Stable Organic Nanoparticles With High Photothermal Energy Conversion Efficiencies For Biomedical And Energy Applications

Photothermal materials with recent breakthroughs in both the biomedical (e.g. photothermal therapy) and solar harvesting systems (e.g. seawater desalination) have attracted much attention. While these materials show promising initial success, they have limited PCEs, narrow spectral response and lack photochemical stabilities. Recently, the PC has developed new organic photothermal materials, with remarkable extinction coefficient (2x times better than current best inorganic materials), high PCEs of ~55%, and prolonged stabilities. More importantly, preliminary results demonstrate direct water vaporization under irradiation and suggest an application of low cost seawater desalination, which are fully consistent with Hong Kong's water management strategy.This proposal aims: 1. To develop organic NPs for efficient photothermal conversion operation with PCEs higher than 60% in each of the following spectral response regions: i) 400 - 700 nm, ii) 700 - 1000 nm and iii) 1000 - 1300 nm. 2. To develop organic NPs aqueous dispersion formulations with wide spectral response (i.e. 400 - 1300 nm), good stability (i.e. at least double that of gold nanorod) and biosafety. 3. To demonstrate in vitro applications of organic NPs with high PCEs at 1000 - 1300 nm excitation for killing cancer cells. 4. To demonstrate seawater desalination by enhanced evaporation rate of seawater under illumination using a standard solar simulator.