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Nanozymes are nanomaterials that possess intrinsic enzyme mimicking activity. In this study, the application of silver nanoparticles coated filter paper (AgNPs/FP) that exhibits a peroxidase-like catalytic activity as a potential sensor is reported. A simple chemical reduction method was used to produce AgNPs/FP. The formation of the particles on filter paper were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and surface-enhanced Raman spectroscopy (SERS). In the presence of hydrogen peroxide, AgNPs/FP oxidized the colorless o-phenylenediamine (OPD) and 3,3′,5,5′-tetramethylbenzidine (TMB) solutions to a yellow colored 2,3-diaminophenazine (DAP) and deep blue colored oxidized TMB (oxTMB), respectively. In the presence of thiocyanate, however, the peroxidase-like activity was inhibited in a concentration dependent manner. This makes the AgNPs/FP a promising catalyst and employed for colorimetric detection of thiocyanate via inhibition of the peroxidase-like activity. The application can be further extended to other environmentally and biologically important analytes. [ABSTRACT FROM AUTHOR]

The surface plasmon resonance property of silver nanoparticles (AgNPs) makes them a top-notch material for developing sensors, especially in surface-enhanced Raman scattering (SERS). The multi-shape silver nanoparticles decorated on cellulose fiber of paper provide flexible paper-based SERS substrates with different sensitivity. The isotropic and anisotropic morphology of AgNPs on filter paper has been controlled by weak and strong reducing agents: sodium borohydride (NaBH4), ascorbic acid (L-AA), glucose, formaldehyde (HCHO). The capping agent's chitosan and the reaction conditions like the ratio of precursors and stirring speed also influence the shape, size, stability, and dispersity of AgNPs on filter paper. Multi-shape AgNPs on paper are obtained as spherical shapes (about 50–100 nm), rods (size 100–500 nm in length, 50-nm wide), or thin wings. Depending on the reduction condition, these AgNPs can be single-dispersed or stuck together to form corals on paper. The fabricated paper-based SERS substrates were investigated the optical characterization and used to detect melamine in an aqueous solution with detection limits as low as 10−8 M with the EF = 2.3 × 109. [ABSTRACT FROM AUTHOR]

The homeostatic control of Sodium (Na+) ion in the human body assumes paramount relevance owing to its physiological importance. Any deviation from the normal level causes serious health problems like hypernatremia, hyponatremia, stroke, kidney problems etc. Therefore, quantification of Na+ levels in body fluids has significant diagnostic and prognostic importance. However, interfering ions like Potassium ion (K+) is the major hurdle in sodium detection. In this work, we synthesized the clusters of 3–9 nm-sized highly stable and pure Copper nanoparticles surface functionalised with curcumin, through chemical reduction method. Each cluster of particles is encapsulated in a curcumin layer which is clearly visible in TEM images. The results show that these curcumin functionalized Cu NPs (CuC) are highly selective to the colorimetric detection of Na+. The ions like K+, Mg2+ and Zn2+ did not interfere with the Na+ in this sensing technique. Low-cost paper-based sensor strips are fabricated and calibrated for the sensing of sodium in the physiological range and shade cards were developed as a calorimetric guide for estimation of Na+ which makes them ideal point of care diagnostic platform. We demonstrate that the proposed CuC paper strip can be used for detecting Na+ concentration within the whole physiological range in both blood serum and urine. [ABSTRACT FROM AUTHOR]

The cellulose derived carbon/graphene/ZnO aerogel composite was prepared as an electrode in order to investigate the electrochemical properties. Carbon aerogel was synthesized using paper as an available cellulose source, and the composite was obtained through a new and simple preparation method including the immersion of monolithic carbon aerogel in graphene oxide/Zn2+ suspension and subsequent chemical reduction and freeze drying. The morphology, functional groups and crystalline structure of the samples were studied with Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction Spectroscopy (XRD), respectively. Electrochemical performance of the prepared binder free electrodes was examined using Cyclic Voltammetry (CV), Galvanostatic Charge-Discharge (GCD) and Electrochemical Impedance Spectroscopy (EIS). The data revealed that flexible carbon/graphene/ZnO composite resulted in a low density (0.035 g cm−3) electrode with the capacitance of 900 mF cm−2 at a high current density of 10 mA cm−2, lower IR drop and high cyclic stability (capacitance retention of 96%) after 1000 cycles, at 10 mA cm−2. These features were due to the presence of 3D porous conductive network, highly reduced graphene oxide, and the formation of ZnO nanoparticles on graphene sheets. Moreover, polyaniline (PANI) was introduced to carbon/graphene/ZnO composite electrode using electro-oxidation method at different reaction time and aniline concentration in order to achieve remarkably improved capacitance of 2500 mF cm−2 (at 10 mA cm−2) and low charge transfer resistance. Also, after the supercapacitor device assembly, the capacitance was retained. Based on the results, the synthesized composite is a promising material for new generation of lightweight freestanding electrodes with the high electrochemical performance. [ABSTRACT FROM AUTHOR]

We report fabrication of reduced graphene oxide (rGO) films using chemical reduction by hydrazine hydrate and rGO paper-like samples using low temperature treatment reduction. Structural analysis confirms the formation of the rGO structure for both samples. Current-voltage (I-V) measurements of the rGO film reveal semiconductor behavior with the maximum current value of ~3×10-4A. The current for the rGO paper sample is found to be, at least, one order of magnitude higher. Moreover, bipolar resistance switching, corresponding to memristive behavior of type II, is observed in the I-V data of the rGO paper. Although precise values of the rGO film conductivity and the Seebeck coefficient could not be measured, rGO paper shows an electrical conductivity of 6.7×102S/m and Seebeck coefficient of -6μV/°C. Thus, we demonstrate a simplified way for the fabrication of rGO paper that possesses better and easier measurable macroscopic electrical properties than that of rGO thin film. [ABSTRACT FROM AUTHOR]

Excellent mechanical and electrical properties of graphene-based paper-like materials are essential for applications in flexible conductors, energy-storage devices, etc. The graphene oxide (GO) supernatant separated by centrifugation and ultrasonication has been used to prepare graphene oxide paper and reduced graphene oxide paper (rGOP) with high strength and conductivity. However, this method has cumbersome steps and low supernatant concentration, which greatly increases time and energy consumption, and is not suitable for rapid batch preparation of high-strength and high-thickness rGOP. Herein, a high-speed mechanical shearing method has been used to efficiently exfoliate graphite oxide suspension into high-concentration GO slurry with large lateral size, and rGOP has been further prepared by blade coating and HI acid chemical reduction. Compared with the product prepared by ultrasonic exfoliation method, the average area of GO sheets obtained via the mechanical shear exfoliation method can reach around 16.31 μm2. As a result, the mechanical properties and conductivity of the prepared rGOP have been increased by 30% and 23.5%, respectively, with the tensile strength and electrical conductivity of 478.2 MPa and 208.4 S/cm being obtained. The developed method is of great significance for the large-scale production and emerging applications of lightweight and high-performance rGOP. [ABSTRACT FROM AUTHOR]

