Polyelectrolyte complexes for assisting the application of lignocellulosic micro/nanofibers in papermaking

Abstract

A novel procedure based on the addition of polyelectrolyte complexes (PECs) onto the pulp containing lignocellulosic micro/nanofibers (LCMNF) is presented. This procedure allows increasing paper strength avoiding an excessive loss in drainability. LCMNF were obtained from partially delignified kraft pine sawdust using a high-pressure homogenizer. Cationic complexes (CatPECs) were prepared by adding the anionic polyelectrolyte solution (polyacrylic acid) on the cationic polyelectrolyte solution (poly(allylamine hydrochloride)). According to turbidity and surface morphology changes, an interaction between CatPECs and LCMNF could be established. Different CatPEC dosages (from 0.3 to 1.0% on pulp) were added on a recycled unbleached softwood kraft pulp containing 3% of LCMNF. For a PEC dosage of 0.75% on pulp, an optimum balances between negatively and positively charged materials [near to zero value of the logarithm of the colloidal titration ratio (logCTR)] was found. Britt Dynamic Drainage Jar test showed a high retention of fines and LCMNF for all PEC dosages. A maximum in retention value was obtained for the addition of 0.75% of PECs on pulp, dosage that was suggested as optimum by the logCTR. In addition, the best drainability value (18°SR) was obtained for this PEC addition level. Papermaking properties were clearly improved for all dosage of PECs. Particularly for a dosage of 0.75% of PECs on pulp, tensile strength was noticeably increased (?48%) and both compressive resistance Concora Medium Test (CMT) and Short-span Compressive Test (SCT) were markedly increased (?64% and ?39%, respectively). These results suggest that PECs are a possible alternative to assist the application of LCMNF in papermaking.

Chinese Calligraphy Inspired Design of Humidity/Light Dual Responsive Magic Paper

“…After treated with different solutions for 24 h, the PCC paper was integrated and the solution was clear without ink diffusion, it demonstrates that the carbon combines well with the inherent cellulose layer, which could be attributed to the severance and good tenacity performance of the hydrophobic PVB layer. [ 29,30 ] As we know, when adding a functional material, the mechanical properties of paper will be affected largely especially inherent flexibility, foldability, and tailorability, [ 31–33 ] making it unsuitable for the raw material of paper flower. But the inherent foldability and tailorability of PCC paper changed rarely.…”

Interfacial Behavior of Solid- and Liquid-like Polyelectrolyte Complexes as a Function of Charge Stoichiometry

“…Complementary interactions like short-range hydrogen-bonding or long-range hydrophobic effect can also participate in the complexation process. Such PE complexes or PECs have endless applications in different technological fields ranging from water treatment [1], paper making [2], and food industry [3] to pharmaceuticals [4], cosmetics [5], tissue engineering [6], and biomedicine [7]. The formation of PECs involves two distinct steps: the generation of primary PECs by ion pairing, followed by their aggregation/reorganization into larger structures [8].…”

Bionic smart recycled paper endowed with amphiphobic, photochromic, and UV rewritable properties

“…Generally speaking, we add various types of secondary components in the papermaking process to increase the beauty and texture of the paper. [7][8][9][10] For example, Si et al modied stearic acid with dopamine and magnesium hydroxide and successfully prepared super-hydrophobic recycled paper with ame retardant properties. 11 Wen et al 12 successfully mixed cotton cellulose and stearate to prepare a colored superhydrophobic paper with uniform internal and external wettability.…”