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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.

With the overarching aim for the development of sustainable, nontoxic wet strength agents for paper, a novel polymer gel system based on oxidized hydroxypropyl cellulose (keto-HPC) cross-linked with polyamines was investigated in detail to gain a deeper insight into the wet strength mechanism. When applied to paper, this wet strength system significantly increases the relative wet strength by using only low amounts of polymer, and it is therefore comparable with established wet strength agents based on fossil resources, such as polyamidoamine epichlorohydrin resins. With the help of ultrasonic treatment, keto-HPC was degraded with respect to its molecular weight and further cross-linked in paper using polymeric amine-reactive counterparts. The resulting polymer-cross-linked paper mechanical properties were analyzed with respect to the dry and wet tensile strength, respectively. In addition, we analyzed the polymer distribution using fluorescence confocal laser scanning microscopy (CLSM). If high-molecular-weight samples are being used for cross-linking, we do find accumulation of the polymer mainly on the surface of the fibers and at fiber crossing points, accompanied with enhancing strong effects on paper’s wet tensile strength. In contrast, if low-molecular-weight (i.e., degraded) keto-HPC is being applied, the macromolecules are capable of entering the inner porous structure of the paper fibers, and almost no accumulation at the fiber crossing points is observed, which also results in a lowered wet paper tensile strength, respectively. This insight into wet strength mechanisms of the keto-HPC/polyamine system can thus lead to new opportunities for the development of alternative biobased wet strength agents where molecular weight dependence of the wet tensile properties allows for a fine tuning of mechanical properties in the wet state.

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.

The rapid economic growth and environmental concerns have led to high demands on paper and paper-based products in terms of variety, quantity, quality, and specialty. Enhancement and functionalization with additives are constantly required. Moving away from traditional petroleum-based additives, researchers have attempted to use “green” nanoadditives by introducing renewable environmentally friendly nanocellulose. This article studies the functions of nanocellulose as bio-additives (enhancer, retention and filtration reagent, and coating aid) in paper and paper products, and overviews the research development of nanocellulose-based additives and their applications in the paper industry for both efficient production and paper functionalization. The review shows that (1) a variety of nanocellulose-based bioadditives have been reported for various applications in paper and paper-based products, while commercially viable developments are to be advanced; (2) nanocellulose was mostly formulated with other polymer and particles as additives to achieve their synergistic effects; (3) major interests have concentrated on the nanocellulose in the specialty papers as representing more value added products and in the efficient utilization of recycled fibers, which remains most attractive and promising for future development. This report shall provide most useful database information for researchers and industries for paper recycling and enhancement, and paper-based products innovation and application.

With the increased awareness of reusing solid wastes for higher sustainability and the concern of water pollution associated with phosphorus over-emission, there are strong interests in developing solid waste based adsorbents for purifying phosphorus-containing wastewater. As a rich calcium resource, paper mill sludge (i.e., a major solid waste from pulping industry) can be used as phosphorus removal adsorbent after calcination. Thus, in this work, a simple and clean thermally treating route has been proposed for preparing calcium-containing biochar from paper mill sludge. The effect of the physicochemical properties of paper mill sludge and its carbonization condition on phosphorus adsorption has been analyzed. Moreover, the influence of some key adsorption parameters, e.g., biochar dosage, initial pH of solution, co-existing anions, initial phosphorus concentration and contact time has also been investigated. The results showed that the phosphorus adsorption data could be fitted well with pseudo-second-order kinetic and Langmuir isothermal models. The calculated maximum adsorption capacity of the as-prepared optimal calcium-containing biochar could reach to 68.49 mg·g−1 at 25 °C. Combined with the characterization results, it can be reasonably inferred that the adsorption process was chemisorption-dominated. Lastly, the application of this spent adsorbent in agriculture field has also been discussed. In brief, this work provided a feasible strategy for converting paper mill solid waste to an environmental functional material (i.e., calcium-rich biochar) for remediation of eutrophic water.

Cellulose paper, a material that is naturally derived, low cost, lightweight, eco-friendly, and mechanically deformable, plays important roles in producing next-generation flexible electronics. Following the booms in the development of functional electronics, the soft actuators built from cellulose paper have attracted great attention. In this focused review, the milestones and recent achievements of cellulose paper-based actuators are summarized. Electro-, thermal, moisture and magnetic actuation mechanisms are utilized to acquire energy from external stimuli. Corresponding functional materials and available fabrication techniques like film assembly and layer deposition are described. Programmable actions for the emerging applications in bionics, paper grippers and robots are realized by pursuing different strategies to control the responding deformation. Along with a conclusion, the existing challenges and possible solutions in evaluating and improving the performance of cellulose paper are summarized in the final section.

