Dynamic Optical Studies of Transport Phenomena Associated with Melting and Recrystallization at the Nanoparticle-Ice Interface

与纳米颗粒-冰界面熔化和再结晶相关的输运现象的动态光学研究

• 批准号: 2107664
• 负责人: Bogdan Dragnea
• 金额: $ 43.5万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2107664&HistoricalAwards=false
• 关键词: Dynamic; Optical; Studies; Transport; Phenomena

With support from the Macromolecular, Supramolecular, and Nanochemistry (MSN) Program in the Division of Chemistry, Professor Bogdan Dragnea at Indiana University is utilizing sophisticated microscopies to study how nanoparticles affect ice melting. It is well-know that ice melts to form water when the temperature reaches 32 degrees Fahrenheit, or 0 degrees Celsius. However, this is not always the case. Nanoparticles, which are about a million times smaller than the period at the end of this sentence, can change this transition temperature. When embedded in ice, a thin layer often forms near the nanoparticle surface that can melt below normal temperatures. Working with his students, Professor Dragnea uses a photothermal microscopy technique to observe the melting of this thin ice layer when the nanoparticle is rapidly heated by a laser. Their discoveries could have implications for understanding a variety of environmental processes such as ice crystal formation in the atmosphere, as well as provide ways of controlling friction and adhesion on icy surfaces. The project is also providing research opportunities for graduate and undergraduate students from diverse backgrounds. In addition, through collaboration with the Indiana University Research and Technology Corporation (IURTC), Professor Dragnea is introducing his students to entrepreneurial concepts as they translate the project's instrumentation and scientific knowledge into useable technologies. Professor Dragnea is developing photothermal microscopy methods to obtain the transport and thermodynamic properties of the interfacial quasi-liquid layer (QLL) that separates the solid surface of a nanoparticle from bulk ice. Single nanoparticles with well-defined surface chemistries and geometries are embedded in a film of polycrystalline ice. The nanoparticle is then heated by laser excitation, raising the temperature of the surrounding solid. The formation of the QLL is detected by measuring the light scattered by the nanoparticle at various temperatures. The measurement is facilitated by modulation of the interfacial liquid thickness through repeated absorption of laser pulses by the nanoparticle. In addition to characterizing the convex surfaces of spherical nanoparticles, the formation of the QLL near concave surfaces of shape-controlled nanoparticles is also studied. By comparing optical and thermal simulations to experimental observations, transport and thermodynamic parameters are extracted. Experiments performed on individual particles alleviate challenges associated with impurities, defects, and particle-to-particle variations that reduce accuracy.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在化学系大分子、超分子和纳米化学（MSN）项目的支持下，印第安纳州大学的Bogdan Dragnea教授正在利用先进的显微镜研究纳米颗粒如何影响冰的融化。众所周知，当温度达到32华氏度或0摄氏度时，冰融化形成水。然而，情况并非总是如此。纳米粒子，比这句话末尾的句号小一百万倍，可以改变这个转变温度。当嵌入冰中时，通常在纳米颗粒表面附近形成一层薄层，该薄层可以在正常温度以下熔化。Dragnea教授与他的学生一起工作，使用光热显微镜技术观察当纳米颗粒被激光快速加热时，薄冰层的融化。他们的发现可能对理解各种环境过程（如大气中的冰晶形成）产生影响，并提供控制冰表面摩擦和粘附的方法。该项目还为来自不同背景的研究生和本科生提供研究机会。此外，通过与印第安纳州大学研究和技术公司（IURTC）的合作，Dragnea教授正在向他的学生介绍创业概念，因为他们将项目的仪器和科学知识转化为可用的技术。Dragnea教授正在开发光热显微镜方法，以获得将纳米颗粒的固体表面与大块冰分离的界面准液体层（QLL）的传输和热力学性质。具有明确的表面化学和几何形状的单个纳米颗粒嵌入多晶冰膜中。 然后通过激光激发加热纳米颗粒，提高周围固体的温度。QLL的形成通过测量在各种温度下由纳米颗粒散射的光来检测。通过纳米颗粒对激光脉冲的重复吸收来调制界面液体厚度，从而促进测量。除了表征球形纳米颗粒的凸面外，还研究了形状控制纳米颗粒的凹面附近的QLL的形成。通过比较光学和热模拟实验观察，运输和热力学参数提取。对单个颗粒进行的实验减轻了与杂质、缺陷和颗粒间变化相关的挑战，这些挑战降低了准确性。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Real-Time Optical Measurements of Nanoparticle-Induced Melting and Resolidification Dynamics

纳米颗粒引起的熔化和再凝固动力学的实时光学测量

• DOI: 10.1021/acsnano.2c09212
• 发表时间: 2023
• 期刊: ACS Nano
• 影响因子: 17.1
• 作者: Jo, Suhun;Schaich, William L.;Dragnea, Bogdan
• 通讯作者: Dragnea, Bogdan