Nanofluids are potential heat transfer fluids with enhanced thermophysical properties and heat transfer performance can be applied in many devices for better performances (i.e. energy, heat transfer and other performances). In this paper, a comprehensive literature on the applications and challenges of nanofluids have been compiled and reviewed. Latest up to date literatures on the applications and challenges in terms of PhD and Master thesis, journal articles, conference proceedings, reports and web materials have been reviewed and reported. Recent researches have indicated that substitution of conventional coolants by nanofluids appears promising. Specific application of nanofluids in engine cooling, solar water heating, cooling of electronics, cooling of transformer oil, improving diesel generator efficiency, cooling of heat exchanging devices, improving heat transfer efficiency of chillers, domestic refrigerator-freezers, cooling in machining, in nuclear reactor and defense and space have been reviewed and presented. Authors also critically analyzed some of the applications and identified research gaps for further research. Moreover, challenges and future directions of applications of nanofluids have been reviewed and presented in this paper. Based on results available in the literatures, it has been found nanofluids have a much higher and strongly temperature-dependent thermal conductivity at very low particle concentrations than conventional fluids. This can be considered as one of the key parameters for enhanced performances for many of the applications of nanofluids. Because of its superior thermal performances, latest up to date literatures on this property have been summarized and presented in this paper as well. However, few barriers and challenges that have been identified in this review must be addressed carefully before it can be fully implemented in the industrial applications.

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A review on applications and challenges of nanofluids

Nanocomposites, a high performance material exhibit unusual property combinations and unique design possibilities. With an estimated annual growth rate of about 25% and fastest demand to be in engineering plastics and elastomers, their potential is so striking that they are useful in several areas ranging from packaging to biomedical applications. In this unified overview the three types of matrix nanocomposites are presented underlining the need for these materials, their processing methods and some recent results on structure, properties and potential applications, perspectives including need for such materials in future space mission and other interesting applications together with market and safety aspects. Possible uses of natural materials such as clay based minerals, chrysotile and lignocellulosic fibers are highlighted. Being environmentally friendly, applications of nanocomposites offer new technology and business opportunities for several sectors of the aerospace, automotive, electronics and biotechnology industries.

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Nanocomposites: synthesis, structure, properties and new application opportunities

The scientific understanding of the molecular size and shape of humic substances (HS) is critically reviewed. The traditional view that HS are polymers in soil is not substantiated by any direct evidence but is assumed only on the basis of laboratory experiments with model molecules and unwarranted

The supramolecular structure of humic substances

A review on surface modification of activated carbon for carbon dioxide adsorption

Note: This article was originally published with an incorrect version of the Acknowledgments, which appeared on p. 218 of the print version. The correct version of the Acknowledgments appeared on pp. 1–2. The corrected article is available below.

/pdf/human-health-risk-assessment-for-aluminium-aluminium-oxide-5dfetd69xm.pdf

Human Health Risk Assessment for Aluminium, Aluminium Oxide, and Aluminium Hydroxide

Several aluminum nanopowders were examined and compared with the final goal to evaluate their application in solid rocket propulsion. A detailed investigation of pre-burning properties by the Brunauer-Emmet-Teller method, electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy was carried out. Ballistic properties and the combustion mechanism of several aluminized propellant formulations were investigated. In particular, aggregation and agglomeration of metal particles at and near the burning surface were analyzed by high-speed high-resolution color digital video recordings. All tested nano-powders are of Russian production; their physical characterization was carried out at the Istituto Donegani (Novara, Italy); ballistic studies were performed at the Solid Propulsion Laboratory (Milano, Italy) using laboratory and, for comparison, industrial composite propellants based on ammonium perchlorate as an oxidizer. Results obtained under a fair variety of operating conditions typical of rocket propulsion indicate, for increasing nano-Al mass fraction or decreasing nano-Al size, larger steady burning rates with essentially the same pressure sensitivity. While aggregation and agglomeration phenomena still occur, their significance may be reduced by using nano-Al instead of micro-Al.

Burning of Nano-Aluminized Composite Rocket Propellants

Chemical modification of carbon fiber surfaces

Nano-aluminum as energetic material for rocket propellants

Pre and Post-Burning Analysis of Nano-Aluminized Solid Rocket Propellants

The characterization of several differently sized aluminium powders, by BET (specific surface), EM (electron microscopy), XRD (x-ray diffraction), and XPS (x-ray photoelectron spectroscopy), was performed in order to evaluate their application in solid rocket propellant compositions. These aluminium powders were used in manufacturing several laboratory composite solid rocket propellants, based on ammonium perchlorate (AP) as oxidizer and hydroxil-terminated polybutadiene (HTPB) as binder. The reference formulation was an AP/HTPB/Al composition with 68/17/15% mass fractions respectively. The ballistic characterization of the propellants, in terms of steady burning rates, shows better performance for propellant compositions employing nano-aluminium when compared to micro-aluminium. Results obtained in the pressure range 1-70 bar show that by increasing the nano-Al mass fraction or decreasing the nano-Al size, larger steady burning rates are measured with essentially the same pressure sensitivity.

http://iopscience.iop.org/article/10.1088/0953-8984/18/33/S15/pdf

Febo Severini

Papers

Burning of Nano-Aluminized Composite Rocket Propellants

Chemical modification of carbon fiber surfaces

Nano-aluminum as energetic material for rocket propellants

Pre and Post-Burning Analysis of Nano-Aluminized Solid Rocket Propellants

Nanoparticles for solid rocket propulsion