Preparation of MCM-41 nanofluid and an investigation of Brownian movement of the nanoparticles on the nanofluid conductivity

In this investigation the silicate nano structure of MCM-41 has been used for the production of nanofluid. The particles have negligible heat conductivity and therefore by their dispersion in a base fluid like water, it is possible to study the increase of heat conductivity due to the Brownian motion effects. In this work a suitable apparatus for the measurement of heat conductivity has been built and calibrated and then using the apparatus and preparing suitable nanofluids, the conductivity and the volumetric heat capacities have been measured. Experimental results show that the preparation time of the nanofluid using the ultrasonic method has pronounced effect on the increase of the conductivity. A twenty four hours preparation time for the nanofluid containing 2.5% (vol) of the particles results in a 7% increase in the conductivity of the base fluid while showing no significant increase in the volumetric heat capacity. Investigating the effect of increasing the temperature and volumetric percentage of the particles it can be deduced that Brownian nano particles movement is one of the main factors in increasing the thermal nanofluids conductivity.