Paper mulch has the advantages of simple process, low production cost and strong degradability, but it is still a great challenge to prepare paper mulch with excellent water resistance and light transmittance. In this paper, through a simple physical brushing method, Zinc oxide (ZnO) solution and silica (SiO2) solution were brushed on the surface of paper mulch film respectively, and ZnO/SiO2 composite superhydrophobic paper mulch film (CSPMF) with micro-nano rough structure was constructed. The microstructure of original paper mulch film (OPMF) and ZnO/SiO2 CSPMF was studied by scanning electron microscope (SEM), and the superhydrophobic surface elements were analyzed by energy dispersive spectrometer (EDS). The contact angle (CA) and rolling angle (RA) of two kinds of sample surfaces are measured by contact angle meter. The static CA and RA of ZnO/SiO2 CSPMF were 160 ± 0.4° and 3 ± 0.3°, respectively. The self-cleaning behavior of soil simulated dust environment was tested on the surface of OPMF and ZnO/SiO2 CSPMF respectively. The horizontal bounce performance and tilt bounce performance of the superhydrophobic surface were tested by high-speed camera. In addition, frost experiments and delayed icing experiments were carried out. The results show that ZnO/SiO2 CSPMF has good self-cleaning performance, bouncing performance and delayed icing performance.

A wide variety of biomass is available all around the world. Most of the biomass exists as a by-product from manufacturing industries. Pulp and paper mills contribute to a higher amount of these biomasses mostly discarded in the landfills creating an environmental burden. Biomasses from other sources have been used to produce different kinds and grades of biomaterials such as those used in industrial and medical applications. The present review aims to investigate the availability of biomass from pulp and paper mills and show sustainable routes for the production of high value-added biomaterials. The study reveals that using conventional and integrated biorefinery technology the ample variety and quantity of waste generated from pulp and paper mills can be converted into wealth. As per the findings of the current review, it is shown that high-performance carbon fiber and bioplastic can be manufactured from black liquor of pulping waste; the cellulosic waste from sawdust and sludge can be utilized for the synthesis of CNC and regenerated fibers such as viscose rayon and acetate; the mineral-based pulping wastes and fly ash can be used for manufacturing of different kinds of biocomposites. The different biomaterials obtained from the pulp and paper mill biomass can be used for versatile applications including conventional, high performance, and smart materials. Through customization and optimization of the conversion techniques and product manufacturing schemes, a variety of engineering materials can be obtained from pulp and paper mill wastes realizing the current global waste to wealth developmental approach.

In vitro epidermis models are important to evaluate and study disease progression and possible dermal drug delivery. An in vitro epidermis model using floating paper chips as a scaffold for proliferation and differentiation of primary human keratinocytes is reported. The formation of the four main layers of the epidermis (i.e., basal, spinosum, granulose, and cornified layers) is confirmed. The development of a cornified layer and the tight junction formation are evaluated as well as the alterations of organelles during the differentiation process. Further, this in vitro model is used to assess keratinocyte migration. Finally, magnetic micromotors are assembled, and their ability to aid cell migration on paper chips is confirmed when a static magnetic field is present. Taken together, this attempt to combine bottom-up synthetic biology with dermatology offers interesting opportunities for studying skin disease pathologies and evaluate possible treatments.

Lignin/tannin/ZnONP composite coatings were designed for paper-based green packaging. Multiple functions, such as high strength, moisture resistance, low air permeance, heat endurance, UV aging resistance, and antibacterial/mold properties, were successfully integrated into one biobased coating. Prepolymerization improved the physical properties of coatings at high lignin contents. The best ingredient ratio was: 40% lignin, 15% tannin, and 10% ZnONPs (based on tannin weight), and the as-prepared biocoating was labeled LTZn-10. After coated with LTZn-10, the tensile strength and bursting strength of the packaging were efficiently enhanced by more than 3 times and were dramatically increased by 51.6 and 5.6 times at the wet state, respectively, which reveals that the packaging has favorable moisture resistance and it can be used in high humidity environments. Scanning electron microscopy (SEM) proved that most of the pores on the paper were blocked by the coatings, which helped to decrease the air permeance by 10.3 times. Meanwhile, ZnONPs were evenly spread on the coatings, which endowed the packaging with excellent antibacterial/mold performance. No colony or mycelium was found in the test against Gram-negative/positive bacteria and eight common molds. Besides, antibacterial activity is only available while the bacteria come in contact with the coating and no active substances were released into the culture medium, which is a good property that can keep the cargo from contamination of antibacterial agents. In addition, the coated paper presented an improved Tg and thermal degradation temperature, indicating that the coated package has favorable thermostability and can maintain its outstanding physical properties in a wider temperature range. Lignin and tannin promoted the UV stability and service life of the coated paper, as a rare physical decrease was observed after UV aging for 72 h. The function-integrated biobased coating with favorable sustainability is a good candidate to be widely used in paper-based green packaging fields.

