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Colored paper is an important industrial paper grade that has applications in various industrial sectors. The increase in coloring efficiency is a key in decreasing the use of dyes, thus can be considered as a "green" process concept; the coloring efficiency depends on the dye retention and dispersion. This work explores the use of nanocellulose, specifically, TEMPO-oxidized cellulose nanofibers (TOCNF), on the coloring efficiency of the preparation of colored paper. Two dyes (i.e. direct blue GL and reactive red 195 (RR195)) were used. Thanks to the large specific surface area and abundant active sites of TOCNF, its use largely improves the direct blue GL retention during the process. The coloring difference (∆E* ab) reached 5.334 with the addition of 13.6 wt% TOCNF and 1.8 wt% direct blue GL in the pulp furnish. The functional group in the dye is a vital factor in determining the dye retention when one chooses TOCNF to enhance the coloring efficiency in the production of colored paper. Furthermore, TOCNF significantly improved the strength properties of both direct blue GL and RR 195 dyed papers. This work demonstrates the potential of nanocellulose in the production of colored paper in improving the coloring efficiency, thus decreasing the environmental impact of the manufacturing process. [Display omitted] • Nanocellulose (i.e. TOCNF) adopted for colored paper preparation • Coloring efficiency improved by TOCNF due to the dye retention improvement • -COO− in TOCNF deteriorating its combination with negatively-charged dye [ABSTRACT FROM AUTHOR]

Frequent oceanic oil spill incidents and the discharge of industrial oily wastewaters have caused serious threats to environments, food chains and human beings. Lignin wastes with many reactive groups exist as the byproducts from bioethanol and pulping processing industries, and they are either discarded as wastes or directly consumed as a fuel. To make full use of lignin wastes and simultaneously deal with oily wastewaters, porous lignin-based composites have been rationally designed and prepared. In this review, recent advances in the preparation of porous lignin-based composites are summarized in terms of aerogels, sponges, foams, papers, and membranes, respectively. Then, the mechanisms and the application of porous lignin-based adsorbents and filtration materials for oil/water separation are discussed. Finally, the challenges and perspectives of porous lignin-based composites are proposed in the field of oil/water separation. The utilization of abundant lignin wastes can replace fossil resources, and meanwhile porous lignin-based composites can be used to efficiently treat with oily wastewaters. The above utilization strategy opens an avenue to the rational design and preparation of lignin wastes with high-added value, and gives a possible solution to use lignin wastes in a sustainable and environmentally friendly way. [ABSTRACT FROM AUTHOR]

A lignin-based PU coating was prepared for paper-based green packaging. Two representative diisocyanate were used to prepare the coatings. Due to the rigid aromatic, the physical properties of the TDI system reached the maximum below the lignin content of 40%. The HDI that contains flexible aliphatic chains alleviated the brittleness of coating, and it showed physical advantages when the lignin content was more than 50%. Owing to the high lignin content, the coating presented enhanced thermal stability. After coated with the lignin-based PU coatings, the dry tensile strength of coated paper was improved by 126%. Amazingly, the wet strength was increased from 0.31 to 12.6 MPa with an improvement nearly 40 times. Based on the coordination of lignin, Ag+ was introduced into the PU matrix, which imparted the coating with excellent antibacterial ability. The colony forming units of E. coli and S. aureus were both less than 1. However, no inhibition halo was observed, which indicated that the Ag was firmly anchored on the coating and the antibacterial ability is only available when the bacterial contact the coating surface. The lignin-based PU coating with favorable sustainability and properties shows great potential in paper-based green packaging fields. The prepared PU coating with high lignin content and firmly anchored Ag+ exhibits outstanding physical properties, thermal stability, and antibacterial property, which makes it an ideal candidate to be used in paper-based green packaging. [Display omitted] [ABSTRACT FROM AUTHOR]

Limnocharis flava is a noxious aquatic weed that poses a threat to paddy cultivation. The high cellulose and low lignin contents in this plant make it a potential raw material for papermaking. Against this backdrop, this study was taken up to develop Limnocharis flava (LF) based sheets containing natural fibres from Banana (B), Pineapple (P), and Rice Straw (RS) as reinforcing agents. The influence of carboxymethyl cellulose (CMC) as a binder on the LF-based sheets was also studied. To enhance the mechanical and moisture resistance properties, a chitosan coating was provided to the sheets. Analytical tests for mechanical properties, water barrier properties, functional groups, structure and microstructure, thermal properties and biodegradability were performed. Among the samples, LF + B showed the highest tensile strength (34.86 Mpa) and bursting strength (13.055 kg/cm2), while LF + R had higher puncture and tearing strengths. Chitosan coating was found to enhance the sheets and improve the water barrier properties mechanically. The contact angle of LF + B increased from 91.6° to 110.65°, while the water vapour transmission rate of LF reduced from 532.18 to 404.47 on providing chitosan coating. The significant interactions of reinforcing agents were confirmed by the results of FTIR and that of the coating by the SEM micrographs. The LF-based sheets were also found to have decent thermal stability. The high value of the crystallinity index in LF + R samples supported their remarkable mechanical properties. This study proclaims the notable suitability of Limnocharis flava in manufacturing paper for packaging applications. [Display omitted] • Limnocharis flava based composite sheets were developed for packaging applications • Bio coating using chitosan was applied to enhance quality parameters • The developed material had impressive mechanical and water barrier properties • The developed material was used for cardamom packaging alternative to wood pulp /plastic packaging [ABSTRACT FROM AUTHOR]

Over the centuries, various types of paper have been produced, each characterized by a different ratio of natural macromolecules, mainly lignin and cellulose. Handmade paper has a higher content of cellulose with respect to the early machine-made paper, where lignin is the other important component. Microorganisms are able to colonize and deteriorate both types. They can release on their surfaces pigments and colorants which produced anesthetic stains. To better understand the microbiota colonizing these stains, 17 samples were analyzed, from both handmade and machine-made paper surfaces, as well as library and archive environments. Combination of microbiological and high-throughput sequencing (HTS) approaches were applied. The culture-dependent methodology comprised: isolation, DNA identification, hydrolytic and paper staining assays. The HTS was performed by MinION platform and for the mycobiome a more suitable bioinformatics analysis pipeline, MetONTIIME based on QIIME2 framework, was applied. The paper model staining assay permitted the direct recognition of colorizing isolates which in combination with sequencing data evidenced a complex microbial community able to stain the two types of paper. Staining abilities were confirmed by frequently isolated and detected fungi as well as newly discovered ones Roussoella euonymi and Achaetomium. We have also evidenced the staining ability of several bacteria. [ABSTRACT FROM AUTHOR]