CAREER: Nanoscale Thermal Transport in Hydrogen-Bonded Materials

职业：氢键材料中的纳米级热传输

• 批准号: 1751610
• 负责人: Ling Liu
• 金额: $ 50万
• 依托单位: Utah State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-05-01 至 2019-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1751610&HistoricalAwards=false
• 关键词: CAREER; Nanoscale; Thermal; Transport; Hydrogen

The hydrogen bond (H-bond) is an essential element of many materials including DNA, proteins, hydrogels and molecular self-assemblies. Despite existing knowledge of energy transport in some large protein systems, a systematic understanding of nanoscale thermal transport across H-bonded materials and, in particular, the role of H-bonds is lacking. The knowledge gap has hindered the understanding of heat transfer in living systems and development of novel biomaterials, e.g. synthetic spider silk, with extraordinary thermal properties. To address these critical challenges, this project investigates a suite of H-bonded materials including protein secondary structures and organic-inorganic interfaces, using state-of-the-art computational approaches combined with experimental validations. The research outcomes will accelerate design, development and deployment of novel H-bonded materials with tunable thermal properties, to meet the increasing needs for biocompatible, multifunctional materials in a wide range of areas including bio-implantation, tissue regeneration, cancer treatment, and energy storage. This project also seeks to achieve three societally relevant outcomes including (1) broadening participation of Female Native American students in engineering through two mentoring programs; (2) fostering skills of materials modeling among undergraduate students using a 3D Printing Challenge and a Fellowship program; and (3) conveying essential concepts of biomaterials and thermal management to high school students and the general public through outreach activities.Building upon recent progress in advanced phonon transport theory and vibrational mode analysis, this project systematically reveals the role of H-bonds in thermal transport across several representative building blocks of H-bonded materials including nanocrystals (e.g. protein beta-sheets), nanowires (e.g. protein alpha-helices and 3-10 helices) and interfaces. By using molecular dynamics simulations and functional theory calculations, the investigations quantifies anisotropy of thermal conduction in the H-bonded building blocks in association with several structural and environmental factors including the H-bond connectivity (e.g. alpha helices vs. 3-10 helices), the side chain chemistry and size, and the solvation. Particular emphasis is given to understanding how different amino acid sequences can affect thermal conductivities and transport characteristics including phonon density of states, group velocities, and lifetimes. New physical insights are generated regarding: (1) how H-bond networks of different forms contribute to nanoscale thermal transport; and (2) how thermal transport in H-bonded materials differs from that in other 1D (e.g. nanotubes), 2D (e.g. graphene) and 3D materials that have no H-bonds. The achieved knowledge base enables development of new synthetic silk with highly conductive building blocks as well as novel H-bonded interfaces that are made, characterized and compared with existing materials for validation of the theory.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.

氢键是DNA、蛋白质、水凝胶和分子自组装等许多材料的基本组成部分。尽管在一些大型蛋白质系统中的能量传输的现有知识，在氢键材料，特别是氢键的作用，纳米级的热传输的系统的理解是缺乏的。知识差距阻碍了对生命系统中热传递的理解和新型生物材料的开发，例如具有非凡热性能的合成蜘蛛丝。为了解决这些关键挑战，该项目研究了一套氢键材料，包括蛋白质二级结构和有机-无机界面，使用最先进的计算方法与实验验证相结合。研究成果将加速设计，开发和部署具有可调热性能的新型氢键材料，以满足生物植入，组织再生，癌症治疗和能量存储等广泛领域对生物相容性，多功能材料日益增长的需求。该项目还寻求实现三个社会相关成果，包括（1）通过两个指导计划扩大美国原住民女学生在工程方面的参与;（2）使用3D打印挑战和奖学金计划培养本科生的材料建模技能;以及（3）通过外展活动向高中生和公众传达生物材料和热管理的基本概念。在先进的声子输运理论和振动模式分析中，该项目系统地揭示了氢键在氢键材料的几个代表性构建块中的热输运中的作用，包括纳米晶体（例如蛋白质β-片层），纳米线（例如蛋白质α-螺旋和3-10螺旋）和界面。通过使用分子动力学模拟和泛函理论计算，研究量化了氢键结构单元中热传导的各向异性与几个结构和环境因素，包括氢键连接性（例如α螺旋与3-10螺旋），侧链化学和大小以及溶剂化。特别强调的是了解不同的氨基酸序列如何影响热导率和传输特性，包括声子态密度，群速度和寿命。产生了新的物理见解：（1）不同形式的氢键网络如何有助于纳米级热传输;以及（2）氢键材料中的热传输如何不同于其他1D（例如纳米管），2D（例如石墨烯）和3D材料中没有氢键。所获得的知识基础使开发具有高导电性结构单元的新型合成丝以及新型氢键界面成为可能，这些界面的制造、表征以及与现有材料的比较都是为了验证理论。该奖项反映了NSF的法定使命，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。