Monolayer on water surface

Seki, T., Fukuda, R., Yokoi, M., Tamaki, T., and Ichimura, K. Photomechanical response of azobenzene containing monolayers on water surface. Bull. Chem. Soc. fpn., 69, 2375... 

Kago, K., Fiirst, M., Matsuoka, H., Yamaoka, H., and Seki, T. Nanostructure of photo-chromic polymer/liquid crystal hybrid monolayer on water surface observed by in-situ x-ray rellectometry. Langmuir, 15, 2237 (1999). 

Figure 2. Langmuir-Blodgett film deposition (a) condensed monolayer on water surface (b) transfer of monolayer on upstroke of solid substrate (c) subsequent transfer on downstroke (d) Y-type multilayer film.

V.M. Rudoy, Hydrolysis of polydimethylsiloxane monolayers on water surfaces, in. Chemistry and... 

Kago K, Fuerst M, Matsuoka H, Yamaoka H, Seki T. 1999. Direct observation of photoisomerization of polymer monolayer on water surface by X ray reflectometry. Langmuir 15 2237 2240. 

Solvent-free bilayer membranes are formed by forming monolayers on water surfaces on either side of a Teflon sheet containing a pinhole. As the water (and monolayer) level is raised slowly past the pinhole, mono-layers from opposite sides merge to form the solvent-free bilayer across the pinhole. 

A-S-D Triad Monolayer Systems Since 1985 [33], Fujihira s group has been studying amphiphilic triad molecules that can spread and form monolayers on water surfaces. The early amphiphilic triads [33, 91] are shown in Fig. 21. In these amphiphilic triads, three functional moieties, a dicationic electron acceptor (A, viologen (V +)), a neutral sensitizer... 

II. Monolayers on water surfaces II. 1. Pressure/area isotherm... 

C12-0080. Stearic acid forms a monolayer on the surface of water. Draw a molecular picture that shows how stearic acid molecules are arranged in this monolayer. 

Fig.33 Surface pressure of the CaM/BSA monolayer on water at different Ca2+ concentrations...

The polymer forms a stable monolayer on the surface of water. The surface pressure-area diagram of the monolayer is shown in Figure 7.1, where the surface area S is calculated per ionic side group. The collapse pressure ofthe monolayer is equal to 54 mN/m. 

The pore diameter of zeolite 13X is about 13 A, which is within the order of size of water vapor, oil vapor, and larger gas molecules (about 10 A). Assuming that the mean molecular diameter is half this value, 5 10 cm, about 5 -10 molecules are adsorbed in a monolayer on a surface of... 

For this study, compounds were selected which formed condensed films when spread as a monolayer on water, yet whose solubility in water was sufficiently high to allow measurements of the rate of film desorption from the surface to the bulk solution. For these compounds the free energies of desorption may be obtained from monolayer desorption studies (6). 

Some amphiphilic molecules such as oleic acid and hexadecyl alcohol containing an alkyl chain and a polar head group form monolayers on the surface of water. The polar head groups of these molecules are attracted to and are in contact with water while their hydrocarbon tails protrude above it (Figure 15). The term monolayer implies the presence of a uniform mono-molecular film on the surface of water. Monolayer films can be classified as gaseous, liquid, or solid depending upon the degree of compression and the effective area per molecule. Clearly the liquid phase of a monolayer film and, more so, the solid represent constrained environments for individual molecules of amphiphiles. Monolayers, just like micelles, are dynamic species. 

The influence of the presence of an organic monolayer on the surface potential measured at the water surface can also provide interesting information. However, this information can be difficult to interpret as it depends on the dipole moments associated with both the upper and the lower ends of the molecules and also the surface double layer in the water immediately below the film. There are two different ways of measuring this quantity. Both, of course, involve a counter electrode below the water surface. 

The amount of water required by chymotrypsin and subhlisin for catalysis in organic solvents is several hundred molecules per protein molecule, less than required to form a monolayer on the surface. While subhlisin and a-chymotrypsin act as catalysts in a variety of dry organic solvents, the vastly different catalytic activities in these organic solvents are partly due to stripping of the essential water from the enzyme by more hydrophilic solvents and partly due to the solvent directly affecting the enzymatic process. 

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