Mixtures of alkyltrimethylammonium bromide (CnTAB, n=12, 14, 16, 18) and Triton X-100 were studied at a range of mole fractions of ionic surfactant per nonionic surfactant. For each mixture, the cmc obtained from surface tension measurements differed from that obtained using potentiometry. The behavior of these mixed-surfactant systems showed three different regions with increasing total surfac...

M41S: A family of mesoporous materials including MCM41, MCM-48, and MCM-50 MSU-1,2,3,4: Michigan State University no. 1, 2, 3, 4, a series of wormhole mesoporous materials prepared in the presence of nonionic surfactants Pluronic: polyethylene oxide–polypropylene oxide triblock surfactant, (EO)m(PO)n(EO)m, for example, P123 = (EO)20 (PO)70(EO)20 SBA-x: Santa Barbara no. x, a series of mesoporou...

Surfactant distributions in model pressure-sensitive adhesive (PSA) films were investigated using atomic force microscopy (AFM) and confocal Raman microscopy (CRM). The PSAs are water-based acrylics synthesized with n-butyl acrylate, vinyl acetate, and methacrylic acid and two commercially available surfactants, disodium (nonylphenoxypolyethoxy)ethyl sulfosuccinate (anionic) and nonylphenoxypol...

The formation of viscoelastic wormlike micelles in mixed amino acid surfactant/nonionic surfactant aqueous systems in the presence of different counterions and salts is reported, and the effects of the different electrolytes on the rheological behavior are discussed. N-dodecanoylglutamic acid (LAD) is neutralized with biologically relevant L-lysine and L-arginine to obtain anionic surfactants (...

Understanding enzyme-substrate interactions is critical in designing strategies for bioconversion of lignocellulosic biomass. In this study we monitored molecular events, in situ and in real time, including the adsorption and desorption of cellulolytic enzymes on lignins and cellulose, by using quartz crystal microgravimetry and surface plasmon resonance. The effect of a nonionic surface active...

Surface tension (ST) measurements were carried out on various binary mixtures of the "normal" surfactants, such as nonionic surfactant, hexaethylene glycol mono-n-dodecyl ether(C12EO6), and cationic surfactant, tetradecyltrimethylammonium bromide (TTAB), and polymeric copolymer, Pluronic F127, F127(PPO)-g-PVP, and F127(PEO)-g-PVP. In all cases mixed micellar aggregates were formed and critical ...

The objective of this study was to model the critical micelle concentration (cmc) of nonionic surfactants in nonaqueous systems using the UNIFAC group contribution method. For the prediction of the cmc the phase separation approach was used, where the micellar phase is approximated as a second liquid phase resulting from the liquid-liquid equilibrium between the solvent and the surfactant, with...

Foaming properties of dilute aqueous nonionic fluorinated surfactants, perfluoroalkyl sulfonamide ethoxylate, C8F17SO2N (C3H7)(CH2CH2O)nH (abbreviated as C8F17EOn, n = 10, 20) has been studied at 25°C. Both the surfactants produced a large volume of foams that are stable for several hours to a few days depending upon the surfactant concentration. The foam stability increases with increasing the...

Although the application of liquid foams is widespread, too little is yet understood about stability control. One promising way to tune their properties is the application of oppositely charged surfactant mixtures. These catanionic surfactant mixtures show a strong synergism. This makes them eco-friendly since it allows reducing the required amount of surfactant. Due to the formation of surface...

The behavior of water molecules at the surface of nonionic surfactant (monomyristolein) and effects of monovalent ions on the behavior are investigated using the heterodyne-detected vibrational sum frequency generation spectroscopy. It is found that water molecules at the surface are oriented with their hydrogen atoms pointing to the bulk, and that the degree of orientation depends on the anion...