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In an article to study the effect of sizing agent and filler on the structural features of paper from the cellulose mass of the inner layer of the bark of mulberry tree branches, mechanical strength, absorbency and sorption properties were studied. Tensile strength was determined on a tensile testing machine by the force causing the destruction of the sample. Surface absorbency at one side wetting was determined by the method of Cobb(30), by determining the mass of water absorbed by the surface of the paper when wetting one side of the test sample. Sorption properties were studied on a high-vacuum setup with mercury gates and McBain quartz balances according to water vapor sorption data. It was found that the internal 2% sizing of the paper pulp with cherry tree resin glue contributes to the strengthening of the paper structure, which is confirmed by the values of mechanical strength and surface absorbency when unilaterally wetted with water, relative to the values obtained when sizing with pine oleoresin rosin glue. When using glue from cherry resin, it is advisable to add 2 g of kaolin to 100 g of pulp from the inner layer of the bark of mulberry tree branches, since the increase negatively affects mechanical strength and hydrophobicity., В статье для исследования влияния проклеивающего вещества и наполнителя на структурные особенности бумаги из целлюлозной массы внутреннего слоя коры веток тутового дерева изучены механическая прочность, впитывающая способность и сорбционные свойства. Прочность на разрыв при растяжении определяли на разрывной машине по усилию, вызывающему разрушение образца. Поверхностную впитываемость при одностороннем смачивании определяли по методу Кобб(30), путем определения массы воды, поглощенной поверхностью бумаги при смачивании одной стороны испытуемого образца. Сорбционные свойства исследовали на высоковакуумной установке с ртутными затворами и кварцевыми весами Мак-Бена по данным сорбции паров воды. Выявлено, что внутренняя 2%-ная проклейка бумажной массы клеем из живицы черешневого дерева способствует упрочнению структуры бумаги, что подтверждается значениями механической прочности и поверхностной впитываемостью при одностороннем смачивании водой, относительно значений, полученных при проклейке канифольным клеем из сосновой живицы. При использовании клея из живицы черешневого дерева целесообразно к 100 г целлюлозной массы из внутреннего слоя коры веток тутового дерева добавлять каолин в количестве 2 г, так как увеличение отрицательно влияет на механическую прочность и гидрофобность.

The use of natural nanocomponents for increasing the mechanical strength of paper in the aerodynamic method has been investigated. Milled bacterial cellulose and a fine fraction of sulphate bleached softwood cellulose formed during grinding (secondary fines) were used as nanocomponents. The treatment with nanocomponents was carried out while moistening the fibrous layer with the use of an anti-adhesive material providing uniform one sided application of substances in the form of a suspension on the paper surface. The growth of the indicators of the mechanical strength of paper occurred due to the formation of additional hydrogen bonds and an increase in the interfacial interaction between the fibrous layer of plant cellulose and the nanocomponent. It was found that the use of a suspension of bacterial cellulose is more promising due to the low consumption of the binder with a significant increase in the mechanical strength of the paper. The application of a bacterial cellulose coating layer on aerodynamically molded eucalyptus cellulose makes it possible to increase the mechanical strength of the paper to consumer requirements with the consumption of bacterial cellulose in an amount of 0.9% to 1.5% by weight of absolutely dry eucalyptus cellulose., Исследовано применение природных нанокомпонентов для повышения механической прочности бумаги при аэродинамическом способе формования. В качестве нанокомпонентов использовали измельченную бактериальную целлюлозу и мелкую фракцию сульфатной беленой хвойной целлюлозы, образующуюся в процессе размола (вторичную мелочь). Введение нанокомпонентов проводили при увлажнении волокнистого слоя с применением антиадгезионного материала, обеспечивающего равномерное одностороннее нанесение веществ в виде суспензии на поверхность бумаги. Рост показателей механической прочности бумаги происходил за счет образования дополнительных водородных связей и возрастания межфазного взаимодействия между волокнистым слоем из растительной целлюлозы и нанокомпонентами. Установлено, что использование суспензии бактериальной целлюлозы более перспективно из-за малого расхода при значительном повышении показателей механической прочности бумаги. Нанесение покровного слоя бактериальной целлюлозы на бумагу аэродинамического формования из сульфатной беленой эвкалиптовой целлюлозы позволяет повысить значение механической прочности бумаги до потребительских требований при расходе бактериальной целлюлозы в количестве от 0.9 до 1.5% к массе абсолютно сухой целлюлозы.