This study provides a systematic approach for assessment of contaminants in materials for recycling. Paper recycling is used as an illustrative example. Three selected chemicals, bisphenol A (BPA), diethylhexyl phthalate (DEHP) and mineral oil hydrocarbons (MOHs), are evaluated within the paper cycle. The approach combines static material flow analysis (MFA) with dynamic material and substance flow modeling. The results indicate that phasing out of chemicals is the most effective measure for reducing chemical contamination. However, this scenario was also associated with a considerable lag phase (between approximately one and three decades) before the presence of chemicals in paper products could be considered insignificant. While improved decontamination may appear to be an effective way of minimizing chemicals in products, this may also result in lower production yields. Optimized waste material source-segregation and collection was the least effective strategy for reducing chemical contamination, if the overall recycling rates should be maintained at the current level (approximately 70% for Europe). The study provides a consistent approach for evaluating contaminant levels in material cycles. The results clearly indicate that mass-based recycling targets are not sufficient to ensure high quality material recycling. [ABSTRACT FROM AUTHOR]

The disappearance of bibliographic heritage is one of the biggest problems facing libraries. One of the most common methods used to restore paper, lining, is to apply a reinforcing layer to the document. This study focuses on lining papers with bacterial cellulose (BC) sheets from Gluconacetobacter sucrofermentans. For this purpose, several model papers have been selected. They have been characterized before and after the lining with this BC and a specific Japanese paper (JP) to compare both materials. Taking into account the differences between bacterial and vegetal cellulose is expected that the results may be similar to other BC and JP. The samples have been characterized before and after an aging process. There are no significant differences in some of the characteristics studied. Nevertheless, BC-lined papers present higher gloss values and b* coordinate. The wettability decreases with both BC and JP. However, in papers lined with BC, the wettability decreases more markedly and independently of the model paper used. This is related to the sealing of the surface structure by BC, which also leads to a reduction of air permeability. When the lined papers go through an aging process, there are no significant changes in any characteristic, except in b* and L* color coordinates. Additionally, the wettability rate decreases in all cases. This study indicates that papers lined with BC are stable over time. Finally, the use of BC as reinforcing material may offer advantages for specific conservation treatments, being more suitable for certain types of paper than JP. [ABSTRACT FROM AUTHOR]

Abstract Zn/Ce redox flow battery (ZRFB) is emerging as a promising technology to store large amount of energy economically and efficiently, wherein a highly efficient positive electrode with a continuous and fast electronic and ionic transportation path is urgently desired. The unique nanostructure of reduced graphene oxide (RGO) paper electrode is prepared by a simply chemical reduction method, which facilitates transference of the electron and Ce3+/Ce4+ at the electrolyte/electrode interface. Thus ZRFB exhibits superior extent of charge (81.0%) and energy efficiency (71.3%). The results show RGO paper is a good candidate for positive electrode of ZRFB. Highlights • The RGOC paper possesses good flexibility with a porous structure. • The C/O ratio of RGOC is different from that of RGOT. • The activity of RGOC towards Ce3+/Ce4+ is better than that of RGOT. [ABSTRACT FROM AUTHOR]

The applicability of using 2-furfural (2-FAL) and methanol as aging markers for synthetic ester impregnated paper insulation was investigated through laboratory aging experiments at temperatures of 80, 100 and 120 ?C. Methanol in the synthetic ester increased linearly with paper aging until degree of polymerisation (DP) reached 400. During this period concentration of methanol in oil was higher than that of 2-FAL, which proved the concept of using methanol to indicate early paper aging in the synthetic ester. However, the rate of methanol increase against the reduction of DP in the synthetic ester was about three times higher than that seen in mineral oil. This is due to a difference in the partitioning of the marker between oil and paper. Since the synthetic ester is more polar than the mineral oil, it attracted more methanol molecules from the paper, resulting in a higher concentration of methanol in oil for the same reduction of DP. In addition, a reduction in methanol was observed at the later stage of paper aging at 120 ?C. This could be due to either a change in the partitioning between oil and paper, or an esterification reaction which consumes methanol in the system. [ABSTRACT FROM PUBLISHER]

A high-performance electrode for the electrocatalytic reduction of concentrated nitric acid is developed from an electrode based on carbon fiber paper supported Pt nanoparticles (nano-Pt/CFP). The nano-Pt/CFP electrode exhibits remarkable electrocatalytic reactivity at room temperature (488.6 mA mg − 1 for nanopolyhedral Pt, and 384.9 mA mg − 1 for nanothorn Pt) with a significant reduction in Pt usage compared with conventional Pt electrodes (0.0190 mA mg − 1 for Pt sheet or 0.3667 mA mg − 1 Pt mesh) and commercial Pt/C (288.5 mA mg − 1 ). The mechanism is discussed based on the electrochemical voltammograms and the composition of gaseous products, indicating a homogeneous autocatalysis process with NO and N 2 O as the main products. [ABSTRACT FROM AUTHOR]

Metal oxide nanoparticles as the electrochemically active second phase were incorporated into the paper-like flexible graphene-based hybrid electrodes. Its size and dispersion are crucial factors for determining the rate capability and cycling stability of the flexible hybrid paper electrode. Herein, we employ in-situ formed ultrafine monodisperse TiO 2 quantum dots (QDs, ∼4.0 nm) as the electrochemically active second phase, which are uniformly incorporated into the flexible hybrid paper via a simple mixed solvothermal reaction together with a vacuum filtration, aiming at achieving a high-rate and long-cycle flexible TiO 2 -based anode in lithium ion batteries (LIBs). By combining the advantages of both ultrafine TiO 2 -QDs and three-dimensional (3D) conductive networks, the as-fabricated TiO 2 -QDs-reduced graphene oxide (TiO 2 -QDs-RGO) hybrid paper electrode shows high reversible capacity of 201 mA h g −1 after 100 cycles at 0.1 A g −1 and superior rate capability as well as long cycle life of 1500 cycles with ∼80.6% capacity retention at 2.0 A g −1 . Detailed electrochemical analysis shows that the improved capability and cyclability of the hybrid paper electrode results from the integrated intercalation-based and interfacial lithium storage behaviors as well as the 3D fast electron/ion transfer of materials, which is ascribed to the ultra-small size of TiO 2 -QDs and the 3D self-standing conductive networks of the hybrid paper electrode. The results demonstrate the distinct advantages of our material design strategy, and also might pave the way for further studies of other flexible metal oxide/graphene hybrid paper electrodes for fast and long-life flexible anodes in LIBs. [ABSTRACT FROM AUTHOR]

