Data supporting "Spatially-Resolved Viscoelastic Response with AFM-IR"

The deposited dataset contains underlying AFM data for figures (Figure 2/4/6 + Figures S2.8) in the paper "Spatially-Resolved Viscoelastic Response with AFM-IR", by Lim et. al. Abstract of the publication: The viscoelastic response of phase-separated polymers systems may deviate from bulk values at the nanoscale. However, current measurement techniques lack the resolution to unmask local variations. We previously demonstrated the advantages of using a focused, pulsed infrared (IR) laser to photothermally heat a sample locally during nanomechanical measurements with an atomic force microscope (AFM), with heating controlled by varying the laser repetition rate. Herein, we demonstrate this IR heating coupled with nano-Dynamic Mechanical Analysis (nDMA). First, we measured the storage and loss modulus of a homogenous copolymer at varying IR repetition rates (i.e., at varying sample temperature), demonstrating a viscoelastic modulus response that is typical near the glass transition temperature. Further, we varied the IR laser repetition rate while modulating the AFM probe between 5 Hz and 100 Hz. With time-temperature superposition, modulus master curves were constructed through the Williams-Landel-Ferry relation, and the shift factors of IR heating-coupled nDMA curves were used to estimate the relation between IR repetition rate and surface temperatures. Lastly, this technique was applied to a phase-separated polymer blend to demonstrate the utility of the technique to decouple the viscoelastic behavior of different phases by leveraging the high spatial resolution of AFM.