Nanocomposites and nanomaterials

Thin films from cooled suspensions by Tape Casting
Ivanchenko S.E., Umerova S.O., Ragulya A.V.
Frantsevich Institute for Problems of Materials Science NASU 
Krzhizhanovsky str., 3, 03680, Ukraine, Kyiv-142 
E-mail: ise89@ukr.net, sergonische@gmail.com

Thin films are one of the most widely used objects in the modern field of printed electronics. Obtaining a large number of high-quality films is possible with the use of highly productive and well-studied industrial methods of production, such as tape casting and screen-printing. However, traditional production approaches are limited to a minimum film thickness of 1-3 microns. The urgent task is to overcome this limit and to adjust the above-mentioned methods for the production of films with a thickness less than one μm in an unsintered state.
Preliminary studies have shown a positive effect, which causes cooling of the suspensions on the properties of films obtained by the tape casting method [1]. It results in a reduction in the thickness and roughness of the films.
The study of rheological properties and flow curves of suspensions based on BaTiO3 nanopowders at temperatures below 20° C causes a great deal of interest since there is almost no data on such studies. With such dependences, the dimensionless number of Péclet can be calculated and used to characterize the state of ordering the suspension due to the displacement strain ratio acting on the system during casting in relation to Brownian motion chaotic forces. Reducing the temperature of the suspension should lead to a decrease in chaotic motion and improve the structure of the system during casting, relaxation, and evaporation of the solvent from the raw film after casting.
The study of this effect is of considerable interest since it will allow casting films of a thickness less than 1 micron and roughness to be close to the size of separate powder particles, expanding the application of industrial tape casting method. 

1.	Іванченко, С. Е., Умерова С.О., Барановський Д.І., Рагуля А.В. Отримання тонких суцільних керамічних плівок на основі нанопорошку BaTiO3 методом плівкового лиття // Керамика: наука и жизнь.-2016.-68, N 4.-P. 55-66.