This manuscript aimed to enhance the mechanical, thermal, and ignition properties of bagasse paper when coated with different coatings synthesized from hydroxyethyl cellulose, 1,3-di-p-toluidine-2,2,2,4,4,4-hexachlorocyclodiphosph(V)azane, Talc powder, NaHCO3, cellulose nanocrystal. The effect of these coatings on the mechanical properties was studied by measuring elongation, tensile strength, and burst strength. The stages of degradation and ash residue of the measuring specimens were determined using thermal gravimetric analysis (TGA), behind that, the ignition properties as the flame chamber (UL/94), and limiting oxygen index (LOI) was measured according to standards. These tests proved that 1,3-di-p-toluidine-2,2,2,4,4,4-hexachlorocyclodiphosph(V)azane has a direct effect on improving the mechanical characteristics and enhancing the ignition properties of the coated specimens compared to uncoated. In this study the physical, mechanical, thermal, and ignition properties of the bagasse paper sheets were enhanced by easy and low-cost method via synthesis of new coatings based on commercially available chemicals in a reasonable cost.

The aim of this study was to investigate the effect of using whey powder (different concentrations and treatment repetitions) as a probiotic agent on the quantitative and qualitative properties of stored bagasse intended for use in the pulp and paper industry. For this purpose, whey powder was added in three concentrations and the treatment was applied once or twice. After that, soda pulp was prepared under conventional conditions. Then, handsheets (80 g/m2) were made and tested in terms of paper properties, and the results were compared. The findings revealed that increasing the concentration of whey powder and the number of treatments significantly improved the pulp and paper characteristics, thus, using the treatment with 2% whey powder twice and 0.4% whey powder once led to the best results for bagasse protection in terms of quality of the raw material, pulp and handsheets.

Resin acid amides of rosin, depending on the structure, can have both a hydrophobizing and hardening effect on paper pulps. It has been established that the developed products of rosin modification (adhesive rosin composition TMAS3N and polyamide resin ProChem DUO) containing amides of resin acids, when introduced into paper pulps made from fibrous suspensions of sulphate cellulose (unbleached and bleached) of coniferous and broad-leaved species and waste paper, different in the degree of grinding (25, 40 and 70 °ShR), contribute to the increase in the strength of interfiber bonds in paper in the z-direction. The effect of the TMAS-3N emulsion was compared with the traditionally used TM and AKD sizing emulsions. The introduction of the TMAS-3N emulsion into paper pulps (0.40 % of a. d. w.) provides the maximum increase in the strength of interfiber bonds in paper in the z-direction made from cellulose, equal to 16.7–88.6 %, and from waste paper – 19.4–75.4 %, which is 1.6–6.4 and 2.3–4.5 times more compared to TM emulsion, respectively. The achieved positive effect is due to the presence in the TMAS-3H emulsion of particles of the dispersed phase of hydroxyethylamides and aminoethyl ethers capable of forming hydrogen bonds with hydroxyl groups on the mating surfaces of cellulose fibers. Sizing paper stocks with AKD emulsion reduces the strength of interfiber bonds in paper in the z-direction over the entire range of paper content studied. Polyamide resin ProChem DUO, which is a polyaminoamide of rosin resin acids, at its content in paper stocks of 0.10 %, increases the strength of interfiber bonds in paper in the z-direction, made from cellulose and waste paper suspensions, by 50.0–92.3 and 44.4–63.5 %, respectively. The obtained results of increasing the strength of interfiber bonds in paper in the z-direction by resin acid amides of rosin are in full agreement with the mechanism of bridged bonds and the theory of hydrogen bonds.

In the modern world, the importance and volumes of packaging produced are constantly increasing. It is a powerful means of promoting goods on the market, but at the same time, the role of its quality increases. Currently, paper and paperboard packaging is not only a significant part of paper and paperboard market in general, but also a large part of the world’s packaging consumption. Currently, the world pays special attention to the use of secondary paper waste for the production of paper and cardboard and increase the volume of their processing. The article is devoted to the production of new types of multilayer paper and cardboard with the addition of chemical fiber and secondary waste, as well as high-quality paper and cardboard that can be used in the printing industry, in order to save valuable cotton cellulose in the country. However, the article shows in what proportions it is advisable to use secondary fibers in combination with cellulose in the production of multilayer composite paper and cardboard for the printing and paper industries.

