Shape-Controlled Iron-Paraffin Composites as γ- and X-ray Shielding Materials Formable by Warmth-of-Hands-Derived Plasticity.

The design of shielding materials against ionizing radiation while simultaneously displaying enhanced multifunctional characteristics remains challenging. Here, for the first time, we present moldable paraffin-based iron nano- and microcomposites attenuating γ- and X-radiation. The moldability was gained by the warmth-of-hands-driven plasticity, which allowed for obtaining a specific shape of the composites at room temperature. The manufactured composites contained iron particles of various sizes, ranging from 22 nm to 63 µm. The target materials were widely characterized using XRD, NMR, Raman, TGA, SEM, and EDX. In the case of microcomposites, the shielding properties were developed at two concentrations: 10 and 50 wt %. The statistically significant results indicate that the iron particle size has a negligible effect on the shielding properties of the nano- and microcomposites. On the other hand, the higher iron particle contents significantly affected the attenuating ability, which emerged even as superior to the elemental aluminum in the X-ray range: at a 70 kV anode voltage, the half value layer was 6.689, 1.882, and 0.462 cm for aluminum, paraffin + 10 wt % Fe 3.5-6.5 µm, and paraffin + 50 wt % Fe 3.5-6.5 µm microcomposites, respectively. Importantly, the elaborated methodology-in situ cross-verified in the hospital studies recording real-life sampling-opens the pathway to high-performance, eco-friendly, lightweight, and recyclable shields manufactured via fully reproducible and scalable protocols.

1,2,4-Triazine-based chromogenic reagents for the detection of microtraces of various metals left on human skin.

This article extends the application of 1,2,4-triazine-based chromogenic reagents to the detection of nonferrous metal traces left on contact with canvas and human skin. The possibility of detection of iron traces resulting from contact with objects made of stainless steel was investigated as well. Additionally, the ability of triazines to form chromatic complexes with Zn(2+), Ni(2+), Co(2+), Cu(2+), Cr(3+), and Al(3+) ions was studied spectrophotometrically. Molar absorption coefficients, ranging from 8.8 to 29.9 x 10(3)/M/cm, provide high sensitivity of 1,2,4-triazines toward nonferrous ions, thus, enabling the detection at concentrations as low as a few muM. The method was sensitive enough to detect traces resulting from a 1-min contact with a stainless steel made object, which is commonly considered as a corrosion-resistant material. The amounts of metal ions transferred to the skin after a 2-min contact with objects made of brass, zinc, and copper were sufficient to develop chromatic imprints.