Preparation and Thermal Conductivity of Nanofluids Consisting of SiO2-Organic Composite Nanorods

SiO2-organic composite nanorods were synthesized in cetyltrimethylammonium bromide-tetraethylorthosilicate-ammonia solution-water media. The length and aspect ratio of the obtained nanorods decreased with increasing addition of water. The collected nanorods were easily dispersed in water producing aqueous nanofluids. The influence of size and fraction of the nanorods on the thermal conductivity of the nanofluids was investigated. The results show that the thermal conductivity of the nanofluids increased with the fraction of dispersed nanorods. The nanofluid, which consisted of silica-organic composite nanorods with the smallest length and aspect ratio, showed the largest enhancement of thermal conductivity.