Coadsorption of human milk lactoferrin into the dipalmitoylglycerolphosphatidylcholine phospholipid monolayer spread at the air/water interface. by Miano, F, Zhao, X, Lu, JR, Penfold, J

“…Whereas the DPPC monolayer effectively prevented lactoferrin insertion at the high surface pressure, a measurable amount of lactoferrin was found at the air/water interface at the two lower surface pressures. …”

ORGANIZATION OF POLY(ETHYLENE OXIDE) MONOLAYERS AT THE AIR-WATER-INTERFACE by Henderson, J, Richards, R, Penfold, J, Thomas, R, Lu, J

“…Poly(ethylene oxide) has been spread at the air-water interface and the organization of the layer investigated using surface pressure isotherms and neutron reflectometry. Surface pressure data lead to the conclusion that the spread polymer is i a thermodynamically favorable environment on pure water which becomes worse as magnesium sulfate is added to the aqueous subphase.Neutron reflectometry data have been analyzed using both optical matrix and kinematic approximation methods. …”

Structure of the monolayer formed at an air-water interface by a novel nonionic (vesicle-forming) surfactant by Barlow, D, Ma, G, Webster, J, Penfold, J, Lawrence, M

“…The structure of the monolayer was determined with the surface pressure maintained at 28 and 34 mN/m, where the individual surfactant molecules are calculated to occupy areas of 125 ± 1 and 116 ± 2 Å2, respectively. …”

Investigation of mixing in binary surfactant solutions by surface tension and neutron reflection: Anionic/nonionic and zwitterionic/nonionic mixtures by Hines, J, Thomas, R, Garrett, P, Rennie, G, Penfold, J

“…The C12maltoside/ C12betaine mixture was found to behave regularly in that βσ showed negligible variation with either surface pressure or composition. On the other hand for the nonideal pair, SDS/C12maltoside, the magnitude of βσ decreased with surface pressure, consistent with reduced interaction as the molecules are more widely spaced, and also decreased with higher SDS fraction in the layer, consistent with an increasing contribution from electrostatic repulsion.…”

NEUTRON REFLECTANCE STUDIES OF A NOVEL NONIONIC SURFACTANT AND MOLECULAR MODELING OF THE SURFACTANT VESICLES by Barlow, D, Ma, G, Lawrence, M, Webster, J, Penfold, J

“…Neutron specular reflectance studies of the monolayer formed at an air-liquid interface by a novel synthetic nonionic surfactant 1,2-di-O-octadecyl-rac-glycerol 3-(ω-methoxydodecakis(ethylene glycol) have been used to determine the structure of the monolayer as a function of surface pressure, in particular to obtain the surfactant area per molecule and the thickness and degree of hydration of the monolayer. …”

A NEUTRON REFLECTIVITY STUDY OF A SPREAD MONOLAYER OF BOVINE SERUM-ALBUMIN by Eaglesham, A, Herrington, T, Penfold, J

“…Neutron reflectivity profiles were obtained for spread layers of the protein bovine serum albumin (BSA) at the air/water interface at a surface pressure of 15 mN m-1. By the use of hydrogen-deuterium isotopic substitution in the subphase, and constrained model fitting, the distribution of protein at the interface has been determined. …”

NEUTRON REFLECTOMETRY FROM STEREOTAXIC ISOMERS OF POLY(METHYL METHACRYLATE) MONOLAYERS SPREAD AT THE AIR-WATER-INTERFACE by Henderson, J, Richards, R, Penfold, J, Shackleton, C, Thomas, R

“…At low surface concentrations, the layer thickness of the syndiotactic polymer increases to an eventually constant value although the surface pressure and concentration increase still further. …”

The influence of sorbitol on the adsorption of surfactants at the air-liquid interface by Staples, E, Thompson, L, Tucker, I, Penfold, J, Thomas, R, Lu, JR

