The complex aerogel generated from nano-polysaccharides, chitin nanocrystals (ChiNC) and TEMPO-oxidized cellulose nanofibers (TCNF), and its derivative cationic guar gum (CGG) is successfully prepared via a facile freeze-drying method with glutaraldehyde (GA) as cross-linkers. The complexation of ChiNC, TCNF, and CGG is shown to be helpful in creating a porous structure in the three-dimensional aerogel, which creates within the aerogel with large pore volume and excellent compressive properties. The ChiNC/TCNF/CGG aerogel is then modified with methyltrichlorosilane (MTCS) to obtain superhydrophobicity/superoleophilicity and used for oil–water separation. The successful modification is demonstrated through FTIR, XPS, and surface wettability studies. A water contact angle of 155° on the aerogel surface and 150° on the surface of the inside part of aerogel are obtained for the MTCS-modified ChiNC/TCNF/CGG aerogel, resulting in its effective absorption of corn oil and organic solvents (toluene, n-hexane, and trichloromethane) from both beneath and at the surface of water with excellent absorption capacity (i.e., 21.9 g/g for trichloromethane). More importantly, the modified aerogel can be used to continuously separate oil from water with the assistance of a vacuum setup and maintains a high absorption capacity after being used for 10 cycles. The as-prepared superhydrophobic/superoleophilic ChiNC/TCNF/CGG aerogel can be used as a promising absorbent material for the removal of oil from aqueous media.

The present study evaluated the possibility to form thin film of cationic guar gum (CGG) associated with poly (carboxylic acid) such as carboxymethyl cellulose (CMC) and poly (acrylic acid) (PAA) through layer-by-layer (LbL) assembly. The thin film thickness and morphology show dependence on pH value, ionic strength and temperature. For pH 3 to pH 4 CGG and poly (carboxylic acids) assemble and form thin film through LbL. For neutral pH region and high pH values CGG and poly (carboxylic acids) do not interacted. In contrast to synthetic polyelectrolyte complex thin film, such as polystyrene sulfonate (PSS)/ poly (diallyldimethylammonium chloride) (PDDA) and PSS/ poly (allylamine hydrochloride) (PAH), the LbL assembly of CGG/CMC and CGG/PAA take place only at low salt concentrations. Deposition at high temperature (up to 60°C) results thicker CGG/ poly (carboxylic acids) films.