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Aromatic sensitizers and related substances (SRCs), which are crucial in the paper industry for facilitating color‐forming and color‐developing chemical reactions, inadvertently contaminate effluents during paper recycling. Owing to their structural resemblance to endocrine‐disrupting aromatic organic compounds, concerns have arisen about potential adverse effects on aquatic organisms. We focused on SRC effects via the aryl hydrocarbon receptor (AHR), employing molecular docking simulations and zebrafish (Danio rerio) embryo exposure assessments. Molecular docking revealed heightened binding affinities between certain SRCs in the paper recycling effluents and zebrafish Ahr2 and human AHR, which are pivotal components in the SRC toxicity mechanism. Fertilized zebrafish eggs were exposed to SRCs for up to 96 h post fertilization; among these substances, benzyl 2‐naphthyl ether (BNE) caused morphological abnormalities, such as pericardial edema and shortened body length, at relatively low concentrations (1 μM) during embryogenesis. Gene expression of cytochrome P450 1A (cyp1a) and ahr2 was also significantly increased by BNE. Co‐exposure to the AHR antagonist CH‐223191 only partially mitigated BNE's phenotypic effects, despite the effects of 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin being relatively well restored by CH‐223191, indicating BNE's AHR‐independent toxic mechanisms. Furthermore, some SRCs, including BNE, exhibited in silico binding affinity to the estrogen receptor and upregulation of cyp19a1b gene expression. Therefore, additional insights into the toxicity of SRCs and their mechanisms are essential. The present results provide important information on SRCs and other papermaking chemicals that could help minimize the environmental impact of the paper industry. Environ Toxicol Chem 2024;00:1–13. © 2024 SETAC [ABSTRACT FROM AUTHOR]

Capturing short‐lived intermediates at the molecular level is key to understanding the mechanism and dynamics of chemical reactions. Here, we have developed a paper‐in‐tip bipolar electrolytic electrospray mass spectrometry platform, in which a piece of triangular conductive paper incorporated into a plastic pipette tip serves not only as an electrospray emitter but also as a bipolar electrode (BPE), thus triggering both electrospray and electrolysis simultaneously upon application of a high voltage. The bipolar electrolysis induces a pair of redox reactions on both sides of BPE, enabling both electro‐oxidation and electro‐reduction processes regardless of the positive or negative ion mode, thus facilitating access to complementary structural information for mechanism elucidation. Our method enables real‐time monitoring of transient intermediates (such as N,N‐dimethylaniline radical cation, dopamine o‐quinone (DAQ) and sulfenic acid with half‐lives ranging from microseconds to minutes) and transient processes (such as DAQ cyclization with a rate constant of 0.15 s−1). This platform also provides key insights into electrocatalytic reactions such as Fe (III)‐catalyzed dopamine oxidation to quinone species at physiological pH for neuromelanin formation. [ABSTRACT FROM AUTHOR]

Herein, a new, direct paper-based fluorimetric method is described for the quantitative determination of glutathione (GSH) molecules in nutritional supplements. Briefly, the proposed analytical method is based on the fluorescence emission resulting from the direct and selective chemical reaction of GSH molecules with the derivatization reagent that is o-phthalaldehyde (OPA) in acidic conditions at room temperature. The intensity of the emitted fluorescence on the surface of the analytical paper devices after irradiation with a lamp at 365 nm is proportional to the concentration of GSH and is measured using a smartphone as the detector. This methodology, which is suitable for measurements in laboratories with limited resources, does not require specialized instrumentation or trained personnel. The protocol governing the proposed method is simple and easily applicable. Essentially, the chemical analyst should adjust the value of pH on the surface of the paper by adding a minimal amount of buffer solution; then, after adding a few microliters of the derivatization reagent, wait for the surface of the paper to dry and, finally, add the analyte. Subsequently, the irradiation of the sensor and the measurement of the emitted fluorescence can be recorded with a mobile phone. In the present study, several parameters affecting the chemical reaction and the emitted fluorescence were optimized, the effect of interfering compounds that may be present in dietary supplements was examined, and the stability of these paper sensors under different storage conditions was evaluated. Additionally, the chemical stability of these paper devices in various maintenance conditions was studied, with satisfactory results. The detection limit calculated as 3.3 S/N was 20.5 μmol L−1, while the precision of the method was satisfactory, ranging from 3.1% (intra-day) to 7.3% (inter-day). Finally, the method was successfully applied to three different samples of dietary supplements. [ABSTRACT FROM AUTHOR]

