ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
An equilibrium osmometer for the measurement of very low osmotic pressures has been designed. It is constructed of metal and employs a large horizontal membrane. A rapid approach to equilibrium is obtained by the use of a fine capillary and a bacterial cellulose membrane (Masson and Melville) in conjunction with complete thermostatting. To avoid displacement, the membrane is stretched in a frame and held over a grooved domed support of the Carter-Record type. Details of procedure, including concentration estimation and the preparation of membranes, are given.Measurements of the osmotic pressure of a fractionated sample of polystyrene, of molecular weight approximately one million, have served to determine the precision of the osmometer. At a pressure of 0.026 cm. of chloroform, the standard deviation was found to be 0.002 cm. The importance of correcting for the density of the solution, when measuring high molecular weights, is discussed.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1951.120060508
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