Adsorption and Micelle Formation of Mixed Surfactant Systems in Water II: A Combination of Cationic Gemini-type Surfactant with MEGA-10

Abstract

Mixed micellization and mixed adsorbed film formation were investigated for the combination of a Gemini type cationic and a nonionic surfactants mixture: Bis-trimethyl ammonium Gemini derived from tartaric acid bromide (BAGTB) and n-Decanoyl-Nmethylglucamide (MEGA-10). The surface tension of the aqueous mixed surfactant solution was measured at every 0.1 mole fraction of MEGA10 in the surfactant mixture applying a drop volume method at 30. From the curves of surface tension (g) vs logarithmic concentration in molality (ln m), critical micellization concentration (CMC), minimum surface tension at CMC (g CMC), surface excess (G), mean surface area occupied by a molecule (A m) and parameters related to synergism in surface activity such as pC 20 and CMC / C 20 were determined. Based on the regular solution theory, the relation of compositions of the singly dispersed phase (X MEGA10) and the micellar phase (Y MEGA10), and the relation of X MEGA10 with the composition in adsorbed film phase (Z 2) were estimated, and along with these, the interaction parameters in micelles (w R) and in adsorbed film (w A) were calculated. Both the CMC-X MEGA-10 and CMC-Y MEGA-10 curves showed a negative deviation from ideal mixing and even the curve of Z MEGA10-m t (bulk phase concentration) produced a slightly negative w A. However, the synergism in surface tension reduction was found to be rather weak from examination of partial molecular area (PMA) and the minimum free energy at surface G min (S) = (g CMC A m L). As for the adsorbed film, the interaction mode between molecules, as well as two dimensional molecular packing, was observed to be separated into three regions; i. e. at X STDS = 0.45 and at X STDS = 0.75 different properties changed discontinuously.

A Review of Recent Studies on Aqueous Binary Mixed Surfactant Systems

“…It is noted here that, as described later, for the mixed system of a cationic Gemini type surfactant: BAGTB with MEGA-10 36,37) , synergism in surface tension reduction was found to be negligible or rather weak from the examination of partial molecular area (PMA) and the minimum surface Gibbs free energy at air/water interface (G min (S) ). In the case of BAGTB/MEGA-10, the g -ln m t curves of mixed systems showed neither a minimum around CMC nor notable synergism when compared with those of the respective single systems: i.e., g -ln m t curves of different mixtures fit between those of the two single systems and they appeared in the order of mole fraction 36) .…”

“…All the materials used for this series work have been described in terms of their sources and purities in the respective reports [35][36][37][38][39][40] . It may be worth noting the surface tension measurements even in the present review paper.…”

“…Previously, we have reported some studies performed by means of surface tension measurements as a series of works, i.e., adsorption and micelle formation of mixed surfactant systems in water I: a combination of top-heavy type anionic surfactants 35) , II: a combination of cationic Gemini-type surfactant with MEGA-10 36) , III: a comparison between cationic Gemini/cationic and cationic Gemini/ nonionic combinations 37) , and IV: three combinations of one of the most typical anionic surfactant, sodium dodecylsulfate (SDS) with MEGA-8, -9 and -10 (MEGA-n's) 38) , in addition to three combinations of zwitterionic surfactant, 3-[(3-cholamidopropyl)dimethylammonio]propanesulfonic acid (CHAPS) which is a derivative of cholic acid in pH 7.2 phosphate buffer solution. These works have followed the previous surface tension study on binary mixed systems of…”

Novel Cationic Schiff Base Surfactants: Surface Studies and Biocidal Activities against Bacteria Fungi and Sulfate Reducing Bacteria

“…of SB8, SB12, SB16 and SB18 at 25 •C. The profile showed sharp break points corresponding to the critical micelle concentration values of the different surfactants (20) . The values of the surface tension appeared relatively high compared to the conventional cationic surfactants, That may be due to the presence of the aromatic rings in the molecules.…”

“…The efficiency values (Pc 20 ) of the synthesized surfactants are defined as the concentration of the amphiphiles solutions that decreases the surface tension to 51 mNm −1 calculated using the data in Fig.1. The Pc 20 values describe the ability of surfactant molecules to adsorb at the interface and also indicate the accumulation extent of the surfactant molecules at the interface.…”