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Thin coating layers of cross-linked polydimethylsiloxane (PDMS) and inorganic particles including glass spheres (GS), colloidal and fumed silica (aero and N20), montmorillonite (MMT), and kaolin (K) were attached onto Grade 1 Whatman filter paper (WFP) substrates using the spraycoating procedure to achieve superhydrophobic hybrid paper sheets. Coating formulations were varied in terms of their PDMS molecular masses and inorganic particles to prepare different samples. The effect of PDMS molecular weight and change in inorganic particle composition on the optical properties, surface roughness, barrier properties, surface chemistry, and topography was investigated. Hybrid paper sheets with ΔE00 values lower than 1 could be achieved, the surface roughness of which could be decreased by increasing the PDMS molecular weight in the coating formulation. Scanning electron microscopy studies revealed a homogeneous coating distribution, resulting in significant improvements in both the air and water barrier properties of the hybrid paper sheets. Spectroscopic investigations revealed the presence of interactions between the coating layer and the underlying paper substrate. Moreover, the distribution behavior of the inorganic particles on the spraycoated surfaces using the proposed method was also investigated using model compounds. [ABSTRACT FROM AUTHOR]

This study explores the efficacy of 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide and 1-hexyl-3-methylimidazolium chloride as cleaning agents for aged cellulosic artifacts. A 10% v/v acetone solution of these ionic liquids (ILs) effectively removes the brownish-yellow color of aged paper in a 10 min immersion treatment. Colorimetric analysis shows a remarkable increase in lightness (L*) by up to 40% and a decrease in red/brownish tones (b*) after IL treatment. The cleaning process also deacidifies the paper, shifting the pH to neutral-slightly basic levels and enhancing its long-term stability. Optimal pH outcomes are achieved, with ionic liquid consumption values of 0.4–0.6 g/g of paper. The FTIR analysis revealed structural changes in cellulose induced by the washing step, which is mainly due to the reorganization effect imparted by the ionic liquids. Furthermore, ILs mobilized degraded compounds and acidic species, aiding in their extraction during the restoration process. Mechanical testing indicated an enhancement in the overall tensile strength and strain at break values for IL-treated papers by up to 33%. This study demonstrates the multiple benefits of alkylimidazolium ionic liquids for preserving and restoring cultural heritage artifacts made of cellulosic materials. [ABSTRACT FROM AUTHOR]

Due to the surface hydrophobicity, the absorbing effect of the tobacco extract droplets on the reconstituted tobacco paper is unsatisfactory. Therefore, the surface property regulation of the tobacco paper has gained increasing attention. This work reports a novel argon (Ar) plasma treatment technique for improving the surface hydrophilicity and bacteriostatic effect of the paper. Firstly, Ar plasma was selected as the treatment gas and its improving effect was demonstrated through studying the contact angle changes of water droplet on the A4 paper. Then, the capillary fibers on the paper were bombarded by Ar plasma jet. The extract droplet contact angle on the reconstituted tobacco paper-15 s surface is only 14.6° within 1 s. In comparison to the pristine paper (5.9°/s), the absorption dynamic of the droplet increased to as high as 62.5°/s, which indicated the hydrophilicity was greatly improved by the Ar plasma method. The mechanism for improving the surface hydrophilicity of the cellulose in the tobacco paper also contributed to the generation of holes by Ar plasma jet, which increased the surface permeability of cellulose. At last, Ar plasma treatment showed excellent bacteriostatic effect, which could effectively inhibit the propagation and growth of fungi, Escherichia coli, and Staphylococcus aureus on the tobacco paper. [ABSTRACT FROM AUTHOR]

• BC/ZnO nanocomposite strengthens paper and improves aging resistance. • The nanocomposite imparts antifungal properties to paper. • The nanocomposite helps in deacidification of paper. Paper, commonly used as an information carrier, can become acidified and brittle over time. In this study, 0.3 % bacterial cellulose (BC) composite with 1.0% zinc oxide (ZnO) nanoparticles was prepared and used to coat brittle book paper for deacidification and consolidation. The BC/ZnO nanocomposite was characterized using zeta potential, micro morphology, elemental mapping, X-ray photoelectron spectra, Fourier transform infrared, and thermogravimetric analyses. The results indicated that the composite exhibited good stability. ZnO nanoparticles were bonded to the hydroxyl groups on BC, enhancing the thermal stability of BC. The composite was uniformly sprayed on the paper surface, and the mechanical properties, color difference, readability, pH, and micromorphology of the paper samples were examined before and after the treatment. The BC/ZnO nanocomposite exhibited good deacidification and consolidation effects on paper samples with low impact on the original paper appearance. Moreover, the BC/ZnO nanocomposite showed a good inhibitory effect on fungi growth on paper. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to find a suitable solution to treat the solidification paper by using hydroxypropyl cellulose (HPC) to improve the mechanical, physical and chemical properties of paper. Design/methodology/approach: The samples have gone several stages, starting with the manufacture of paper from the linen pulp and the same components of the hardened manuscript papers. It was subjected to artificial aging to reach an age comparable to the manuscript age, then it was subjected to natural aging by inoculation it with A. niger. Mechanical cleaning of the leaves was done with soft brushes. The samples have been consolidated by HPC 2%. Digital microscopy, scanning electron microscopy, mechanical properties measurement, color change, Fourier transform infrared and pH measurements were used to assess the effect of HPC on the qualities of leaves. Findings: HPC succussed in strengthening and restoring the natural, chemical and mechanical properties for the solidified leaves. Originality/value: The solidified papers phenomenon constitutes severe suffering for manuscripts and books conservators. The paper consolidation initial stage is one of the most important conservation stages because paper has lost many natural, mechanical and chemical properties. The most important feature of this study is providing a solution to the hardened leaves strengthening problem and restoring their chemical, natural and mechanical properties. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to find an applicable solution for the consolidation of petrified paper after disassembling it to complete other stages of treatment. Design/methodology/approach: The samples were subjected to natural aging by being inoculated with Aspergillus niger until they reached the stage of adhesion and petrification. After that, the leaves were separated, and cellulose nanocrystals were applied, then the leaves were subjected to wet thermal aging for 21 days. Digital microscope, scanning electron microscope, mechanical properties measurement, measurement of color change, Fourier transform infrared spectroscopy and pH measurement were used to evaluate the effects of the cellulose nanocrystal on paper. Findings: The results proved that cellulose nanocrystal (5%) successes consolidation of petrified paper Without affecting its natural, mechanical and chemical properties. Originality/value: This study was based on the effectiveness of cellulose nanocrystal in strengthening the petrified papers and testing its effect on the physical, mechanical and chemical paper properties. [ABSTRACT FROM AUTHOR]

