Laccase-Mediated Coupling of Nonpolar Chains for the Hydrophobization of Lignocellulose

Abstract

We investigate the use of laccase enzymes to couple short nonpolar chains containing aromatic groups onto flax fibers and nanofibrillated cellulose (NFC) with different lignin contents. Trametes villosa , Pycnoporus cinnabarinus , and Myceliophthora thermophila were used to facilitate surface coupling and to produce materials with different levels of hydrophobicity. Heat treatment of fiber webs after lacccase-mediated coupling markedly increased the resistance to water absorption. The highest hydrophobization levels of flax fibers was achieved by coupling dodecyl 3,4,5-trihydroxybenzoate (HB-C12), which yielded water contact angles (WCAs) of 80-96 degrees and water absorption times (drop tests) of ca. 73 min. The results from apparent aromatic content and FTIR analyses confirmed the laccase-mediated coupling of HB-C12 onto the cellulose fibers. Ultrathin films of NFC were also used as substrates for enzyme-mediated hydrophobization with HB-C12. In these cases, WCAs in the range of 87-104 degrees were achieved, depending on the conditions. Quartz crystal microgravimetry (QCM) was used to study the dynamics and the extent of the coupling process onto cellulose. The results help to better understand the mechanisms involved in laccase-mediated hydrophobization and provide a proof of a biotechnological platform for the development of value-added fiber products.

Characterisation and properties of homo- and heterogenously phosphorylated nanocellulose

“…However, such a functionalisation may not be adequately applied if the integrity of the cellulose polymer chain is to be preserved without a side-reaction such as intermolecular crosslinking (Garcia-Ubasart, Vidal, Torres, & Rojas, 2013). Thus, the phosphorylation of cotton (Tzanov et al, 2002) or NFC (Božič, Liu, Mathew, & Kokol, 2014) using site-specific hexokinase-mediated reactions in the presence of phosphoryl donor adenosine-5 -triphosphate was achieved with low DS of up to 0.43 at the C6 hydroxyl group of the cellulose glucopyranose ring.…”

Enzymatic hydrophobization of jute fabrics and its effect on the mechanical and interfacial properties of jute/PP composites

“…The monomers of the laccase-mediated grafting can be divided into two categories, phenolic compounds and amine compounds. It is generally reported that the laccase-mediated grafting of phenolic monomers onto lignocellulosic materials has been successfully achieved to endow such polymers with novel functions [18][19][20][21][22][23][24][25]. However, the homopolymerization of these phenols will occur inevitably accompanied with the desired enzymatic grafting reaction.…”

“…Studies show that lignin is a suitable substrate for laccase and the phenolic sites of lignin molecules can be oxidized to phenoxyl radicals by laccase [17]. With the laccasecatalyzed oxidation of lignin moieties rich on the surface, the lignocellulosic materials could be activated to create a radical-rich reactive surface to which oxidized (radical-containing) phenolic molecules of interest by laccase simultaneously can be grafted [18][19][20][21][22][23]. Natural jute fiber, a widely used lignocellulosic bioresource with lignin content of 14-20%, also has the potential to be modified by this green biotechnology for endowing it with better performance or novel functions [24,25].…”

Nanocellulose and Proteins: Exploiting Their Interactions for Production, Immobilization, and Synthesis of Biocompatible Materials

“…Garcia-Ubasart et al [55] showed that the hydrophobicity of nanofibrillated cellulose can be controlled through laccase-mediated coupling of different short, hydrophobic chains to its surface. The coupling reaction, catalyzed by laccase, showed that hydrophobization could be maximized by coupling dodecyl 3,4,5-trihydroxybenzoate (HB-C12) with flax fiber-based nanofibrillated cellulose [55]. The resulting water contact angles of the fiber webs were found to be 80-96 degrees, significantly greater than those of the control [55].…”

“…The coupling reaction, catalyzed by laccase, showed that hydrophobization could be maximized by coupling dodecyl 3,4,5-trihydroxybenzoate (HB-C12) with flax fiber-based nanofibrillated cellulose [55]. The resulting water contact angles of the fiber webs were found to be 80-96 degrees, significantly greater than those of the control [55]. Cusola et al [56] also manipulated surface hydrophobicity through applying a novel, multicomponent colloidal system comprised of laccase, hydrophobic dodecyl 3,4,5-trihydroxybenzoate (LG), and dispersant (sulfonated lignin) to couple LG onto the surface of CNF.…”