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The composite materials combining quantum dots (QDs) and photonic crystals (PCs) could produce complex and high-dimensional anti-counterfeiting patterns, which solves the problems of simple coding information and low anti-counterfeiting level...

Thermoplastic elastomer ethylene/α-octene co-polymer (POE) is a special polymer material with both elasticity and thermoplasticity. However, the nonpolarity and lowtensile strength of POE limit its application in polar materials and high-strength materials fields. In this study, we synthesized a specific molecule with C═C bonds and N H bonds, which was introduced into POE to construct hydrogen bonding network, and the prepared modified POE is further blended with carboxyl terminated polystyrene nanospheres as toughening agent to prepare modified POE elastomer composites. Based on such dual toughening strategy containing chemical modification and physical toughening, the modified POE elastomer composites possess improved mechanical properties. The composites achieve a tensile strength of 21.4 MPa, elongation at break of 1268%, fracture energy of 109.6 MJÁm À3 and exhibit improved thermal stability. Impressively, the tensile strength of reprocessed composites is restored to more than 90% of their original tensile strength even after four times of reprocessing steps, demonstrating excellent reusability.

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Currently, there have been widespread investigation conducted into responsive photonic crystal hydrogels (RPCHs) characterized by high selectivity and sensitivity for colorimetric indicators and physical/chemical sensors. In spite of this, it remains challenging to use RPCHs for sensing due to their limited mechanical property and molding capability. In the present study, a double-network structure is proposed to design highly stretchable, sensitive, and reusable ion-detection photonic papers (IDPPs) for assessing the quality of visual and portable comestible liquids (e.g., soy sauce). It is constructed by integrating polyacrylamide and polymethacryloxyethyl trimethyl ammonium chloride with highly ordered polystyrene microspheres. The double-network structure improves the mechanical properties of IDPPs with their elongation at break increasing from 110 to 1600%. Meanwhile, the optical properties of photonic crystals are retained. The IDPPs achieve a fast ion response by applying control on the swelling behavior of the hydration radius of the counter ions through ion exchange. Given a certain concentration range (0.01−0.10 M), chloride ions can be detected fast (3−30 s) by exchanging ions with a small hydration radius through an IDPP, which is clearly observable. Due to the improvement of mechanical properties and the reversible exchange of ions derived from IDPPs, their reusability is significantly enhanced (>30 times). Characterized by a simple operation, high durability, and excellent sustainability, these IDPPs are promising for practical application in food security and human health assessment.