Lithium metal is deemed a promising anode material for the next-generation batteries with high specific energy. Unfortunately, the growth of Li dendrites and infinite volume change during cycling, caused by the "hostless" feature of metallic Li, have posed a great challenge to the commercialization of Li metal anode. The introduction of appropriate host materials for Li metal is highly desirable. In this work, a N, P dual-doped 3D carbon derived from low-cost quantitative filter paper (NPCQP) is designed and fabricated for direct using as a host for Li metal anode. The resulting NPCQP host achieves a high deposition/stripping Coulombic efficiency of above 97.5 % with a low nucleation overpotential. Moreover, the NPCQP@Li symmetric cells enable an excellent long-term cycling performance (1000 h) with an ultralow voltage hysteresis (12 mV) and stable interface behavior. When paired with the commercial LiFePO

The article to study the texture of paper, in the composition of which the cellulose pulp from the inner layer of mulberry branches bark is added, studies the paper’s absorbency and sorption properties. The absorbency of the paper was determined by the volume of water absorbed by the paper surface while wetting one side of the test sample. It was found that the addition of cellulose pulp from the inner layer of mulberry branch bark to the cotton paper pulp contributes to the strengthening of the structure which is confirmed by the values of mechanical strength and surface absorbency during one-side wetting with water. To study the physical structure of a paper sheet water vapor sorption was investigated in a high-vacuum sorption plant with mercury valves and quartz balances. On the basis of S-shaped sorption isotherms it is determined that the paper sample where the composition contains only cellulose pulp from the inner layer of the mulberry branches bark has the highest sorption properties which indicates the presence of disordered amorphous areas where the accessibility for water molecules is higher. It has been established that in order to obtain paper the structure of which ensured selective absorption of low-molecular fluid it is enough to add 10–20% of cellulose pulp from the inner layer of mulberry branches bark to the paper pulp; and further addition will result in misalignment of the paint contour during printing due to significant deformation of paper size.

The article gives the consideration to the properties of paper with the addition of pulp mass from the waste of the pharmaceutical industry, namely licorice root after removing extraction. Licorice roots were dried to air-dry state after extraction, cleaned of wastes and cut into fragments 10–30 mm long, then subjected to pulping with 2–4% NaOH solution at a hydro module 1 : 5, at a temperature of 95–98 °С for 60–90 minutes. After washing with hot water, they are bleached in an alkaline medium with a solution of hydrogen peroxide at a consumption of 3–4% of the mass of absolutely dry cellulose, hydro module 1: 5, temperature 70–95 °C for 60–90 minutes. After washing, grinding to a gristing degree of ~60°ShR, prepared castings weighting 80–90 g/m2 on a leaf-casting mashine. Physical, mechanical and optical properties of experimental castings are determined. Revealed that the addition of malt mass of the cotton contributes to the formation of dense orderly structures of the paper sheet, as short fibers of licorice filled the gaps between the long fibers of cotton pulp, thereby reducing the pore volume and reactive surface availability and receipt paper with the highest mechanical strength. Adding malt mass to cotton mass at a ratio of 10 : 2 is optimal, further replenishment contributes to an increase in sorption absorption, that is, to obtain paper with a porous structure, which is not desirable for high-quality reproduction.

The present review provides a comprehensive outlook toward the possibilities of developing a functional in vitro liver tissue model on a paper platform. To this end, we first addressed the suitabil...

