A5046844635- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Spectroscopy and Quantum Chemical Studies
- Molecular spectroscopy and chirality
- Surfactants and Colloidal Systems
- Photochemistry and Electron Transfer Studies
- Spectroscopy and Laser Applications
- Lanthanide and Transition Metal Complexes
- Health and Conflict Studies
- Metal complexes synthesis and properties
- Analytical Chemistry and Chromatography
- Magnetism in coordination complexes
Clark University
2019
University of Oxford
1972-2003
University of Cambridge
1997
Vibrational spectra of seven surfactants adsorbed at the surface aqueous solutions have been obtained by IR–VIS sum-frequency generation. From these degree conformational disorder and angle terminal methyl group are inferred. In general, number gauche conformations increases as area per chain increases. The group, which is an indicator tilt hydrocarbon chains, not simply related to chain. Comparison with same length molecule shows that structure region monolayer sensitive nature head just...
A new experimental arrangement is described for acquiring sum-frequency (SF) spectra from surfactants at the oil−water interface. The key features of this approach are stabilization a thin oil film between sapphire prism and an aqueous phase use total internal reflection to enhance signal discriminate against signals other interfaces in system. With methodology, first SF vibrational surfactant monolayers alkane−water interface were obtained. Surface tensiometry was used characterize further....
Sum-frequency vibrational spectroscopy has been used to determine the structure of monolayers cationic surfactant, hexadecyltrimethylammonium p-tosylate (C16TA+Ts-), at surface water. Selective deuteration cation or anion allowed separate detection sum-frequency spectra surfactant and counterions that are bound monolayer. The ions oriented with their methyl groups pointing away from aqueous subphase C2 axis tilted, on average, by 30−40° normal. C16TA+ indicate number gauche defects in...
Sum-frequency (SF) spectroscopy and ellipsometry have been used to study monolayers of the cationic surfactants CnTAB (CH3(CH2)n-1N+(CH3)3Br-) (n = 12, 14, 16, 18) at air-water interface a constant surface area 44 Å2/molecule. The SF spectra all four are very similar yield mean chain tilt 58° near methyl terminus. ellipsometric data suggest that density region in is close liquid hydrocarbon, which consistent with derived from sum-frequency spectra. These results quantitative agreement...
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTStructure of a Monolayer Hexadecyltrimethylammonium p-Tosylate at the Air−Water InterfaceG. R. Bell, C. D. Bain, Z. X. Li, K. Thomas, Duffy, and J. PenfoldView Author Information Physical Theoretical Chemistry Laboratory Oxford University, South Parks Rd., OX1 3QZ, U.K. Department Chemistry, Cambridge University Lensfield CB2 1EW, ISIS, CCLRC, Chilton, Didcot, Oxon OX11 0QX, Cite this: Am. Chem. Soc. 1997, 119, 42, 10227–10228Publication Date...
Vibrational spectra of a monolayer tetradecyltrimethylammonium bromide (C14TAB) on the surface water in presence benzoate ions have been obtained by infrared–visible sum-frequency spectroscopy (SFS) with three different polarization combinations. The arise solely from those bound to and not diffuse double layer or bulk solution. From an analysis intensity ν2 C—H stretching mode, values for second-order nonlinear susceptibility are derived. Interpretation these susceptibilities terms...