Sub-microsecond molecular motion analysis of polymer resins via transmitted X-ray blinking

Area of Science:

• Materials Science
• Polymer Physics
• X-ray Imaging

Background:

• Distinguishing polymers with similar X-ray absorption is challenging.
• Sub-microsecond molecular dynamics are difficult to probe with conventional methods.

Purpose of the Study:

• To introduce transmitted X-ray blinking (TXB) as a novel time-resolved imaging technique.
• To demonstrate TXB's capability in probing sub-microsecond molecular dynamics.
• To differentiate between semi-crystalline polyetheretherketone (PEEK) and amorphous polyetherimide (PEI) using TXB.

Main Methods:

• Developed transmitted X-ray blinking (TXB) with 900-nanosecond resolution.
• Applied TXB to PEEK and PEI samples.
• Utilized single-pixel autocorrelation analysis (spACF) for dynamic behavior analysis.
• Employed machine learning for enhanced dynamic contrast and classification.
• Performed spectral decomposition to identify periodic fluctuations.

Main Results:

• TXB revealed statistically significant differences in dynamic behavior between PEEK and PEI.
• Machine learning analysis achieved >90% classification accuracy for material differentiation.
• Spectral decomposition identified periodic fluctuations in the 300-400 kHz range.
• TXB successfully differentiated materials despite indistinguishable static images and similar X-ray absorption.

Conclusions:

• TXB is effective for probing sub-microsecond molecular dynamics.
• TXB enables material differentiation based on intrinsic dynamic properties, even without static contrast.
• TXB offers new possibilities for visualizing subtle motions in soft and biological systems.