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In this paper, the capillary rise and sorption ability of hemp fibers oxidized with hydrogen peroxide and potassium permanganate were studied, with the aim to get more insight into the changes in the structure of hemp fibers caused by oxidation, and to compare the influence of applied oxidative agents on hemp fibers. Capillary rise was presented as a function of a liquid rise height vs times, with determined all three capillary coefficients, while sorption ability was determined as water retention values and moisture sorption. For structural analysis of the samples the ATR-FTIR technique was used. Also, the amount of aldehyde and carboxyl groups and the lignin content in oxidized fibers were determined. The surface fibers morphology was observed by FESEM. In all oxidized hemp fibers an increase in capillarity was obtained for both oxidizing agents (33-75 mm for H2O2, and 40-114 mm for KMnO4), compared to 31 mm for unmodified fibers, but decreased sorption ability. Application of both oxidative agents, were successful for introduction of functional groups into oxidized fibers, for reduction of the amount of non-cellulosic substances, as well as moisture sorption. Simultaneously, the fibers became finer, cleaner, whiter, softer and more suitable for further processing, while, generally, higher influence on changes into oxidized hemp fibers was achieved by oxidation with KMnO4, compared to oxidation with H2O2.

This study elaborates the application of composite films based on nanofibrillated cellulose obtained from cotton linters oxidized in the 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)/NaBr/NaClO system, with the use of CaCO3 and/or Al(OH)(3) as fillers, and glycols as plasticizers, to improve the mechanical, optical, and sorption properties of paper. The paper coating with nanofibrillated cellulose-based films, without additional adhesive, depending on the concentration of nanofibrillated cellulose in the dispersion and the type of filler, improves the mechanical properties of paper, and decreases sorption properties, while no significant changes were observed in optical properties compared to the initial papers.

As one of the most promising groups of microbes, lactic acid bacteria (LAB) can synthesize metabolites that can be used in different industries over the world, mainly in the pharmaceutical, food, and dairy industries. In this study, a novel exopolysaccharide was extracted and isolated from the probiotic strain Lactobacillus reuteri B2, and assessed on biological activity and its possible application as a biosorbent for the removal of Ni2+ ions from contaminated water. New exopolysaccharide was characterized using FTIR, SEM, XRD, NMR, MALDI-TOF MS, and TGA/DTG analysis. Biological assays included antioxidative activity, cytotoxic assay, and adhesion assay of L. reuteri B2 to HT29 cells. Our hypothesis was that if this exopolysaccharide is nontoxic, it can be used as a novel biomaterial for the possible application of the removal of Ni2+ ions from contaminated water. The scavenging effect of nontoxic exopolysaccharide was 76% at 2 mg/mL using ABTS assay, in biological assays, while the removal efficiency of nickel from the aqueous solution was 92.96% in biosorption study. According to these results, this exopolysaccharide can be considered a very promising biomaterial for potential application in different industries, from pharmacy to wastewater treatments.

Applications of hemp fibers, as a promising natural material in the textile field, mostly require improved fiber properties. In this paper, the oxidation of hemp fibers with potassium permanganate was applied to reduce the amount of noncellulosic substances and moisture sorption; to introduce functional groups and increase capillarity; make fibers finer, softer and suitable for application in sport wears. The changes in sorption properties were characterized by capillary rise measurement and the ability of water retention and moisture sorption, while changes in mechanical properties were estimated by determination of tenacity and elongation of modified hemp fibers in comparison to the appropriate characteristic of unmodified fibers. ATR-FTIR, SEM techniques, and zeta potential measurement were used for the characterization of fiber structure, morphological and electrokinetic properties. We obtained a finer fiber with increased capillarity (up to 3.68 times) but reduced moisture sorption (down to 1.5 times) and water retention capacity (down to 2.8 times), with accomplished satisfactory preservation of mechanical properties. Obtained oxidized hemp fibers with attained features present a very suitable material for sportswear production. Additionally, in this paper, an improvement of the capillary rise measurement is given.