The possibility of exfoliating graphite into graphene sheets allows the researchers to produce a material, termed "graphene paper" (G-paper), conductive as graphite but more flexible and processable. G-paper is already used for electronic applications, like conductors, antennas, and heaters, outperforming metal conductors thanks to its high flexibility, lightness, chemical stability, and compatibility with polymeric substrates. Here, the effectiveness in the use of G-paper for the realization of electrodes on flexible plastic substrates and textiles, and their applicability as amperometric sensors are demonstrated. The performance of these devices is compared with commercial platforms made of carbon-based inks, finding that they outperform commercial devices in sensing nicotinamide adenine dinucleotide (NADH), a key molecule for enzymatic biosensing; the electrodes can achieve state-of-the-art sensitivity (107.2 ?A mm cm) and limit of detection (0.6 × 10 m) with no need of additional functionalization. Thanks to this property, the stable deposition of a suitable enzyme, namely lactate dehydrogenase, on the electrode surface is used as a proof of concept of the applicability of this new platform for the realization of a biosensor. The possibility of having a single material suitable for antennas, electronics, and now sensing opens new opportunities for smart fabrics in wearable electronic applications.

Influence of the thermochemical processing (the cook) conditions and of the milling on characteristic of the waste paper with polyurethan and polyaziridin was studied. The waste paper was reduced to the degree size of the particles 5...8 mm in mill of the dry grind and chemical processing under higher temperature (to 70 °C) by solution, contain sodium persulfate and hydroxide; duty of water 6. Duration of cook varied from 1 to 5 hours, expense of persulfate sodium varied from 2 to 12%, hydroxide sodium – from 0.5 to 3% from mass of the waste-papers. The secondary fiber was obtaining by breaking-up of the pulp in the hydropulper. The dependency of the length and factor of the form of the secondary fiber from conditions cook was absent. The slight width increasing of the fibers with the higher pH of cooking liquor was determined: from 26.5 мкм under pH 3–4 to 29 мкм under pH 8–9. The conjectural reason is swelling of the cell wall. The waste paper milling was executed in the «stream-barrier» machine. The strength properties of the paper correspond with the feature, inherent of the secondary pulp.

© 2022 The Authors. Advanced Biology published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited., The role of astrocytes in brain function has received increased attention lately due to their critical role in brain development and function under physiological and pathophysiological conditions. However, the biological evaluation of soft material nanoparticles in astrocytes remains unexplored. Here, the interaction of crosslinked hybrid vesicles (HVs) and either C8-D1A astrocytes or primary astrocytes cultured in polystyrene tissue culture or floatable paper-based chips is investigated. The amphiphilic block copolymer poly(cholesteryl methacrylate)-block-poly(2-carboxyethyl acrylate) (P1) and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine lipids are used for the assembly of HVs with crosslinked membranes. The assemblies show no short-term toxicity towards the C8-D1A astrocytes and the primary astrocytes, and both cell types internalize the HVs when cultured in 2D cell culture. Further, it is demonstrated that both the C8-D1A astrocytes and the primary astrocytes could mature in paper-based chips with preserved calcium signaling and glial fibrillary acidic protein expression. Last, it is confirmed that both types of astrocytes could internalize the HVs when cultured in paper-based chips. These findings lay out a fundamental understanding of the interaction between soft material nanoparticles and astrocytes, even when primary astrocytes are cultured in paper-based chips offering a 3D environment., This project was supported by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No. 818890), the Lundbeck Foundation (R346-2020-1617), and the Carlsberg Foundation (CF 20–0418). The HRM Queen Margrethe II's travel grant (C.A.M.) is acknowledged for support. T

Photocatalytic materials have been widely used to remove dyes from printing and dyeing wastewater. However, difficulty in recycling of photocatalysts is the great concern in the real catalytic applications, which significantly raises the application cost. This study developed a low-cost catalyst by loading magnetic Ni onto filter paper (FP) via an easy going in-situ reaction. The characterization results displayed that the Ni particles were uniformly anchored onto the FP. The Ni@FP material presented a strong magnetic ability which was evidenced by a saturation magnetization (Ms) of 5.014 emu·g−1, a remanent magnetization (Mr) of 2.067 emu·g−1 and a coercivity (Hc) of 133.868 Oe. Meanwhile, the magnetic Ni@FP material displayed a recyclable advantage in photocatalytic degradation of methyl orange (MO) via an external magnetic field. There existed an optimal photocatalytic degradation rate of 93.40% within 5 min when MO concentration was 15 mg·L−1 at pH 8.0. Three cycle experiments confirmed that the Ni@FP possessed a satisfied stability and recycling ability. Moreover, the Ni@FP material presented a strong antibacterial activity which can prevent it from being contaminated by microorganisms. The versatility of the newly proposed photocatalyst in this study demonstrated its great application prospect in dyeing wastewater treatment.