Enhancing paper hydrophobicity is of key importance for many paper-based applications. Fatty acids or vegetable oils and their derivatives replace environmentally harmful conventional coating materials but still require challenging chemical reactions for covalent attachment onto paper. Here, we show that simple storage of olive oil-coated cotton linter paper at 70 °C and subsequent Soxhlet extraction is able to endow paper with hydrophobic properties, reaching water contact angles above 130°. In-depth chemical and morphological analytics show the relevance of temperature and air accessibility during the aging process compared with aging at ambient temperature and under the exclusion of oxygen, underlining the importance of assessing a coating's long-term performance and stability under diverse storage conditions. Simple storage of vegetable oil-coated paper at elevated temperatures followed by extraction proves to be an easy way to produce stable covalently attached hydrophobic paper coatings with exceptionally low coating amounts. [ABSTRACT FROM AUTHOR]

• Filter paper was selected as the template for synthesis of 1D NiO/NiCo 2 O 4 composite. • Ultra simple synthetic procedures of only metal salts adsorption and calcination was referred. • The effective bandwidth is up to 6.08 GHz at thin thickness of 1.88 mm. Filter paper, as a widely used and low-cost lab consumable, can serve as template for the synthesis of one-dimensional (1D) materials since it is composed of 1D cellulosic fiber. In this work, 1D NiO/NiCo 2 O 4 composite was simply fabricated by adsorption of Ni and Co acetate on the filter paper and subsequent calcination process. The precursors were obtained without further treatment to filter paper or chemical reaction between metal salts. Calcination process leads to the removal of template and formation of binary NiO/NiCo 2 O 4 composite. Electromagnetic (EM) wave absorption performance of NiO/NiCo 2 O 4 composite could be tuned by adjusting the calcination temperatures and dosage of metal salts. For the optimized absorber (calcination temperature of 600 °C and dosage of Ni and Co acetate with 2 mmol and 4 mmol), a wide absorption bandwidth of 6.08 GHz could be achieved with thickness of 1.88 mm and minimum reflection loss value was up to −57.4 dB by changing the thickness. The facile synthetic route may also inspire the preparation of other high-performance one-dimensional EM wave absorbing materials. [ABSTRACT FROM AUTHOR]

The pigment coating of paper is usually performed to enhance the physical properties of paper and its printability. The coating generally makes paper whiter, brighter and more opaque. The properties of the coated paper depend, among others, on the porous structure of the coating developed, which is determined by the pigments, binders and their reactions. The influence of the type and quantity of coating components and ink absorption into the coating layer was studied in this work. Printing ink penetration was measured using a Penetration Dynamic Analyser with a HVL module (High Viscous Liquid). The evenness of liquid penetration into paper was measured using a Penetration Dynamic Analyser with a PEA module (Print Evenness Analyser). Results obtained indicate that all three variables - coating pigment type, latex dose and ink type - may have an equally strong influence on liquid and ink penetration, and thus on print quality. [ABSTRACT FROM AUTHOR]

High‐barrier performance, especially under extreme working conditions, is the key to replacing other types of packaging materials with paper‐based materials. In this paper, two biomass‐based polymers, sodium alginate (SA), and chitosan, were used to form a barrier coating with silicone emulsions to prepare a high‐performance paper‐based barrier material. By double coating, the water and oilproof functions were superimposed. The two prepared coated papers were characterized by infrared spectroscopy analysis, contact angle test, and scanning electron microscopy analysis, while their water resistance, oil resistance, thermal oil resistance, and thermal stability were tested. The water and oil repellency were achieved by double coating. The Cobb value of the chitosan‐silicone emulsion‐coated paper reached 5.3 g/m2, with a Kit grade of Level 12, and could block the penetration of castor oil at 80°C within 24 h. The Cobb value of the sodium alginate‐silicone emulsion‐coated paper was 41.6 g/m2, much higher than that of the uncoated paper, with a Kit grade of up to Level 10, which could slow down the rate of castor oil penetration at 80°C within 24 h. The test results showed that there was no chemical reaction between the paper‐based coatings, and the coated paper surface had good film formation, while the double coating method increased the thermal decomposition temperature of the overall barrier coating, effectively improving the thermal stability of the coating and achieving high‐barrier performance at lower cost and under extreme working conditions. Highlights: Water and oil resistance under extreme operating conditions.High‐performance paper‐based barrier materials.Dual‐layer coating method for water and oil repellency.High‐barrier performance at lower cost.Excellent hot oil resistance and thermal stability. [ABSTRACT FROM AUTHOR]

This article focuses on the nature of acidity in pulp paper as found in comic books and library collections. Some of the various factors that contribute to the deterioration of paper are considered from a chemical perspective. (CW)