Beeswax is a bio-sourced, renewable, and even edible material that stands as a convincing option to provide paper-based food packaging with moisture resistance. Nonetheless, the difficulty of dispersing it in water limits its applicability. This work uses oxidized, negatively charged cellulose nanofibers along with glycerol to stabilize beeswax-in-water emulsions above the melting point of the wax. The synergistic effects of nanocellulose and glycerol granted the stability of the dispersion even when it cooled down, but only if the concentration of nanofibers was high enough. This required concentration (0.6–0.9 wt%) depended on the degree of oxidation of the cellulose nanofibers. Rheological hindrance was essential to prevent the buoyancy of beeswax particles, while the presence of glycerol prevented excessive aggregation. The mixtures had yield stress and showed pseudoplastic behavior at a high enough shear rate, with their apparent viscosity being positively influenced by the surface charge density of the nanofibers. When applied to packaging paper, the nanocellulose-stabilized beeswax suspensions not only enhanced its barrier properties towards liquid water (reaching a contact angle of 96°) and water vapor (<100 g m−2 d−1), but also to grease (Kit rating: 5) and airflow (>1400 Gurley s). While falling short of polyethylene-coated paper, this overall improvement, attained using only one layer of a biobased coating suspension, should be understood as a step towards replacing synthetic waxes and plastic laminates. [ABSTRACT FROM AUTHOR]

This work focuses on a systematic method to produce Ag, Cu, and Ag/Cu metallic nanoparticles (MNPs) in situ assisted with ultrasound on cellulose paper. By tuning the concentration of AgNO3 and CuSO4 salt precursors and ultrasound time, combined with a fixed concentration of ascorbic acid (AA) as a reducing agent, it was possible to control the size, morphology, and polydispersity of the resulting MNPs on cellulose papers. Notably, high yield and low polydispersity of MNPs and bimetallic nanoparticles are achieved by increasing the sonication time on paper samples pre-treated with salt precursors before reduction with AA. Moreover, mechanical analysis on paper samples presenting well-dispersed and distributed MNPs showed slightly decreasing values of Young's modulus compared to neat papers. The strain at break is substantially improved in papers containing solely Ag or Cu MNPs. The latter suggests that the elastic/plastic transition and deformation of papers are tuned by cellulose and MNPs interfacial interaction, as indicated by mechanical analysis. The proposed method provides insights into each factor affecting the sonochemistry in situ synthesis of MNPs on cellulose papers. In addition, it offers a straightforward alternative to scale up the production of MNPs on paper, ensuring an eco-friendly method.

The three cellulosic key chromophores, 2,5-dihydroxy-[1,4]-benzoquinone, 5,8-dihydroxy-[1,4]-naphthoquinone and 2,5-dihydroxy-acetophenone, are nearly ubiquitous in cellulosic materials because of their special structures and resonance stabilization with highly delocalized double bonds that renders them thermodynamically very stable and resistant towards bleaching. All of these compounds possess acidic hydroxyl groups. The current work explores the derivatization of these OH groups by a phosphitylation agent followed by 31P NMR analysis, an approach that is very frequently used for quantitative OH group analysis and differentiation in lignins and lignin derivatives. The chemical shifts are reported and structural peculiarities of the chromophore derivatives are discussed. The 31P NMR approach adds to the toolbox of methods applicable in cellulose chromophore analysis, bleaching and aging studies. [ABSTRACT FROM AUTHOR]

A new biodegradable cellulose derivative-non-isocyanate polyurethane (NIPU) was prepared, and densities, viscosities, and surface tension of NIPU were measured by density bottle method, capillary viscometer and BZY-2 type full automatic surface tension meter respectively from 298.15 to 318.15 K. The results showed that densities, viscosities and surface tension were related to temperature and concentration. The viscosity and surface tension decreased with the increase in temperature at the same concentration; at the same temperature, viscosity and surface tension were positively correlated with concentration. And the experimental data were correlated by the correlation equations of viscosity and temperature, they showed a good agreement with the fitting results of the related equations. [ABSTRACT FROM AUTHOR]

This paper presents the limitations and potential of ATR-FTIR spectroscopy applied to the study of cellulosic textile collections. The technique helps to differentiate natural fibres according to the content of lignin, pectin, hemicellulose, and wax, although some problematic issues should be considered. The spectral differences derived from the environmental humidity uptake and the plant composition are reviewed and discussed in the light of new experimental data. Diagnostic bands are proposed that can discriminate between different fibres from different plants. The contribution of ageing is also considered, demonstrating that sometimes aged fibres cannot be reliably recognised. In contrast, the potential of ATR-FTIR spectroscopy to discriminate between natural and modified fibres is discussed and proven. The best results were obtained when microinvasive ATR-FTIR spectroscopy was coupled with SEM observations. The proposed protocol was tested on microsamples of various cellulosic materials from traditional Japanese samurai armours dating from the 16th to the 20th centuries (Morigi Collection, Museo delle Culture, Lugano, Switzerland). The results facilitated a complete characterisation of the materials and demonstrated that the protocol can be used to study a wide variety of cellulosic materials, including both natural and man-modified fibres, and paper.

