Naslov
Kallay, Nikola ; Lovrak, Matija ; Šupljika, Filip ; Selmani, Atiđa ; Preočanin, Tajana
(Charging of water at inert surface)

Autori
Kallay, Nikola ; Lovrak, Matija ; Šupljika, Filip ; Selmani, Atiđa ; Preočanin, Tajana

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, neobjavljeni rad, znanstveni

Izvornik
244th American Chemical Society National Meeting & Exposition: Materials for Health & Medicine / - Philadelphia (PA) : American Chemical Society (ACS), 2012

Skup
244th American Chemical Society National Meeting & Exposition: Materials for Health & Medicine

Mjesto i datum
Philadelphia (PA), Sjedinjene Američke Države, 19.08.2012. - 23.08.2012

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
inert surfaces ; electrokinetics ; air water interface ; electrical interfatial layer ; surface charge ; surface potential

Sažetak
Electrokinetic measurements of bubbles (argon or nitrogen) in aqueous electrolyte solution obeyed negative surface charge (charge of stagnant interfacial water layer) in the region of pH > 3, and positive in the region pH < 3 [1]. This finding was interpreted as preferential accumulation of OH– ions at the surface, with respect to H3O+ ions accumulation. Similar findings were obtained for the interfacial properties of other inert (hydrophobic) materials (such as hydrocarbon oils, Teflon, ice, diamond, etc.) [2]. The fast and simple method for measurement of electrokinetic properties of argon bubbles in aqueous electrolyte solution was introduced. It was found that bubbles in a contact with the ceramic frit of reference electrode affected the measured electrode potential i.e. contact potential. The contact potential depends on pH (it is zero near pH ≈3) and ionic strength (decreasing with increase of electrolyte concentration) [3]. Surface tension data for air/water interface was interpreted by comprehensive thermodynamic treatment without assumption of constant surface content. The theoretical analysis predicted a minimum of surface tension data and explained the experimental finding [4]. Additionally the surface properties of hydrophobic silver halides were analyzed from the results of surface potential and electrokinetic measurements [5]. It was found that pH doesn't influence the surface potential but shifts the isoelectric points of silver halides. This finding supports the hypothesis of different affinities of H3O+ and OH– ions within the interfacial water layer near hydrophobic surfaces.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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