“…The addition of 300 g/liter of sorbitol to an aqueous solution of C12E6 reduces the critical micellar concentration, cmc, from ~7 x 10-5 to ~3 x 10-5 M, and increases the surface pressure at the cmc; the effect on the C12E3/SDS mixture is less. …”

ADSORPTION OF AMMONIUM PERFLUOROOCTANOATE AND AMMONIUM DECANOATE AT THE AIR SOLUTION INTERFACE by Simister, E, Lee, E, Lu, J, Thomas, R, Ottewill, R, Rennie, A, Penfold, J

“…In each case it was necessary to include fugacity corrections and to fit the surface pressure-In c curve by least squares for there to be agreement with the surface excess as measured by neutron reflection. …”

NEUTRON REFLECTOMETRY USING THE KINEMATIC APPROXIMATION AND SURFACE QUASI-ELASTIC LIGHT-SCATTERING FROM SPREAD FILMS OF POLY(METHYL METHACRYLATE) by Henderson, J, Richards, R, Penfold, J, Thomas, R

“…The dilational modulus (ε 0) obtained from surface quasi-elastic light scattering has the same general features as that obtained from surface pressure data but is shifted to a lower concentration. …”

Adsorption of oil into surfactant monolayers and structure of mixed surfactant plus oil films by Binks, B, Crichton, D, Fletcher, P, MacNab, JR, Li, Z, Thomas, R, Penfold, J

“…The method involves measuring the surface pressure of oil, π(oil), as a function of its activity, a(oil), varied by changing the relative vapour pressure. …”

ADSORPTION AT THE LIQUID SURFACE STUDIED BY MEANS OF SPECULAR REFLECTION OF NEUTRONS by Bradley, J, Lee, E, Lee, E, Thomas, R, Thomas, R, Willatt, A, Willatt, A, Penfold, J, Penfold, J, Ward, R, Ward, R, Gregory, D, Gregory, D, Waschkowski, W, Waschkowski, W

“…The reflectivity profile of an insoluble monolayer of fully deuteriated butyl arachidate on water was measured as a function of surface pressure. The changes of reflectivity with surface concentration were found to be easily measurable. …”

STRUCTURE OF ADSORBED LAYERS OF ETHYLENE-GLYCOL MONODODECYL ETHER SURFACTANTS WITH ONE, 2, AND 4 ETHYLENE-OXIDE GROUPS, AS DETERMINED BY NEUTRON REFLECTION by Lu, J, Li, Z, Su, T, Thomas, R, Penfold, J

“…The structures of the adsorbed layers have been determined at the critical micelle concentration (cmc), at a constant surface pressure of 38 mN m-1, and at a constant area per molecule of 55 A2. …”

X-RAY AND NEUTRON REFLECTIVITY FROM SPREAD MONOLAYERS by Grundy, M, Richardson, R, Roser, S, Penfold, J, Ward, R

“…X-ray and neutron reflectivity measurements on spread films of docosanoic acid on an aqueous subphase have been used to deduce structural information. At surface pressures of 30-40 mN m-1 the molecules are perpendicular to the subphase surface. …”

POLYMER SURFACTANT STRUCTURE AT THE AIR-WATER-INTERFACE by Gentle, I, Saville, P, White, J, Penfold, J

“…The system shows a highly reversible π-A isotherm and remarkable constancy in the film thickness determined by neutron reflectivity at surface pressures above and below the classical "collapse transition". …”

SPECULAR AND OFF-SPECULAR NEUTRON REFLECTIVITY OF A LOW-MOLECULAR-WEIGHT POLYSTYRENE SURFACTANT AT THE AIR-WATER-INTERFACE by Saville, P, Gentle, I, White, J, Penfold, J, Webster, J

“…Multidetector reflectivity profiles showed only specular reflection for surface pressures below the collapse point, but in the collapse region, some off-specular reflection was clearly present, indicating the presence of surface texture on the micron length scale in the plane of the interface. …”