Water hyacinth (Eichhornia crasspies) was used as a renewable cellulose source to prepare nanofibrillated cellulose (NFC). Due to the porous structure and low lignin content of water hyacinth, a 10 min-treatment time using the high-speed homogenization was sufficient to disintegrate nanofibers. The average width of the NFC treated for 40 min was 16.8 nm. With longer treatment times, a slight decrease in thermal stability of NFC was found while no changes in the crystallinity index of NFC were detected. Moreover, paper was formed from NFC with respect to mechanical treatment times. Results showed NFC treated with longer treatment times could prepare the paper with lower pore sizes between adjacent fibrils and porosity, resulting in higher wettability and mechanical properties. The contact angle of the 40 min-treated NFC paper was 36.0° while this contact angle result could not be measured from the samples of 0 min-treated NFC due to occurrence of large pores between fibers. The tensile strength of the NFC paper with 40 min-treatment time was ~18 times stronger than that of the 0 min-treated NFC paper. Mechanical energy consumption of the high-speed homogenization used to disintegrate NFC was also compared to that of the industrial defibrillation techniques.

The manufacturing of paper with new functional properties is a current problem today. A method of modifying the surface layer of paper by the partial dissolution of cellulose on its surface is proposed. N-Methylmorpholine-N-oxide (NMMO) is proposed for use as a solvent, the regeneration of which provides an environmentally friendly process. It was shown that among the possible hydrate forms of the solvent, the monohydrate and higher-melting forms are optimal for modifying the paper surface. The temperature–time modes of processing were revealed and the weight gain and density increase in the course of modification were estimated. The structural and morphological features of the original and modified paper were studied by X-ray imaging and scanning microscopy. The NMMO surface treatment makes it possible to vary the air permeability of the paper, making it practically non-permeable. The capillary and pore system were radically transformed after the partial dissolution of cellulose and its coagulation, as the formed cellulose film isolates them, which leads to a decrease in surface absorbency. The processing conditions allowing for the optimization of the optical and strength properties of the modified paper samples are revealed. The resulting paper with a modified N-methylmorpholine-N-oxide surface layer can be used for printing valuable documents. [ABSTRACT FROM AUTHOR]

Pulp fibers are among the most abundant and cost effective cellulose source for the fabrication of polymer-cellulose composites. A straightforward method is to impregnate pulp fibers into thermoplastic films by hot press forming. As such, tissue materials made from hard or soft wood lignin-free Kraft fibers are attractive. In this work, we prepared cellulose fiber-polylactic acid (PLA) composite films by impregnating PLA films into a 40 g/m2 tissue paper texture. A PLA film was sandwiched between single and multiple layers of cellulose tissues by hot pressing, forming composite films. Up to 40 wt% cellulose could be incorporated into PLA in this way. The effect of cellulose fiber content on the composite thermomechanical properties has been studied and reported. A natural terpene, limonene, was infused into the cellulose fibers by immersion coating to produce antioxidant composites. Limonene-modified composites demonstrated long-term antioxidant release and activity for three days, verified by 2, 2-Diphenyl-1-picrylhydrazyl (DPPH), cupric ion reducing antioxidant capacity (CUPRAC) and free iron ions (Fe2+)/ferrozine chelating assays separately. The short-term (2 h) antioxidant activity of the biocomposites reached 50–70% levels depending on the cellulose fiber concentration for the DPPH and CUPRAC assays but remained lower at 20–55% levels in the metal chelating assay. Due to sustained release of limonene from the composites, at the end of the 5-day period, the iron chelating antioxidant activity of the composites improved reaching 75%, whereas for DPPH and CUPRAC assay, 90% activity was recorded. These biocomposite films can be used in active protective packaging of both food (fruit) and cosmetic products. [ABSTRACT FROM AUTHOR]

Cellulose-based materials represent a renewable, biodegradable, and environmentally friendly alternative to plastic from fossil resources. Nanopaper is a strong and lightweight material formed from cellulose nanofibrils (CNFs). Paper and nanopaper have been considered as excellent alternatives to plastics for use in agriculture and for packaging applications. However, common for both paper and nanopaper is their hydrophilic character, and consequently, poor water-resistance properties. ORMOCER®s are a class of inorganic–organic polymers with excellent barrier and protective properties used for a range of coating applications. Here we present ORMOCER®-coated paper and nanopaper. The coated papers and nanopapers are characterized, both in terms of their morphology, hydrophobicity, and mechanical properties. We demonstrate that the pressure used during the pressing and drying of paper and nanopaper influence their tear and tensile—properties, and that the morphology of the coated nanopaper differs significantly from that of the coated paper. While the ORMOCER® was impregnated within the porous network of the paper, a well-defined two-layered morphology was obtained with the coated nanopaper. Further, the biodegradability of the nanopaper with and without coating was assessed. The degradation study demonstrated that both the pressure used during the pressing and drying of the nanopaper, and the composition of the ORMOCER®, influenced the rate of degradation. Taken together, ORMOCER®-coated paper and nanopaper are promising for the preparation of materials that are both water-resistant, renewable, and biodegradable. [ABSTRACT FROM AUTHOR]

Wet-strength paper production is of great significance due to its prominent importance in everyday consumer activities. Recently, market demands for paper with specific properties and purposes are increasing. Production of these paper types is very challenging for the manufacturer since they have to meet very specific demands. Wet-strength paper products include bags that come in contact with moisture and wet products, hygienic and kitchen towels, paper towels, packaging products (packages for liquids, aseptic dishes, and a variety of packaging for food), and other special purposes items (tea bags, coffee filters, paper money, etc.) Throughout this research, the focus was on the effects a wetstrength agent has on the tensile strength of paper. The wet strength property of paper is the ratio between the strength of paper in the wet and dry state. The strength in the dry state comes from the hydrogen bonds present in natural cellulose, while the strength of paper in the wet state requires waterproof (covalent) bonds created by the use of a wet strength agent. The wet strength agent used is a cationic PAE resin. The aim of the work is to determine the optimal amount of agent needed in relation to the required value of the tensile strength property of the paper. The investigation of these influences was carried out on Semi Extensible Standard Kraft type of paper in Natron-Hayat. [ABSTRACT FROM AUTHOR]

