A comprehensive survey on experimental techniques, results and theoretical interpretations concerning the self-dissociation and protonic charge transport in water and ice is given. Recent investigations of fast protolytic reactions in pure water and aqueous solutions by means of relaxation techniques complete our knowledge about state and kinetic properties of the proton in this medium. In comparison here with our experience regarding the same properties in ice crystals are far less complete, as usual techniques of aqueous solutions are not applicable. Direct measurements of individual properties of ‘excess’ and ‘defect’ protons in ice (mobilities, concentrations, reaction rates) are presented. The proton transport in hydrogen-bonded media is completely different from normal ionic migration and corresponds more to electronic transport processes in semi-conductors. Generally the proton transport through hydrogen bonds includes two processes: (1) The formation (or rearrangement) of (H-bond) structure with orientation, favourable for a proton transition, and (2) the charge transfer within the H bond. The first step is rate determining in water, whereas the second one is decisive for the charge transport in ice. The requirements for a theoretical treatment therefore are (1) for water: a theory of ‘structural diffusion’ of the H-bonded hydration complex of H 3 O + , and (2) for ice: a (quantum-mechanical) theory of the protonic motion within the potential well of the H bond. The mechanism of structural diffusion provides an explanation of the anomalous H 3 O + and OH - mobility and their recombination rate in water. The difference between protonic and normal ionic charge transport occurs most obviously in the absolute values of mobilities in ice. The proton mobility in ice differs by many orders of magnitude from that of normal ions, but only by a factor of about 50 from electronic mobilities in some metals and semi-conductors. Further arguments, demonstrating the analogy between protonic and electronic charge transport are given. The reaction kinetics of protolytic systems and the fast proton transport in H-bonded systems are of certain importance with respect to biological problems.

A recently proposed method for analyzing polydispersity with photon correlation spectroscopy is verified experimentally by directly estimating the molecular weight distributions (MWD’s) of two well characterized National Bureau of Standards (NBS) polystyrene samples in cyclohexane at 35.0 °C. The MWD’s were reproducible and in good agreement with the NBS molecular weight averages. The method finds the smoothest nonnegative MWD that is consistent with the data without requiring initial estimates or subjective judgements. It is shown to work at dust levels where the method of cumulants fails. Minimum necessary precautions against dust and other sources of error are discussed.

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This work was presented on 12 November 2020 as a 'podium presentation' at the online European Urogynaecological Association (EUGA) meeting 2020.

Bd. 67, Nr. ' KBergmann, M. Eigen und L. de Maeyer: Dielektrische Absorption als Folge chemischer Relaxation Tabelle I Geschwindigkeitskonstanten und Arrheniusglieder fur die Athylenoxydanlagerung an Phenol mit basischen Katalysatoren 819 ~ .. Fur die freundliche Unterstiitzung der Arbeiten durch die Max Buchner-Forschungsstiftung mochten wir auch an dieser Stelle besonders danken. E 450 Auszugsweise vorgetragen von K. B e r g m a n n anlaBlich der 62. Hauptversammlung der Deutschen Bunsen-Gesellschaft fur Physikalische Chemie e.V. am 24. Mai 1963 in Maim Es ist bekannt, daB gewisse Dipolmolekiile in unpolaren Losungsmitteln, zykljsche, wasserstoff briickenstabilisierte Dimere bilden. Im elektrischen Feld ist die Dimerisierung mit einer Anderung der elektrischen Polarisation der Losung verknupft, da im Dimeren eine weitgehende Kompensation der Dipolmomente der beiden Monomeren erfolgt. Das Dimerisationsgleichgewicht ist daher von der elektrischen Feldstarke abhangig. Endliche Gleichgewichtsversckebungen treten auf Grund der nichtlinearen Feldabhingigkeit jedoch nur bei sehr hohen Feldstarken auf. Ein einfaches Verfahren zur Messung dieses Feldeffektes besteht darin, daB man einem sehr starken Gleichfeld ein hochfrequentes Wechselfeld kleiner Amplitude iiberlagert. Im Falle chemischer Relaxation ergeben sich dann dielektrische Verluste, aus deren Frequenz-und Konzentrationsabhangigkeit sich die Geschwindigkeitskonstanten k,, und k,, fur H-Brucken-Bildung und -Zedall bestimmen lassen. Berichte der 820 Kurzvortrage zum Hauptthema Bunsengesellschaft -~~ ~ ~~~ ~ ~