Aerogels of polysaccharides with chelating functions can be useful as supports in many applications because of their hosting properties. This work demonstrates a facile method for the preparation of aerogels of chitosan derivative “ureido‐chitin”, containing ureido functional groups. The nanofibrillar networks of “ureido‐chitin” were produced by the nucleophilic addition of amine groups of chitosan with isocyanic acid prepared in situ. The presence of ureido functional groups was confirmed by FTIR, solid‐state CP‐MAS 13C and 15N NMR analyses. No crosslinking of molecular chains was observed. The maximum degree of ureido functional groups was estimated to be about 66 %. Characterization by powder XRD confirmed that the polymer chains self‐assembled, with the chitin polymers oriented in a highly ordered crystalline structure. The nanofibrillar networks showed no solubility under either aqueous acidic or alkaline conditions. Bio‐based hosting materials of this kind with two different hosting functional groups, ureido and amine, can potentially be utilized for a wide range of applications in aqueous medium, including filters, catalysis and biomedicine.

Within this study, monolithic three-dimensional silica aerogel (SA) composite parts with super insulating properties are presented. A generic part based on fiber-reinforced (FR) silica aerogel for thermal insulation of the exhaust tubing system—to keep the exhaust gases as hot as possible to improve the efficiency of the catalyst system—was produced via a sol-gel-based molding process in combination with a supercritical drying using scCO2. A thermal conductivity of 16 mW m−1 K−1 was measured via a heat flow meter technique. In this manuscript, we present a full cycle of the material compound design, starting with fundamental material evaluation including aerogel optimization, opacifier influence, and casting process. The obtained generic part in shape of a half-shell for pipe insulation is characterized under real conditions.

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