Preparation of cellulose nanofibers with hydrophobic surface characteristics

Abstract

The aim of this study was to develop cellulose nanofibers with hydrophobic surface characteristics using chemical modification. Kenaf fibers were modified using acetic anhydride and cellulose nanofibers were isolated from the acetylated kenaf using mechanical isolation methods. Fourier transform infrared spectroscopy (FTIR) indicated acetylation of the hydroxyl groups of cellulose. The study of the dispersion demonstrated that acetylated cellulose nanofibers formed stable, well-dispersed suspensions in both acetone and ethanol. The contact angle measurements showed that the surface characteristics of nanofibers were changed from hydrophilic to more hydrophobic when acetylated. The microscopy study showed that the acetylation caused a swelling of the kenaf fiber cell wall and that the diameters of isolated nanofibers were between 5 and 50 nm. X-ray analysis showed that the acetylation process reduced the crystallinity of the fibers, whereas mechanical isolation increased it. The method used provides a novel processing route for producing cellulose nanofibers with hydrophobic surfaces.

Dry, hydrophobic microfibrillated cellulose powder obtained in a simple procedure using alkyl ketene dimer

“…It should be stressed here that the pellets measured were not entirely compacted, but still porous, as confirmed by the instantaneous wetting of the variant MFC 0.0 AKD. The hydrophobization effect demonstrated here is in good agreement with-or even surpasses the values of earlier studies (Jonoobi et al 2009;Missoum et al 2013). The highest value of 140°for MFC 4.0 AKD even attains almost superhydrophobic character, which begins at a water-contact angle of 150° (Sousa and Mano 2013).…”

Nanocellulosic fillers for waterborne wood coatings: reinforcement effect on free-standing coating films

“…The acetylation of CNF was done according to protocols published in the literature (Ashori et al 2014;Ernest-Saunders et al 2014;Jonoobi et al 2010). As a first step, a solvent exchange from water to a mixture of acetone and methanol (2:1) was carried out.…”

Synthesis and Characterization of Cellulose Nanofibers From Coconut Coir Fibers

“…It could be more important due to having crystalline and amorphous regions; which will generate a more reactivity with the other chemicals to achieve the nano material functionality. The process of acetylation reduced the crystallinity of the fibers 19 . It was observed clearly that material obtained from coconut coir fiber has a partial amorphous and crystalline nature.…”