Excellence in Research: Development of a Non-Fluorinated Etching Procedure to Prepare MXene Hybrid Materials for Composite Applications

非技术描述：MXenes是一种2D材料，具有优异的电磁性能，用于许多应用，如电磁辐射屏蔽、超级电容器和电池。在这个项目中，佛罗里达农工大学(FAMU)、FAMU-FSU(佛罗里达州立大学)工程学院(COE)和克拉克亚特兰大大学(CAU化学)的一组研究人员致力于用一种危险程度较低的方法制备一类具有均一表面功能的MXenes。这种合成MXenes的新方法将为开发不同用途的杂化材料和产生独特的复合材料开辟新的途径。随后，该项目寻求通过参与MXene材料研究来增加进入工程和科学课程的本科生和研究生的数量，以攻读更高的学位。学生对研究生项目和暑期研究机会的兴趣也将增加，这将导致2+3双学位工程课程的建立。技术细节：MXenes来自MAX相，在MAX相中，A元素，通常是铝，通过用有毒的氟化氢蚀刻来去除。采用一种新型的非氟方法对MXenes进行系统研究，使用以下研究旨在了解使用非氟化蚀刻过程的合成/蚀刻/剥离过程，从而能够控制所得对MXenes应用至关重要的微观结构和宏观性能：1)使用MAX相上的非氟化蚀刻技术制备具有更高稳定性和均匀表面功能的MXenes。2)了解刻蚀过程对MXene的化学、形态和化学环境的影响，以及对流变性、电性和磁自旋性质的影响。3)利用溴或其他官能团端基的热力学稳定性计算、单层和双层MXene结构的几何优化以及振动频率计算建立了基于特定官能团端基的MXene模型，并与实验结果进行了比较。4)开发新型MXene复合结构，用于制造具有良好磁性和电学性能的器件。5)探索一种新的刻蚀方法对其他类型的MAX相的适用性。该EIR项目的发现将有助于制度变革，使跨学科研究的质量与教育成果保持一致，并使学生接触到新的化学合成和剥离技术、国家强磁场实验室(NHMFL)国家用户设施的仪器，以及使用最先进的设备制造MXene结构和设备的3D打印。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

NON-TECHNICAL DESCRIPTION: MXenes are 2D materials with excellent electrical/magnetic properties for use in a number of applications such as electromagnetic radiation shielding, supercapacitors and batteries. In this project, a team of researchers at the Florida A & M University (FAMU), FAMU-FSU (Florida State University) College of Engineering (COE), and Clark Atlanta University (CAU-Chemistry), aim to prepare a class of MXenes with homogenous surface functionality using a less hazardous procedure. This novel method of synthesizing MXenes will open new avenues of developing hybrid materials for different applications and the generation of unique composite materials. Subsequently, this project seeks to increase the number of undergraduate and graduate minority students enrolling in engineering and science programs to pursue advanced degrees through involvement in MXene materials research. Student interest about graduate programs and summer research opportunities will also increase, leading to the establishment of a 2+3 dual-degree engineering program. TECHNICAL DETAILS: MXenes are derived from MAX phases, where the A element, usually aluminum, is removed by etching with toxic hydrogen fluoride. The systematic investigation of MXene with a novel non-fluorine based method using the following research aims to understand the synthesis/etching/exfoliation processes using a non-fluorinated etching procedure allows for control of the resultant microstructure and macroscopic properties crucial to MXenes applications: 1) Preparing MXenes with improved stability and homogenous surface functionality using non-fluorinated etching techniques on MAX phases. 2) Understanding the impact of this etching process on the MXene chemistry, morphology, and chemical environment on rheological, electronic, and magnetic/spin properties. 3) Building a MXene model based on specific functional groups terminations using thermodynamic stability calculations of bromine or other functional group terminations, geometry optimizations for single and bilayer MXene structures, and vibrational frequency calculations to compare with experimental results. 4) Developing novel MXene composite structures for manufacturing devices with desirable magnetic and electronic properties. 5) Exploring the suitability of a novel etch method for other types of MAX phases. The findings from this EiR project will contribute to institutional change by aligning the qualities of interdisciplinary research with educational outcomes and exposing students to new chemical synthesis and exfoliation techniques, instrumentation at the National High Magnetic Field Lab (NHMFL) national user facility, and 3D printing using state-of-the-art equipment to fabricate MXene structures and devices.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.