NER: Nanoscale Profiling of the Elastic and Viscoelastic Response of Individual Nanotubes

单个碳纳米管弹性和粘弹性响应的纳米尺度分布摘要：所提出的活动的目标是定量地、纳米尺度地研究多壁纳米管(MWNTs)的弹性和粘弹性特性的局部变化。超声力显微镜(UFM)和外差力显微镜(HFM)将分别用于定量提取和绘制沿弧光放电或化学气相沉积生长的单管的折合杨氏模数和损耗因子。模数提取将利用超声振动(10 MHz)下扫描探头尖端和纳米管表面之间的非线性相互作用来确定沿轴向小范围(10 Nm X 10 Nm)内的多壁碳纳米管接触刚度。粘弹性成像将利用外差方法，将超声波振动应用于多壁碳纳米管和纳米探针尖端，以产生多壁碳纳米管粘弹性响应的时间分辨机械相图像。还将对HFM纳米管仿形进行热研究(100K至600K)，以研究粘弹性的热演化。

TITLE: Nanoscale Profiling of the Elastic and Viscoelastic Response ofIndividual Carbon NanotubesAbstract: The goal of the proposed activity is the quantitative, nanoscale profiling of local variations in the elastic and viscoelastic properties of multiwall nanotubes (MWNTs). Ultrasonic force microscopy (UFM) and heterodyne force microscopy (HFM) will be utilized for the quantitative extraction and mapping of the reduced Young's modulus and loss factor, respectively, along the axis of single tubes grown via arc-discharge or chemical vapor deposition. Modulus extraction will exploit the nonlinear interaction between a scanning probe tip and the nanotube surface at ultrasonic vibrations ( 10 MHz) to determine the MWNT contact stiffness within a small (10nm x 10nm) area along the axis. The viscoelastic imaging will utilize a heterodyne approach wherein ultrasonic vibrations are applied to both the MWNT and the nanoprobe tip to produce a time-resolved mechanical phase image for the MWNT viscoelastic response. Thermal studies (100K to 600K) will also be undertaken for HFM nanotube profiling to investigate the thermal evolution of visoelasticity.