Adhesion of an Air Bubble to Quartz Surface in Aqueous Solution of Aliphatic Amine Hydrochloride

Abstract

Abstract Measurements of the force of air bubble detachment from a quartz surface in aqueous solutions of decylamine hydrochloride (DAC1), dodecylamine hydrochloride (DDAC1) and tetradecylamine hydrochloride (TDAC1) were made in the concentration range from 0 to 200mg/dm3. At the same time, the instantaneous contact angle for the system quartz-air bubble-aqueous solution of aliphatic amine hydrochloride was photographed at the moment of detachment. Wetting contact angles for the system quartz-air bubble-aqueous solution of DDAC1 were also measured. On the basis of the measured values of the instantaneous angle and surface tension of the solutions studied, the changes of polar components of surface free energy of quartz/monolayer water film under the influence of adsorption of molecules of aliphatic amine hydrochloride (RAC1) from aqueous solution were calculated and compared with the literature data. Using these data, the force of air bubble detachment from the quartz surface in the presence of RAC1 was also calculated and compared with the measured force, obtaining a good agreement. From the studies and calculations it appears that a little addition of RAC1 to water considerably changes the stability of the system quartz-air bubble-solution, and that this change is first of all caused by reduction of a polar component of the surface free energy of quartz/monolayer water film as a result of adsorption of RAC1 molecules in the negative places of such a surface. As a result of RAC1 adsorption this surface becomes similar to that of paraffin.