Water hyacinth (Eichhornia crasspies) was used as a renewable cellulose source to prepare nanofibrillated cellulose (NFC). Due to the porous structure and low lignin content of water hyacinth, a 10 min-treatment time using the high-speed homogenization was sufficient to disintegrate nanofibers. The average width of the NFC treated for 40 min was 16.8 nm. With longer treatment times, a slight decrease in thermal stability of NFC was found while no changes in the crystallinity index of NFC were detected. Moreover, paper was formed from NFC with respect to mechanical treatment times. Results showed NFC treated with longer treatment times could prepare the paper with lower pore sizes between adjacent fibrils and porosity, resulting in higher wettability and mechanical properties. The contact angle of the 40 min-treated NFC paper was 36.0° while this contact angle result could not be measured from the samples of 0 min-treated NFC due to occurrence of large pores between fibers. The tensile strength of the NFC paper with 40 min-treatment time was ~18 times stronger than that of the 0 min-treated NFC paper. Mechanical energy consumption of the high-speed homogenization used to disintegrate NFC was also compared to that of the industrial defibrillation techniques. [ABSTRACT FROM AUTHOR]

This paper presents the limitations and potential of ATR-FTIR spectroscopy applied to the study of cellulosic textile collections The technique helps to differentiate natural fibres according to the content of lignin, pectin, hemicellulose, and wax, although some problematic issues should be considered. The spectral differences derived from the environmental humidity uptake and the plant composition are reviewed and discussed in the light of new experimental data. Diagnostic bands are proposed that can discriminate between different fibres from different plants. The contribution of ageing is also considered, demonstrating that sometimes aged fibres cannot be reliably recognised. In contrast, the potential of ATR-FTIR spectroscopy to discriminate between natural and modified fibres is discussed and proven. The best results were obtained when microinvasive ATR-FTIR spectroscopy was coupled with SEM observations. The proposed protocol was tested on microsamples of various cellulosic materials from traditional Japanese samurai armours dating from the 16th to the 20th centuries (Morigi Collection, Museo delle Culture, Lugano, Switzerland). The results facilitated a complete characterisation of the materials and demonstrated that the protocol can be used to study a wide variety of cellulosic materials, including both natural and man-modified fibres, and paper. [ABSTRACT FROM AUTHOR]

Cellulose microspheres (CMS) are a type of spherical regenerated cellulose particles with versatile properties which have been used as carrier materials in medical and technical applications. The integration of CMS into paper products opens up novel application scenarios for paper products in a wide range of fields. However, the incorporation of CMS carriers into paper products is challenging and hitherto no reports do exist in literature. Here, we present a feasibility study to incorporate up to 50 w.% CMS in paper hand sheets using retention aids. Our primary observations highlight the successful formation of uniform paper hand sheets retaining its tensile strengths at elevated CMS concentrations. Sheets with high CMS contents exhibit an increase in density and display enhanced surface smoothness — an outcome of a CMS layer forming atop the fiber base — which effectively bridges voids and rectifies surface irregularities as supported by Gurley testing, infinite focus microscopy and scanning electron microscopy. While our primary objective centered on the general feasibility to manufacture CMS-containing papers, the resulting composite scaffold carries significant potential as a platform for innovative, functional paper-based materials. [Display omitted] [ABSTRACT FROM AUTHOR]

This publication presents the results of the fundamental research on the interaction of laser radiation and lignocellulosic fibres with respect to the melting of the fibre main components cellulose, hemicellulose and lignin. In the first part, hand sheets made of different lignocellulosic fibres were irradiated with laser radiation from a carbon monoxide laser. Fluence-dependent interaction regimes, the dynamics of flash pyrolysis and chemical changes due to irradiation are discussed. Using a high-speed camera, an intermediate liquid state could be observed as a result of the irradiation. This is decomposed into gaseous reaction products by a highly dynamic boiling process. In addition to the time-resolved investigations, extensive FTIR studies were carried out. The second part is intended to further investigate former work on melting of cellulose. The basic idea is to combine laser radiation and mechanical pressure by compressing the sample between two steel bolts and simultaneously irradiating the joint. The processed samples show some visual indications of intermediate melting, such as increased transparency or flow behaviour. However, these can be traced back to effects that do not require a melting state. [ABSTRACT FROM AUTHOR]

The hydroxyl groups on the cellulose macromolecular chain cause the cellulose surface to have strong reactivity. In this study, 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane (PDOTES) was used to modify cellulose to improve its triboelectric properties, and a triboelectric nanogenerator (TENG) was assembled. The introduction of fluorine groups reduced the surface potential of cellulose and turned it into a negative phase, which enhanced the ability to capture electrons. The electrical properties increased by 30% compared with unmodified cellulose. According to the principles of TENGs, a self-powered human-wearable device was designed using PDOTES-paper, which could detect movements of the human body, such as walking and running, and facilitated a practical method for the preparation of efficient wearable sensors. [ABSTRACT FROM AUTHOR]

Direct fire, indirect heat, and extinguishing water cause great damage to cultural assets upon a fire disaster in a library or archive. Conservation and restoration of heat-damaged papers are particularly challenging due to the complexity and severity of the damage. Since valuable originals obviously cannot be used for the development of treatment methods and only to a limited extent for the analysis of the damage, it is necessary to produce model paper materials that have a high degree of similarity to fire-damaged papers, which was addressed in the present study. Three different heating methods were tested to produce model papers of different heating levels. Their altered optical, structural, and chemical properties were analyzed and compared with the results of original fire-damaged samples. The study points out pathways to enable the production of comparable sample materials. Heating between hot plates or in an oven produces papers that have properties quite similar to the originals in terms of surface area, paper structure, cellulose integrity, and interactions with water. Stack heating in the oven has proven to be a particularly effective manufacturing method for larger quantities of model papers. [ABSTRACT FROM AUTHOR]