Abstract: An oxygen diffusion cathode for a PEMFC has been prepared by directly depositing the catalyst (pure Pd) on a carbon paper support containing 5% of PTFE through an electroless deposition method. A very low-Pd loading of 0.04 mgPd cm−2 and a higher one, containing 0.22 mgPd cm−2, were obtained. Two different experimental approaches were used to evaluate their catalytic activity towards the oxygen reduction reaction. The overall results revealed that the prepared catalysts exhibit a high catalytic activity, but a low efficiency on the catalyst utilization. PEMFC tests, carried out in a single cell, showed the feasibility of using the novel procedure on the preparation of oxygen diffusion cathodes, and its similar performance to a conventional one prepared by spraying the catalyst ink (Pt black) on a carbon paper support. [Copyright &y& Elsevier]

Cobalt-based nanomaterials have received considerable attention in electric energy-storage devices due to their outstanding electrochemical characteristics. However, multiple time- and energy-consuming steps and complex reduction processes for producing cobalt and cobalt oxide nanostructures are disrupting their substantive commercialization. Here, we propose a facile, ultra-fast, and versatile method for the fabrication of cobalt and cobalt oxide nanostructures using an intense pulsed white light (IPWL) photothermal reduction technique. The mechanism of the IPWL photothermal reduction of cobalt and cobalt oxide is firstly studied by measuring the in-situ temperature of the Co(NO 3 ) 2 -coated carbon fiber paper (CFP) substrate during IPWL irradiation and analyzing the crystal structures of the IPWL-irradiated samples. Cobalt nanoflakes and cobalt oxide nanoparticles are synthesized on the surface of the CFP substrate by irradiating IPWL for 10 ms at ambient temperature and pressure with various energy densities from 10 to 30 J cm −2 . The Co 3 O 4 nanoparticle/CFP and Co nanoflake/CFP samples are further utilized as an electrode, and each electrode exhibits high specific capacity of 29 and 73 mA h g −1 , respectively, at a current density of 1 A g −1 . Since this novel photothermal reduction technique is applicable to other transition metals and metal oxides, it is a promising method for not only energy storage systems, but also for energy generation applications, filters, sensors, and catalysis systems. [ABSTRACT FROM AUTHOR]

To enhance catalytic activity and durability for methanol oxidation reaction (MOR), we have fabricated bimetallic Pt-Fe catalysts on carbon fiber papers (denoted as Pt-Fe@CFP) by a facile chemical reduction method using iron as the precursor, ascorbic acid and sodium hypophosphite as the reductants, respectively. When ascorbic acid is using as the reductant, the Pt-Fe@CFP catalysts are composed of platinum and disordered Pt-Fe phases. The atomic ratio between Pt and Fe can be adjusted by altering deposition conditions. The Pt-Fe@CFP catalysts with Pt/Fe ratio of 1.1, which deposited with surfactant CTAB in bath at room temperature, exhibit excellent catalytic activity and stability in MOR. However, when sodium hypophosphite is employed as the reductant, the co-deposition of phosphorus would lead to a decreased catalytic performance in MOR. [ABSTRACT FROM AUTHOR]

Chlorine bleaching technology (C process, CEH process, H process and theirs combination), which was identified as a primary formation source of PCDD/Fs, is still widely used by the vast majority of Chinese non-wood pulp and paper mills (non-wood PMs). The purpose of this study was to provide information and data support for further eliminating dioxin for non-wood PMs in China, and especially to evaluate the PCDD/Fs release reduction for those mills converting their pulp bleaching processes from CEH to ECF. The PCDD/Fs concentrations of the bleached pulp and bleaching wastewater with ECF bleaching were in the ranges of 0.13–0.8 ng TEQ kg −1 , and 0.15–1.9 pg TEQ L −1 , respectively, which were far lower than those with CEH process, indicating that the ECF process is an effective alternative bleaching technology to replace CEH in Chinese non-wood PMs to reduce dioxin release. The release factor via flue gas of the alkali recovery boiler in Chinese non-wood PMs was first reported to be 0.092 μg TEQ Ad t −1 in this study. On the assumption that pulp bleaching processes of all Chinese non-wood PMs were converted from CEH to ECF, the annual release of PCDD/Fs via the bleaching wastewater and bleached pulp would be reduced by 79.1%, with a total of 1.60 g TEQ. [ABSTRACT FROM AUTHOR]

For practical applications of graphene-based materials in flexible supercapacitors, a technological breakthrough is currently required to fabricate high-performance graphene paper by a facile method. Herein, highly conductive (∼6900 S m −1 ) graphene paper with loose multilayered structure is produced by a high-efficiency in-situ chemical reduction process, which assembles graphite oxide suspensions into film and simultaneously conducts chemical reduction. Graphene papers with different parameters (including different types and doses of reductants, different thicknesses and areas of films) are successfully fabricated through this in-situ chemical reduction method. Meanwhile, the influences of the graphene papers with different parameters upon the supercapacitor performance are systematically investigated. Flexible supercapacitor based on the graphene paper exhibits high areal capacitance (152.4 mF cm −2 at current density of 2.0 mA cm −2 in aqueous electrolyte), and excellent rate performance (88.7% retention at 8.0 mA cm −2 ). Furthermore, bracelet-shaped all-solid supercapacitor with fascinating cycling stability (96.6% retention after 10 000 cycles) and electrochemical stability (an almost negligible capacity loss under different bending states and 99.6% retention after 4000 bending cycles) is established by employing the graphene paper electrode material and polymer electrolyte. [ABSTRACT FROM AUTHOR]

The article provides insights into the kinetics of paper degradation. The most important parameter to evaluate the degradation of paper is the number of scissions, which can be estimated by the degree of polymerization. The presence of potential degradation sites should always be verified by comparing the value of the viscometric degree of polymerization before and after reduction.

Deals with a study which investigated reducing methods for paper conservation. Information on the conservation of paper; Experimental set up; Preparation of samples; Conclusions.

