Different States Of Water Research Articles

Dimethylsiloxane‐ethylene oxide block copolymers, 1. Microphase separation of low segment mass copolymers and their compatibility with water and oil

AbstractTernary phase diagrams of linear tri‐block and multi‐block copolymers consisting of poly(dimethylsiloxane) with a constant segment mass of M̄n = 103 and varying poly(oxyethylene) segment masses in the range 100 ≤ M̄n ≤ 2000 with water and oil (cyclohexane) are reported. Also binary mixtures of the same copolymers with water and oil are investigated by differential scanning calorimetry (DSC). Microphase separation of the copolymers and different states of water are detected as a function of composition and structure of the copolymers as well as oil and water content, respectively. The results are discussed in terms of a model having an interphasial zone where intermixing of the dissimilar segments occurs.

States of water associated with electrodeposited manganese dioxide as revealed by pyknometric density measurements

The densities of different states of water associated with an electrodeposited manganese dioxide have been estimated from the original density of the manganese dioxide, the weight of water removed by outgassing and the outgassed density. Outgassing at room temperature removed water which in the associated state had the density of normal water. This water resided in the second and outer physisorbed layers and required two days' outgassing for complete removal. Temperatures of 60–120°C were necessary to remove further water which in the associated state had a density of about 1.25 g cm −3. This water is considered to be ordered or structured and in its amount corresponded to a monolayer. After removal this ordered layer required several days of immersion in water to reform. Outgassing at 170–250°C caused condensation of hydroxyl groups, and products resulting from such treatments reacted slowly with water on immersion.

Characterization of water structure in cellulose acetate membranes by calorimetric measurements

AbstractThe heat capacities of homogeneous and asymmetric cellulose acetate membranes have been measured at different water contents within the temperature range of −40 to +20°C. The experimental heat capacity–temperature curves were verified by DTA measurements within a temperature range of −120 to +20°C. The results for the partial heat capacity of water within the membranes as well as for the heat of fusion were interpreted by assuming two different states of water—unfreezing bound water due to a sorption process and unbound water due to capillary phenomena, which freezes with a freezing point depression and a reduced heat of fusion.

Differentiation of interlayer and adsorbed water in hydrated portland cement by thermal analysis

Work leading to the new model of hydrated portland cement has shown that much of the water previously considered to reside on free surfaces exists as interlayer water. In the present work samples were conditioned at various relative humidities for times varying from 1 1 2 to 14 months and were dried to two different levels before conditioning, one being d-dry. Conditions were chosen, based on the model, so that the different states of water could be clearly illustrated. It was concluded that thermal analysis allows differentiation of interlayer and physically adsorbed water and that the different degrees of drying and very long times allowed for equilibration support all sorption results on which the new model of hydrated portland cement was based.

The constitution of water in different states

In a previous communication, the author described the behaviour of water with changes of temperature and with addition of electrolytes as revealed by the changes in the structure of its Raman band. This band is found to consist of three components with mean Raman frequencies 3217, 3433, and 3582 cm. -1 . With increasing temperature, the component 3582 increased in intensity, while the first diminished, the central one remaining nearly constant. A comparison of the above changes with the results obtained by the author for ice indicated that the component which becomes more intense with increasing temperature is absent in the Raman band of ice. The first component with the smallest Raman frequency, however, is very conspicuous in ice, and the central one retains the same relative intensity. The above differences in the structure of the band were explained on the hypothesis that water consists not only of single (H 2 O) but also of double (H 2 O) 2 and triple (H 2 O) 3 molecules, the relative proportions of which depend upon its state of aggregation as well as on its temperature. Ice is supposed to consist only of double and triple molecules, which reveal themselves as the two components of its Raman band. In the liquid state, the presence of all the three components in this band is taken as evidence of the fact that there are all the three types of molecules in this state. No data were then available as regards the Raman band for water-vapour. But the infra-red absorption band observed by Hettner at 2.66 μ has its corresponding component in the water band which is supposed to arise out of the single H 2 O molecules.

