Optical Methods for Studying the Drying Dynamics of Fe_2O_3 Nanocolloid Droplets Depending on Variation of Substrate Temperature

摘要

This work is devoted to investigation of the way light transmittance of drying drop of Fe_2O_3 nanocolloid deposited on flat surface changes as liquid evaporates. According to results of transmitted light intensity measuring it is assumed that drying process can be divided into separate stages each being characterized by particular quality level of ability to transmit light because of different behavior and, thus, density of suspended nanoparticles inside the droplet. The last stage ends by forming of a ring-shaped pattern (known as "coffee ring"). Temperature of the surface was being changed by applying a varying potential difference to lower layer of transparent substrate made of ITO. Time dependences of integral transmitted light intensity for every single temperature are represented in graphs. They are compared with dependences for water drops of the same volume.