Filtration Capacity and Radiation Cooling of Cellulose Aerogel Derived from Natural Regenerated Cellulose Fibers

Abstract

Natural cellulosic materials are attractive biopolymers for their naturally abundant source, mechanical toughness, bioactivity, etc. However, porosity and flexibility remain challenges for the preparation of aerogels from natural cellulose. To maintain the characteristics of cellulose aerogels possessing the toughness of fibers and high porosity of aerogels, cellulose aerogels with three-dimensional void structures and high compressive resilience were prepared by mixing cellulose fiber suspension and polyvinyl alcohol (PVA). The PM 2.5 removal rate and thermal conductivity of cellulose aerogel reached 92.4% and 0.028 W/mK, respectively, when a PVA content of 0.7% was added, and the radiation cooling temperature was about 10.0°C lower than that of PE foam. The three-dimensional void structure and surface morphology of the cellulose aerogels were investigated by scanning electron microscopy (SEM). The cellulose aerogel porosity and pore size distribution were evaluated by a mercury intrusion meter. The crystal structure of cellulose was analyzed by X-ray diffraction (XRD). UV-Vis-NIR spectroscopy was used to investigate the infrared reflectance of cellulose aerogels. Then the air purification efficiency and radiation cooling effect of porous cellulose aerogels were evaluated in a homemade device, respectively.