A tulip tree was used to synthesize a holocellulose aerogel from an aqueous alkali hydroxide-urea
solution with the substitution of an organic solvent followed by freeze-drying. For comparison,
the synthesized holocellulose aerogels were divided into two groups according to the source of the
hydrogel, an upper suspended layer and a bottom concentrated layer of the centrifuged solution of
cellulose and NaOH/urea solvents. We investigated the effects of the temperature of the pre-cooled
NaOH/urea solution (i.e., dissolution temperature) on the pore structure and the adsorption capacity
of the holocellulose aerogel. A nano-fibrillar network structure of the holocellulose aerogel
was observed, with little morphological difference in pore structure for different dissolution temperatures.
Both micropores and mesopores were observed in the holocellulose aerogel. The specific
surface area of the holocellulose aerogel was generally greater at lower dissolution temperatures.
In a series of adsorption tests using methylene blue, the holocellulose aerogel showed the greatest
adsorption capacity at the lowest dissolution temperature tested (−2
◦
C). However, the dissolution
temperature generally had little effect on the adsorption capacity. The holocellulose aerogel produced
from the upper suspended layer of the centrifuged hydrogel solution showed a greater porosity
and adsorption capacity than the one produced from the bottom concentrated layer. Overall, the
aerogel made by utilizing a delignified tulip tree display a high surface area and a high adsorption
property, indicating its possible application in eco-friendly adsorption materials.