CAREER: Pushing the Lower Limit of Thermal Conductivity in Layered Materials

事业：突破层状材料导热率的下限

• 批准号: 1943813
• 负责人: Jun Liu
• 金额: $ 51.88万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-03-01 至 2025-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1943813&HistoricalAwards=false
• 关键词: CAREER; Pushing; Lower; Limit; Thermal

Identifying effective strategies to achieve exceptionally low thermal conductivity in solid-state materials can potentially push the extremes in heat conduction. The proposed project seeks to enable novel thermal control functionalities in disordered, layered materials to be applied in sustainable energy infrastructure, such as energy savings by thermal insulation, energy storage in batteries, energy conversion in thermoelectrics, and thermal management in electronics. The integration of research, education, and outreach programs aims to raise the public awareness of challenges in sustainable energy, and motivate students to pursue appropriate education pathways to STEM occupations. Cinematic 360 Virtual Reality lab tours will be developed to "teleport" online K-12 students into the lab to visualize thermal transport research and its applications in sustainable energy. Teachers will be invited to collaborate and pilot educational activities promoting the importance and challenges in sustainable energy infrastructure. The enhancement of students' preparation for a STEM career will be achieved by a summer program with a particular emphasis on reaching out to female and African-American students.The research goal of this CAREER project is to understand how to suppress vibrational energy transport in anisotropic layered materials by disorder. Precise and reversible control of the degree and inhomogeneity of disorder and thus interlayer spacing are achieved by an electrochemistry process, which inserts ions or molecular chains into the van der Waals gaps of layered crystals. The investigations will focus on a model transition metal dichalcogenide crystal, using complementary state-of-the-art theoretical and experimental approaches. The thermal conductivity of bulk crystals with a controllable amount and type of ions or molecular chains inserted into the gaps will be measured by the time-domain thermoreflectance method. The contribution from different types of vibrational modes to the microscopic thermal transport in these disordered crystals will then be analyzed using a combination of lattice dynamics and molecular dynamics methods. The success of this project will enable the first set of experimental and theoretical studies to elucidate the roles of interlayer spacing and bonding environment on suppressing vibrational energy transport, thereby advancing the current understanding on the microscopic thermal transport mechanisms in anisotropic disordered, layered materials.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.

确定有效的策略来实现固态材料的极低热导率，可能会推动热传导的极端化。该项目旨在使无序分层材料中的新型热控制功能能够应用于可持续能源基础设施，例如通过隔热节能，电池储能，热电能量转换和电子热管理。研究，教育和推广计划的整合旨在提高公众对可持续能源挑战的认识，并激励学生追求适当的教育途径，以STEM职业。将开发电影360虚拟现实实验室图尔斯之旅，将在线K-12学生“传送”到实验室，以可视化热传输研究及其在可持续能源中的应用。教师将被邀请合作和试点教育活动，促进可持续能源基础设施的重要性和挑战。通过暑期项目，以女性和非裔美国学生为对象，加强学生的STEM职业准备。CAREER项目的研究目标是了解如何通过无序抑制各向异性层状材料中的振动能量传输。通过将离子或分子链插入层状晶体的货车范德华间隙中的电化学过程，实现了对无序程度和不均匀性的精确和可逆控制，从而实现了对层间距的精确和可逆控制。调查将集中在一个模型过渡金属dichalcogenide晶体，使用互补的最先进的理论和实验方法。用时域热反射法测量了插入间隙中的离子或分子链的数量和类型可控的大块晶体的热导率。从不同类型的振动模式在这些无序晶体的微观热输运的贡献，然后将使用晶格动力学和分子动力学方法的组合进行分析。该项目的成功将使第一组实验和理论研究能够阐明层间距和键合环境对抑制振动能量输运的作用，从而推进目前对各向异性无序中微观热输运机制的理解，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。

项目成果

In-Plane Thermoelectric Properties of Flexible and Room-Temperature-Doped Carbon Nanotube Films

• DOI: 10.1021/acsaem.0c00995
• 发表时间: 2020-07-27
• 期刊: ACS APPLIED ENERGY MATERIALS
• 影响因子: 6.4
• 作者: Chatterjee, Kony;Negi, Ankit;Ghosh, Tushar K.
• 通讯作者: Ghosh, Tushar K.

Size Effects in the Thermal Conductivity of Amorphous Polymers

• DOI: 10.1103/physrevapplied.14.044023
• 发表时间: 2020-10-14
• 期刊: PHYSICAL REVIEW APPLIED
• 影响因子: 4.6
• 作者: Feng, Tianli;He, Jixiong;Shrestha, Som S.
• 通讯作者: Shrestha, Som S.

Molecular dynamics simulation of thermal transport in semicrystalline polyethylene: Roles of strain and the crystalline-amorphous interphase region

• DOI: 10.1063/5.0067999
• 发表时间: 2021-12-08
• 期刊: JOURNAL OF APPLIED PHYSICS
• 影响因子: 3.2
• 作者: He, Jixiong;Liu, Jun
• 通讯作者: Liu, Jun

Evaluating the roles of temperature-dependent eigenvectors in predicting phonon transport properties of anharmonic crystals using normal mode analysis methods

• DOI: 10.1063/5.0053287
• 发表时间: 2021-06
• 期刊: Journal of Applied Physics
• 影响因子: 3.2
• 作者: Jixiong He;Jun Liu

Molecular Dynamics Simulation of Steady-State Droplet Condensation on A Fiber in Direct Contact Membrane Distillation Settings

• DOI: 10.1016/j.molliq.2022.120736
• 发表时间: 2022-11
• 期刊: Journal of Molecular Liquids
• 影响因子: 6
• 作者: S. Raza;Jixiong He;H. Tafreshi;J. Liu