A green and simple approach was demonstrated to prepare reduced graphene oxide (rGO) paper using Zn powder in ammonia solution as the reducing system at room temperature and GO paper obtained via vacuum filtration of GO aqueous dispersion as precursor. The effect of immersing time in the system, morphology and structure on the resulting rGO paper were investigated by X-ray diffraction, scanning and transmission electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy and capacitive behavior. Results showed that the rGO-60 paper (reduced for 60 min) displayed superior capacitive performance with high specific capacitance (130 F/g) as compared with other rGO papers under various treating times. The reduction time plays a key role in the morphology, structure, reduction degree and capacitive performance. [ABSTRACT FROM AUTHOR]

Abstract: The experiments were carried out in an electrocoagulation reactor with aluminum as sacrificial electrodes. The influence of electrolysis time, current density, pH, NaCl concentration, rotational speed of the stirrer and electrode distance on reduction of color, COD and BOD were studied in detail. From the experimental results, 15mA/cm2 current density, pH of 7, 1g/l NaCl, 100rpm, 28°C temperature and 3cm electrode distance were found to be optimum for maximum reduction of color, COD and BOD. The reduction of color, COD and BOD under the optimum condition were found to be 94%, 90% and 87% respectively. The electrode energy consumption was calculated and found to be varied from 10.1 to 12.9kWh/m3 depending on the operating conditions. Under optimal operating condition such as 15mA/cm2 current density, pH of 7, 1g/l NaCl, 100rpm, 28°C temperature and 3cm electrode distance, the operating cost was found to be 1.56US $/m3. The experimental results proved that the electrocoagulation is a suitable method for treating bleaching plant effluents for reuse. [Copyright &y& Elsevier]

The study reports on the preparation of polyacrylonitrile fiber paper (PANFP) functionalized with polydopamine (PD) and silver nanoparticles (Ag NPs), named as Ag NPs/PD/PANFP. The composite material was obtained via a simple two-step chemical process. First, a thin polydopamine layer was coated onto the PANFP surface through immersion into an alkaline dopamine (pH 8.5) aqueous solution at room temperature. The reductive properties of polydopamine were further exploited for the deposition of Ag NPs. The morphology and chemical composition of the composite material were characterized using scanning electron microscopy (SEM), X-ray diffraction pattern (XRD) and X-ray photoelectron spectroscopy (XPS). The catalytic activity of the nanocomposite was evaluated for the reduction of 4-nitrophenol using sodium borohydride (NaBH 4 ) at room temperature. The Ag NPs/PD/PANFP displayed good catalytic performance with a full reduction of 4-nitrophenol into the corresponding 4-aminophenol within 30 min. Moreover, the composite material exhibited a good stability up to 4 cycles without a significant loss of its catalytic activity. [ABSTRACT FROM AUTHOR]

We have developed nanoparticle-embedded paper-spray mass spectrometry for studying three types of heterogeneously catalyzed reactions: 1) Palladium-nanoparticle-catalyzed Suzuki cross-coupling reactions, 2) palladium- or silver-nanoparticle-catalyzed 4-nitrophenol reduction, and 3) gold-nanoparticle-catalyzed glucose oxidation. These reactions were almost instantaneous on the nanocatalyst-embedded paper, which subsequently transferred the transient intermediates and products to a mass spectrometer for their detection. This in situ method of capturing transient intermediates and products from heterogeneous catalysis is highly promising for investigating the mechanism of catalysis and rapidly screening catalytic activity under ambient conditions. [ABSTRACT FROM AUTHOR]

Graphene paper has attracted considerable attention because of its impressive electrical and mechanical properties, which endow it with the great potential for applications in future flexible electronics. Therefore, developing a high-efficiency route to fabricate large-area and foldable graphene paper with good electrical and mechanical properties is quite necessary. In this work, a facile in-situ chemical reduction method for the preparation of graphene paper was successfully developed. The in-situ chemical reduction process involves simultaneous film formation and reduction, and the produced graphene paper has high integrity and good foldability. The thickness and area of graphene paper can also be readily regulated by adjusting the experimental parameters. Furthermore, the dissipation of reductant air stream (HI/CH 3 COOH air stream) can “push up” the graphene nanosheets to form a loose layered structure. This inside-out reduction process gives the produced graphene paper a sheet resistance as low as 17.8 Ω sq −1 , verifying the advantages of this in-situ chemical reduction method. For the application of the obtained graphene paper, a flexible solid-state supercapacitor based on the graphene paper was fabricated, which had a device areal capacitance of 44 mF cm −2 (device volumetric capacitance of 858 mF cm −3 ) and excellent electrochemical stability. [ABSTRACT FROM AUTHOR]

Pulp and paper wastewater (PPW) is a high strength effluent which requires advanced treatments for achieving the discharge standards. Integrated processes were used for the first time to treat PPW including permanganate (PM), electro-Fenton (EF) and Co 3 O 4 /Peroxymonosulfate/UV (sulfate radical, SR). The main operating parameters of each process were investigated on chemical oxygen demand (COD) removal. The results showed that the combination of PM, EF and SR processes could provide the discharge standard in a way that COD was reduced from 1450 to 62 mg/L. Moreover, the biodegradability of effluents obtained from EF and SR was improved. As an important result, pH of the wastewater was adjusted for one time at first process (PM) and final effluent reached neutral condition. Phytotoxicity of the effluents obtained in each process was evaluated by germination index. Their results showed that phytotoxicity was dramatically reduced for four plants species in final effluent. The sequence of the processes was assessed in case of COD removal. The results indicated that the sequence of processes (PM + EF + SR) was the best choice for PPW treatment. The sludge of PM and EF was evaluated by FTIR analysis. Finally, these combinations of the chemical, electrochemical and photochemical processes were proposed as an excellent option for treatment of PPW. [ABSTRACT FROM AUTHOR]

We have developed nanoparticle-embedded paper-spray mass spectrometry for studying three types of heterogeneously catalyzed reactions: 1) Palladium-nanoparticle-catalyzed Suzuki cross-coupling reactions, 2) palladium- or silver-nanoparticle-catalyzed 4-nitrophenol reduction, and 3) gold-nanoparticle-catalyzed glucose oxidation. These reactions were almost instantaneous on the nanocatalyst-embedded paper, which subsequently transferred the transient intermediates and products to a mass spectrometer for their detection. This in situ method of capturing transient intermediates and products from heterogeneous catalysis is highly promising for investigating the mechanism of catalysis and rapidly screening catalytic activity under ambient conditions. [ABSTRACT FROM AUTHOR]

