Environmental copper: Behaviour when involved in physical adsorption at several interfaces

Intentionally Added Ionic Surfactants Induce Jones-Ray Effect at Air-Water Interface

“…However, the surface tension of the electrolytes shows a characteristic minimum at millimolar electrolyte concentration values when the concentration is varied, known as the Jones-Ray effect [6,7]. The Jones-Ray effect has been controversial, but it has been experimentally reproduced by different methods and by different research groups [8][9][10][11][12][13][14][15]. The Jones-Ray effect was first explained by anion adsorption [16], which was supported by surface-sensitive nonlinear spectroscopy [17].…”

“…However, this scenario contradicts with the surface tension of NaOH solutions because the surface tension of NaOH solutions is larger than that of NaCl solutions, meaning Email address: uematsu@chem.kyushu-univ.jp (Yuki Uematsu) that OH − is more surface-inactive than Cl − [2,3,22]. Although other explanations were suggested [23,24], the experimental fact that the concentration and depth of the minima depend on independent measurements [6][7][8][9][10][11][12][13] implies uncontrolled hidden parameters in the experiments. Recently, one of the authors constructed the theory of the surface tension of electrolytes, and the Jones-Ray effect is explained by the traces of charged impurities in the water [22,25].…”

“…Additionally, Langmuir has explained the Jones-Ray effect by the reduction of the capillary radius because of the wetting films in the capillary rise method [18]. However, this mechanism does not work for the du Noüy ring [8], maximum bubble pressure [9,10], and Wilhelmy plate methods [11][12][13], which were also used to observe the Jones-Ray effect. Another explanation for the Jones-Ray effect is OH − adsorption [19,20].…”