Laser‐induced graphene (LIG) produced by irradiation of paper (paper‐LIG)holds substantial promise for flexible devices. This article presents paper‐LIG humidity and temperature sensors fabricated by single‐step irradiation of common filter paper with a pulsed UV laser (355 nm). The influence of the process parameters on the conversion of cellulose fibers into LIG is discussed based on the resulting morphology, structure, conductivity, and chemical composition, revealing a distinct barrier to transformation and a propagation behavior not seen under CO2 laser irradiation. The obtained material is constituted by a porous, electrically conductive network of fibers. The paper‐LIG relative humidity (RH) and temperature sensors with sensitivities of up to 1.3 × 10−3%RH−1 and ‐ 2.8 × 10−3 °C−1, respectively, are examined in terms of their linearity, reproducibility, and response time. A detailed discussion on the response mechanism is presented in the context of literature, pointing towards the absorption of water molecules in the interlayer spacing of graphene as the main reason for the increase in resistance with RH. Additionally, a contribution from variable range hopping along the ab plane of graphene at high RH is suggested. These results demonstrate the potential of paper‐LIG for low‐cost, sustainable, and environmentally friendly sensing. [ABSTRACT FROM AUTHOR]

In the present society, the recycling and reuse of valuable substances are of utmost importance for economic and environmental purposes. At the same time, there is a pressing need to develop new methods to protect the ecosystem from many human activities, including those that have contributed to an ever-increasing presence of pharmaceutical pollutants. In this study, a straightforward approach that applies a magnetic carbon composite for the effective removal of NSAIDs from biological fluids is reported. The composite was produced by recycling wasted handkerchiefs, to provide cellulose to the reactive system and then transformed into carbon via calcination at high temperature. The morphological and structural features of the prepared "Fe3O4@-activated carbon" samples were investigated via thermal analysis, X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. Magnetic solid-state extraction was carried out to reveal the adsorption capabilities of the magnetic carbon composite and then combined with UHPLC–PDA for the determination and quantification of five NSAIDs (furprofen, indoprofen, ketoprofen, flurbiprofen, and indomethacin). The method developed herein proved to be fast and accurate. The adsorbent could be reused for up to 10 cycles, without any decrease in performance; thus, it contributes to an intelligent and sustainable economic strategy projected toward minimal waste generation. [ABSTRACT FROM AUTHOR]

Objective: To determine the cellulose, hemicellulose, and lignin production in six Cenchrus purpureus cultivars, with and without fertilization, harvested every 21 days during 168 days. Design/methodology/approach: The evaluated cultivars were CT-115, elephant grass, king grass, Maralfalfa, Roxo, and Taiwan, with and without fertilization. The experimental design was a randomized complete block with a split-plot arrangement and four replications. The fertilization dose was 141-43-20 of NPK. Forage was harvested every 21 days during six months in the rainy season. We tested the samples for dry matter (DM), ash, NDF, ADF, hemicellulose, cellulose, and lignin. We performed a nonlinear regression analysis. We determined biomass production with the estimated values and the percentage of each component. The goodness-of-fit indicators were: R², the coefficient of determination (R), and the model selection criterion (MSC). The parameters and goodness-of-fit coefficients were analyzed in ANOVA with the SAS software using the GLM procedure. Means were compared with Tukey's test. Results: The Maralfalfa cultivar presented a higher cellulose production (3,786 kg ha-1), similar (p>0.05) to the elephant grass and Taiwan cultivars, which presented values of 3,451 kg ha-1 and 3,329 kg ha-1, respectively, and different (p<0.05) from CT-115 and king grass, which produced more than 1 t ha-1 of cellulose. Limitations/implications: Cellulose production increased by the effect of fertilization. Findings/conclusions: The fertilized Maralfalfa, elephant grass, and Taiwan cultivars produced more than 4,000 kg ha-1 of cellulose, 3,000 kg ha-1 of hemicellulose, and 1,000 kg ha-1 of lignin. [ABSTRACT FROM AUTHOR]

There is current interest in replacing petroleum-based additives in consumer paper products with abundantly available, renewable and sustainable biopolymers such as lignin-containing cellulose nanofibers (LCNFs) and cottonseed protein. This research characterized the performance of cottonseed protein isolate with/without LCNFs to increase the dry strength of filter paper. The application of 10% protein solution with 2% LCNFs as an additive improved the elongation at break, tensile strength and modulus of treated paper products compared to the improved performance of cottonseed protein alone. Improvements in tensile modulus and tensile strength were greatest for samples containing larger amounts of lignin and a greater degree of polymerization than for those with less lignin from the same biomass sources. [ABSTRACT FROM AUTHOR]

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]

Correctness and reliability of molar mass data by viscometry in organometallic solvents (cuen, cuoxam, cadoxen) are compromised by the alkalinity of these solvents which causes immediate depolymerization especially in the case of pulps with higher carbonyl content (oxidative damage). The viscosity values thus correspond to the molar mass after the beta-elimination reactions that underly these degradative processes, which is sometimes significantly smaller than the molar mass determined by gel permeation chromatography (GPC) in the non-degrading solvent system DMAc/LiCl. Despite this well-known drawback, viscosity measurements have become a standard approach for molar mass measurements due to their ease and fastness, especially in the pulp and paper industries. A potential way to reduce the inherent error of these molar mass determinations via viscosity measurements is a reductive treatment prior to dissolution of the pulp in the organometallic solvents, which converts the labile, alkali-sensitive carbonyl structures back to the respective alcohols. Using sodium borohydride (NaBH4) on different types of cellulosic pulps, we demonstrate the beneficial effects of such a reduction step on the determined degree of polymerization (DP) for all three common solvents: cuen, cuoxam and cadoxen. Molar mass distributions and profiles of carbonyl groups were determined by GPC and by carbonyl selective fluorescence labeling ("CCOA method"). Such a reductive treatment was especially valuable for hemicellulose-containing pulps. While the decreased measurement error according to the new protocol is beyond doubt, an immediate acceptance in the pulp and paper industries is at least questionable, because the new, more correct data would not agree with the old – wrong, but consistent – numbers accumulated over years and decades. In the long run, however, the new, improved protocol will prevail here as well due to its lower error rate. [ABSTRACT FROM AUTHOR]

