Synthesis of highly flexible silica aerogels by photoacids generation

An atmospheric water harvester with fast and energy‐saving water removal and recovery

“…The absorption bands at 3437 cm −1 , 1680 cm −1 , 1599 cm −1 , and 1156 cm −1 belong, respectively, to the N‐H and O‐H stretching, the N‐H bending of the primary amine, the C‐C stretching, and the C‐O‐C asymmetric stretching in chitosan [22, 23]. The band at 3353 cm −1 corresponds to Si‐OH stretching, while the signals at 1015 cm −1 and 783 cm −1 belong to the symmetric vibration and asymmetric stretching of Si‐O‐Si [24–27]. The hydrophobicity of the silica arises from methyl groups, and the peaks at 1275 cm −1 and 840 cm −1 , belonging to the vibration of C‐H and Si‐C bonds of ‐Si‐CH 3 , confirm their presence.…”

Facile Preparation of a Novel HfC Aerogel with Low Thermal Conductivity and Excellent Mechanical Properties

“…Figure3bhighlights a noteworthy trend, wherein the prominence of the HfC phase increases with higher Hf/R molar ratios.In Figure4, the FT−IR spectra of RF/HfO 2 and HfC aerogels fabricated under reaction conditions are displayed. The broad absorption band at 3430 cm −1 is attributed to the -OH bonds within water molecules adsorbed within the sample[25,26]. At 2923 cm −1 , the spectrum reveals the stretching vibration absorption of the C−H bond found in -CH 2 .…”