Synthesis, Surface Properties, and Self‐Aggregation Behavior of a Branched N,N‐Dimethylalkylamine Oxide Surfactant

Abstract

Amine‐oxide surfactants have emerged as highly stable, nontoxic, and cost‐effective constituents of detergent formulations, specifically as wetting agents and foam boosters. With the aim of enhancing their functional behavior, a new member of this family, N,N‐dimethyl‐2‐propylheptan‐1‐amine oxide, bearing a branched alkyl tail (C10DAO‐branched) was synthesized and purified using a simple and easily scalable strategy starting from 2‐propylheptan‐1‐ol. 2D‐nuclear magnetic resonance (NMR) and mass spectrometry confirm the obtainment of the desired product in high yield and purity. The protonation behavior of the branched surfactant is not affected by alkyl tail branching, as shown by potentiometric titrations. In contrast, surface activity and aggregation behavior of C10DAO‐branched is dramatically different from that of the linear analog N,N‐dimethyldecyl‐1‐amine oxide (C10DAO‐linear), in that it occupies a higher area at the solution interface and aggregates at much higher concentration, forming larger aggregates, as detected using tensiometry and dynamic light scattering (DLS), respectively. Aggregation behavior of C10DAO‐branched is less sensitive to pH variations. Foaming tests show that C10DAO‐branched is a more effective foam booster than its linear analog, in both acidic and basic solutions. The experimental results indicate that the branched surfactant can be used in applications that require enhanced and pH‐independent surface activity and foamability.

Hydrocarbon-Based Statistical Copolymers Outperform Block Copolymers for Stabilization of Ethanol–Water Foams

“…Prior studies of both hydrocarbon and silicone-based small-molecule surfactants indicate that more branched hydrophobic moieties lower the surface tension to a greater extent. 41,53 This is believed to be related to weaker tail−tail interactions and the large volumes occupied by bulky hydrophobic tails at an interface. 54 The length of the spacer group between the backbone and methyl groups also appears to be an important determinant of surface activity: copolymers bearing methyl-rich t BuA repeat units cannot stabilize foams in ethanol−water mixtures (Table 1).…”

Synthesis and Characterization of Multifunctional Nanovesicles Composed of POPC Lipid Molecules for Nuclear Imaging

“…The surface tension, γ, of the aqueous mixture containing NOTA-OL was measured by the De Nouy ring method using a KSV Sigma 70 digital tensiometer, (KVS, Helsinki, Finland) [32]. Weighed amounts of a NOTA-OL solution at a concentration well above its critical micelle concentration (cmc) were added to a weighed amount of aqueous solution in the tensiometer circular vessel at 25 • C.…”

Synthesis and pH-stimuli responsive research of gemini amine-oxide surfactants containing amides

“…On the contrary, the negative z values showed the charge reversal on the micellar surface in alkaline conditions mainly because of the existence of the specic binding of OH À with the micellar surface. 22 Moreover, z is a key indicator of the stability of the colloidal dispersions. 28 When pH < 3 and pH > 7, the absolute values of z were greater than 40 ( Fig.…”

“…19,20 Based on these advantages, researchers have reported many studies on the basic physical and chemical properties, and the applications of amine oxide surfactants. [21][22][23][24] There are relatively few reports on the synthesis and application of gemini oxide amine surfactants, even though they may have more special properties and broader application prospects. Markus et al previously reported that a sugar-based gemini surfactant had similar molecular occulation within an extremely narrow pH range, and the possibility of its use in drug and gene delivery was under further investigation.…”