Anisotropic aerogel-foam composites were developed by embedding a reduced graphene oxide (rGO)/chitosan aerogel directly into an open-cell polyurethane foam through an in situ bidirectional ...freeze-drying process. The resulting aerogel-foam composites possess both excellent compression-resilience performance and stable piezo-resistive properties due, respectively, to the excellent mechanical properties of polyurethane foams and to the presence of a chitosan-based aerogel loaded with rGO. The latter, indeed, provides outstanding electrical properties due to its conductive and parallel flat lamellar structure. It has been proven that both mechanical and piezo-resistive properties are stable even after 1000 loading/unloading cycles and a reduction of the electrical resistance of about 86% is observed upon the application of a 60% strain. The high sensitivity, long cycling life, and reliable performance over a wide strain range make this unique anisotropic aerogel-foam composite a highly promising candidate for the production of wearable sensors and healthcare monitoring devices.
Anisotropic aerogel-foam composites were developed by embedding a reduced graphene oxide (rGO)/chitosan aerogel directly into an open-cell polyurethane foam through an
in situ
bidirectional ...freeze-drying process. The resulting aerogel-foam composites possess both excellent compression-resilience performance and stable piezo-resistive properties due, respectively, to the excellent mechanical properties of polyurethane foams and to the presence of a chitosan-based aerogel loaded with rGO. The latter, indeed, provides outstanding electrical properties due to its conductive and parallel flat lamellar structure. It has been proven that both mechanical and piezo-resistive properties are stable even after 1000 loading/unloading cycles and a reduction of the electrical resistance of about 86% is observed upon the application of a 60% strain. The high sensitivity, long cycling life, and reliable performance over a wide strain range make this unique anisotropic aerogel-foam composite a highly promising candidate for the production of wearable sensors and healthcare monitoring devices.
In situ
bidirectional freeze-drying process for the development of anisotropic aerogel-foam composites.
In this study the proof of principle of the use of naked semiconductor directly generated on metal oxide surface as mediators in gas sensing is provided. Successive ionic layer absorption and ...reaction (SILAR) technique has been applied to sensitize a WO3 thin film with CdS quantum dots. Response to gases of bare WO3 is deeply modified: quantum dots dramatically increase the metal oxide conductance, otherwise rather poor, and modify the capability of detecting environmental pollutants, such as CO and NO2. A modified sensing mechanism is proposed to rationalize the mediation exerted by the semiconducting active layer on the interaction between gaseous species and WO3 surface.
