Modification of Paper Surface by All-Lignin Coating Formulations

Abstract

All-lignin coating formulations were prepared while combining water-soluble cationic kraft lignin (quaternized LignoBoost®, CL) and anionic lignosulphonate (LS). The electrostatic attraction between positively charged CL and negatively charged LS led to the formation of insoluble self-organized macromolecule aggregates that align to films. The structures of the formed layers were evaluated by atomic force microscopy (AFM), firstly on glass lamina using dip-coating deposition and then on handsheets and industrial uncoated paper using roll-to-roll coating in a layer-by-layer mode. Coated samples were also characterized by optical microscopy, scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (SEM/EDS), and contact angle measurements. It was suggested that the structure of all-lignin aggregates is the result of the interaction of amphiphilic water-soluble lignin molecules leading to their specifically ordered mutual arrangement depending on the order and the mode of their application on the surface. The all-lignin coating of cellulosic fiber imparts lower air permeability and lower free surface energy to paper, mainly due to a decrease in surface polarity, thus promoting the paper’s hydrophobic properties. Moderate loading of lignin coating formulations (5–6 g m−2) did not affect the mechanical strength of the paper.

Spray Coating of Wood with Nanoparticles from Lignin and Polylactic Glycolic Acid Loaded with Thyme Essential Oils

“…Other options to make wood protection more environmentally friendly is to replace fossil-based ingredients in traditional wood protection formulations with bio-based additives like lignin or to use lignin nanoparticles (LNPs) as coatings or as carriers of bioactives [37,[43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60]. Lignin coatings were investigated in a wide range of applications [61][62][63], including as water vapor and oxygen barriers in fiber-based packaging solutions [64], as protective coatings for natural fibers for textile production [65], or for the surface modification of paper products [66,67]. Others prepared novel, bio-based anti-viral surface coatings via spin-coating of lignin where the anti-viral effect was obtained due to reactive oxygen species formation through lignin phenol oxidation and therefore, the lignin coating is not consumed [68].…”

Surface Modification and Properties of Thin Ink Films with Added TiO2 and ZnO Nanoparticles Applied on Paperboard Substrates

“…Surface modification techniques are sometimes applied to different substrates to adjust properties and control the interaction between materials. In printing processes, various surface modification techniques can be applied, such as plasma and corona treatment, laser alloying of the surface, vapor deposition, thermal diffusion, and others [ 18 , 19 , 20 , 21 , 22 , 23 , 24 ].…”

Partial Replacement of Cationic Starch by Cationic Hardwood Kraft Lignin Does Not Compromise Key Paper Properties

“…In addition to wet cationization, "dry" approaches also exist, with the starch surface being impregnated with small quantities of alkaline CHPTAC solution [14]. The high water-solubility of cationic LignoBoost ® Eucalyptus kraft lignin across the full pH scale along with further features inherent to lignin, such as the potent absorption of UV light, antimicrobial activity or trapping of oxidants [15], literally invite their own use in a wide range of applications [9,[16][17][18].…”

“…Therefore, this work investigated for the first time whether and to what extent cationic starch-an essential additive in papermaking to increase fiber and ash retention, accelerate dewatering, and improve process runnability-can be replaced by this novel type of cationic kraft lignin. At the example of handsheets made from bleached Eucalyptus kraft pulp, key paper mechanical (tensile, bursting, and tearing indexes), structural The high water-solubility of cationic LignoBoost ® Eucalyptus kraft lignin across the full pH scale along with further features inherent to lignin, such as the potent absorption of UV light, antimicrobial activity or trapping of oxidants [15], literally invite their own use in a wide range of applications [9,[16][17][18].…”