Influence of pre-gelation temperature on mechanical properties of cellulose aerogels based on a green NaOH/PEG solution—a comparative study

Cellulose aerogels with porous three-dimensional network structure often suffer from weak mechanical strength, which imposes huge restrictions on their applications. In this work, an easily-operated pre-gelation treatment was introduced to the conventional fabrication technique of regenerated cellulose aerogels (i.e., dissolution, regeneration, and drying treatment) to improve their structure uniformity, crystallinity, and mechanical strength. These properties were found to be closely related to the pre-gelation temperature, and a relatively lower temperature (50 °C) makes the greatest contribution. Especially for the mechanical strength, the elasticity modulus and energy absorption of the aerogels treated at 50 °C reach the maximums of 1.03 MPa and 476.2 kJ m−3, which are 5.4 times and 94.3 % higher than those of the untreated aerogels. As an example of potential application, the surface of the aerogels was decorated with multiwalled carbon nanotubes. The obtained composite displays a good electromagnetic interference shielding ability.