Graphene paper assembled from graphene oxide (GO) sheets has attracted great attention due to the intriguing physical and chemical properties. Here, we discovered that the size stability and mechanical performances of reduced graphene oxide (RGO) papers obtained by chemical reduction of the vacuum filtered GO papers are strongly dependent on the pH value of the starting GO suspensions. Moreover, it is found that RGO paper obtained from GO suspension with pH = 7 demonstrated superior performance of both flexural endurance and electrical conductivity. By investigating the structural differences of the prefabricated GO papers and their swelling behaviors during reduction, as well as the unlike microstructures of the obtained RGO papers, we interpreted the origin of the pH-mediated controllable contraction and mechanical performance of RGO papers. This study suggests a simple strategy for controlling the size stability, mechanical performance and electrical conductivity of RGO paper. [ABSTRACT FROM AUTHOR]

A multi-amplified paper-based electrochemical strategy using Pb 2+ dependent DNAzyme as the recognition unit for Pb 2+ detection was developed. In this work, flower-like reduced graphene (FrGO) was prepared utilizing flower-like ZnO as template, which was first one step grown on the gold nanoparticles modified paper working electrode (Au-PWE). After being treated with acid and then modified with Au, a novel sensor platform named Au/FrGO/Au-PWE with large specific surface area and good electrical conductivity was fabricated. The Mn 2 O 3 nanoparticle-assembled hierarchical hollow spheres (H-Mn 2 O 3 ) was served as nanocarrier to immobilize GOx, HRP and signal strand (S3), resulting to the formation of S3/H-Mn 2 O 3 /HRP/GOx bioconjugations. In the presence of Pb 2+ , the DNAzyme (S1) was activated and the substrate strand (S2) was cleaved. After the incubation with S3/H-Mn 2 O 3 /HRP/GOx in 0.1 M HAc–NaAc solution (pH 4.3) containing 30 mM aniline and 15 mM glucose, a readily measurable “turn-on” electrochemical signal could be measured. On the basis of the signal amplification strategy of Au/FrGO/Au-PWE sensing platform and S3/H-Mn 2 O 3 /HRP/GOx bioconjugations, the developed biosensor exhibited a good linear response toward over a wide range of concentration from 0.005 to 2000 nM. [ABSTRACT FROM AUTHOR]

Graphene papers (GP) modified with alkaline earth metal ions (Mg 2 + , Ca 2 + ) were prepared by reduction of graphene oxide papers, which were obtained through a facile vacuum filtration of graphene oxide solution aqueous. The thermal conductive properties of graphene paper and its modified analogues were measured with a laser flash method. The thermal diffusivities of Mg-modified GP and Ca-modified GP are 1003.4 mm 2 /s and 2232.2 mm 2 /s, respectively, which is significantly improved compared with unmodified graphene paper (694.9 mm 2 /s). The corresponding thermal conductivities are 100.4 W/mK (GP), 147.7 W/mK (Mg-GP) and 331.8 W/mK (Ca-GP), respectively, from which a substantial enhancement in thermal conductivity of M-modified GP is also observed. It is found that the ion chelating between carboxyl groups of graphene oxide and alkaline earth metal ions will bridge the small graphene oxide sheets, and it will decrease the thermal resistance of the boundary and increase the contact surface of graphene sheets. The reduction of M-modified graphene oxide can partly recover the structure of graphene, thus can further improve the heat transfer property of graphene paper. [ABSTRACT FROM AUTHOR]

Water quality assessment requires a continuous and strict analysis of samples to guarantee compliance with established standards. Nowadays, the increasing number of pollutants and their synergistic effects lead to the development general toxicity bioassays capable to analyse water pollution as a whole. Current general toxicity methods, e.g. Microtox ® , rely on long operation protocols, the use of complex and expensive instrumentation and sample pre-treatment, which should be transported to the laboratory for analysis. These requirements delay sample analysis and hence, the response to avoid an environmental catastrophe. In an attempt to solve it, a fast (15 min) and low-cost toxicity bioassay based on the chromatic changes associated to bacterial ferricyanide reduction is here presented. E . coli cells (used as model bacteria) were stably trapped on low-cost paper matrices (cellulose-based paper discs, PDs) and remained viable for long times (1 month at −20 °C). Apart from bacterial carrier, paper matrices also acted as a fluidic element, allowing fluid management without the need of external pumps. Bioassay evaluation was performed using copper as model toxic agent. Chromatic changes associated to bacterial ferricyanide reduction were determined by three different transduction methods, i.e. (i) optical reflectometry (as reference method), (ii) image analysis and (iii) visual inspection. In all cases, bioassay results (in terms of half maximal effective concentrations, EC 50 ) were in agreement with already reported data, confirming the good performance of the bioassay. The validation of the bioassay was performed by analysis of real samples from natural sources, which were analysed and compared with a reference method (i.e. Microtox). Obtained results showed agreement for about 70% of toxic samples and 80% of non-toxic samples, which may validate the use of this simple and quick protocol in the determination of general toxicity. The minimum instrumentation requirements and the simplicity of the bioassay open the possibility of in-situ water toxicity assessment with a fast and low-cost protocol. [ABSTRACT FROM AUTHOR]

There is increasing concern about chemical pollutants that have the ability to mimic hormones, the so-called endocrine-disrupting compounds (EDCs). One of the main reasons for concern is the possible effect of EDCs on human health. EDCs may be released into the environment in different ways, and one of the most significant sources is industrial wastewater. The main objective of this research was to evaluate the treatment performance of different wastewater treatment procedures (biological treatment, filtration, advanced oxidation processes) for the reduction of chemical oxygen demand and seven selected EDCs (dimethyl phthalate, diethyl phthalate, dibutyl phthalate, benzyl butyl phthalate, bis(2-ethylhexyl) phthalate, bisphenol A and nonylphenol) from wastewaters from a mill producing 100 % recycled paper. Two pilot plants were running in parallel and the following treatments were compared: (i) anaerobic biological treatment followed by aerobic biological treatment, ultrafiltration and reverse osmosis (RO), and (ii) anaerobic biological treatment followed by membrane bioreactor and RO. Moreover, at lab-scale, four different advanced oxidation processes (Fenton reaction, photo-Fenton reaction, photocatalysis with TiO2, and ozonation) were applied. The results indicated that the concentrations of selected EDCs from paper mill wastewaters were effectively reduced (100 %) by both combinations of pilot plants and photo-Fenton oxidation (98 %), while Fenton process, photocatalysis with TiO2 and ozonation were less effective (70 % to 90 %, respectively). [ABSTRACT FROM PUBLISHER]

