Soap-based detergent formulations: III. Surface activity of fatty derivatives of 3-hydroxypropanesulfonic acid

Comparative Study of Conventional/Ethoxylated/Extended n-Alkylsulfate Surfactants

A series of novel anionic e-surfactants n-C _cP _pS was molecular designed and synthesized from long-chain fatty alcohols by polypropoxylation and sulfation followed by neutralization. Excellent all-round performance of extended surfactants (e-surfactants) interests us how a simple polypropylene oxide (PPO) spacer has great effects on properties. By a comparative study of conventional/ethoxylated/extended n-alkylsulfate surfactants, we were surprised to find that e-surfactants are in an obvious rugby shape at the air/water surface according to molecular surface area ( a_m), and it comes down to the intramolecular PPO spacer coiling and surface-induced collapse. On the basis of the interfacial properties of the e-surfactants, it is found that the PPO spacer can provide both hydrophilic and lipophilic contributions to an e-surfactant molecule. The synergism between PPO spacers and alkyl chains indicates that a certain PPO spacer can adjust the contributions in view of different alkyl chain lengths. Therefore, it is both the rugby-shaped molecular geometry of e-surfactants and the dynamic amphipathicity of a PPO spacer that makes e-surfactants behave with excellent interfacial and solution properties for household cleaning. Therefore, this work gives us a hint that the molecular geometry of surfactants plays a vital role in interfacial and solution properties similar to molecular amphipathicity.

Adsorbed surfactants for affinity chromatography. end-group modification of ethylene glycol polymers

The hydroxyl end-groups of Pluronic F108 [a tri-block copolymer surfactant of poly(ethylene glycol) and poly(propylene glycol) [PEG-PPG-PEG]] were converted into primary amine and quaternary ammonium equivalents for use in a new approach to affinity chromatography. The preparation of sulphonic acid end-groups was also attempted.

Sugar-based anionic surfactants: synthesis and micelle formation of sodium methyl 2-acylamido-2-deoxy-6-O-sulfo-D-glucopyranosides

The following sequence of reactions has been employed to synthesize the title anionic surfactants: [chemical reaction: see text] where R=C7H15; C11H23; and C15H31, respectively, and Py refers to pyridine. Aggregation of the surfactants synthesized (predominantly alpha anomers) in water was studied at 40 degrees C by conductivity measurements. Increasing the chain length of R decreases the critical micelle concentration (CMC) and the degree of counter-ion dissociation. The dependence of the Gibbs free energy of micellization and CMC on the length of R is similar to other ionic surfactants, but the head-group, i.e., the sulfated sugar moiety is less hydrophilic than the structurally related group -(OCH2-CH2)2-OSO3-Na+, most probably because of intermolecular H-bonding in the micellar pseudo-phase