Colloids and interfaces: where Science meets Engineering, a hands-on learning approach

Abstract

This article describes two sets of experiments designed to enhance the understanding of colloidal systems. These experiments were designed as a part of the theme “Colloids: Where Science Meets Engineering” taught in the Department of Chemical Engineering and additionally offered to physics, chemistry, and materials science departments as an advanced course at IIT Gandhinagar, India. Through this article, we describe experiments planned and conducted simultaneously with the course content to improve the student interaction with the subject matter and enhance their learning. The first set of experiments deals with preparing and characterizing gold nanoparticle sol and observing phenomena such as the Tyndall effect and aggregation with the addition of salt by UV analysis, DLS sizing, and zeta potential measurements. The second set of experiments deals with understanding interfaces, including contact angle, surface tension, critical micellar concentration of surfactants, and surface energy. The students are not only able to visualize course content but also exposed to the lab environment, learn basic preparation protocols, and handle or observe the application of high-tech equipment. Thus, this article aims to help develop further teaching protocols for instructors with similar course plans by suggesting key experiments that are easy to perform along with the course and facilitate student learning.