Soft shape memory polymers typically embody a permanently memorized geometry that cannot be altered, and therefore a new sample must be fabricated each time a new structure is required. We present a shape memory elastomeric composite featuring thermoplastic fibers as a fixing phase and a polyanhydride-based elastomer as the permanent, elastic phase. Interestingly, dynamic covalent exchange reactions at elevated temperatures (T > 50 °C) among the network chains of the elastomer allow near-complete reconfiguration of the permanent shape in the solid state. Together, these features combine to create a shape memory elastomer capable of arbitrary programming of both temporary and permanent shapes.

Mechanically robust forms of HKUST-1 metal− organic frameworks (MOFs) were fabricated by embedding the MOF crystals in a passive polyacrylonitrile (PAN) matrix at different MOF loadings of 10−90 mass %. PAN is highly porous and acts as a scaffold that holds the active MOF adsorbent in place. These MOF−PAN composites were then evaluated for capturing Xe. Data presented herein show that the PAN matrix does not notably interfere with the Xe capture process, where the Xe capacities scale somewhat linearly with the increase in MOF loadings within the composites. Also, γ radiation exposures to the composites revealed that they are highly tolerant to these types of radiation fields.

Various radionuclides are released as gases during reprocessing of used nuclear fuel or during nuclear accidents including iodine-129 ( 129 I) and iodine-131 ( 131 I). These isotopes are of particular concern to the environment and human health as they are environmentally mobile and can cause thyroid cancer. In this work, silver-loaded heat-treated aluminosilicate xerogels (Ag-HTX) were evaluated as sorbents for iodine [I 2(g) ] capture. After synthesis of the base NaAlSiO 4 xerogel, a heat-treatment step was performed to help increase the mechanical integrity of the NaAlSiO 4 gels (Na-HTX) prior to Ag-exchanging to create Ag-HTX xerogels. Samples were characterized by powder X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, Brunauer–Emmett–Teller analysis, gravimetric iodine loading, nanoindentation, and dynamic mechanical analysis. The structural and chemical analyses of Ag-HTX showed uniform distribution of Ag throughout the gel network after Ag-exchange. After I 2(g) capture, the AgI crystallites were observed in the sorbent, verifying chemisorption as the primary iodine capture mechanism. Iodine loading of this xerogel was 0.43 g g –1 at 150 °C over 1 day and 0.52 g g –1 at 22 °C over 33 days. The specific surface area of Ag-HTX was 202 m 2 g –1 and decreased to 87 m 2 g –1 after iodine loading. The hardness of the Na-HTX was >145 times higher than that of the heat-treated aerogel of the same starting composition. The heat-treatment process increased Young’s modulus (compressive) value to 40.8 MPa from 7.0 MPa of as-made xerogel, demonstrating the need for this added step in the sample preparation process. These results show that Ag-HTX is a promising sorbent for I 2(g) capture with good iodine loading capacity and mechanical stability.

A chemical recycling approach of mixed PET was demonstrated here that provides a mechanism by which PET waste can be efficiently recovered and repurposed to value-added products. The approach utilizes aminolysis of PET with a variety of amine nucleophiles, generating a small library of terephthalic amides with distinct structures, such as polar, nonpolar, and lipophilic. In order to probe the value of these products, the terephthalic amides were added to road-grade asphalt binder at 5 wt %, and the fresh resulting composite was evaluated. Specifically, rutting and fatigue characteristics as well as thermomechanical and creep performance were characterized and found to be improved by the inclusion of these additives by as much as 18%. In this work, additives made from deconstructed PET wastes were shown to improve the performance properties of asphalt at a variety of environmental conditions. It is important to note that the asphalt binder utilized in this work was a commercial product already optimized for road conditions, not the raw bitumen; perhaps higher performance metrics could be obtained with virgin bitumen.