According to an implementation of the present subject matter, a method for producing stable nanofluids is described. The method includes mixing of a base fluid with a dispersant and a metal oxide powder to form a primary mixture. The base fluid is a heat transfer fluid and the metal oxide powder includes particles of size greater than 100nm. The method further includes grinding the primary mixture to obtain a concentrated nanoparticle suspension where the dispersant is added to the primary mixture during the grinding after every pre-determined time period.