The article uses the example of artificially polluted soil to consider the effect of urea sorbent-a biological product "Unisorb-Bio" modified by waste paper on the biodegradation of oil with subsequent phyto-control of the soil by a test culture of pink-Swedish clover (Trifolium hybridum). It is shown that during 18 weeks of exposure "Unisorb-Bio" with immobilized on it the oil-oxidizing strains of Pseudomonas sp. and Bacillus subtilis, the oil content in the soil decreased by 10 times, which is on an order of magnitude higher to comparison with the control. High seeding qualities (germination energy, seed germination – 82%) are observed when using "Unisorb-Bio" modified waste paper from newsprint in conditions of 10% initial soil contamination, with a content of nitrophosca 0.05%. In the soil with" Unisorb-Bio "modified waste paper from the paper "Snegurochka" the indicators are lower by 17–20% than in the soil samples with biologics product modified by waste paper from newsprint, which is probably perhaps is bound up with more the greater destructibility of the latter under these conditions and an increase of mobile forms of nitrogen and phosphorus in the soil. The results of phytocontrol (germination energy, seed germination-52%) indicate a relatively good level of soil recovery with 15% initial contamination and almost independent of the type of biological product. The observed seeding quality and morphophysiological indicators give reason to conclude that the "Unisorb-Bio" biological product modified with waste paper is able to restore the soil even with a high level of contamination within one season.

A novel nacre-like flame-retardant paper based on graphene oxide (GO), and phytic acid (PTA) is fabricated via evaporation-induced self-assembly. This facile method is time saving and low energy consuming. A facile approach is proposed to improve thermal oxidative stability of GO paper by in situ phosphorus doping during flame exposure. Then fire-alarm system is designed based on the high-temperature thermal reduction characteristic of GO. The GO paper functionalized with PTA (GO-PTA) can provide ultrasensitive, reliable and longtime fire early-warning signal. Fire alarm can be triggered at approximately 0.50 s when GO-PTA samples are attacked by fire. Phosphorus atoms are in situ doped into graphene layers during fire exposure, endowing GO-PTA paper with outstanding thermal oxidative stability, and thus alarm duration time of GO is greatly improved. The work develops advanced fire detection and early-warning sensors that provide reliable and continuous signals, which provide more available time for fire evacuation.

While basic concepts of paper-based microfluidic analytical devices (μPADs) have appeared considerably, elemental technology development is worth working from different specialized points of view. Herein, we show that 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-oxidized cellulose nanofiber (TOCN) can be reasonably used as a module of μPADs; we adopted a biochemical reaction of indigo formation by oxidation of indoxyl acetate (IDA) via its hydrolysis with acetylcholinesterase (AChE) as an example. First, we demonstrate that TOCN stably stores unstable AChE and IDA when dried and acts as a biochemical reaction field when wet. The thixotropic nature of TOCN aqueous dispersion gave inkjet printability, which will facilitate the μPADs production. The exchange of substances in the wet TOCN network took more time than in solution, but this can be read as control of reaction kinetics. Finally, we constructed semiquantitative μPADs for an organic phosphorus pesticide. We illustrate that by mounting TOCN, various functions can be incorporated on one sheet of paper to lead to the extension of design flexibility and universal use for μPADs.

As enzymes in the outer membrane of the mitochondrion, monoamine oxidases (MAOs) can catalyze the oxidative deamination of monoamines in the human body. According to different substrates, MAOs can be divided into MAO-A and MAO-B. The imbalance of the MAO-A is associated with neurological degeneration, while excess MAO-B activity is closely connected with Parkinson's disease (PD) and Alzheimer's disease (AD); therefore, detection of MAOs is of great significance for the diagnosis and treatment of these diseases. This work reports the multiplexed detection of MAO-A and MAO-B using paper-based devices based on chemiluminescence (CL). The detection limits were 5.01 pg/mL for MAO-A and 8.50 pg/mL for MAO-B in human serum. In addition, we used paper-based devices to detect MAOs in human cells and tissue samples and found that the results of paper-based detection and Western blotting (WB) showed the same trend. While only one antibody can be incubated on the same membrane by WB, multiple antibodies incubated on the same paper enabled simultaneous detection of MAO-A and MAO-B by paper-based devices. The paper-based assay could be used for preliminary early screening of clinical samples for MAOs and can be extended as an alternative to WB for multiplexed detection of various proteins in disease cell or tissue samples.