This study aimed to determine the effect of recycling elemental chlorine free (ECF) bleaching effluent (D0EpD1 and OD0EpD1) after treatment through electrocoagulation under optimum conditions on paper properties. The effect of pH, current density, time and dose of electrolyte on the reduction of chemical oxygen demand (COD) and color was studied. Maximum decrease in COD and color was found under optimum conditions (i.e., pH 7, treatment time of 30 min, current density of 29.16 mA/cm2, and 1 g/L NaCl). Under these optimum conditions, the reduction in COD and color was of 79.9% and 99.10%, respectively. The reduction in the strength properties of paper, caused by recycling, was found to be insignificant, but a decline of 2.11% for D0EpD1 and of 1.43% for OD0EpD1 in brightness was found. Using the electrocoagulation method to treat the bleaching effluent can prove to have valuable potential towards wastewater utilization, pollution control, and sustainable development of the industry.

We employed a microwave-assisted two-pot in-situ deposition technique to incorporate zinc oxide particulates in the structure of filter paper to produce antimicrobial paper. The process involved successive immersion of filter paper samples in ZnSO4 (precursor solution) and NaOH (precipitating agent) to form Zn(OH)2, which transformed into ZnO during microwave treatment. Successful deposition of ZnO particles on the filter paper was confirmed via X-ray diffraction and the corresponding morphologies were observed using field emission scanning electron microscopy. The ZnO-deposited papers were tested for antimicrobial activity and were found to be more effective against Staphylococcus aureus (gram-positive) than Escherichia coli (gram-negative). Bacterial populations were reduced by up to 92 ± 2% and 57 ± 4% for S. aureus and E. coli, respectively. Also, it was found that the samples prepared using higher concentrations of ZnSO4 and NaOH exhibited better antimicrobial properties.

Free-standing flexible supercapacitive electrodes have practical application for wearable energy storage devices. In this paper, graphene paper (GP), a flexible electrode substrate, was prepared by one-step reduction of graphene oxide (GO) using HI solution. GP can be used independently as a flexible electrode with specific capacitance of 227 F/g. In order to make up for the shortage of GP specific capacitance storage, polyaniline (PANI) with high specific capacitance and good electrical conductivity was selected to composite with GP by electrochemical polymerization approach. This method to fabricate electrode material by direct electrochemical polymerization avoids the use of conductive binder and organic solvent. Owing to the specific capacitance contribution of PANI and GP, the PANI/GP composites exhibit higher specific capacitance when the polymerization time is 30 s and the polymerization voltage is 0.8 V. At 1 A/g current density, the specific capacitance of composite is up to 759 F/g, which is 3.34 times of neat GP.

Herein is presented a novel and efficient portable paper-based sensing platform using paper-incorporated histidine stabilized gold nanoclusters (His-AuNCs), for the sensitive and selective detection of Fe ions from low-volume real water samples based on photoluminescence (PL) quenching. Highly photoluminescent colloidal His-AuNCs are obtained via a novel microwave-assisted method. The His-AuNCs-based sensor reveals a limit of detection (LOD) as low as 0.2 μM and a good selectivity towards Fe ions, in solution. Further, the fabricated portable sensing device based on paper impregnated with His-AuNCs proves to be suitable for the easy detection of hazardous Fe levels from real water samples, under UV light exposure, through evaluating the level of PL quenching on paper. Photographic images are thereafter captured with a smartphone camera and the average blue intensity ratio (I/I0) of the His-AuNCs-paper spots is plotted against [Fe2+] revealing a LOD of 3.2 μM. Moreover, selectivity and competitivity assays performed on paper-based sensor prove that the proposed platform presents high selectivity and accuracy for the detection of Fe ions from water samples. To validate the platform, sensing assays are performed on real water samples from local sources, spiked with 35 μM Fe ions (i.e., Fe2+). The obtained recoveries prove the high sensitivity and accuracy of the proposed His-AuNCs-paper-based sensor pointing towards its applicability as an easy-to-use, fast, quantitative and qualitative sensor suitable for on-site detection of toxic levels of Fe ions in low-volume real water samples.

To improve the storage and transport of clinical specimens for the diagnosis of Neisseria meningitidis (Nm) infections in resource-limited settings, we have evaluated the performance of dried blood spot (DBS) and dried cerebrospinal fluid spot (DCS) assays. DBS and DCS were prepared on filter paper from liquid specimens previously tested for Nm in the United Kingdom. Nm was detected and genogrouped by real-time PCR performed on crude genomic DNA extracted from the DBS (n = 226) and DCS (n = 226) specimens. Targeted whole-genome sequencing was performed on a subset of specimens, DBS (n = 4) and DCS (n = 6). The overall agreement between the analysis of liquid and dried specimens was (94.2%; 95% CI 90.8–96.7) for blood and (96.4%; 95% CI 93.5–98.0) for cerebrospinal fluid. Relative to liquid specimens as the reference, the DBS and DCS assays had sensitivities of (89.1%; 95% CI 82.7–93.8) and (94.2%; 95% CI 88.9–97.5), respectively, and both assays had specificities above 98%. A genogroup was identified by dried specimen analysis for 81.9% of the confirmed meningococcal infections. Near full-length Nm genome sequences (>86%) were obtained for all ten specimens tested which allowed determination of the sequence type, clonal complex, presence of antimicrobial resistance and other meningococcal genotyping. Dried blood and CSF filter spot assays offer a practical alternative to liquid specimens for the molecular and genomic characterisation of invasive meningococcal diseases in low-resource settings.