Milk is considered a complete meal that requires supervision to determine its suitability for human consumption. The development of sustainable devices that evaluate food properties has gained importance due to the necessity of integrating these instruments into the production chain. However, the materials employed to develop it, such as polymers, semiconductors, and glass, lack sustainability and require specialized equipment to fabricate them. Different chemical techniques have been used to miniaturize these detection systems such as microfluidics, which have been used in milk component detection using colorimetry. In this work, a cantilever beam paper-based microfluidic system is proposed to evaluate differences in milk, according to nutritional information, using its electromechanical response. A 20-microliter milk drop is deposited in the system, which induces hygroexpansion and deflection due to liquid transport within the paper. Likewise, a conductive path is added on the beam top surface to supply a constant current that induces heat to evaporate the solution. According to the results obtained, it is possible to point out differences between trademarks with this microfluidic system. The novelty of this system relies on the paper electromechanical response that integrates the hygroexpansion-induced displacement, which can be used for further applications such as milk microtesters instead of colorimetric tests that use paper as a property-evaluation platform in combination with chemical reactions. [ABSTRACT FROM AUTHOR]

Rationale: Paper spray (PS) is a simple and innovative ambient ionization technique for mass spectrometry (MS) analysis. Under PS‐MS conditions, chemical reactions, which usually occur slowly on a bulk scale, are accelerated. Moreover, the formation of products and transient species can be easily monitored. In this manuscript, reactions between phthalic anhydride and diamines were conducted and monitored using a PS‐MS platform. The reaction products (phthalimides) have many pharmaceutical applications, but their traditional syntheses can take hours under reflux, requiring laborious purification steps. Methods: In situ reactions were performed by dropping methanolic solutions of phthalic anhydride and diamines on a triangular paper. The analyses were achieved by positioning the triangle tip in front of the mass spectrometer entrance, whereas a metal clip was attached to the triangle base. After adding methanol to the paper, a high voltage was applied across the metal clip, and the mass spectra were acquired. Results: The intrinsic reactivity of alkyl and aromatic diamines was evaluated. The carbon chain remarkably influenced the reactivity of aliphatic diamines. For aryl diamines, the ortho isomer was the most reactive. Moreover, for aryl amines with electron‐withdrawing substituents, no reaction was noticed. Conclusions: Taking advantage of the unique characteristics of PS‐MS, it was possible to investigate the intrinsic reactivity of model alkyl (ethylene versus propylene) and aryl (o‐phenylene versus m‐phenylene and p‐phenylene) diamines towards phthalic anhydride. Some crucial parameters that affect the intrinsic reactivity of organic molecules, such as isomerism, intramolecular interaction, and conformation, were easily explored. [ABSTRACT FROM AUTHOR]

With the implementation of plastic restrictions and the increasingly serious problem of environmental pollution, paper with green and recyclable characteristics is gradually becoming a substitute for packaging materials. However, the rich cellulose structure in the paper, which contains hydroxyl groups leading to its hydrophilicity, allows water molecules to penetrate the paper and disrupt the hydrogen bonds between cellulose, resulting in a decrease in mechanical properties. Therefore, waterproof coatings are crucial for paper‐based materials to be used in many applications. Based on this, the paper surface was chemically modified with castor oil‐based resin (CO‐590) monomer prepared by coupling agent and castor oil (CO). The results indicated that the modified paper with the contact angle (CA) of 114° had excellent waterproof performance and had a reduction by 40.3% in water vapor transmission rate (WVTR), but also its mechanical increased to 26.9 MPa and the decomposition temperature to 410.5°C. In addition, the coating on its surface could be removed in an alkaline solution and had a possibility to recycle blank paper in the future for manufacturing sustainable production. This work not only provides a method for preparing modified packaging paper, but also expands the application fields of materials. [ABSTRACT FROM AUTHOR]

Abstract: Various parameters that may affect the efficiency of tri- and di-functional aminoalkylalkoxysilanes (AAAS) copolymer treatments to deacidify and mechanically strengthen aged complex papers (lignocellulosic pulp, additives) were studied. Three model papers were first hydrothermally aged (90 °C—50% RH) in order to achieve physicochemical characteristics similar to those of a naturally aged newsprint, and were then treated with AAAS copolymers. The chemical composition of the treatments varied from 50 to 5 wt% of tri-functional monomer APTES, the latter acting as cross-linker in the copolymer network. The respective ratio of tri- and di-functional monomers in the mixture was shown to greatly influence the mechanical properties of the treated papers in the case of APTES/DIAMINO but less so in the case of APTES/AMDES. If APTES/DIAMINO (50/50 wt%) did not strengthen the degraded papers, a higher proportion of DIAMINO (95 wt%) and lower proportion of APTES (5 wt%) led to improving the tensile strength and, more importantly for the function properties of paper, significantly enhancing the folding endurance. The treatment efficiency decreased at higher state of deterioration of the papers and in the presence of alum-rosin sizing. Lastly, the treatments developed for the artificially aged model papers were applied to the degraded newsprint paper specimen and successfully enhanced its mechanical properties.Graphical abstract: [ABSTRACT FROM AUTHOR]

