diluted with water and stirred for few minutes before each measurement. The values of equilibrium surface tension at 1 and 0.1 wt.% of aqueous solutions of copolymers were cross-checked using spinning-drop tensiometer (Site 400, Krüss) to see whether the results were affected by the wetting of the plate with solution or not in Wilhelmy plate method [12].…”

“…There are many reports on the equilibrium surface properties [8][9][10][11][12][13][14] as well as dynamic surface properties [11,15,16] of fluorocarbon surfactants solutions, but to our knowledge, there are scarcity of report on the interfacial properties of amphiphilic fluorinated random copolymers, although there are some reports on the surface properties of the thin film of copolymer containing perfluoroalkyl and other hydrophobic side chains [3,[17][18][19]. In this context, we studied the phase behavior, equilibrium surface tension, and dynamic surface tension of aqueous solutions of some amphiphilic fluorinated random copolymers.…”

Mixed Solutions of Anionic and Zwitterionic Surfactant (Betaine): Surface-Tension Isotherms, Adsorption, and Relaxation Kinetics

“…This effect is well known for cationic surfactants, and it is explained with a gradual (evaporation driven) deposition of surfactant in the vicinity of the contact line, which results in a contact angle, which is greater than zero and increases with time. [24][25][26][27] Because at pH = 5.5 the Betaine is in its zwitterionic form (section 2.3), it turns out that a similar contact-angle effect can take place also with a zwitterionic surfactant (not only with a cationic one). To check that, we carried out test measurements of σ with the pendant drop method, which showed relaxation times, which are very close to those obtained from the short-time linear dependence (see Figure 1 and Table 1).…”

Hydrophilic carotenoids: surface properties and aggregation of an astaxanthin-lysine conjugate, a rigid, long-chain, highly unsaturated and highly water-soluble tetracationic bolaamphiphile

“…Surface data for cationic (bola) surfactants have been incompletely described (Okahata and Kunitake, 1979) or are rather uncertain (Franceschi et al, 1999). It has been stated that cationic surfactants are difficult to handle (Rodríguez et al, 2001) and the data, if reported, should be considered unreliable (Li et al, 1999) due to unusual chemical effects encountered with cationic surfactants (Eastoe et al, 2000). Nonetheless, tensiometric data for ammonium bolas have been obtained without reported difficulties (Han et al, 2004;Menger and Wrenn, 1974;Esumi et al, 1996).…”