Showing papers on "Water cluster published in 1977"
TL;DR: In this paper, a model calculation has been carried out in which successive hydrations of NO + take place through clustering with N 2 and CO 2, followed by switching reactions with H 2 O. The results are in reasonably good agreement with observations as far as the water-cluster species are concerned.
112 citations
TL;DR: Water cluster ions are reduced to H3O+ by collision-induced dissociation at ca 1 torr as mentioned in this paper, and the cluster ion abundance changes drastically with the electric field strength in the collision region.
31 citations
01 Jan 1977
TL;DR: In this paper, the saturation water content of polyethylene was determined by clustering of associated water molecules in the polymer matrix, and the diffusion coefficient was found to range from 1.5 × 10−7 to 1.1× 10−6 cm2/sec.
Abstract: The diffusion coefficient, D, of water in several polymers has previously been reported to decrease as the concentration of water is increased.1,2 From these findings, it has been inferred that the decrease in mobility of the sorbed water is due to clustering of associated water molecules in the polymer matrix.1,3 Probably due to this effect, D for polyethylene at 25°C has been found to range from 1.5×10−7 to 1.1×10−6 cm2/sec.4,5 In addition, the solubility, S, of water in polyethylene is dependent upon the structure of the polymer and has been difficult to measure since it is in the parts per million (ppm) range. Therefore, we have undertaken an experimental program to determine the saturation water content of polyethylene and to isolate clustered water from the vapor form.
12 citations
TL;DR: In this paper, the reaction mechanism for the formation of H3O+⋅H2O ions in ionized nitrogen containing small amounts of water vapor impurity is found.
Abstract: The reaction mechanism for the formation of H3O+⋅H2O ions in ionized nitrogen containing small amounts of water vapor impurity is found to differ from that established previously by Good, Durden, and Kebarle in that the reaction chain involves not only H3O+, but also N2⋅H2O+ and N2⋅H3O+ ions. The predominant reactions are identified and the associated rate coefficients are estimated.
9 citations
01 Sep 1977
TL;DR: In this paper, it is known that an ion-nucleated, polymolecular phase of water exists in the vapor phase, as well as in the liquid phase, where the number of molecules per cluster is dependent upon relative humidity and other meteorological parameters.
Abstract: : Until recently, it was assumed that atmospheric water was found in one of three phases: vapor (monomer), liquid droplets or ice crystals. Now it is known that an ion-nucleated, polymolecular cluster phase of water exists in the vapor phase, as well. These water clusters consist of numbers of water molecules gathered about small ionic nuclei, where the number of molecules per cluster is dependent upon relative humidity and other meteorological parameters. In real atmospheres, mean cluster sizes range from about 11 to about 14 molecules per cluster. Their infrared absorption is due to intermolecular hydrogen bonding, and the 'continuum'-like absorption spectrum which they produce is shifted in wavelength by changes in mean cluster size. Water clusters are always present in the atmosphere and in the cleanest of laboratory experimental equipment. Except under supersaturations of about 420% relative humidity, clusters are not able, because of equilibrium considerations, to attain 'critical' size and to grow to droplets. Water cluster theory and equations give excellent agreement with observed data for infrared 'continuum' absorption.
2 citations