Determination of Surface Tension of Surfactant Solutions through Capillary Rise Measurements: An Image-Processing Undergraduate Laboratory Experiment

CRISTIÁN HUCK-IRIART; CARLOS RINALDI; ARIEL DE CANDIA; JAVIER RODRIGUEZ

JOURNAL OF CHEMICAL EDUCATION

AMER CHEMICAL SOC

Lugar: Washington; Año: 2016

0021-9584

ABSTRACT: In this work, we described an image processing procedure for themeasurement of surface tension of the air−liquid interface using isothermal capillaryaction. The experiment, designed for an undergraduate course, is based on the analysisof a series of solutions with diverse surfactant concentrations at different ionicstrengths. The objective of the work is to illustrate some concepts such as Gibbsisotherm and surface excess for the case of ionic surfactants. To perform theexperiment, it is necessary to use glassware commonly found in a chemistry lab alongwith an USB microscope and digital image processing program (available in the publicdomain). The experiment can be completed in a 4 h laboratory session.