Cellulose nanofibers/polyvinyl alcohol blends as an efficient coating to improve the hydrophobic and oleophobic properties of paper

Abstract

The effect of cellulose nanofibers (CNFs)/polyvinyl alcohol (PVA) coating on the hydrophobic, oleophobic, and strength properties of paper were investigated. The results showed that the size of bamboo fibers (BFs) decreased significantly and the crystallinity increased significantly after biological enzyme treatment. The average length of CNFs obtained by high pressure homogenization was 2.4 µm, the diameter was 28.7 nm, and the crystallinity was 63.63%. When the coating weight of PVA/CNF was 2.0 g/m2 and the CNF dosage was increased from 0.0% to 3.0%, the paper grease resistance grade was increased from 7 to 9, the Cobb value was decreased from 22.68 ± 0.29 g/m2 to 18.37 ± 0.63 g/m2, the contact angle was increased from 67.82° to 93.56°, and the longitudinal and transverse tensile index were increased from 67.72 ± 0.21 N m/g and 37.63 ± 0.25 N m/g to 68.61 ± 0.55 N m/g and 40.71 ± 0.78 N m/g, respectively. When the CNF dosage was 3.0% and the coating weight of PVA/CNF was 4.0 g/m2, the grease resistance grade of the paper was 12, the Cobb value was 21.80 ± 0.39 g/m2, and the longitudinal and transverse tensile indices were 72.11 ± 0.43 N m/g and 42.58 ± 0.48 N m/g, respectively. In summary, the increase of CNFs can effectively improve the lipophobicity, hydrophobicity and tensile strength of the PVA coated paper.

Rheological, Physicochemical, Thermal, and Mechanical Properties of Biopolymeric Films Incorporated with Micro‐Holocellulose from Coffee Residues

“…Besides, the increasing of reinforced material over the polymer is explained with the water contact angle (CA, insets in Figures 3a–d) since this is a parameter often used to describe and evaluate the wetting state of a surface and/or the wettability of a liquid in the plain surface [36,37] . In this case, the polymeric mixture between CS and PVA used as a surface for the CA measurements is likely wettable since the polymers have a hydrophilic character [38] . Actually, holocellulose is a solid material whose main composition is cellulose and hemicellulose, and the particle presents a very well‐known hydrophobicity but is very absorbent due to the easy way to form hydrogen bonds with fluids thanks to the hydroxylic groups in the molecules [36] …”

“…[36,37] In this case, the polymeric mixture between CS and PVA used as a surface for the CA measurements is likely wettable since the polymers have a hydrophilic character. [38] Actually, holocellulose is a solid material whose main composition is cellulose and hemicellulose, and the particle presents a very well-known hydrophobicity but is very absorbent due to the easy way to form hydrogen bonds with fluids thanks to the hydroxylic groups in the molecules. [36] Then, it is noticeable that CS : PVA film (Figure 3a) presents a very low CA with values around 60°that increases when HOLO-SCG is added into the CS : PVA film (Figure 3b, CA � 70°).…”

Cellulose Nanofiber as Mask/Personal Protective Equipment Surface Agent for Enhanced Anti-Bacterial Performance

“…This method is a departure from others, such as a manual coater or airless spray pump. 21,22 A handheld spray bottle was chosen for its portability and user-friendliness. CNF/PVA was selected specifically due to its unique properties and potential.…”

Flexible and Transparent PVA/CNF Hydrogel with Ultrahigh Dielectric Constant

“…Furthermore, PVA is hydrophilic, which promotes the strong interface interaction between the PVA chains and CNFs, forming a strong hydrogen bond network between the adjacent cellulose and changing the elasticity of the matrix. 8 This study presents a straightforward method for the preparation of a highly transparent and self-healing flexible hydrogel that exhibits exceptional dielectric properties. As illustrated in Scheme 1, the dynamic chemical bonds and hydrogen bonds among PVA, borax, and CNFs formed a physically and chemically cross-linked uniform network.…”

“…In particular, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated CNFs contain a large amount of carboxyl groups on their backbone chains; the presence of carboxyl groups not only enriches the raw material choices for finite components but also facilitates the formation of noncovalent bonds in material systems. Furthermore, PVA is hydrophilic, which promotes the strong interface interaction between the PVA chains and CNFs, forming a strong hydrogen bond network between the adjacent cellulose and changing the elasticity of the matrix …”