Solar-based distillation methods have the potential to significantly reduce the current energy-intensive distillation processes. This method is based on the use of metallic light-harvesting nanoparticles that capture solar energy for direct liquid-vapor conversion, an inherently non-equilibrium vaporization process, eliminating the energy requirement of heating the entire fluid volume. To further investigate the effect of the metallic nanoparticles on the distillation process, two azeotropic systems, with different hydrogen bonding network strength, ethanol-water and 1-propanol-water mixtures were selected. In the case of nanoshell-ethanol-water mixtures, the mole fraction of ethanol obtained in the laser induced distillation process was higher than that obtained by thermal flash distillation process. Additionally, in a controlled N2 environment that avoids vapor water contamination, the ethanol-water azeotrope was overcome. In contrast, in the case of nanoshell-1-propanol-water mixtures the mole fraction resulted from laser induced distillation process was found to be equivalent with the thermal distillation process without significant shift in the azeotrope. Additionally, when the nanoshells-1-propanol-water mixtures with 0.49-0.9 1-propanol mole fraction were illuminated from the top, a phase separation was observed. The top solution that contains the flocculated nanoparticles is richer in 1-propanol content compared with the bottom solution. However, the laser induced nanoshells flocculation is a reversible process and the nanoshells maybe redispersed by shaking the container.
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