Hydrophobic coatings are of utmost importance for many applications of paper-based materials. However, to date, most coating methods demand vast amounts of chemicals and solvents. Frequently, fossil-based coating materials are being used and multiple derivatization reactions are often required to obtain desired performances. In this work, we present a solvent-free paper-coating process, where olive oil as the main biogenic component is being used to obtain a hydrophobic barrier on paper. UV-induced thiol-ene photocrosslinking of olive oil was pursued in a solvent-free state at a wavelength of 254 nm without addition of photoinitiator. Optimum reaction conditions were determined in advance using oleic acid as a model compound. Paper coatings based on olive oil crosslinked by thiol-ene reaction reach water contact angles of up to 120°. By means of Fourier transform infrared spectroscopy and differential scanning calorimetry, a successful reaction and the formation of a polymer network within the coating can be proven. These results show that click-chemistry strategies can be used to achieve hydrophobic polymeric paper coatings while keeping the amount of non-biobased chemicals and reaction steps at a minimum. [ABSTRACT FROM AUTHOR]

• Nacre-like FG/Al energetic paper was designed and prepared. • A significantly enhanced energy and pressure output are obtained. • FG/Al energetic papers shown self-propagate combustion reaction at micro-scale. • The chemical reaction mechanism was distinctly elucidated. • FG/Al energetic paper displayed high flexibility and strain. Developing functional devices requires energetic materials with comprehensive performance including high energy density, excellent chemical reactivity and mechanical properties. Herein, an effective strategy inspired by nacre-like architecture was employed to construct new fluorographene (FG)/nano-aluminum (Al) energetic paper through a vacuum filtration induced self-assembly process. FG/Al energetic paper showed ultrahigh reactivity and high flexibility owing to combined effect of the nacre-like architecture and interfacial interaction. FG/Al energetic paper exhibited significantly enhanced energy output (3257.7 J/g) and self-propagate combustion reaction with high pressure output at micro-scale. Chemical reaction mechanism was distinctly elucidated based on reactive molecular dynamics simulations and the combustion products of FG/Al energetic paper. More interestingly, FG/Al energetic paper displayed high flexibility and strain (5.39%) reported for the first time. The bio-inspired route provides a promising approach to design advanced energetic materials for applications in transportation, aerospace, and military industries. [ABSTRACT FROM AUTHOR]

Points out a different and much simpler approach for the study of equilibria of multiple and heterogeneous chemical reactions. A simulation on coal methanation is used to teach the technique. An example and the methodology used are provided. (MVL)

Outlined are recent developments in the field of organosilicon chemistry. Discussed are processes for synthesizing organosilanes, chemical bonding in silicon compounds, silicone polymers, and catenated polysilanes. (CS)

Considering only environmental impact or only profit is not enough to manage chemical processes. This study focuses on the optimal scheduling of cutting papers using the multiobjective optimisation programming. Two independent objective functions are introduced in this paper, the production cost and trim loss with the constraints of satisfying the customer orders. The Goal Constrained Programming (GCP) algorithm is created for the multiobjective optimisation with priority. The proposed algorithm takes the deviation for the weighting factor. The GCP provides various optimal schedule sets satisfying the economic and environmental requirements. [ABSTRACT FROM AUTHOR]

Predictive models for the transport of volatile organic compounds in paper need to consider the complex interplay of diffusion, adsorption, desorption, or chemical reactions. The relative importance of each of these processes is determined by the polarity of the volatile. Hence, it is challenging to pick a valid theoretical model that correctly predicts transport regardless of the polarity. Here, physics-informed neural networks (PINNs) assess which of five different models correctly describe transport of DMSO as polar and n-tetradecane as apolar model compound: (i) a pseudo first-order adsorption model for an irreversible sorption process, (ii) a first-order kinetics model allowing reversible sorption, (iii) a second-order model with a reversible process, and an effective diffusion model accounting for a constant (iv) and for a variable effective diffusivity (v). Each tested model is given as set of partial differential equations (PDE). Considering the model under testing and experimentally obtained spatially and temporally resolved concentration profiles through stacks of paper sheets, PINNs predict concentration of the volatiles and associated material constants such as sorption constants and effective diffusion coefficients by solving the inverse problem. Our PINNs revealed two models, pseudo first-order sorption and second-order reversible sorption, that correctly predict concentration profiles and polarity-driven differences in sorption times. While a PINN-based picking of valid transport models has important implications for the development of effective methods for controlling emission of volatiles from paper materials, PINNs represent a versatile mathematical tool to validate or refute the capability of PDE-based theoretical models to describe experimental data. • PINNs evaluate sorption kinetics in porous materials. • Focus: Transport of organic volatiles in cellulose. • Pseudo first-order model suits organic volatiles. • Predicting transport of volatiles through paper. [ABSTRACT FROM AUTHOR]