Abstract: The tertiary treatment of paper mill wastewaters was investigated by testing the effect of batch electrocoagulation for 90min with two parallel iron or aluminum plates at two values of the current density (100 and 150A/m2). Dissolved organic carbon removal ranged between 24% and 46%, and chemical oxygen demand removal ranged between 32% and 68%. UV–visible spectroscopy showed a reduction of the aromaticity of the treated effluent. The process was also very efficient for the removal of lignin-based pollution, characterized by the fluorescence of humic substances. Arsenic was selected as an example of a non-organic micropollutant and was also satisfactorily removed (from 4 to 0.5μg/L). The settling characteristics of the sludge obtained after the electrocoagulation treatment were also evaluated. The sludge aptitude to settling is better with Fe electrodes than with Al electrodes. The experimental results obtained in the present study indicate that electrocoagulation treatment can be very effective and was capable of improving the paper mill wastewaters’ quality downstream of the biological treatment. [Copyright &y& Elsevier]

Abstract: Sulfide can be removed from wastewater and recovered as elemental sulfur using an electrochemical process. Recently, we demonstrated this principle of product recovery on synthetic feeds. Here, we present a lab scale electrochemical reactor continuously removing sulfide from the effluent of an anaerobic treatment process operated on paper mill wastewater. The effluent contained 44 ± 7 mg of sulfide-S L−1. Sulfide was reduced to 8 ± 2 mg-S L−1, at a removal rate of 0.845 ± 0.133 kg-S m−3 of total anodic compartment (TAC) d−1. The removed sulfide was recovered (75 ± 4% recovery) as pure concentrated alkaline sulfide/polysulfide solution, from which solid elemental sulfur was obtained. The electrochemical sulfide removal was not affected by different soluble constituents or particulate materials present in the wastewater. However, over time sulfide removal decreased due to biological sulfur reduction using the organics present in the wastewater. Therefore, a periodic switching strategy between anode and cathode was developed. Biofilm formation was avoided as the pH of the cathode solution increased to inhibitory levels during cathodic operation, while still allowing full recovery of the sulfur as end product. [Copyright &y& Elsevier]

In this review, particular importance is given to the fabrication and properties of carbon nanotube and graphene oxide-based paper-like materials (buckypapers). Different strategies for the reduction and functionalization of graphene oxide were also discussed. The chemistry of buckypapers is conversed with special emphasis on structure and essential characteristics of buckypaper. Various techniques for buckypaper processing have been critically reviewed including significance of each method. Moreover, importance of polymer/graphene oxide and polymer/carbon nanotube composite papers has been highlighted. Due to outstanding physical, thermal, and electrical properties, polymer-based buckypapers are potentially important as nanofilters, fuel cell components, and miniaturization of electrical connections. [ABSTRACT FROM PUBLISHER]

Pseudocapacitive materials are known to suffer from severe capacitance loss during charging/discharging cycling. Here we report flexible all-solid-state supercapacitors (ASSSCs) based on reduced graphene oxide (rGO)/polypyrrole nanotube (PPy NT) papers prepared by a facile vacuum filtration method. It is revealed that the incorporation of rGO nanosheets can improve the electrochemical stability of PPy NT paper electrodes for pseudocapacitors. The hybrid paper electrode shows a high areal specific capacitance of 807 mF/cm 2 at 1 mA/cm 2 and a large volumetric specific capacitance of 94.3 F/cm 3 at 0.1 A/cm 3 . The assembled ASSSC possesses a maximum areal specific capacitance of 512 mF/cm 2 at 1 mA/cm 2 and a maximum volumetric specific capacitance of 59.9 F/cm 3 at 0.1 A/cm 3 . Moreover, it also exhibits excellent rate capability (86.3% capacitance retention from 1 to 10 mA/cm 2 ) and cycling stability, little capacitance deviation under different bending states, a small leakage current and a low self-discharge characteristic. The device can provide an areal energy density of 61.4 μWh/cm 2 at 10 mW/cm 2 and a volumetric energy density of 7.18 mWh/cm 3 at 1.17 W/cm 3 , indicating this high-performance ASSSC is a promising candidate for flexible high-power supply devices. [ABSTRACT FROM AUTHOR]

This study demonstrates chromatic analysis based on a simple red green blue (RGB) color model for sensitive and selective determination of mercury(II). The analysis was performed by monitoring the color change of a microfluidic Paper-based Analytical Device (µPAD). The device was fabricated by using alkyl ketene dimer (AKD)-inkjet printing and doped with unmodified silver nanoparticles (AgNPs) which were disintegrated when being exposed to mercury(II). The color intensity was detected by using an apparatus consisting of a digital camera and a homemade light box generating constant light intensity. A progressive increase in color intensity of the tested area on the µPAD (3.0 mm) was observed with increasing mercury(II) concentration. The developed system enabled quantification of mercury(II) at low concentration with the detection limit of 0.001 mg L −1 (3 SD blank/slope of the calibration curve) and small sample volume uptake (2 µL). The linearity range of the calibration curve in this technique was demonstrated from 0.05 to 7 mg L −1 (r 2 =0.998) with good precision (RSD less than 4.1%). Greater selectivity towards mercury(II) compared with potential interference ions was also observed. Furthermore, the percentage recoveries of spiked water samples were in an acceptable range which was in agreement with the values obtained from the conventional method utilizing cold vapor atomic absorption spectrometer (CVAAS). The proposed technique allows a rapid, simple, sensitive and selective analysis of trace mercury(II) in water samples. [ABSTRACT FROM AUTHOR]

Lithium sulfide (Li2S) is a promising cathode material for Li-S batteries with high capacity (theoretically 1166 mAh g-1) and can be paired with nonlithium-metal anodes to avoid potential safety issues. However, the cycle life of coarse Li2S particles suffers from poor electronic conductivity and polysulfide shuttling. Here, we develop a flexible slurryless nano-Li2S/reduced graphene oxide cathode paper (nano-Li2S/rGO paper) by simple drop-coating. The Li2S/rGO paper can be directly used as a free-standing and binder-free cathode without metal substrate, which leads to significant weight savings. It shows excellent rate capability (up to 7 C) and cycle life in coin cell tests due to the high electron conductivity, flexibility, and strong solvent absorbency of rGO paper. The Li2S particles that precipitate out of the solvent on rGO have diameters 25-50 nm, which is in contrast to the 3-5 µm coarse Li2S particles without rGO. [ABSTRACT FROM AUTHOR]