As a green material, cellulose is widely used in friction triboelectric nanogenerators (TENGs). However, the weak polarity of the cellulose fibers surface leads to its weak contact electrification performance, which is not conducive to its utilization in TENGs. In this study, epoxy chloropropane and ethylenediamine were grafted onto cellulose fibers to form paper and were assembled with an Fluorinated ethylene propylene film. The output voltage, current, and surface charge density were 34.9%, 26.7%, and 16.7% higher than those of ordinary paper, respectively. When 20% nano TiO2 filler was added to the paper made from amino-modified cellulose fibers, the output voltage, current, and surface charge density of the TENG increased by 70.9%, 226.7%, and 122.2%, respectively, compared with ordinary paper. As the air humidity of the TENG increased from 60 to 90%, the output voltage, current, and surface charge density were maintained at 53.7%, 38.9%, and 61.0%, respectively. When a 5 × 107 Ω resistor was connected to the working circuit, its output power reached 13.78 μ W cm2. This showed that cellulose as a green material has wide application prospects in the field of TENG. [ABSTRACT FROM AUTHOR]

We combine biodegradable plastic (polyvinyl alcohol/glycerol polymer), and cellulose-based tissue paper in a very short time (5 s) by a facile way to form a new matrix, named plastic-paper, which has high optical transmittance (~ 89%) and high optical haze (~ 90%) in broadband. Results showed that the plastic-paper is durable in different solvents, with high folding strength (over 3500 folding times) and good mechanical strength (> 30 MPa tensile strength). Interestingly, the plastic-paper presents a two-sidedness of surface morphology. The smooth side shows high light transmittance and the rough side presents high optical haze. The smooth side of the plastic-paper is successfully applied to Organic Light-Emitting Diode (OLED). When the rough surface of plastic-paper is used in solar cells, the maximum output power increases by 2.6% compared with bare solar cells. The developed plastic-paper with high optical transmittance and high optical haze holds a great potential in flexible optoelectronic devices. [ABSTRACT FROM AUTHOR]

El desarrollo y la investigación de nuevos productos que puedan sustituir parcial o completamente materias primas empleadas para la producción de energía, productos químicos de alto valor añadido e incluso la fabricación de papel, ha permitido que el cáñamo industrial (Cannabis sativa L.) se vuelva atractivo como principal materia prima en la reactivación de una economía de base biológica con altas condiciones y capacidades de producción. A partir de lo anterior, el objetivo de este trabajo investigativo es profundizar sobre el potencial del uso de fibra de cáñamo en la industria del papel, soportado por estudios realizados por el Estado Colombiano en lo referente a las disponibilidad de cultivos forestales con fines comercialesque inicialmente se destinan para la siembra y producción de recursos madereros como el pino y eucalipto. Se ha considerado de importancia demostrar que el cáñamo, como fuente de producción primaria, brinda ventajas competitivas económicas, ambientales y sociales frente a los cultivos tradicionales, incluso para las nuevas fuentes de investigación de base biológica.

Cellulose-based materials are considered to be green and sustainable substitutes for plastics. However, their hydrophilicity and water instability limit further applications. Herein, ethyl cellulose (EC) and hydrophobic SiO2 nanoparticles (NPs) were employed to prepare hydrophobic SiO2@EC/P materials by dipping-spraying method. A series of cellulosic papers with various hydrophobicity (water contact angle (WCA) from about 90° to 166°, and contact angle hysteresis (CAH) less than 5°) were fabricated by varying the amount of SiO2 NPs. The dry and wet strength of the modified paper increased by 72.3% and 916.7%, respectively. Soaking test shows that the SiO2@EC/P straws remain intact after being placed in different beverages and water at the temperature of 0 to 90 °C for 2 h. Furthermore, these straws can be completely degraded after being buried into the soil for 200 days. Therefore, SiO2@EC/P materials are promising alternative materials for plastic straws. The potential application of SiO2@EC/P materials would effectively alleviate the 'white pollution' problem. [ABSTRACT FROM AUTHOR]

The manufacturing of paper with new functional properties is a current problem today. A method of modifying the surface layer of paper by the partial dissolution of cellulose on its surface is proposed. N-Methylmorpholine-N-oxide (NMMO) is proposed for use as a solvent, the regeneration of which provides an environmentally friendly process. It was shown that among the possible hydrate forms of the solvent, the monohydrate and higher-melting forms are optimal for modifying the paper surface. The temperature–time modes of processing were revealed and the weight gain and density increase in the course of modification were estimated. The structural and morphological features of the original and modified paper were studied by X-ray imaging and scanning microscopy. The NMMO surface treatment makes it possible to vary the air permeability of the paper, making it practically non-permeable. The capillary and pore system were radically transformed after the partial dissolution of cellulose and its coagulation, as the formed cellulose film isolates them, which leads to a decrease in surface absorbency. The processing conditions allowing for the optimization of the optical and strength properties of the modified paper samples are revealed. The resulting paper with a modified N-methylmorpholine-N-oxide surface layer can be used for printing valuable documents.

The hydroxyl groups on the cellulose macromolecular chain cause the cellulose surface to have strong reactivity. In this study, 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane (PDOTES) was used to modify cellulose to improve its triboelectric properties, and a triboelectric nanogenerator (TENG) was assembled. The introduction of fluorine groups reduced the surface potential of cellulose and turned it into a negative phase, which enhanced the ability to capture electrons. The electrical properties increased by 30% compared with unmodified cellulose. According to the principles of TENGs, a self-powered human-wearable device was designed using PDOTES-paper, which could detect movements of the human body, such as walking and running, and facilitated a practical method for the preparation of efficient wearable sensors.

