Green Synthesis, Surface Activity, Micellar Aggregation, and Corrosion Inhibition Properties of New Gemini Quaternary Ammonium Surfactants

Abstract

A new series of gemini quaternary ammonium surfactants containing amide groups with the formula C n H2n+1CONH­(CH2)2N+(CH3)2(CH2)2 N+(CH3)2(CH2)2NHCOC n H2n+1·2CH3CO3 – (n = 11, 13, 15, 17) have been synthesized by the using green reagent dimethyl carbonate. The structures of these surfactants were confirmed by Fourier transform infrared spectroscopy, 1H NMR, 13C NMR, and mass spectra. Their surface activities and aggregation properties were investigated by surface tension, conductivity, steady-state fluorescence, dynamic light scattering, and transmission electron microscope measurements. The results show that these synthesized gemini quaternary ammonium surfactants reduce the surface tension of water to a minimum value of 28.21 mN·m–1 at a concentration of 0.256 mmol·kg–1 and self-assemble spontaneously into double layer aggregates which are mostly single-room vesicles and multilamellar vesicles. Furthermore, with increasing alkyl chain length, their critical micelle concentration values and the degree of counterion binding (β) decrease; and the spontaneous tendency of vesicle formation and the micellar aggregation numbers (N m) increase. They are also found to be effective corrosion inhibitors for A3 steel in acid solution.

The surface adsorption, aggregate structure and antibacterial activity of Gemini quaternary ammonium surfactants with carboxylic counterions

“…Due to the different volumes of head groups and the tail chains, the aggregates have a diverse morphology. According to the space ( V H ) occupied by the hydrophilic group and the chain length ( l c ) of the hydrophobic group, the P- values are calculated by the following equation [37]:P=true0VnormalHlnormalca0,where a0 can be approximated to a half of A min with n = 2 [38], and the Tanford equation is used to calculate the V H and l c values [20,37],VnormalH=0.0274+0.0269 nandlnormalc≤0.15+0.1265n,where n is the hydrophobic alkyl chain length inserted into the aggregates, l c is approximated to 80% of the calculated value for the fully extended alkyl chains. The values of P , which are between 1/2 and 1, are listed in table 3.…”

“…The values of P , which are between 1/2 and 1, are listed in table 3. Combining with the relationship between P and the structures of aggregates [20,37], when 1/2 < P < 1, the geometry of surfactants turns into an ellipse cone with wide hydrophilic head base area and tiny hydrophobic chain and it forms a flexible and closed bilayer structure more readily. So, it is reasonable for these Gemini surfactants to form vesicles and bilayer aggregates observed by TEM.…”

“…The high-purity water ( ρ = 18.25 MΩ cm −1 ) was supplied by an ultrapure laboratory water purification system. N , N , N ′, N ′-tetramethyl- N , N ′-di(2-laurylamideethyl) ethylenediamine methyl carbonate, N , N , N ′, N ′-tetramethyl- N , N ′-di(2-myristylamideethyl) ethylenediamine methyl carbonate and N , N , N ′, N ′-tetramethyl- N , N ′-di(2-palmitylamideethyl) ethylenediamine methyl carbonate (purity greater than 98%) were prepared according to a green method reported in our previous paper [20].…”

Gemini and Bicephalous Surfactants: A Review on Their Synthesis, Micelle Formation, and Uses

“…In addition, the morphology of the micelles can be tuned by varying some parameters, including the size and type of the hydrophobic tail of the surfactant, the nature and size of the polar head, as well as the concentration, temperature, pH, etc. [35][36][37]. molecules, while the hydrophobic one forms the core (Figure 6).…”

Surface Activities, Antibacterial Activity and Corrosion Inhibition Properties of Gemini Quaternary Ammonium Surfactants with Amido Group and Carboxylic Counterions

“…The 17-2-17-2Y gemini surfactants were synthesized according to the method reported in our previous paper 13,18 . The general formula and synthesis procedure for the 17-2-17-2Y surfactants were shown in Scheme 1.…”