The continuing increase of interest in ionic liquids prompts us to search both for new compounds and for their new potential application. The aim of this study was to examine the influence of ionic liquids (ILs) on the cellulose product, paper. In the studies, commercially available 3-alkyl-1-methylimidazolium tetrafluoroborates and prepared 3-alkoxymethyl-1-methylimidazolium tetrafluoroborates and 3-alkoxymethyl-1-methylimidazolium bis(trifluoromethanesulfonyl)imides were used. Obtained salts with bis(trifluoromethanesulfonyl)imide anion are new compounds. ILs were found to impregnate paper, affecting its strength and other physical parameters. Various properties of paper were distinctly altered after treatment with ILs of varying anions. In general, IL-treated paper had decreased strength, which resulted from weakening of cellulose hydrogen bonds. On the other hand, paper wettability improved. Paper treated with 1-methyl-3octyloxymethylimidazolium tetrafluoroborate proved to be fully resistant to activity of moulds and fungi, inducing the blue discoloration of the paper.

The objective of the presented research was to determine the influence of cellulose coating, obtained from the cellulose solution in N-Methylmorpholine N-oxide (NMMO), on the structural and mechanical properties of paper. The effect of heating time of paper samples coated with cellulose dissolved in NMMO was also investigated. Depending on the heating time of the coating, a continuous or porous layer was obtained. Coating without any heating stage yielded a continuous cellulose layer of hydrophobic properties (higher contact angle in comparison to base paper), and paper of higher smoothness and increased tear resistance. Analysis of the paper samples showed that cellulose coating not only changed the surface properties of paper, but also significantly improved paper strength properties, such as the tensile index, elongation, bursting strength index and double folds number. Despite the process' limitations (e.g. necessity of removing the NMMO), this method can be considered as a novel approach for paper property modification.

Cellulose fines are-in general-small particles removed from natural cellulose fibres during refining process which is typically carried out in papermaking industry. Fines have been recognized as a separate component of papermaking fibrous raw material since their properties differ considerably from those of cellulosic fibres. Fines are characterized by low dewatering ability, very high specific surface area, and high swelling ability. Knowledge about the possibility of effective control over fines generation and swelling during refining process are nowadays of key importance. Beside its significance in papermaking process (e.g. impact on paper structure and mechanical properties and dewatering properties of the pulp), nowadays the cellulose fines fraction is considered as a raw material for the production of novel materials e.g. microfibrilled cellulose and nanocellulose. The main objective of the presented study was to determine the impact of the most important refining parameters (e.g. net refining energy, rotor speed, and pulp consistency) which could be used to control the fines development and their swelling degree. On the basis of presented research results it may be concluded that the amount of the fines generated during refining process was mainly affected by the effective refining power (net power) and the rotational speed of the refiner rotor. Also, the final swelling degree of fines varies depending on the refining operating conditions used. It was found that the swelling degree of fines was mostly influenced by the rotational speed of the refiner rotor, refined pulp consistency, and-for very low consistency (1-2%)-also pulp volumetric flow rate through the refiner. As a result, it could be concluded that-for more effective control of the refining process-greater attention to the control of these parameters should be paid.

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