Development and application of the in situ radiotracer thin gap method for the investigation of corrosion processes. I. Adaptation of the thin gap method for the application of porous surfaces

Comparative study of the adsorption of SO42-/HSO4- and Cl−

“…A combined radio-electrochemical cell -developed by Varga and coworkers [34,36,38,39] -was applied for the adsorption experiments using in-situ thing gap method. The calculation of the surface excess values of sulfate/bisulfate and chloride ions took place on the basis of the intensity measurment of the emitted β¯-radiation of 35 S (E max = 167 keV) and 36 Cl (E max = 714 keV) radionuclides used for labelling.…”

“…The radiation intensity increment measured is proportional to the entered quantity. The most often applied pure  -emitting radioisotopes in these measurements are 3 H [7,8], 14 C [9-12], 32 P [13,14], 35 S [4,5,13,[15][16][17][18][19][20][21][22][23][24][25] and 36 Cl [13,16,22,[25][26][27][28][29][30][31][32].…”

“…This fact implies that there were some strong limitations of the applicability of the original method considering both labelled species and metallic constructional materials to be investigated [34,35]. For instance, the thin gap version of the above procedure did not allow to measure the adsorption/desorption processes and to determine quantitatively the surface excess () values of labelled species having low specific activity (chloride labelled with 36 Cl) on smooth surfaces (roughness factor2). By a further development of the original methodology of the thin gap technique for the investigation of porous metal electrodes (roughness factor  10), the sensitivity was increased and the detection limit was improved.…”

“…applicability for porous surfaces and for radionuclides having low specific activity). Following a methodological improvement, we can get some information on the adsorption of radiolabelled species with low specific activity ( 36 Cl) on rough surfaces [36,37].…”

“…The present work is focused on the comprehensive investigation of the applicability (advantages and limitations) of the original thin gap method for the study of the competitive sulfate/bisulfate (labelled with 35 S) and chloride (labelled with 36 Cl) adsorption on smooth Au and Pt electrodes in supporting electrolyte consisting of 0.1 mol dm -3 HClO 4 . In addition, we report some new findings obtained upon the above adsorption processes in perchlorate solution containing H 3 BO 3 .…”