Graphene oxide aerogels constructed using large or small graphene oxide with different electrical, mechanical and adsorbent properties

The performances of graphene oxide aerogels (GOA) are studied by constructing them using different lateral sizes of graphene oxide (GO). Gelatinization of GO hydrosol is realized using a cross-linking agent, poly(vinyl alcohol) (PVA), and then solution-freeze-lyophilization is carried out to construct the crosslinking network of GOA. The contact points in GOA constructed using large sized GO (GOA(325)) were fewer than those in the GOA using small sized GO (GOA(10 000)). It is the contact points that decide the micro-structure of GOA, and hence the performances. The size effect of the structural units is studied by investigating the electrical conductivity, mechanical strength, and adsorption capacity. The electrical conductivity of GOA(325) can reach 0.78 S m(-1) after carbonization at 800 degrees C, which was much higher than that of carbonized GOA(10 000) (0.53 S m(-1)). The compression modulus of GOA(325) was 0.51 MPa, while the value for GOA(10 000) was 0.04 MPa. The adsorption capacity of GOA(325) was also higher than that of GOA(10 000) for adsorbing both hydrophilic and oleophilic media.