Bulk morphology of porous materials at sub-micrometer scale studied by multi-modal X-ray imaging with Hartmann masks

TL;DR

This study employs multi-modal X-ray imaging with Hartmann masks to quantitatively analyze the sub-micrometer pore structure of porous graphite, revealing detailed morphological parameters and anisotropy with a flexible setup.

Contribution

It introduces a novel application of Hartmann mask-based X-ray imaging for detailed bulk pore morphology analysis at sub-micrometer scales.

Findings

Measured average pore size and pore fraction

Determined fractal dimension and Hurst exponent

Identified pore size anisotropy

Abstract

We present the quantitative investigation of the submicron structure in the bulk of porous graphite by using the scattering signal in the multi-modal X-ray imaging with Hartmann masks. By scanning the correlation length and measuring the mask visibility reduction, we obtain average pore size, relative pore fraction, fractal dimension, and Hurst exponent of the structure. Profiting from the dimensionality of the mask, we apply the method to study pore size anisotropy. The measurements were performed in a simple and flexible imaging setup with relaxed requirements on beam coherence.