Preparation of MCM-41 nanofluid and the 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 likewater, it is possible to study the increase of heat conductivity due to the Brownian motion effects. In thiswork a suitable apparatus for the measurement of heat conductivity has been built and calibrated andthen using the apparatus and preparing suitable nanofluids, the conductivity and the volumetric heatcapacities have been measured. Experimental results show that the preparation time of the nanofluidusing the ultrasonic method has pronounced effect on the increase of the conductivity. A twenty fourhours preparation time for the nanofluid containing 2.5% (vol) of the particles results in a 7% increasein 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 canbe deduced that Brownian nano particles movement is one of the main factors in increasing the thermalnanofluids conductivity.Keywords: Nanofluid, Nano particles, Effective thermal conductivity, Specific heat capacity.