Surface Modification of Bacterial Cellulose Aerogels’ Web-like Skeleton for Oil/Water Separation

Abstract

The cellulose nanofibers of bacterial cellulose aerogel (BCA) are modified only on their surfaces using a trimethylsilylation reaction with trimethyichlorosilane in liquid phase followed by freeze-drying. The obtained hydrophobic bacterial cellulose aerogels (HBCAs) exhibit low density (≤6.77 mg/cm(3)), high surface area (≥169.1 m(2)/g), and high porosity (≈ 99.6%), which are nearly the same as those of BCA owing to the low degrees of substitution (≤0.132). Because the surface energy of cellulose nanofibers decreased and the three-dimensional web-like microstructure, which was comprised of ultrathin (20-80 nm) cellulose nanofibers, is maintained during the trimethylsilylation process, the HBCAs have hydrophobic and oleophilic properties (water/air contact angle as high as 146.5°) that endow them with excellent selectivity for oil adsorption from water. The HBCAs are able to collect a wide range of organic solvents and oils with absorption capacities up to 185 g/g, which depends on the density of the liquids. Hence, the HBCAs are wonderful candidates for oil absorbents to clean oil spills in the marine environment. This work provides a different way to multifunctionalize cellulose aerogel blocks in addition to chemical vapor deposition method.

Grafting of thermosensitive poly(N-isopropylacrylamide) from wet bacterial cellulose sheets to improve its swelling-drying ability

“…Such observations indicated that the applied chemical modifications involved essentially hydroxyl groups on the fibers' surface or those in the amorphous regions of WBC, while the internal structure of the fibers was not affected (Tomé et al 2011;Lee et al 2011). A similar phenomenon was reported for surface modification of nanocellulose by organic acids (Ramírez et al 2014) and trimethylchlorosilane (Sai et al 2015), for example.…”

Facile fabrication of robust superhydrophobic porous materials and their application in oil/water separation

“…[1][2][3] Traditional oil/water separation methods such as flotation, centrifugation or filtration usually involve complicated operations and time-consuming processes. [15][16][17][18][19][20][21][22][23][24][25][26] For example, pioneering work of Jiang group reported using a Teflon coated mesh to separate oil/water mixture. [5][6][7][8][9][10][11][12][13][14] Up to now, various superhydrophobic porous materials have been prepared via various chemical and physical strategies.…”

Biomimetic fabrication of superhydrophobic loofah sponge: robust for highly efficient oil–water separation in harsh environments

“…[39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54] Yang et al 39 prepared a novel diisocyanate-modied lignin xerogel using renewable lignin as the precursor via a solgel process and ambient pressure drying method. The asprepared xerogel showed high performance in self-cleaning and superhydrophobicity without further hydrophobic modi-cation.…”