Self-Assembly of Sodium Carboxymethyl Cellulose on Glass
Surface from Evaporating Drops

Abstract

The advancement of modern science and technology needs day by day smaller microprocessors, chips, sensors, machines and devices, as a result the existing method of fabrication are slowly becoming obsolete. The fabrication of devices at small scale by the help of self-assembly is an inexpensive and promising technique. Evaporation of sessile droplets containing Sodium Carboxymethyl Cellulose induces outward flow within the drop, which is commonly well known as “coffee ring” effect or a dense ring like deposition along the perimeter. In this work, the formation of self-assembled structure during drying of microliter drops containing Sodium Carboxymethyl Cellulose with different organic (oxalic, acetic, citric) as well as inorganic (hydrochloric, nitric, sulphuric, phosphoric) acids is investigated with the help of optical microscope. The structure formation is also influenced by evaporative flux and Marangoni flow inside the liquid drop. The different parameters such as sodium carboxymethylcellulose concentration, acid concentration, drying time, drying temperature, humidity, stirring velocity, stirring temperature, pH and drop volume strongly influences the structure formation.