TY - JOUR KW - Particulate matter KW - Temperature KW - Water KW - Lasers KW - Melting KW - Silver KW - Nanoparticles KW - Nanofluids KW - Subcooling AU - Soochan Lee AU - Patrick E Phelan AU - Robert A Taylor AU - Ravi S Prasher AU - Lenore Dai AB -

Continuous, laser-heated boiling heat transfer experiments with silver nanofluids were conducted to identify the nonequilibrium melting behavior of silver nanoparticles in de-ionized (DI) water. Experimental results with transmission electron microscopy (TEM) and dynamic light scattering (DLS) suggest that surface melting of silver nanoparticles (which have a bulk melting point of 961 °C) can occur at ambient pressure when particles are suspended in saturated, and even subcooled (e.g., <100 °C) water due to the localized (volumetric) heat absorption. These findings are supported by calculating a temperature-dependent Hamaker constant of silver nanofluid—i.e., the interaction between interfaces (Ag-melt-water) at the melting temperature. This finding is significant because of the difficulty to identify the melting of silver nanoparticles in water at present, even though it is important to understand such potential melting to use aqueous silver nanofluids in solar applications.

BT - J. Heat Transfer DA - 01/2016 DO - 10.1115/1.4032310 LA - eng M1 - 5 N2 -

Continuous, laser-heated boiling heat transfer experiments with silver nanofluids were conducted to identify the nonequilibrium melting behavior of silver nanoparticles in de-ionized (DI) water. Experimental results with transmission electron microscopy (TEM) and dynamic light scattering (DLS) suggest that surface melting of silver nanoparticles (which have a bulk melting point of 961 °C) can occur at ambient pressure when particles are suspended in saturated, and even subcooled (e.g., <100 °C) water due to the localized (volumetric) heat absorption. These findings are supported by calculating a temperature-dependent Hamaker constant of silver nanofluid—i.e., the interaction between interfaces (Ag-melt-water) at the melting temperature. This finding is significant because of the difficulty to identify the melting of silver nanoparticles in water at present, even though it is important to understand such potential melting to use aqueous silver nanofluids in solar applications.

PY - 2016 EP - 052301 T2 - J. Heat Transfer TI - Low-Temperature Melting of Silver Nanoparticles in Subcooled and Saturated Water VL - 138 ER -