Elektrochemie der Kolloide

Dilatometric Measurement of Protein Hydration1

“…The few semi-quantitative data contained in the paper cited are, however, sufficient to establish the fact that the phenomenon measured and labeled as hydration of the proteins bears no relation to the actual hydration of the protein. Around this hydration concept, which it is the intention of the present paper to show to be a fallacy, a number of more or less systematic investigations of several tanning processes have been carried out by Theis and his collaborators. tion of proteins, as a function of the H-ion concentration of the medium as advanced in this earlier work, have more recently undergone a radical change, which is shown by his recent monograph (1,8).…”

“…From Tammann's research (10) it is known that aqueous solutions of substances, with marked tendencies for hydration, behave, in regard to their compressibility, as -water under increased pressure. The latter is a measure of the hydration forces for substances -with a high degree of «hydration, such as inorganic ions (2,8). This is the same view that Pauli applied to the polar aquo groups which take part in the hydration of proteins and which concept was uncritically annexed by Theis. The hydration capacity of proteins is relatively small compared to inorganic ions, and the change in internal pressure, due to the hydration forces, is dwarfed by other factors which influence the total volume of the system.…”

High Viscous Alginic Acid

“…Kuhn's equation (15)11) refers to a bar molecule. (15) here, 1=length of a bar particle d=longitudinal diameter in cross section of a bar particle Placing (16) or and putting the above value of a into equation (16), the value of 1/d of sodium alginate becomes 8 to 9.…”

The Sol-Gel Transformation in Gelatin

“…(Accepted for publication, September 16, 1931) In recent years there has been a revival of interest in the micellar theory of structure proposed by N~tgeli in 1852 as a theory for the structure of protoplasm. This theory has been taken over by colloid chemists and applied to the structure of many colloids as a result of the work of Zsigmondy (1), Pauli (2), McBaln (3,4) and their coworkers. Laing and McBain (4) have further extended the micellar theory to the sol-gel transformation by proposing that the micellar unit of the gel state is identical with that in the sol.…”