Adhesion and Surface Issues in Cellulose and Nanocellulose

Abstract

This paper provides a review of the scientific literature concerned with adhesion and surface properties of cellulose and nanocellulose. Cellulose is the most abundant chemical compound on earth and its natural affinity for self-adhesion has long been recognized. The ease of adhesion that occurs in cellulose has contributed to its use in paper and other fiber-based composite materials. Cellulose adhesion, which has received considerable attention over the past half century, occurs over a practical length scale ranging from the nanoscale to millimeters. Adhesion theories that have been examined in the bonding of cellulose fibers include: mechanical interlocking, adsorption or wetting theory, diffusion theory, and the theory of weak boundary layers. Cellulose fibers on the nanoscale are prepared in four different ways: (1) bacterial cellulose nanofibers, (2) cellulose nanofibers by electrospinning, (3) microfibrillated cellulose plant cell fibers and (4) nanorods or cellulose whiskers. Structure and properties of nanocellulose that are important include: morphology, crystalline structure, surface properties, chemical and physical properties, and properties in liquid suspension. Cellulosic nanofibers present a very high surface area which makes the adhesion properties the most important parameter to control for nanocomposite applications. In this paper, we will focus on discussion of the adhesion and surface characteristics of cellulose nanofibers that impact its properties and application in nanomaterials.  Koninklijke Brill NV, Leiden, 2008

Surface properties of distinct nanofibrillated celluloses assessed by inverse gas chromatography

“…The adhesion and surface properties of nanocellulose are key points that have to be considered regarding the aforementioned uses, for instance, in composites or in barrier materials [1,[9][10]. Studies on the surface properties of nanofibres have been generally focused on i) the determination of "surface" charge by zeta potential measurements or by polyelectrolyte titration, ii) the determination of the amount of carboxylate and aldehyde groups formed during chemical pre-treatments, by conductometric and potentiometric titrations and, iii), the assessment of the chemical composition and reactivity of the nanocellulose surface during chemical pre-treatments/surface modification, by using X-ray photoelectron spectroscopy [1,10].…”

Initial wet web strength of paper

“…For interactions to occur, the distances between the fibers and/or fibrils must be very small. The distances described in the literature are between 0.15 and 0.35 nm (Gardner et al 2008;Linhart 2005). Remarkably, these distances are considerably smaller than the fiber roughness, which ranges between 10 and 10,000 nm (Heinemann et al 2011).…”

“…A share of the strength developed at low dryness levels may be attributed to acid/base interactions (Gardner et al 2008;Lindström 1980;Wågberg and Annergren 1997;Williams 1983). As a general rule, carboxyl groups and/or sulfonic acid groups are fixed at lignocellulosic fibers (Sjöström 1989).…”

Site-specific functionalization for chemical speciation of Cr(III) and Cr(VI) using polyaniline impregnated nanocellulose composite: equilibrium, kinetic, and thermodynamic modeling

“…NC is a quintessence of nanomaterials attesting to incredible physical and chemical attributes which formulate them highly lucrative as a nanosorbent because of larger surface area, high crystallinity, renewability, and sustainability (Gardner et al 2008;Srivastava et al 2012;Xue et al 2015). Indeed, attendance of prodigious hydroxyl groups within their structure which can offer suitable platform for functionalization (Klemm et al 2011;Wei et al 2014).…”