RUI: Controlling the Spectral Radiative Properties of a Dispersion of Core-Shell Multifunctional Nanoparticles

1066705 otanic5是否有可能动态控制分散在流体中的纳米颗粒的光谱辐射特性？这是本研究计划的核心问题。众所周知，纳米颗粒对热传输有多种好处，特别是通过纳米颗粒的分散可以实现辐射特性的巨大变化。随着纳米粒子的出现，控制分散体的辐射特性成为可能，而不是仅仅被动地观察这种特性。特别是，一个分散的核-壳多功能纳米粒子将被创建，能够动态改变它们的体积，从而改变它们的光谱辐射特性。初步实验表明，这些多功能纳米颗粒能够被合成以实现温度敏感的体积变化。迄今为止，大多数这些粒子都是用聚合物壳和无机壳合成的，而本提案计划用聚合物核和无机和金属壳来逆转这一点，以实现可见-红外波长的大辐射特性偏移。本提案通过一套全面的实验和分析来解决这个问题。实验将主要集中在使用分光光度法测量不同色散在不同温度和不同体积下的光谱辐射特性。然后，这些测量结果将与建模结果相关联，以提高对辐射输运动态控制的基本理解，这是核心材料、壳材料、尺寸和可实现的体积位移的函数。知识价值。本研究包含了一个有趣的纳米尺度热输运问题。拟议项目的潜在变革性质是动态（可逆）改变纳米粒子分散的辐射特性的令人兴奋的能力。一些基本问题将被解决，例如：核壳多功能纳米粒子的单一分散是否可以被控制，使其既可以作为吸收剂，也可以作为能量的发射器？这种控制可以通过被动的方式来实现吗？这是否可以使用成本效益高、环保的材料来实现？通过将辐射特性控制与多功能纳米颗粒提供的动态能力相结合，将研究创新的被动控制方法，以解决诸如：体积变化能否随温度变化而变化？是否可以用其他被动方法（如分散体的化学环境）来改变体积？色散可以经历多少次可逆的体积变化过程？导致吸光度变化的这些核-壳材料的基本结构-性质关系是什么？如何调整这种关系？更广泛的影响。这个项目的更广泛的影响来自三个不同的领域。首先是在纳米颗粒分散体中开发动态可控辐射特性可能带来的技术机遇。这种系统可能产生的一个潜在系统是两用太阳能热收集器和夜空散热器。使用纳米颗粒作为直接吸收接收器已被证明比传统的基于表面的接收器提供更高的效率。另一个有趣的选择是创造热光开关的能力。这样的开关将允许创造一种液体过滤器，有时是透明的，而在其他时候可能是不透明的。第二个影响在于本科研究和教育的方向。作为该项目的一部分，研究结果将通过设计一个全尺寸实验演示和一个关于色散辐射特性的台式实验室演示，整合到本科课程中。最后，将积极鼓励和促进占lmu本科生总数29%的未被充分代表群体通过研究和课堂机会的参与。

1066705 OtanicarIs it possible to dynamically control the spectral radiative properties of nanoparticles dispersed in a fluid? That is the fundamental question at the heart of this research proposal. Nanoparticles are known to offer a variety of benefits for thermal transport, and of particular relevance here the vast changes to the radiative properties that can be achieved through the dispersion of nanoparticles. With the advent of nanoparticles it is possible to control the radiative properties of dispersions as opposed to just passively observing such properties. In particular, a dispersion of core-shell multifunctional nanoparticles will be created that are capable of dynamically changing their volume and thus their spectral radiative properties. Preliminary experiments have shown that these multifunctional nanoparticles are capable of being synthesized to achieve temperature sensitive volumetric changes. To date most of these particles have been synthesized with polymer shells and inorganic cores while this proposal plans to reverse this with polymer cores and inorganic and metallic shells to achieve large radiative property shifts in the visible-infrared wavelengths. This proposal addresses this question through a comprehensive set of experiments and analyses. The experiments will largely focus on measuring the spectral radiative properties of different dispersions at different temperatures and thus different volumes using spectrophotometric techniques. These measurements will then be correlated with modeling results to improve fundamental understanding of the dynamic control of radiative transport as a function of the core material, shell material, size and volumetric shift achievable. Intellectual Merit. This research comprises an intriguing nanoscale thermal transport problem. The potentially transformative nature of the proposed project is the exciting capability to dynamically (and reversibly) change the radiative properties of a dispersion of nanoparticles. Fundamental questions will be addressed such as: can a single dispersion of core-shell multifunctional nanoparticles be controlled so that it can serve as either an absorber, or as an emitter of energy? Can this control be achieved in a passive manner? Can this be done using cost effective, environmentally benign materials? By coupling radiative property control with the dynamic capabilities offered by multifunctional nanoparticles innovative passive control methods will be investigated addressing further questions such as: Can volumetric changes be effected with changes in temperature? Are volumetric changes possible with other passive methods such as the chemical environment of the dispersion? How many times can the dispersion go through the reversible volume change process? What are the fundamental structure-property relationships in these core-shell materials that give rise to changes in absorbance and how can this relationship be tuned?Broader Impacts. The broader impacts of this project come in three different areas. The first is the technological opportunities that may be enabled by developing dynamically controllable radiative properties within the proposed nanoparticle dispersions. One potential system that may result from such a system is a dual-use solar thermal collector and night-sky radiator. The use of nanoparticles acting as direct absorption receivers has been shown to offer improved efficiencies over conventional surface-based receivers. Another intriguing option is the ability to create a thermo-optical switch. Such a switch would allow for creating a liquid filter that at times is transparent while at other times could be opaque. The second impact lies in the direction of undergraduate research and education. As part of this project the results of the research will be integrated into the undergraduate curriculum through the design of one full-scale experimental demonstration and one bench-top laboratory demonstration on the radiative properties of dispersions. Lastly, the participation of underrepresented groups, through research and classroom opportunities, which make up 29% of LMUs undergraduate population will be actively encouraged and promoted.