Jan Zawala

Dr. Jan Zawala

Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, 31-342 Krakow, Poland
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orcid

Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 March 2009 in Advances in Colloid and Interface Science
Verified
Journal Article
Closed access
Marta KrasowskaMarta Krasowska
Marta Krasowska
Jan ZawalaJan Zawala
Jan Zawala
KMK. Malysa
K. Malysa

10 February 2011 in Langmuir
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Journal Article
Closed access
Jan ZawalaJan Zawala
Jan Zawala
KMKazimierz Malysa
Kazimierz Malysa

1 April 2007 in Colloids and Surfaces A: Physicochemical and Engineering Aspects
Verified
Journal Article
Closed access
MKMarcel Krzan
Marcel Krzan
Jan ZawalaJan Zawala
Jan Zawala
KMK. Malysa
K. Malysa

1 October 2007 in The Canadian Journal of Chemical Engineering
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Journal Article
Closed access
PDF file
Jan ZawalaJan Zawala
Jan Zawala
Marta KrasowskaMarta Krasowska
Marta Krasowska
TDT. Dabros
T. Dabros
KMK. Malysa
K. Malysa

1 January 2014 in Colloids and Surfaces A: Physicochemical and Engineering Aspects
Verified
Journal Article
Closed access
Dominik KosiorDominik Kosior
Dominik Kosior
Jan ZawalaJan Zawala
Jan Zawala
KMK. Malysa
K. Malysa

12 December 2012 in Physical Chemistry Chemical Physics
Verified
Journal Article
Closed access
PDF file
Dominik KosiorDominik Kosior
Dominik Kosior
Jan ZawalaJan Zawala
Jan Zawala
Marta KrasowskaMarta Krasowska
Marta Krasowska
KMKazimierz Malysa
Kazimierz Malysa
We have investigated the influence of concentration of surfactants typically used as flotation frothers (α-terpineol and n-octanol) and roughness of the solid surface on phenomena occurring during rising bubble collisions with a model hydrophobic Teflon surface. The time of three-phase contact (TPC) formation (tTPC) and the time of drainage (tD) of the film formed between the colliding bubble and Teflon surfaces were determined using a high-speed camera working with a frequency 1040 Hz. The Teflon surface roughness was varied on a microscopic scale, within a roughness ranging between 1 and 100 μm. We have found that the roughness of the Teflon surface is a crucial factor of the kinetics of the TPC formation, both in the absence and in the presence of the surfactants. With the surface roughness increasing from ca. 1 to 80 μm the tTPC can be shortened by an order of magnitude, i.e. from 105 ms down to a few milliseconds. We have demonstrated that bouncing of the colliding bubble is responsible for the large differences in the times of TPC formation at the Teflon surfaces of different roughness. Low concentrations of α-terpineol and n-octanol caused a decrease in the tTPC with respect to distilled water. However, at high concentrations the tTPC was prolonged. The prolongation of the time of the TPC formation was dependent on the Teflon surface roughness and we have attributed this effect to different amounts of air present in the cavities and scratches of hydrophobic surfaces of different roughness. The mechanism of prolongation of the tTPC at high concentration of surface-active substances (frother overdosage) is proposed.