Epilogue

Abstract

Nanofluids are part of the emerging technological area, which is often referred to as nanotechnology. The name nanotechnology was coined in the early 1990s, and the subject attracted very high levels of private, corporate, and governmental funding, both at the national and the local level. In the USA the National Nanotechnology Initiative was established in 2000 to coordinate nanotechnology funding from the several governmental agencies. Similar institutions that coordinate governmental research funding in nanotechnology exist in the European Union, most of the OECD countries, India, the Russian Federation, and the People’s Republic of China. The significant volume of fundamental research, which occurred in the last two decades, has shown that several nanofluids have excellent transport properties and, therefore, may be used as heat and mass transfer media. However, and despite all the research efforts and the impressive number of publications and patents, the large-scale commercialization of new nanofluid products and processes has not yet materialized. Actually, there are precious few nanofluid products and the revenue these products generate is insignificant.

The first part of this chapter examines the cost of the production of nanoparticles and nanofluids. The data on nanotechnology investments between 2005 and 2014 shows a reduction of the venture capital in this area, which will significantly affect the future development of nanofluids. Based on the materials and processes used as well as on past experience with other high-technology materials, it is concluded that it is unlikely that nanofluids will become inexpensive commodities. Therefore, among the applications that have been proposed—cooling of electronic components; nuclear reactor cooling; engine cooling for vehicles; waste energy utilization, solar energy, and HVAC; cooling of electricity transformers and other power elements; and mass transfer applications—the ones that will be commercially successful will be the processes and applications that may pass to the consumer the high cost of the nanofluid.

The last part of the chapter is devoted to the technological challenges that still need to be overcome for the application of nanofluids related to (a) stability, particle sedimentation/removal, and system reliability and (b) environmental and health concerns. Finally a few general observations on the nanofluid research and some general recommendations are given for future research and development efforts with nanofluids.