Efficient and reliable methods for the generation of bioactive papers are of growing interest in relation to point‐of‐care testing devices that do not require extensive analytical equipment. Herein, we report the immobilization of functional proteins on paper fibers using a modular chemoenzymatic approach. The synthetic strategy relies on a combination of highly efficient spatially controllable photo‐triggered cycloaddition followed by site‐specific sortase A‐catalyzed transamidation. This site‐directed and regiospecific method has allowed unidirectional and covalent immobilization of several proteins displaying different functional properties, with ramifications for application in paper‐based diagnostics. Protein‐functionalized paper: A modular approach to covalent protein immobilization on paper fibers is reported, which relies on a set of highly efficient pericyclic reactions in combination with site‐specific enzymatic coupling. Following initial derivatization of a cellulosic surface (see figure), light‐triggered covalent anchoring of an enzyme recognition site ensures enzyme‐promoted ligation of desired proteins with preservation of their function. [ABSTRACT FROM AUTHOR]

The article compares the effectiveness of three washing methods in removing acid compounds from aged papers. The three washing methods include immersion washing, blotter washing and suction table washing with the aid of ultrasonic mist. In samples of thin and porous papers, it was found that immersion washing was the most effective followed by the suction table washing with the aid of ultrasonic mist. However, suction table washing was ineffective for the treatment of thick and dense papers while blotter washing showed the lowest effectiveness in removing organic acids particularly oxalic acid. It is noted that the suction table washing with ultrasonic mist uses the least amount of water.

The power transformer is an important part of the power grid. The aging of oil-paper insulation is affected by many factors such as temperature and moisture. In order to accurately evaluate the service life of transformer and ensure the stable operation in power system, a method for predicting the lifetime of oil-immersed pressboard under different temperatures and moisture content was proposed. This method is mainly realized by the chemical reaction kinetic equations and transformation factor. Firstly, the effect of temperature and moisture content on the frequency dielectric response of oil-paper insulation was studied by frequency domain dielectric spectroscopy method. The results show that the dielectric loss of oil-immersed pressboard increases with the increase of moisture content and temperature. The activation energy of oil-immersed pressboard also increases exponentially with the increase of moisture content. Then, we analyzed the trend of polymerization degree of insulation pressboard in aging process and calculated the insulation life and the remain lifetime by combining the cellulose degradation kinetic models and translation factor. When the moisture content of the oil-immersed at 70 °C, the life expectancy of oil-paper insulation is about 19.26 years. [ABSTRACT FROM AUTHOR]

This research was planned to clarify the relationship between natural ageing and accelerated ageing of paper using naturally aged paper. First, samples of paper which had deteriorated over time for 130 to 80 years were artificially aged at 80°C, 65% RH, and their physical and chemical changes were investigated. Oxalic acid contained in the samples before accelerated ageing increased, while glycolic acid showed a tendency to decrease. This means that accelerated ageing test did not simulate the chemical processes occurring during natural ageing in a straight forward manner. On the other hand, paper in which many organic acids had accumulated by natural ageing showed larger degradation rate indicators of tear index and burst index i.e. initial degradation rate constant divided by initial tear index or initial burst index before accelerated ageing and discolouration rate. That of values of the degradation rate indicators of tear index and burst index and the discolouration rate showed good correlation with the number of cellulose chain breaks. However, the number of cellulose chain breaks is not simply correlated with the concentration of hydrogen ion which is an index of the acidic hydrolysis of paper. Oxidation contributes to the rate of cellulose chain breaks. [ABSTRACT FROM AUTHOR]

The article examines the effectiveness of deacidification of lignocellulosic and cellulosic paper samples with dispersions of Ca(OH)2 and Mg (OH)2 nanoparticles in alcohols as a preventive conservation technique. Using an accelerated thermal ageing test, it was found that deacidification dispersion is not advisable as a preventive conservation technique of unaged paper sheets since the pH was kept at very high levels and there was a substantial decrease in the degree of polymerization (DP) of the cellulose. It concludes that the protective effects of deacidification with nanoparticles could only be achieved with preaged paper samples.

The article presents several patents related to paper deacidification, the most common and widely used process of paper conservation. The early years of paper making tends to be more acidic, and preserving proves to be a big challenge for the early conservator. The search for remedies to deacidify the paper begun as early as 19th century and the first patent dates for paper deacidification started on 1936. Environment friendly processes of paper making begun on the early 1990.

We report a method for fabricating inexpensive microfluidic platforms on paper using laser treatment. Any paper with a hydrophobic surface coating (e.g., parchment paper, wax paper, palette paper) can be used for this purpose. We were able to selectively modify the surface structure and property (hydrophobic to hydrophilic) of several such papers using a CO2laser. We created patterns down to a minimum feature size of 62 ± 1 µm. The modified surface exhibited a highly porous structure which helped to trap/localize chemical and biological aqueous reagents for analysis. The treated surfaces were stable over time and were used to self-assemble arrays of aqueous droplets. Furthermore, we selectively deposited silica microparticles on patterned areas to allow lateral diffusion from one end of a channel to the other. Finally, we demonstrated the applicability of this platform to perform chemical reactions using luminol-based hemoglobin detection. [ABSTRACT FROM AUTHOR]

The article presents an experimental study on the deacidification of paper using sodium and calcium ions. The role of acidity in the degradation of paper materials is widely acknowledged since its beginning in 1930. Deacidification is the process of removing the acid from the paper to avoid degradation and for conservation purpose employing the most common deacidifying aqueous solutions called calcium bicarbonate. The process gives different output depending on the acid use in deacidifying.

