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It is known that X‐ray CT of organic polymer materials usually provides low‐contrast images because of the low X‐ray absorption of these materials. In this paper, we describe a new method to enhance the contrast of X‐ray CT images of organic polymer materials. We demonstrate that gamma‐ray irradiation of poly (ethylene terephthalate) (PET) fibers in dichloromethane containing 2‐bromoethyl methacrylate, 2‐chloroethyl methacrylate, or 4‐bromostyrene results in the grafting of halogen‐containing oligomeric chains onto the PET fibers. Focused ion beam scanning electron microscopy (FIB‐SEM) and time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS) analyses revealed a homogeneous distribution of bromine atoms within the 2‐bromoethyl methacrylate‐modified PET fibers, not only on the surface. This uniform incorporation translated to a significant improvement in X‐ray CT image contrast compared with pristine fibers. Similar treatment of polypropylene pellets also enhanced the contrast of their X‐ray CT images. This is a new simple and effective method to enhance the X‐ray CT image contrast and potentially applicable to various polymer materials including polymer composites and porous polymer materials, readily allowing the observation of their 3D microstructures finely. [ABSTRACT FROM AUTHOR]

A commercial high‐resolution X‐ray computed tomography (CT) was utilized for non‐destructive analysis of single fibers. The micro‐CT apparatus was employed because it is applicable to both colored and colorless fibers. A sample preparation using adhesive sheets was demonstrated, and the method is similar to typical tape‐lift sample collection method in crime cases. Different cross‐sectional shapes of nylon and polyester single fibers were non‐destructively distinguished, and the method is applicable to all types of fibers. Cross‐sectional areas, aperture ratios, and volumes of individual fibers were directly and automatically measured using the open‐source software. The observed parameters were within a coefficient of variation of 3%. In addition, a mass of a single fragment of a fiber can be estimated when the local density is given. [ABSTRACT FROM AUTHOR]

Three-dimensional imaging of trace elements in a single hair strand was achieved by a micro X-ray fluorescence computed tomography (μXRF-CT) using synchrotron radiation. A simple rotational mechanism was attached to a two-dimensional XRF imaging system and a wide range of longitudinal scans was realized. The experimental determination of centroid of projections helped to maintain the spatial resolution around 2 μm that was determined by the beam size. Determination of trace element concentration in a single hair strand was realized by combining measurements of both scattered X-ray and XRF intensities, and longitudinal changes in concentration were observed. Cross-sectional distribution of Br, Zn, Fe and Cu were obtained at the positions of interest after the longitudinal scan, and changes in distribution forms were observed. [ABSTRACT FROM AUTHOR]