Interfacial Effects during Phase Change in Multiple Levitated Tetrahydrofuran Hydrate Droplets.

Recent strategies developed to examine the nucleation of crystal structures like tetrahydrofuran (THF) hydrates without the effects of a solid interface have included acoustic levitation, where only a liquid-gas interface initially exists. However, the ability now exists to levitate and freeze multiple droplets simultaneously, which could reveal interdroplet effects and provide further insight into interfacial nucleation phenomena. In this study, using direct digital and infrared imaging techniques, the freezing of up to three simultaneous THF hydrate droplets was investigated for the first time.

Dynamic viscosity of methane hydrate systems from non-Einsteinian, plasma-functionalized carbon nanotube nanofluids.

The viscosity of oxygen-functionalized multi-walled carbon nanotube (O-MWCNT) nanofluids was measured for concentrations from 0.1 to 10 ppm under conditions of 0 to 30 MPag pressures and 0 to 10 °C temperatures. The presence of O-MWCNTs did not affect the temperature dependence of viscosity but did reduce the effective viscosity of solution due to cumulative hydrogen bond-disrupting surface effects, which overcame internal drag forces.

TinyLev acoustically levitated water: Direct observation of collective, inter-droplet effects through morphological and thermal analysis of multiple droplets.

Hypothesis: Understanding the crystallization of atmospheric water can require levitation techniques to avoid the influence of container walls. Recently, an acoustic levitation device called the TinyLev was designed, which can levitate multiple droplets at room temperature. Proximal crystallization may affect droplet phase change and morphological characteristics.

The behaviour of plasma-functionalized graphene nanoflake nanofluids during phase change from liquid water to solid ice.

Emerging nanofluid-based technologies for cooling, transport, and storage applications have previously been enhanced through the use of graphene nanoflake (GNF) nanofluids. Many of the beneficial effects of GNFs have now been documented, though little work has yet been completed to characterize the morphological behaviour of GNF nanofluids both during and after the phase change process. In this study, the crystallization behaviour of sessile water droplets was evaluated for two plasma-functionalized, hydrophilic GNF concentrations (20 and 100 ppm) at three driving force temperatures (-5 °C, -10 °C, and -20 °C).