XCIII.Raman effect for water in different states

XCIII.<i>Raman effect for water in different states</i>

Constitution of Water in Different States

IN a former publication1, the changes in the distribution of intensity of the Raman band of water with temperature have been explained on the hypothesis that water consists of three types of molecules, single (H2O), double (H2O)2 and triple (H2O)3, as revealed by the presence of three components in the band. Since these components were mixed up, it was not then possible to analyse the band to estimate quantitatively their relative intensities, for the determination of the proportions of these three types of molecules. Further work with ice and water at 0°, 4°, 38°, and 98°C. has now made such an analysis possible.

On the laws of the tides on the coast of Ireland, as inferred from an extensive series of observations made in connexion with the Ordnance survey of Ireland

The elaborate investigations of which the results are communi­cated in the present paper, were suggested by the necessity of adopting some standard mean height of the sea, as a line of refer­ence for the elevations ascertained in the operations of the Ordnance Survey of Ireland. Colonel Colby, R. E, who conducted that survey, had with this view determined to institute a series of observations on the height of the water in different states of the tide; and conceiving that these observations might be made subservient to im­provement in the theory of the tides, requested the assistance of the author in laying down the plan of observation best calculated to effect that object. The suggestions which were, in consequence, made by the author were adopted in their utmost extent by Colonel Colby; and the collection of observations was placed in the author’s hands in the winter of 1842. The whole number of observations exceeds two hundred thousand; and they derive extraordinary value from the circumstance of the localities, of their simultaneity, their extensive range, and the uniformity of plan on which they were con­ducted. Their reduction was made by the computers at the Royal Observatory, Greenwich, under the superintendence of the author, and with the authority of the Lords Commissioners of the Treasury. The nature of the different branches of the inquiry may be gathered from the titles of the several sections into which the paper is divided, and which are as follows :— Section I.—Account of the stations, levellings, times and methods of observation.

I. On the laws of the tides on the coasts of Ireland, as inferred from an extensive series of observations made in connection with the ordnance survey of Ireland

In the spring of 1842 I was informed by Colonel Colby, R. E., Director of the Trigonometrical Survey, that in the operations of the Survey of Ireland it had become necessary to adopt a line of reference for the elevations ascertained in the running of various lines of level through the country; and that it was his intention to institute a series of observations of the height of the water in different states of the tide, in order to refer the levels to the mean height of the sea, or to its height at some definite phase of the tide. Colonel Colby stated also that he was desirous that the observa­tions should be made subservient to improvements in the theory of the tides, and requested my assistance in sketching a plan of observation which would be most likely to contribute to that end. In reply, I made the following suggestions:—That great care should be taken in the accurate determination of time at every station, and that for this purpose the non­commissioned officer of the Royal Sappers and Miners who had the care of the observations at each station, should be entrusted with a pocket chronometer, and that an officer should, at least twice during the series of observations, visit every station, carrying, for comparison, an itinerant chronometer whose error on Greenwich time was accurately known from astronomical observations. That stations should be chosen on the eastern as well as on the western coast, in order to determine the difference of level, if any, between an open sea and a partially inclosed sea. That on the north-eastern coast, stations should be selected at smaller intermediate distances than at other parts of the coast, with the purpose of removing, if possible, the doubt which appears to exist as to the progress of the semidiurnal tide-wave through the North Channel. That, where practicable, several stations should be selected on each of the large rivers or estuaries, in order to ascertain the nature of the modification which the tide-wave undergoes in passing up a contracted channel of comparatively small depth. That the series of observations should be so arranged, that, at every station, one complete tide (from high water to high water, or from low water to low water) should be completely observed on every day, its observations being made at small equidistant intervals. That supplementary observations, applying only to the neighbourhood of the low water or high water omitted in the observations of the complete tide, should also be made, for the development of the principal facts of diurnal tide. Finally, that the zeros of the tide-gauges should be connected with the principal lines of level, so that every observation should be referred to the same hydrostatic level.