Sorption and other properties of polytetrafluoroethylene/cellulose composite aerogels

Polytetrafluoroethylene/cellulose composite aerogels containing PTFE from 0 to 40 wt.% were obtained by drying the corresponding suspension mixtures at a temperature of 50°C. Cellulose isolated from the stem of Sosnowski hogweed was used as the main component of the aerogels. In present work, the composite aerogels were heated in an inert atmosphere at a temperature of 370°C to partially hydrophobize cellulose and remove surfactants that were present in the initial PTFE suspension. It was found that at this temperature, the thermal degradation of cellulose proceeded differently in the presence and absence of PTFE. The maximum water contact angle (156°) was obtained for the sample with 10 wt.% PTFE. Hydrophobized samples of aerogels were studied with the help of infrared spectroscopy, scanning electron microscopy, and powder x-ray diffractometry and tested as sorbents for various solvents. It was found that the volume of solvent absorbed by the aerogel, in the case of a sample with a PTFE content of 40 wt.%, can even exceed the initial volume of the absorber.