Collaborative Research: Nanoscale Heat Transfer and Phase Transformation Surrounding Intensely Heated Nanoparticles

纳米级物体，如金属纳米粒子或碳纳米管，容易高效地吸收电磁辐射。当高强度的电磁辐射被传递到这些物体上时，比如通过聚焦激光束，吸收的能量会导致纳米级物体和周围介质的极端局部加热和温度的大幅升高。这些高度局域化的热漂移对应的热通量可能比在宏观尺度上持续的热通量大几个数量级。智力优势：本研究建立在以下方面的进步之上：(a)基于激光的超快光学技术，能够在皮到纳秒的时间尺度上捕捉相关现象；(b)计算能力和建模技术，允许在相同的时间和特殊尺度上同时对这些系统进行实验和理论检查。特别是，分子动力学模拟和时间分辨泵-探针实验将促进对纳米级固体和周围液体之间界面上产生的传热、相变和相平衡的理解。更广泛的影响：该研究集中在强烈加热的固体纳米颗粒和周围液体之间的热能交换。这对生物医学应用具有重要意义，例如用于癌症治疗的高选择性热疗法。从事研究的研究生将在传热、材料科学、软硬物质相互作用和相平衡等方面做出贡献。本科生也将参与研究。将开发相关的视觉学习和网络工具，以整合研究和教育活动。

1033356CahillNanoscale objects, such as metal nanoparticles or carbon nanotubes, are prone to highly efficient absorption of electromagnetic radiation. When high intensity electromagnetic radiation is delivered to such objects, such as by a focused laser beam, the absorbed energy can lead to extreme local heating of and very large temperature increases in both the nanoscale objects and the surrounding medium. These highly localized thermal excursions correspond to heat fluxes that can be orders of magnitude larger than those sustained at the macroscale. Intellectual Merit: This research builds upon advances in (a) laser-based ultrafast optical techniques capable of capturing relevant phenomena at pico- to nanosecond time scales and (b) computational power and modeling techniques allowing simultaneous examination of such systems experimentally and theoretically at the same temporal and special scales. In particular, molecular dynamics simulations and time resolved pump-probe experiments will advance the understanding of heat transfer, phase transformation, and phase equilibria arising at the interface between the nanoscale solids and a surrounding liquid.Broader Impacts: The research focuses on the exchange of thermal energy between an intensely heated solid nanoparticles and a surrounding liquid. This has important implications for biomedical applications such as highly selective thermal therapy for cancer treatment. Graduate students engaged in the research will make contributions in heat transfer, materials science, soft-hard matter interactions, and phase equilibria. Undergraduate students will also be engaged in the research. Pertinent visual-learning and web-based tools will be developed to integrate the research and education activities.