Highlights: [•] First examination on reduced ignition cigarette combustion. [•] Quantitative volume fractions at given gas-phase temperatures. [•] A net reduction in high temperature volume fraction for RIP cigarette. [•] Different internal temperature contour for RIP cigarette at different puffing time. [Copyright &y& Elsevier]

Abstract: The catalytic activity towards the oxygen reduction reaction (ORR) of a novel material consisting of clusters of Pd nanoparticles directly deposited on porous carbon paper by electroless deposition, has been investigated in sulphuric acid medium. It is shown that this new material exhibits a very high electrocatalytic activity for the ORR, compared to the commercial carbon paper-supported Pt. [Copyright &y& Elsevier]

Here we show that the graphene sheets in reduced graphene oxide papers (rGOPs) can be cross-linked by electron-irradiation-induced sp 3 carbon atoms, resulting in significant enhancements in both the mechanical and electrical properties compared to unirradiated rGOPs. We find that the residual oxygen-containing functional groups in rGOPs are removed during irradiation. We also observe that the Wigner energy release temperature in rGOPs is 102–188°C, which is lower than that (∼200°C) in pure graphite. The mechanisms to form sp 3 cross-links and the evolutions of sp 3 carbon atoms under irradiation are revealed through molecular dynamics simulations. [ABSTRACT FROM AUTHOR]

Abstract: Pd/Fe-modified carbon paper (Pd/Fe-C) electrode was prepared from PdCl2 and FeSO4 via electrodeposition onto carbon paper. It was observed that the diameters of electrodeposited Pd/Fe particles were around 20nm with a uniform distribution on carbon paper, which is smaller than Pd/Fe particles of impregnated and calcined electrode. The electrodeposited Pd/Fe-C electrode exhibited higher activity in dechlorination of chloroacetic acids than impregnated and calcined electrode. Under optimal experiment conditions of Pd:Fe molar ratio of 2:1 at −1.5V (vs SCE), 95% of trichloroacetic acid (TCAA) with the initial concentration of 500μg/L was removed within 20min at pH 3. The dechlorination of chloroacetic acids followed the order of TCAA>dichloroacetic acid (DCAA)>monochloroacetic acid (MCAA). MCAA cannot be dechlorinated at C and Fe-C electrodes via direct reduction. However, a part of chloroacetic acids was directly dechlorinated to acetic acid at Pd-C and Pd/Fe-C electrodes via indirect reduction. The Pd(0) and Pd(II) species were detected by X-ray photoelectron spectroscopy. Compared with the individual Pd-C electrode, in situ formation of Fe(0) decreased the interface impedance as observed by electrochemical impedance spectroscopy analysis. In conclusion, the presence of Pd(0) nanoparticles played a significant role in forming atomic H* to realize indirect reduction process which could achieve the complete dechlorination of chloroacetic acids. [Copyright &y& Elsevier]

A facile photoreduction strategy to attach silver nanoparticles on filter paper (AgNPs@FP) to form surface-enhanced Raman scattering (SERS) substrate array was proposed and examined. As prepared, SERS substrate array was applied to detect low concentration of adenine and other nucleobases in aqueous solutions. In addition, the formed SERS substrate array allows mass analysis of aqueous samples with a requirement of only 10 μL in sample volume. To optimize and understand the parameters in preparations, factors such as the concentrations of citrate and silver nitrate, photoreduction time, and concentration of sodium hydroxide were varied and examined. Para-nitrothiophenol was used as a Raman probe molecule and scanning electron microscope (SEM) images of the substrates were used to explore the influences of experimental factors in the preparation of SERS array. Results indicated that silver ions could be effectively reduced and deposited in/on filter paper with the presence of citrate. The formed AgNPs@FP exhibits a three-dimensional structure as the particles formed on and beneath the surface of the cellulosic fibers could be observed. Deposition of analyte on restricted substrate array rendered reproducible results and the spot-to-spot SERS intensity varied within 8%. At optimal conditions, the substrate enhancement factor approached 107. We demonstrated that the filter paper-based SERS substrates can be used as a suitable tool for biological analysis, and a limit of detection better than 160 nM was obtained in detection of adenine molecules in aqueous solutions with a linear range up to 20 μM. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: This research investigated the mineral aluminum silicate catalyst effect on the enhancement of energy yield efficiency and reduction of the tar yield concentration in the gasification of paper-reject sludge. Experimental results indicated that the energy yield efficiency is enhanced by the tested mineral catalyst. When gasification temperature operated at 600 °C, the lower heating value (LHV) of syngas increased significantly from 8.66 MJ/Nm3 to 13.38 MJ/Nm3 with an increase in aluminum silicate catalyst addition from 0% to 20%. The energy density of syngas also increased from 0.53 to 0.82. This implied that the energy utilization of syngas produced by a low temperature catalytic gasification could increase approximately 1.5 times the energy content of paper-reject sludge. The tar reduction efficiency could reach approximately 50% which was also proportional to the catalyst addition ratio. In summary, the aluminum silicate catalyst can help to improve the efficiency of tar reduction and energy yield in a low temperature catalytic gasification of paper-reject sludge. [Copyright &y& Elsevier]

Abstract: Reduced graphene oxide (r-GO) paper is easily synthesized by a flame-induced reduction of graphene oxide (GO) paper under ambient conditions. The X-ray diffraction and X-ray photoelectron spectroscope results confirm the effectivity of the flame-induced reduction. The resulting r-GO paper has a high surface area of 274.9 m2 g−1 and contains a certain amount of oxygen-containing groups. Electrochemical behaviors of the electrode built with the r-GO paper are investigated in two kinds of electrolytes, 2 M KOH aqueous solution and 1 M Et4NBF4-acetonitrile solution, respectively. The results show that the high values of the specific capacitance for the r-GO can be obtained in both electrolytes, which reach 212 and 160 F g−1 at the same current density of 1 A g−1 respectively. Also, the r-GO-based electrode and supercapacitor exhibits stable cycling performance. The good capacitive performances in KOH aqueous electrolyte are due to the high surface area and the remaining oxygen containing groups of the r-GO paper. [Copyright &y& Elsevier]