Abstract: Lime mud (LM), a solid waste that results from the causticization reaction in alkali recycling process of paper manufacture industry, was utilized as CO2 sorbent in calcium looping process in this study. The carbonation behavior of LM in the calcination/carbonation cycles was investigated in a dual fixed-bed reactor and a thermo-gravimetric analyzer. The results show that the carbonation conversions of LM are lower than those of limestone at the same reaction conditions. It attributes to the high chlorine content in LM which leads to more pronounced sintering and decreases the CO2 capture performance of LM. A pre-wash process was employed to decrease the chlorine content in LM. Based on an overall consideration of various factors, the pre-wash process is effective enough if the Cl/Ca molar ratio in LM is smaller than 1:100. Pre-washed lime mud (PLM) achieves higher carbonation rates and carbonation conversions, compared with LM. When calcined at 850°C and carbonated at 700°C, the carbonation conversion of PLM maintains at 36% after 100cycles, which is 1.8 and 4.8 times as high as LM and limestone after the same number of cycles, respectively. The pore volume and surface area of calcined PLM were greater than those of calcined LM after the same number of cycles, especially the volume of the pores in the range of 10–100nm in diameter. That is the reason why PLM exhibits higher CO2 capture capacity than LM in the multiple calcination/carbonation cycles. The carbonation conversions of LM and PLM are further enhanced by hydration of their calcines. [Copyright &y& Elsevier]

Abstract: Plasma polymerized fluorocarbon films have been deposited on paper and regenerated cellulose surfaces to enhance their barrier properties and to achieve hydrophobic surfaces. The primary monomers used for plasma polymerization were pentafluoroethane (CF3CHF2) and octafluorocyclobutane (C4F8). The equilibrium moisture uptake of films deposited from either precursor was less than 0.14 wt.%. Although water vapor uptake of the fluorocarbon films is low, moisture diffusivity through the films is high; that is, moisture penetrates the films but is not chemically bonded. Quartz crystal microbalance (QCM) studies demonstrate that the absorption of water vapor is a bulk phenomenon in which the moisture penetrates into the film. Transient moisture absorption studies were conducted using the QCM to evaluate the rate of moisture uptake and diffusivity. Although the films allow water vapor diffusion, the films are hydrophobic and are not “wetted” when liquid water contacts these layers. Contact angle studies reveal that a minimum fluorocarbon film thickness of about 70 nm on paper is required to completely cover surface and near-surface fibers, thereby providing the paper with long term hydrophobic character. The films also impart the paper with an improved barrier to lipophilic material. [Copyright &y& Elsevier]

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Pulp and paper industry has generated a higher contamination burden of the final mill wastewater which must be further treated to comply with the standards imposed by the legislation requirement. In this study, the removal efficiencies for chemical oxygen demand (COD) and color from pulp and paper wastewater using sequencing batch reactor (SBR) in combination with advanced oxidation processes (AOPs) at a bench scale were investigated. Response surface methodology (RSM) based on a three-variable-three-level central composite design (CCD) was employed to optimize the SBR process. At the optimal conditions of initial COD of 1000 mg/L, MLSS of 3000 mg/L and cycle time of 24 h, 74.8% COD, 58.3% of color removal and 80 mL/g of SVI were obtained in the pretreatment stage. The use of Fenton oxidation as post-treatment enhanced COD reduction and color removal. A percentage of 92.1% COD reduction and 90.3% of color removal was achieved in dosages of 3 mM Fe2+ and 9 mM H2O2 at pH of 3.0 for a reaction time of 30 min, while a total of 98% reduction of COD and 94% removal of color for the combined treatment was achieved. [ABSTRACT FROM AUTHOR]

A distance-based paper analytical device (dPAD) for loop mediated isothermal amplification (LAMP) detection based on distance measurement was proposed. This approach relied on visual detection by the length of colour developed on the dPAD with reference to semi-quantitative determination of the initial amount of genomic DNA. In this communication, E. coli DNA was chosen as a template DNA for LAMP reaction. In accordance with the principle, the dPAD was immobilized by polyethylenimine (PEI), which is a strong cationic polymer, in the hydrophilic channel of the paper device. Hydroxynaphthol blue (HNB), a colourimetric indicator for monitoring the change of magnesium ion concentration in the LAMP reaction, was used to react with the immobilized PEI. The positive charges of PEI react with the negative charges of free HNB in the LAMP reaction, producing a blue colour deposit on the paper device. Consequently, the apparently visual distance appeared within 5 min and length of distance correlated to the amount of DNA in the sample. The distance-based PAD for the visual detection of the LAMP reaction could quantify the initial concentration of genomic DNA as low as 4.14 × 10 3 copies µL −1 . This distance-based visual semi-quantitative platform is suitable for choice of LAMP detection method, particular in resource-limited settings because of the advantages of low cost, simple fabrication and operation, disposability and portable detection of the dPAD device. [ABSTRACT FROM AUTHOR]