The features of the use of sizing emulsions of alkyl ketene dimers (AKD) and resin acids modified with monoethyl cellosolve maleate (TM) and monoethanolamine (TMAS-3N) for hydrophobization of fibrous suspensions containing primary (sulphate cellulose (unbleached and bleached) from coniferous and hardwood) and secondary (waste paper) semi-finished products, differing in fractional composition and degree of grinding (25-70 °SR). The content of particles of the dispersed phase of the emulsions varied from 0.08 to 0.30 % for the AKD emulsion and from 0.20 to 2.00 % for TM and TMAS-3N. It has been established that the hydrophobic effect of AKD, TM and TMAS-3N emulsions increases when secondary fibrous semi-finished products are replaced with primary ones; it depends on the grinding degree of the fibrous suspension and its fractional composition. A feature of the use of alkyl ketene dimers emulsion lies in the ability of its particles to form hydrophobic β-ketoether bonds with hydroxyl groups of fibers, the number of which increases singnificantly when cellulose fibers are used instead of recycled ones. A feature of the use of TM and TMAS-3N rosin emulsions is their ability to form sizing complexes in the presence of electrolyte, which makes it possible to ensure their electrostatic interaction with the surface of fibers (cellulose and waste paper). The advantage of the TMAS-3N emulsion as compared to TM is the possibility of reducing the content of particles of the dispersed phase by 1.8-6.6 times while achieving high hydrophobicity (absorption with one-sided wetting does not exceed 21 g/m2) and maintaining the original strength of paper and cardboard.

The article is devoted to solving an important scientific and technical task, improving the technology of production of tissue-paper. The study pays special attention to the problems related to the use of recovered paper, microscopic images of the surface of samples obtained from recovered paper sampling at various stages of the production of tissue-paper at the enterprise of Syktyvkar Tissue Group OJSC are presented. The main result of scientific research was a preliminary assessment of the study of the recovered paper stock preparation technology at the enterprise, for which the sampling from various stages of production were examined by a scanning electron microscope, which made it possible to visually assess the degree of cleaning of recovered paper from impurities from images of the microstructure of the surface of various scales. The chemical composition of the main additives was established by energy-dispersive X-ray spectral micro assay (EDX). Preliminary assessment of the nature of contamination, visual assessment of the microstructure of samples obtained from recovered paper stock from various stages of cleaning, allowed the engineers of the enterprise to evaluate the effectiveness of individual units of the stock preparation department for the production of tissue-paper. The obtained data will make it possible to specify the scientific and technical task and direct subsequent scientific work to improve the recovered paper stock preparation unit, which more requires perfection.

"Moringa oleifera (drumstick) wood was evaluated in terms of its chemical composition, morphological features, Kraft pulping behavior, ECF bleaching and mechanical strength properties – important parameters for pulp and paper making – in comparison with Acacia mangium. Moringa oleifera was found to have the following composition: holocellulose 65.5%, lignin 20.5%, pentosan 11.6%, -cellulose 40.5% and extractives content of 5.15%, which made it comparable with the Acacia mangium wood sample. The alkali prehydrolysis of Moringa oleifera was carried out using 2% NaOH at 150 °C. The prehydrolysis liquor (PHL) was found to contain 50.9 mg/kg of calcium, 5140 mg/kg of potassium and 312 mg/kg of iron content. The prehydrolysis step was followed by Kraft pulping in order to obtain chemical grade pulp of kappa number 15-16 under optimized conditions. The Moringa oleifera pulp was bleached using the DEpD bleaching sequence to reach 85% brightness (ISO). The bleached pulp had an average fiber length of 1.21 mm, which was higher than that of Acacia mangium – 0.782 mm. The mechanical strength properties of the unbleached and bleached pulps, such as tear, tensile and burst indices, were also determined to show their suitability for pulp and paper production."