Abstract: The one-step synthesis of gold nanoparticles (AuNPs) was achieved, in situ, on a microstructured paper composite that consisted of ceramic fibers which acted as the main frame with zinc oxide (ZnO) whiskers being used as the selective support for the AuNPs. Initially, ZnO whiskers were incorporated into a ceramic paper matrix using a high-speed and low-cost papermaking technique, and the AuNPs were then synthesized onto the embedded ZnO whiskers via a simple soaking treatment using an aqueous solution of tetrachloroauric acid (HAuCl4). The as-prepared hybrid material has the appearance of paperboard and is denoted as AuNPs@ZnO paper. It was lightweight, flexible, sufficiently strong and easy-to-handle in practical use, and possessed a paper-like porous microstructure. In the liquid-phase reduction process of 4-nitrophenol, the AuNPs@ZnO paper demonstrated excellent catalytic performance compared with conventional Au/ZnO catalyst powders. This suggests that the unique paper structure, which has an open pore system throughout the structure, promotes the efficient transport of the reactants to the surfaces of the highly effective AuNPs. Thus, this AuNPs@ZnO paper is expected to be a promising catalytic material having a high degree of practical utility and catalytic efficiency. [Copyright &y& Elsevier]

The complexity of mathematical models in biology has rendered model reduction an essential tool in the quantitative biologist's toolkit. For stochastic reaction networks described using the Chemical Master Equation, commonly used methods include time-scale separation, Linear Mapping Approximation, and state-space lumping. Despite the success of these techniques, they appear to be rather disparate, and at present, no general-purpose approach to model reduction for stochastic reaction networks is known. In this paper, we show that most common model reduction approaches for the Chemical Master Equation can be seen as minimizing a well-known information-theoretic quantity between the full model and its reduction, the Kullback–Leibler divergence defined on the space of trajectories. This allows us to recast the task of model reduction as a variational problem that can be tackled using standard numerical optimization approaches. In addition, we derive general expressions for propensities of a reduced system that generalize those found using classical methods. We show that the Kullback–Leibler divergence is a useful metric to assess model discrepancy and to compare different model reduction techniques using three examples from the literature: an autoregulatory feedback loop, the Michaelis–Menten enzyme system, and a genetic oscillator. [ABSTRACT FROM AUTHOR]

Graphene in the form of film, fiber, fabrics and composites is widely investigated research area because of its remarkable physical, chemical and thermal properties. The acceptance of plant-derived products to synthesize graphene or reduced graphene oxide (RGO) has the supremacy of environmentally friendly, mild reaction condition, sustainability, cost effective and simple reaction procedure compared with conventional chemical synthesis methods. To synthesize RGO from graphene oxide (GO) in traditional chemical reduction method, highly toxic and hazardous reducing agents, capping agents, solvents are generally employed which severely affect and threaten ecological equilibrium and human well-being. In this paper, different highly facile and eco-friendly, low-cost green synthesis of RGO using aqueous plant extracts have been surveyed. The phytochemical present in plant extract, methods of preparation of the extract, detection of phytochemical present in extract, preparation of GO, methods of reduction of GO, mechanism of reduction of GO by greener way are discussed. Graphene has been widely recognized as one of the most significant new 2D nanomaterials and graphene oxide (GO) plays as a building block to synthesize graphene. Though there are several ways to produce reduced graphene oxide, the greener approach is superior due to its environmentally friendly, mild reaction condition, sustainable, cost-effective procedure. The discussed topic includes the phytochemicals found in plant extracts, extract preparation methods, detection of phytochemicals present and how to reduce GO in a more environmentally friendly way. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this present study is to investigate the removal efficiency of chemical oxygen demand (COD) from pulp and paper wastewater using laccase-polymerized membrane filtration process. The membranes with molecular weight cut-off (MWCO) of 5000 and 10,000, 30,000 and 54,000 were used in a cross-flow module to treat the pulp and paper wastewater containing high phenolic constituents and COD. With 2.98IU/L of activated laccase applied at room temperature for 180min, the contaminants in raw wastewater and second effluent were polymerized to form larger molecules with average molecular weight of 1300 and 900Da (Dalton), respectively. With laccase polymerization prior to filtration, over 60% removals of COD by the four investigated membranes were observed, compared with low COD removal without laccase polymerization. Moreover, the addition of laccase resulted in 4–14% reduction of membrane permeability during the first 180min filtration operation due to gel layer formation by the polymerization. No further flux decline was observed afterwards indicating the steady state was reached and the membranes could be used to remove the polymerized pollutants without significant fouling. The maximum apparent resistance occurrence for raw wastewater treated with laccase also supported the effectiveness for COD removal with laccase polymerization before membrane filtration. Additionally, pretreatment by inactivated laccase only caused further flux reduction without additional removal of COD. [Copyright &y& Elsevier]

Abstract: Platinum nanoparticles (PtNPs) were synthesized on surface-activated carbon fibers with high thermal conductivity, and paper-structured composites were fabricated by a papermaking technique, using the PtNPs-supported carbon fibers and ceramic fibers as matrix materials. As-prepared materials, denoted paper-structured PtNPs catalyst, possessed a unique porous microstructure derived from entangled inorganic fiber networks on which PtNPs were well dispersed. In catalytic reduction of nitrogen oxides (NO X ) in the presence of methane (CH4), both of which are model exhaust gas components of combustion engines, paper-structured PtNPs catalyst demonstrated excellent NO X and CH4 removal efficiency and rapid thermal responsiveness by comparison with the PtNPs-supported carbon fibers, commercial Pt catalyst powders and a monolithic Pt-loaded honeycomb. These features of the new catalyst material are thought to arise from synergistic effects of the highly active PtNPs in association with the unique paper-like microstructure, in promoting effective transfer of heat and reactants to the active sites of the Pt nanocatalysts. The paper-structured PtNPs catalyst with paper-like practical utility is expected to be a promising catalytic material for efficient NO X gas purification. [Copyright &y& Elsevier]

Papers of silicon nitride nanofibers were synthesized by a carbothermal reduction process. These nanofiber papers were synthesized in situ and did not require a secondary processing step. The process utilized silica nanopowders and silica gel as the precursor material. Processing geometry played a crucial role in regulating the growth of the nanofiber papers. Characterization of the nanofiber papers indicated that the nanofibers were of the alpha silicon nitride phase. Both mechanical stiffness and strength of the nanofiber papers were measured. Thermal conductivity and specific heat of the papers were also measured and were found to be lower than many common thermal insulation materials at much smaller thicknesses and were comparable to those values that are typically reported for carbon-nanotube-based buckypaper. Results of the mechanical and thermal characterization indicate that these silicon nitride nanofiber papers can be utilized for specialized thermal insulation applications. [ABSTRACT FROM AUTHOR]