Growth morphologies, phase formation, optical & biological responses of nanostructures of CuO and their application as cooling fluid in high energy density devices

Abstract

Different nanoscale objects of CuO have been synthesized by a simple chemical route where the Cu(OH) 2 nanostructures were first synthesized by the alkaline hydrolysis of Cu(NO 3 ) 2 ?3H 2 O using NaOH as a base and the synthesized precipitate was subsequently annealed at a temperature of 130 uC. The alkaline content (pH) of the solutions during the hydrolysis process was varied to tailor the morphologies and dimensions of the nanostructures, consequently a series of fascinatingly shaped nanostructures, e.g. seeds, ellipsoidal, rods and leaves were obtained. Topographical characteristics along with the mechanism behind the structural variation have been rationalized by XRD, FTIR, SEM and HRTEM investigations. Optical performance of these samples provided simultaneous emission in the visible bands of blue, green, yellow and red, which were correlated to the size, shape and structural defects of these nano-scaled objects. The toxicity of these nanostructured materials were also put into perspective and it was found that the leaf shaped particles were the most toxic among the various shapes of nano-CuO. Finally the synthesized particles, when applied as nanofluids (water medium) showed their ability to enhance the thermal conductivity of water to a noticeable degree (above 40%) at high temperatures, even at very small concentrations, bespeaking their applicability in cooling fluids.

Synthesising Metal Oxide Materials and Their Composite Nanostructures for Sensing and Optoelectronic Device Applications

“…CuO NSs have many popular advantages such as non-toxicity, cheap production and a high surface area to volume ratio, good electrochemical activity and electron transfer at low potential, which is good for bio and chemical sensing applications [77]. CuO NSs are also used for the fabrication of solar energy (cells) transformation, dry cell batteries and as an anode in lithium ion batteries [78,79]. CuO…”

Strong enhancement in thermal conductivity of ethylene glycol-based nanofluids by amorphous and crystalline Al2O3 nanoparticles

“…[1][2][3][4][5][6][7][8][9]19 Such increment in the heat transport characteristics of base fluids suggests the crucial benefits which give credence to liquid coolants for moving heat away from electronic, optical, machinery, or nuclear reactor systems. [5][6][7]9 Various nanoparticles (NPs) of metals and metal oxides have been added to EG for enhancing the thermal conductivity (TC) of base fluid and are potentially used in heat transfer system.…”

“…Moreover, to predict and explain the TC enhancement in nanofluids, numerous theoretical studies have been focused and debated extensively over the past decade. 3,10,[18][19][20][21][22][23] Several participating factors include Brownian motion of NPs, internanoparticle potential, radiative heat transfer, particle aggregation, and dynamic interactions have been attempted to account the anomalous enhancement in TC of nanofluids combined with the effects of NPs size and shape, volume concentration of NPs, and temperature. In addition to describe the enhancement in TC of EG fluid with volume fraction/particle loadings of NPs, the model of Prasher et al for the TC enhancement ratio of nanofluid is given as follows:…”

“…[5][6][7]9 Various nanoparticles (NPs) of metals and metal oxides have been added to EG for enhancing the thermal conductivity (TC) of base fluid and are potentially used in heat transfer system. 2,[5][6][7][8][9]19,21,[23][24][25] The nanofluids based on EG reveal a higher TC having nonlinear relationship with temperature. 23,29 A very recent report to examine the effects of nanoparticle size and temperature has been published focusing on the TC enhancement of water-based Al 2 O 3 nanfluids.…”

Prospects of Emerging Engineered oxide nanomaterials and their Applications

“…In addition to above, reduction in crystal size would significantly increase the sensor performance and the band gap engineering by possible modification of MON which is one of the most exciting research area. Therefore, by altering these characteristics, the structural, sensing, optical and chemical properties of MON may be tuned and adapted to their potential to facilitate both fundamental research and practical applications through their advantageous chemical and physical properties [43][44][45][46][47][48][49][50] . Their novel properties can be tailored significantly by producing them at nanoscale in different morphologies.…”