However, in a comparison to a covalentbond, physical or ionic absorption is reversible, and hydrophobicity
could be easily lost due to desorption of the
modifiers. Thus, the more environmentally friendly method for
CNF surface modification directly in water to produce
hydrophobic aerogel upon freeze-drying remains a challenge.
In this study, we report an in situ surface modification method
that can convert hydrophilic CNF to hydrophobic species in
aqueous medium directly, which has many advantages
compared to organic solvent or vapor deposition methods.
Furthermore, our method does not use expensive and toxic
fluorine chemical or inorganic Si, which is an environmentally
friendly method to convert hydrophilic cellulose surface to
hydrophobic material in situ.