Abstract
Atomic-force microscopy coupled with infrared spectroscopy (AFM-IR) deciphers surface morphology of thin-film polymer blends and composites by simultaneously mapping physical topography and chemical composition. However, acquiring quantitative phase and composition information from multi-component blends can be challenging using AFM-IR due to the possible overlapping infrared absorption bands between different species. Isotope labeling one of the blend components introduces a new type of bond (carbon-deuterium vibration) that can be targeted using AFM-IR and responds at wavelengths sufficiently shifted toward unoccupied regions (around 2200 cm−1). In this project, AFM-IR was used to probe the surface morphology and chemical composition of three polymer blends containing deuterated polystyrene; each blend is expected to exhibit various degrees of miscibility. AFM-IR results successfully demonstrated that deuterium labeling prevents infrared spectral overlap and enables the visualization of blend phases that could not normally be distinguished by other scanning probe techniques. The nanoscale domain composition was resolved by fast infrared spectrum analysis. Overall, we presented isotope labeling as a robust approach for circumventing obstacles preventing the quantitative analysis of multiphase systems by AFM-IR.
| Original language | English |
|---|---|
| Pages (from-to) | 7365-7373 |
| Number of pages | 9 |
| Journal | Nanoscale |
| Volume | 15 |
| Issue number | 16 |
| DOIs | |
| State | Published - Apr 4 2023 |
Funding
The work presented by the authors was supported by the US Army Engineer Research and Development Center (ERDC) under PE 0603734A, Project T15, Task “Advanced Polymer Development” under ERDC BAA 18-0500 “Multifunctional Materials to Address Military Engineering” executed under Contract No. W912HZ-18-C-0022. Permission to publish was granted by the Director, Geotechnical and Structures Laboratory. Part of the research used resources at the Spallation Neutron Source and the Center for Nanophase Materials Sciences, DOE Office of Science User Facilities operated by the Oak Ridge National Laboratory.