Utilizing the Photothermal Effect of Metal Nanoparticles for Processing of Polymers

这笔赠款提供资金，用于研究将嵌入聚合物复合材料中的金属纳米颗粒的光激活加热(光热效应)用作材料加工和驱动的工具。在这个光热过程中，通过调节到特定纳米粒子属性的可见光进行照射，导致纳米粒子加热并将能量局部转移到周围的聚合物。复合材料内部温度的测量将被用来确定固化、熔化或致动所需的纳米颗粒浓度和光强度。形状记忆聚合物的光热激活(随着温度变化而改变其形状或大小的材料)将与通过传统加热方法的激活进行比较。还将研究纳米纤维样品由于光热加热而产生的机械强度和模数的变化。纳米颗粒被限制在特定区域的多组分样品将被研究，以测试加热的空间特异性。如果成功，这项研究的结果将使聚合物材料的新加工方法成为可能，即从内部而不是从外部加热，使内部温度超过材料表面的温度。聚合物结构可以被交联以提高强度、被修复或在工作位置经历形状变化，同时避免环境温度的显著增加。纳米颗粒的选择性放置将使特定区域能够加热，以允许熔化、固化或重新结晶，而材料的其余部分不会受到影响。通过这种方式，可以设计和开发具有新的混杂性能的材料。

This grant provides funding to investigate the use of light-activated heating (photothermal effect) of metal nanoparticles embedded in a polymer composite as a tool for material processing and actuation. In this photothermal process, irradiation with visible light tuned to the specific nanoparticle properties results in nanoparticle heating and local transfer of energy to the surrounding polymer. Measurements of the internal temperature within the composite will be utilized to determine the nanoparticle concentration and light intensity required to cure, melt, or actuate. Photothermal activation of shape memory polymers (materials that alter their shape or size upon temperature change) will be compared with actuation via traditional heating methods. Changes in mechanical strength and modulus due to photothermal heating of nanofibrous samples will also be studied. Multi-component samples where nanoparticles are limited to a specific region will be investigated to test the spatial specificity of the heating. If successful, the results of this research will enable new processing approaches for polymeric materials, where heat is applied from within rather than from the exterior, enabling the internal temperature to exceed that of the material surface. Polymeric structures could be cross-linked to improve strength, be repaired, or undergo a shape change at a working location while avoiding significant increase in the temperature of the surroundings. The selective placement of nanoparticles would enable heating of specific regions to allow for melting, curing, or re-crystallization, while the remainder of the material would be unaffected. In this manner, materials with new hybrid properties can be designed and developed.