The high cost of regular diagnostic kits severely impeded its uses for routine clinical assay and fieldworks. A cost-effective chromatography paper is chemically modified with Ag nanostructures using the simple electroless silver deposition, producing a scalable and disposable substrate for surface-enhanced Raman spectroscopy, as well as a large scale of catalytic active sites over many chemical reactions. Synergetic measurement including surface-enhanced Raman spectroscopy and laser desorption ionization-mass spectrometry is performed on Ag decorated filter paper using a thiol containing compound as indicator, allowing for the acquisition of spatially correlated spectroscopy in the tandem mode. In addition, hydrophilic porous cellulose network that contains a certain amount of liquid naturally served as a chemical reactor for molecular transport and reaction. Positive results from catalytic reaction on metallized paper convincingly demonstrated that total microanalysis system on paper (μ-TASoP), as a compelling alternative would find a wide breadth of applications in developing disposable medical devices and customary laboratory assays. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

New chemicals, based on the synergistic effect between inorganic polyaluminium salts and organic cationic polyelectrolytes, have been tested for the chemical optimization of a dissolved air flotation (DAF) unit, used as internal treatment of process waters in a paper mill based on 100% recovered paper. Laboratory tests have demonstrated that polyamine modifications of the aluminum salts are the most efficient in the removal of contaminants, the combination of a polyaluminium nitrate sulfate salt and a polyamine being the most efficient. This chemical has been studied under different conditions, such as different dosages or in combination with a flocculant for the treatment of waters from different paper grades production, and the results have demonstrated a good performance at laboratory scale. Therefore, a field trial has been recommended for assessing its potential benefits at mill scale, which will be described in a future paper. [ABSTRACT FROM AUTHOR]

Voltammetric determination of morin on carbon fiber paper (CFP) electrode modified by electropolymerization of 2,5-dimercapto-1,3,4-thiadiazole (DMTD) in phosphate buffer solution (PB, pH 9.0) have been studied. This modified electrode showed strong electrocatalytic activity toward the oxidation of morin, a flavonoid at physiological pH (PB, pH 7.0). Morin gave a sensitive anodic peak at 0.245 V (vs. SCE). The parameters influencing the anodic peak of morin such as effect of pH, effect of scan rate and concentration have been optimized. The electrochemical process was found to be irreversible and adsorption-controlled. Under the optimum conditions, the anodic peak current was linear to concentration of morin in the range of 2.5 × 10-10-2.75 × 10-9 M and detection limit was found to be 8.3 × 10-11 M. The practical application of the modified electrode was successfully demonstrated for the determination of morin in mulberry leaves. [ABSTRACT FROM AUTHOR]

The radio frequency (RF) argon plasma induced surface modification of paper revealed novel surface characteristics and substantially changed surface topography. It was found that RF-argon glow discharge affects surface properties resulting in photo-degradation and chain-scission mechanism on paper network structure. High-power and extended treatment time caused increasing elemental carbon, while decreasing the oxygen concentration on paper surface. However, increased hydroxyls and the creation of new carbonyl functionalities were verified by trifluoroacetoanhydride and pentafluorophenylhydrazine in vapor-phase derivatization reactions. [ABSTRACT FROM AUTHOR]

A new method for enhancement of ninhydrin or 1,8-diazafluoren-9-one (DFO)-treated latent fingerprints on thermal paper will be described. Most thermosensitive surfaces of thermal paper become dark when treated with DFO or ninhydrin petroleum ether (NPB) solution. This effect minimizes contrast between the developed fingerprints and the background. The new method described reduces this dark staining without removing the thermosensitive layer and parts of the developed fingerprints, as occurs with acetone washing. Through the new method, the developed fingerprints appear in sharp lines and high contrast. Extensive tests were performed, leading to an optimized working solution, which charges the paper with a minimum of chemicals, is cheap, and enables a large quantity of papers to be treated in a short time. The working solution contains commercially available, nonvolatile, nitrogenous organic compounds and can be used like the application of NPB solution by dipping. [ABSTRACT FROM AUTHOR]

