Modification of the Wettability of a Polymeric Substrate by pH Effect. Determination of the Surface Acid Dissociation Constant by Contact Angle Measurements

Langmuir ◽  
2006 ◽  
Vol 22 (20) ◽  
pp. 8424-8430 ◽  
Author(s):  
Chantal Badre ◽  
Alain Mayaffre ◽  
Pierre Letellier ◽  
Mireille Turmine
Keyword(s):  
Contact Angle ◽  
Dissociation Constant ◽  
Ph Effect ◽  
Acid Dissociation ◽  
Acid Dissociation Constant ◽  
Polymeric Substrate ◽  
Angle Measurements ◽  
Contact Angle Measurements

Chromatographic Determination of Thermodynamic Acid Dissociation Constants of Tetracycline Antibiotics and Their Epimers

2019 ◽  
Vol 57 (8) ◽  
pp. 745-750
Author(s):  
İlkay Konçe ◽  
Ebru Çubuk Demiralay ◽  
Hülya Yılmaz Ortak
Keyword(s):  
Experimental Data ◽  
Dissociation Constant ◽  
Binary Mixtures ◽  
Dissociation Constants ◽  
Reversed Phase ◽  
Acid Dissociation ◽  
Acid Dissociation Constant ◽  
Chromatography Method ◽  
Ph Values

Abstract The presented study describes the development of reversed-phase liquid chromatography method using a core-shell particle column with a pentafluorophenyl stationary phase for the dissociation constant (pKa) determination of the tetracycline group antibiotics (tetracycline, oxytetracycline, chlortetracycline) and their epimers (4-epitetracycline, 4-epioxytetracycline, 4-epichlortetracycline). The pH values were measured in the acetonitrile (ACN)–water binary mixtures, used as mobile phases, instead of in water and take into account the effect of the activity coefficients. Thermodynamic acid dissociation constant (pKa1) values of studied antibiotics and their epimers were calculated using retention factor (k) at different mobile phase pH values in studied binary mixtures with ACN percentages of 20, 25, 30 and 35% (v/v). Experimental data were analyzed by using an Origin 7.0 program to fit experimental data to the nonlinear expression derived. From calculated pKa1 values, the aqueous pKa values of studied compounds were calculated by different approaches and these values were compared.

scholarly journals Comments on “An Essay on Contact Angle Measurements”: Determination of Surface Roughness and Modeling of the Wetting Behavior

2011 ◽  
Vol 8 (11) ◽  
pp. 998-1002 ◽  
Author(s):  
Antonia Terriza ◽  
Rafael Alvarez ◽  
Francisco Yubero ◽  
Ana Borras ◽  
Agustin R. González-Elipe
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Wetting Behavior ◽  
Angle Measurements ◽  
Contact Angle Measurements

Determination of Components of Cassiterite Surface Free Energy from Contact Angle Measurements

1993 ◽  
Vol 161 (1) ◽  
pp. 209-222 ◽  
Author(s):  
B. Jańczuk ◽  
J.M. Bruque ◽  
M.L. González-Martı́n ◽  
J.Moreno del Pozo
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Surface Free Energy ◽  
Angle Measurements ◽  
Contact Angle Measurements
Sign in / Sign up

Export Citation Format

Share Document