Two kinds of cellulose/ZnO piezoelectric papers are prepared by crushing and dissolving methods. The papers are characterized by SEM and analyzed by a piezoelectric equipment. The differences in the structure and piezoelectric performance of the two kinds of papers are explored. The effects of ZnO add-on amount, thickness of the papers, and pressure on the piezoelectric properties are discussed and compared with a PVDF film. The mutts show that the fibers of the piezoelectric paper prepared by the dissolving method are smooth and tightly bounded to ZnO, which makes ZnO uniformly coat on the surface of the fibers. The higher the pressure, the higher the piezoelectric properties. The thicker the piezoelectric paper, the higher the piezoelectric properties. The piezoelectric paper with 20% ZnO added by the dissolving method has high piezoelectric properties, and the maximum output current is 52.36 nA/cm². The piezoelectric properties of the piezoelectric paper are comparable to the purchased PVDF film. [ABSTRACT FROM AUTHOR]

This contribution focuses on understanding of paper wet-strength properties, by taking a closer look at the spatial distribution of wet-strengthening polymers inside the cellulosic fiber network deposited under different treatment conditions using confocal laser scanning microscopy as in situ imaging tool. We compare the behavior of paper samples treated with a photochemically cross-linkable copolymer using an impregnation process employing three different solvents, namely water, 2-propanol (IPA) and 1-butanol (BuOH), respectively. As these solvents swell paper fibers to quite different extents, the deposition of the polymer, on, in or in-between the cellulosic fibers varies quite strongly, as is shown by in-depth analysis using confocal laser scanning microscopy. The difference in accessibility of distinct surface sites exclusively on or also in and between the fibers controls the macroscopic tensile strength under both dry and wet conditions. [ABSTRACT FROM AUTHOR]

To more accurately predict the permanence of paper during natural aging, we studied cellulose aging according to closed vial setup, which compared to alternative paper aging methods is closer to natural aging with regard to predictions of paper life expectancy. To improve kinetic evaluation, not only cellulose degradation by hydrolysis and oxidation, but also the moisture content in the closed vial were measured during the aging process. This allowed to eliminate the long-known errors of the method caused by vial leakage which falsely produce different aging rates for different aging periods. With the aim of predicting paper permanence more accurately, several ways of considering the moisture changes and the influences of paper moisture and vial leakage were considered and an improved protocol was elaborated that corrects the rate of cellulose chain scission based on the average moisture content in the paper. Based on this hydrolysis rate, the expected half-life DP becomes independent of the aging period and thus less error-prone and more reliable. We hope that this improvement of the very common closed-vial aging method will quickly be accepted and welcomed by the paper conservation community. [ABSTRACT FROM AUTHOR]

Liquid penetration in porous cellulosic materials is crucial in many technological fields. The complex geometry, small pore size, and often fast timescale of liquid uptake makes the process hard to capture. Effects such as swelling, vapor transport, film flow and water transport within cellulosic material makes transport deviate from well-known relations such as Lucas-Washburn and Darcy's Law. In this work it is demonstrated how Ultra-Fast Imaging NMR can be used to simultaneously monitor the liquid distribution and swelling during capillary uptake of water with a temporal- and spatial resolution of 10 ms and 14.5–18 μm respectively. The measurements show that in a cellulose fiber sheet, within the first 65 ms, liquid first penetrates the whole sheet before swelling takes place for another 30 s. Furthermore, it was observed that the liquid front traps 15 v% of air which is slowly replaced by water during the final stage of liquid uptake. Our method makes it possible to simultaneously quantify the concentration of all three phases (solid, liquid and air) within porous materials during processes exceeding 50 ms (5 times the temporal resolution). We hence believe that the proposed method should also be useful to study liquid penetration, or water diffusion, into other porous cellulosic materials like foams, membranes, nonwovens, textiles and films. [Display omitted] [ABSTRACT FROM AUTHOR]

The effect of paper thermal destruction on its luminescence spectra and luminescence excitation spectra in the spectral ranges of 400-550 nm and 250-450 nm, respectively, was studied. It is proposed to use the characteristic changes in the intensity and shape of the luminescence spectra as a criterion for the state of paper insulation of power transformers. On the basis of the analysis performed, it was concluded that when luminescence is excited at a wavelength of 360 nm, none of the main components of the paper can contribute to the recorded luminescence spectra. It is assumed that the resulting luminescence spectra are due to the emission of various impurities that enter the paper during its production.

In the present society, the recycling and reuse of valuable substances are of utmost importance for economic and environmental purposes. At the same time, there is a pressing need to develop new methods to protect the ecosystem from many human activities, including those that have contributed to an ever-increasing presence of pharmaceutical pollutants. In this study, a straightforward approach that applies a magnetic carbon composite for the effective removal of NSAIDs from biological fluids is reported. The composite was produced by recycling wasted handkerchiefs, to provide cellulose to the reactive system and then transformed into carbon via calcination at high temperature. The morphological and structural features of the prepared “Fe3O4@-activated carbon” samples were investigated via thermal analysis, X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. Magnetic solid-state extraction was carried out to reveal the adsorption capabilities of the magnetic carbon composite and then combined with UHPLC–PDA for the determination and quantification of five NSAIDs (furprofen, indoprofen, ketoprofen, flurbiprofen, and indomethacin). The method developed herein proved to be fast and accurate. The adsorbent could be reused for up to 10 cycles, without any decrease in performance; thus, it contributes to an intelligent and sustainable economic strategy projected toward minimal waste generation.

