Proton and deuteron mobility in normal and heavy water solutions of some alkali halides (NaCI, KCl, KBr and KI) and tetra-alkylammonium bromides (where alkyl is Me, Et, Pr or Bu) is measured polarographically and the diffusion coefficients calculated from a corrected IIkovic equation. The results are analysed in terms of the effect of electrolyte concentration on the excess or Grotthuss mobility of the hydrogen and deuterium ion. The results raise some questions about the accepted mechanism for the transport of the proton and deuteron in solution.Earlier studies 1-5 on proton mobility in aqueous electrolyte solutions using polarography gave useful information about the degree of hydration of the proton and the structure of water in the presence of electrolytes. In this paper we give a more detailed analysis as a result of further work on deuteron mobility in heavy water solutions of electrolytes. EXPERIMENTAL Apparatus, purification techniques and special procedures are described elsewhere. 1-5 As was noted previously4 it is important to purify all salts thoroughly before use. For example, different samples of A.R. KCI gave different results before purification and the most marked difference was observed in the case of the tetra-alkylammonium salts. After purification the order of the diffusion currents for the hydrogen ion in the presence of the tetra-alkylammonium salts was altered from that reported previou~ly,~ fig. l(e) and (f).However, the half-wave potentials remained unchanged. Tetramethylammonium bromide (Kodak) was recrystallised three times from distilled de-ionised water and dried under reduced pressure at 110°C for 1 week. Tetraethylammonium bromide (Kodak) and tetrapropyIammonium bromide (Kodak) were recrystallised three times from super-dry ethanol and methanol respectively, and dried under reduced pressure at 110°C. Tetrabutylammoniuin bromide (Kodak) was recrystallised five times from dry acetone, and dried under reduced pressure at 80°C. The purity of the recrystallised tetra-alkylammonium salts was determined by titration against silver nitrate using the Mohr method as percentage bromide and gave the following results, Me4NBr 100.00 %, Et4NBr 100.00 %, Pr4NBr 99.88 %, Bu4NBr 99.69 %. The alkali halides (A.R.) were recrystallised twice from distilled deionised water and dried under reduced pressure at 110°C for at least a week. In two previous publications 4-5 and in this work all salts were exhaustively purified as described above and the diffusion coefficients for the proton and deuteron so obtained were reproducible within 1 %.The DzO, 99.75 % by weight, was obtained from the Australian Institute of Nuclear Science and Engineering and was made 1 . 1 7~ mol dm3 in DCI by adding a small quantity of a solution of DCl in D 2 0 (Stohler Isotope Chemicals). The concentration of DCl was determined by potentiometric titration with sodium tetraboraie. The solution of DCl in D20 was de-aerated with high purity nitrogen and stored in a glass dispensing vessel under nitrogen. To make up the solutions a q...

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Interactions between poly(ethy1ene oxide) and phenol-formaldehyde resin play important roles in the mechanism by which the two polvmers improve fibre retention in the papermaking process. These were investigated at the concentration level and shear conditions found in this vrocess. The results indicste that the comvlex formed varies with pH and ionic strength over a very narrow range of conditions, and that the self association of the resin an important part in the quantity of resin io the complex.Because the amount of resin interactine with the ~olvethvlene oxide amears to be -. ----related to the molecular weight, and hence chain length, of the two polymers, cooperative binding of the polymers seems to be involved. A minimum size of the network was found to be necessary for the polymers to improve fibre retention.

The ESR spectra were recorded on an x-band E-9 ESR spectrometer. The temperature was controlled with a Varían V-4557 variable-temperature controller calibrated with an iron constantan thermocouple. The method used to determine the thermodynamic parameters for the dissociation of the p -benzosemiquinone ion pair (eq 1) was exactly the same as previously described.7®Care must be taken in the handling of HMPA, since it has been found to be a possible carcinogen.