The contamination of water and food in agricultural areas, where an enormous volume of pesticides is widely employed to enhance crop production, is a challenging reality. The rapid assessment of these contaminants is fundamental to assure water and food quality and safety, particularly for local community members. This work presents a nonexpensive and easy-operational paper-based testing device for the fast detection of insecticides (carbamates and organophosphates) in water samples. The structural design "dip-and-fold" allows us to carry out the analysis without introducing reagents or samples. The device is prepared using different high-quality papers to support the active acetylcholinesterase (AChE) and the customized chemical formulation for colorimetric detection. The chemical principle is based on the AChE inhibition reaction and Ellman's method. The experiments using standard solutions of carbofuran, propoxur, and chlorpyriphos indicated satisfactory detection at concentrations between 0.1 and 0.0001 mM, and the color results are revealed within 10 min. Therefore, this technique represents a promising alternative for implementing low-cost and efficient water monitoring and management solutions.

We report a colorimetric paper-based microfluidic device based on an enzyme inhibition assay that allows the on-site detection of nerve agents by sampling and wicking. The sample and reagents are automatically transported through the channel where an enzyme inhibition reaction is conducted, followed by an enzyme-substrate reaction and a color reaction. This device can detect 0.1 μg/mL of the nerve agent VX in a 2.5 μL drop and is nerve agent selective and robust against temperature, pH, and several liquids. We confirmed that sampling procedures (dilution and wiping) are applicable to this device. Furthermore, the fabrication procedure is easy, and the cost is at most a few tens of cents. Thus, the present device provides a practical method for the urgent detection of nerve agents in suspected chemical terrorism incidents.

This study analyzed the effect that pulp fibers have on the surface softness component of hygiene paper. The surface softness component has more of an influence on the evaluation of subjective softness results than the bulk softness component. Using the surface softness measurement technique, this study aimed to evaluate the effect that fibers have on the softness of hygiene paper substrate via objective numerical values to measure the surface softness component of hand sheets composed of various pulp species. The results indicate that coarseness effects had the largest effect on softness among the various fiber characteristics, such as average fiber length, width and coarseness. As fiber coarseness increased, a rough surface formed, which resulted in an increase in the mean deviation from the average friction (MMD). Nonwood fibers had long fiber length and low coarseness, which enables the production of hygiene paper with high strength and softness. This study hopefully could lead to the development of various process technologies that may improve the softness of hygiene paper products.

Simultaneous enhancement in water flux and removal efficiency during the filtration process remains a big challenge for separation membranes. The porous structure of the filter paper can provide many channels for water transportation, but the separation performance is generally poor. The purpose of this study is to develop a new kind of filter paper consisting of ultralong hydroxyapatite (HAP) nanowires, cellulose fibers (CFs) and double metal oxide (LDO) nanosheets, and to achieve the simultaneous enhancement of both water flux and removal efficiency for high-performance dye separation. In this work, a novel kind of LDO/HAP/CF nanocomposite filter paper consisting of ultralong HAP nanowires and CFs and LDO nanosheets has been developed for rapid water filtration and highly efficient dye adsorption. Positively charged LDO nanosheets can adsorb on the surface of negatively charged ultralong HAP nanowires and embed in the porous networked structure of the LDO/HAP/CF nanocomposite filter paper, which can provide a porous structure for rapid water transportation and can adjust the pore size of the nanocomposite filter paper. As a result, the pure water flux of the LDO/HAP/CF nanocomposite filter paper can be adjusted. The optimized pure water flux of the LDO/HAP/CF nanocomposite filter paper can reach 783.6 L m-2 h-1 bar-1, which is 1.51 times that of the HAP/CF filter paper without LDO nanosheets (518.6 L m-2 h-1 bar-1). More importantly, the adsorption capacity of LDO nanosheets is high for dye molecules, the rejection percentage of Congo red (CR) by the as-prepared HAP/CF filter paper is only 59.8%, and its water flux is 534.7 L m-2 h-1 bar-1. The optimized rejection percentage and water flux of the LDO/HAP/CF nanocomposite filter paper for CR are significantly enhanced (98.3% and 736.8 L m-2 h-1 bar-1, respectively) compared to those of the HAP/CF filter paper. The size of LDO nanosheets has a significant effect on the water flux and dye rejection percentage of the LDO/HAP/CF nanocomposite filter paper. The as-prepared LDO/HAP/CF nanocomposite filter paper is promising for the applications in highly efficient purification of wastewater containing dye molecules.