Directional preparation of superhydrophobic magnetic CNF/PVA/MWCNT carbon aerogel.

Carbon aerogels have attracted considerable attention in basic research and for their potential applications in many fields. Here, the fabrication of a magnetic cellulose nanofibre (CNF)/poly(vinyl alcohol) (PVA)/multiwalled carbon nanotubes (MWCNT) carbon aerogel (m-CPMCA) is reported using a simple freeze-drying followed by a carbonisation process, and direct immobilisation of Fe3O4 nanoparticle on the surface of aerogels. The obtained target aerogel has the characteristics of low density (0.098 g/cm3), high porosity (>90%) and 3D interpenetrating porous structures. Furthermore, m-CPMCA has a surprising compressive strength (about 0.35 MPa) which is obviously higher than many other cellulose-based carbon aerogels. After Carbonization, m-CPMCA exhibits superhydrophobicity, selective absorption for organic solvents and fire-resistance. The m-CPMCA also exhibited a magnetic response and can absorb oil on the water surface and can be actuated by a small magnet. More importantly, the m-CPMCA could be recycled many times by combustion, which showed economic significance. To sum up, the authors believe that m-CPMCA will become a very potential adsorbent for dealing with the increasingly serious problem of organic pollution.