Cationic blocked waterborne polyurethane (CBWPU) as paper strength agent was prepared by the reaction of N-[(1,1-dimethyl-2-acetyl)ethyl]-β-dihydroxyethylamino propanamide(DDP), isophorone diisocyanate(IPDI), polycaprolactone glycol(PCL) and bisphenol A, with imidazole as blocking agent and N-methyldiethanolamine as hydrophilic chain-extending agent. Effects of the blocked ratio and the dosage of CBWPU on the physical properties of the treated paper were studied. The chemical structure of CBWPU and the surface morphology of the paper surface are characterized by Fourier transform infared spectrometer(FT-IR) spectra and scanning electron microscopy(SEM). The results show that the paper strength, especially the wet tensile index and the wet strength of paper can be obviously improved with the increasing of the blocked ratio and the dosage of CBWPU. FT-IR result shows that structures of tertiary amine group, imidazole ring and urethane group are found in CBWPU molecular structure. SEM obsevation of the treated paper reveals that the exiestence of a lot of filamentous materials and films, which can improve the crosslinking between fibers. [ABSTRACT FROM AUTHOR]

Abstract The deposition of chemical reagent inks on paper is a crucial step in the development and fabrication of microfluidic paper-based analytical devices (μPADs). A pen-plotting approach, delivering chemical ink deposition using technical pens filled with reagents and inserted into a desktop electronic plotter, is shown herein to be a versatile, low-cost, simple, rapid, reproducible, and high-throughput solution. The volume of the deposited ink was quantified gravimetrically, confirming that nanoliter volumes of reagents can be deposited reproducibly (e.g. 7.55 ± 0.37 nL/mm for a plotting speed of 10 cm/s) in detection zones of μPADs, typically spatially defined using wax printing. This approach was further investigated with regard to deposition of reagents in different geometrical forms (circular and linear), so demonstrating its applicability for preparation of μPADs with flexible design and application. By adjusting the plotting speed for linear deposition, lines with a relatively large range of widths (≈628–1192 μm) were created. Circular deposition was also demonstrated via delivery of reagents within wax printed circular fluidic barriers of a range of diameters (inner diameter = 1.5–7 mm). These capabilities were practically demonstrated via the fabrication of μPADs, based upon differing detection principles for determination of aluminum in natural waters using Morin as the fluorescent reagent. Traditional μPADs based on digital image colorimetry (DIC) were produced using circular deposition, whilst distance-based μPADs exploited linear deposition. Both types of μPADs developed using this method showed excellent precision for determination of trace concentrations of aluminium (average RSDs = 3.38% and 6.45%, and LODs = 0.5 ng (0.25 ppm) and 2 ng (0.5 ppm), for traditional and distance-based detection, respectively). Graphical abstract Image 1 Highlights • A pen-plotting technique is characterized for chemical ink deposition on μPADs. • A gravimetric approach is introduced to measure the deposition volume. • Deposition is studied for different geometrical forms (circular and linear). • The effect of plotting parameters on deposition is investigated. • The approach is demonstrated by a fluorescence-based determination of Al in waters. [ABSTRACT FROM AUTHOR]

Part I. Describes the results of an experiment designed to observe the migration of volatile acidic products through stacks of sheets. Description of the accelerated aging of papers in stacks; Information on the tests performed in the experiment; Trends observed from a series of zero-span tensile strength and pH measurements.

It is important to monitor the water concentration in the insulation of aging power transformers, because over time the insulation becomes wet, due to water ingress from the atmosphere and water formed in chemical reactions involving oxygen. If the water concentration is sufficiently high, the insulation will age prematurely [1] and the transformer may fail if overloaded [2]. In a previous article [3] we reported on the measurement of water concentration in the insulation paper of a power transformer that had been in service for only seven years. The waterconcentration data obtained using on-line water-activity probes were compared with corresponding data obtained from dielectric response measurements. In that work cellulose adsorption isotherms were used to process the water-activity-probe data. However, according to [4] and [5], inaccuracies in the waterconcentration estimates may result from the use of adsorption isotherms. According to [6], these inaccuracies may exceed 200%. The probable main causes are the transformer insulation materials not reaching thermal equilibrium, the water concentration within the insulation not being uniform, and variability in the properties of the insulating materials. [ABSTRACT FROM AUTHOR]

Inorganic fillers are inexpensive materials used to increase the density, smoothness and other properties of paper that are important for printing. In the current study, the adhesion of pressure-sensitive adhesives (PSAs), a common type of adhesive used in labels and tapes, to papers containing varying amounts and types of fillers is investigated. Papers with three types of fillers, precipitated calcium carbonate (PCC), ground calcium carbonate (GCC) and kaolin clay, were investigated. The compositions of the papers were examined with SEM/EDX, while peel and double cantilever beam (DCB) tests were used to assess PSA-paper adhesion. The results indicate that fillers enhance the adhesion between PSA and paper. In the case of the peel tests, a combination of inter-fiber bond strength and PSA-paper adhesion determines the peel strength. While in the DCB tests, failure is isolated to the PSA-paper interface, thus allowing measurements of pure interfacial failure. [ABSTRACT FROM AUTHOR]