Moisture absorption in the cell wall structure of wood is well known to induce considerable swelling of the wood exerting high expansion forces. This swelling is mainly induced by the sorptive action of the hydroxyl groups of the carbohydrate wood polymers; cellulose and hemicelluloses. On the ultrastructural level, there are, however, still questions with regard to the detailed deformations induced by this moisture absorption. Here, FTIR spectroscopy and synchrotron-radiation-based X-ray diffraction were used on paper samples to study the deformation of the cellulose crystals as a consequence of moisture absorption and desorption. Both techniques revealed that the moisture absorption resulted in a transverse contraction of the cellulose crystals accompanied by a somewhat smaller elongation in the cellulose chain direction. The deformations were found to be a direct response to the increased moisture content and were also found to be reversible during moisture desorption. It is hypothesised that these deformations are a consequence of the swelling forces created by the combined longitudinal and lateral expansions of the non-crystalline cellulose molecules and the glucomannan hemicellulose aligned along the cellulose crystals. These forces will impose a lateral contraction of the cellulose crystals, as well as a longitudinal extension of it. [ABSTRACT FROM AUTHOR]

Summary: Solar steam generation has proven to be a sustainable method to handle water shortage. Various materials for solar steam generation have been introduced in the past few years. However, the utilization of tedious and complicated synthesis to generate a photoactive layer is a matter of concern in the fabrication solar steam generation devices. Thus, improved methods toward cost‐effectiveness by exploring economical materials with simple manufacturing process are urgently and essentially needed. In this study, we first report on manufacturing hybrid membranes using commercially accessible materials, that is, cellulose paper and pencil graphite. The proposed method is to trace and coat a cellulose paper directly with a pencil without the use of solvents and chemicals, and it is possible to create an ecofriendly photoactive layer without a complicated process. The formed pencil graphite‐traced membranes were successfully utilized in solar steam generation and showed excellent steam generation rate of 4.32 kg/m2h which is almost 3.5 times more than that of pristine membrane at solar intensity of 3 Sun. The developed method could be widely utilized in the field of solar steam generation, since it is very facile and simple, and can be integrated to other commonly used materials for solar steam generation such as fabric and wood. In addition, on‐site production is possible, so it has a potential to be utilized in remote and resource‐limited areas for steam generation. [ABSTRACT FROM AUTHOR]

Cellulose nanofibers isolated from unbleached pulp are characterized by different surface properties due to presence of lignin at their surface, in addition to lower cost than isolated from bleached pulp. In the current work, the effect of cellulose nanofibers isolated from unbleached neutral sulfite and bleached soda rice straw pulps (so called UBCNF and BCNF) on improving paper sheet properties of unbleached and bleached rice straw pulp (so called UBP and BP) was studied. The effect on mechanical properties (tensile strength, burst strength, and tearing resistance) and physical properties (porosity and water vapor permeability) was studied. Scanning electron microscopy (SEM) was used to assist in explaining the obtained results. The result showed that using BCNF and BP resulted in better improvement in mechanical properties and also more effective in reducing porosity of paper sheets than in case of using UBCNF and UBP. These results indicated stronger bonding between nanofibers and pulps' fibers in case of using BCNF and BP (surfaces rich in cellulose hydroxyl groups) than in case of UBCNF and UBP (surfaces rich in lignin). Water vapor permeability of paper sheets made from unbleached or bleached pulps did not significantly affect by the addition the nanofibers. [ABSTRACT FROM AUTHOR]

Cellulosic fibres have been obtained by green procedures from the cladodes of Opuntia ficus indica (L.) Mill., constituting a large agro industrial waste in our territory. The materials have been analysed for its relative composition, applying, IR and TG methodologies and it was characterised by the absence of lignin. The fibrous material allowed the manufacture of a handmade paper obtaining an ecological material suitable for packaging purposes. The authors evidenced that the simple protocol based on hot water treatment was able to decrease the amount of hemicellulose in the final material. [ABSTRACT FROM AUTHOR]

This study examined the use of Plantago psyllium seed husk flour as paper additive with the aim of improving the properties of cellulose sheet. The husk flour was added in 5 wt%, 10 wt%, 20 wt% and 30 wt% to the cellulose suspensions and its effect on the handsheet properties was studied. The results showed that the direct addition of husk flour highly improves the mechanical properties of the handsheets like tensile index (with up to 400 %), burst index (with up to 600 %) and tear index (with up to 1200 %). Cobb and contact angle tests with distilled water showed that the handsheets containing husk flour are more hydrophobic compared to the unmodified handsheets. The Cobb-Unger and contact angle tests with oil revealed that the additive reduces the oil absorbency of the handsheets as well, at the highest by 86 %. Additionally, the water vapor and especially the air barrier properties were improved. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant capacity test showed that the modified handsheets had free radical scavenging properties. The direct addition of Plantago psyllium seed husk flour can be a promising, easy and green method to improve the mechanical and barrier properties, oil and water resistance of cellulose sheets. [ABSTRACT FROM AUTHOR]

In paper containing multilayer composite structures and laminates, polarization is usually investigated under dry environmental conditions. The aim of this research is to determine polarization dependence of paper and paper-dielectric structures on environmental relative humidity (RH). The role of each component was identified. The obtained and recorded data are used for identification and clarification of the physical mechanism of polarization. The polarization was studied by applying a dosed charging and forced discharge method and was evaluated by a depolarization potential and its formation kinetics. The polarization level of investigated structures increases with RH and is determined mainly by the paper (cellulose) and moisture content in it. In composite structures of the paper between dielectric films and dielectric on paper the polarization dependence on RH correlates with moisture absorption isotherm. It was found that the surface electrical conductivity of paper distorts the results of the paper and structure paper on dielectric. Analysis of the formation kinetics of the depolarization potential together with the potential decay of the charged paper has determined the role of orientation polarization and space charges. The formation of space charges is faster than orientation polarization and dominates in polarization process at higher RH. The process modeling by superposition of two exponents confirms this polarization mechanism. [ABSTRACT FROM AUTHOR]