Mechanical properties and degradation profile are important parameters for the applications of biodegradable polyester such as poly(glycerol sebacate) in biomedical engineering. Here, a strategy is reported to make palmitate functionalized poly(glycerol sebacate) (PPGS) to alter the polymer hydrophobicity, crystallinity, microstructures and thermal properties. The changes of these intrinsic properties impart tunable degradation profiles and mechanical properties to the resultant elastomers depending on the palmitate contents. When the palmitates reach up to 16 mol%, the elastic modulus is tuned from initially 838 ± 55 kPa for the PGS to 333 ± 21 kPa for the PPGS under the same crosslinking conditions. The elastomer undergoes reversible elastic deformations for at least 1000 cycles within 20% strain without failure and shows enhanced elasticity. The polymer degradation is simultaneously inhibited because of the increased hydrophobicity. This strategy is different with other PGS modifications which could form a softer elastomer with less crosslinks but typically lead to a quicker degradation. Because the materials are made from endogenous molecules, they possess good cytocompatibility similar to the PGS control. Although these materials are designed specifically for small arteries, it is expected that they will be useful for other soft tissues too.
Mesoscale order can lead to emergent properties including phononic bandgaps or topologically protected states. Block copolymers offer a route to mesoscale periodic architectures, but their use as structure directing agents for metallic materials has not been fully realized. A versatile approach to mesostructured metals via bulk block copolymer self‐assembly derived ceramic templates, is demonstrated. Molten indium is infiltrated into mesoporous, double gyroidal silicon nitride templates under high pressure to yield bulk, 3D periodic nanocomposites as free‐standing monoliths which exhibit emergent quantum‐scale phenomena. Vortices are artificially introduced when double gyroidal indium metal behaves as a type II superconductor, with evidence of strong pinning centers arrayed on the order of the double gyroid lattice size. Sample behavior is reproducible over months, showing high stability. High pressure infiltration of bulk block copolymer self‐assembly based ceramic templates is an enabling tool for studying high‐quality metals with previously inaccessible architectures, and paves the way for the emerging field of block‐copolymer derived quantum metamaterials.
In article number 2100469, Ulrich Wiesner and co-workers create quantum metamaterials in the form of double-gyroid structured indium metal superconductors via soft matter self-assembly. High pressure infiltration of molten metal into a block copolymer structure directed ceramic template transfers the polymer derived architecture into a ceramic/indium composite with high fidelity. The resulting mesoscale structure is shown to dictate electronic behavior via modification of fundamental, quantum level characteristics.
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