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An efficient method that utilizes simple techniques, easy operation, and low‐cost production to create flexible graphene‐based materials is a worthy practical challenge. A rapid strategy for preparing flexible, functional graphene oxide (GO) is introduced using GO‐ethanol dispersion filtration. The filtration process is highly efficient and drying time is significantly reduced by employing ethanol as solvent, due to the fact that ethanol is a volatile liquid. Freestanding GO papers can be harvested with ultralarge size (700 cm2), color variety, and writable characteristics. After reduction, N‐doped graphene (NDG) papers still maintain good foldability with improved electric conductivity and porous structure. When used as an electrode for a supercapacitor, the flexible NDG paper device demonstrates good electrochemical performance even with size expansion and extreme double folding. Moreover, this NDG paper capacitor device shows a good electrosorption performance for capacitive deionization of sulfate and chromate in groundwater system. These flexible GO and NDG papers promise potential to facilitate the production of graphene‐based materials for practical applications in energy and environmental related fields.

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

Vapor phase polymerization has been used for the synthesis of polypyrrole-coated filter paper (PPy-FP) using a simple experimental setup. In addition, we have doped the polymer-coated filter papers...

The development of actuators for power sources is essential for the efficient manipulation of fluids in microfluidics systems. In this work, a capacitor-type three-layer paper actuator was fabricated by sandwiching a polyelectrolyte layer between two films of poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT/PSS). The paper actuator exhibited stable large electromechanical deformations in bilateral symmetry under alternating square-wave electric field. The actuation properties were examined in a function of voltage (±0.5, ±1, ±1.5, ±2, and ±2.5 V) and frequency (1, 0.5, 0.2, and 0.05 Hz). In addition, the PEDOT/PSS electrode films with different thicknesses were prepared, and the effects of actuator thickness on actuation properties were examined. As a result, it was found that the actuator displacement increased considerably with reducing actuator thickness. In addition, the actuator with a thickness of 48 μm demonstrated a maximum displacement of 5.8 mm at a voltage of 1.5 V and a frequency of 0.05 Hz. The proposed actuator can be potentially used in the development of power sources for micropumps and check valves of microfluidic devices.

This work reports a modification of a fibrous cellulose material (paper) by the addition of polyacrylonitrile (PAN) fibres doped with 10,12–pentacosadiynoic acid (PDA). The fibres are sensitive to ultraviolet (UV) light. When the paper containing PAN–PDA is irradiated with UV light it changes colour to blue as a consequence of interaction of the light with PDA. The colour intensity is related to the absorbed dose, content of PAN–PDA fibres in the paper and the wavelength of UV radiation. The features of the paper are summarised after reflectance spectrophotometry and scanning microscopy analyses. All the properties of the modified paper were tested in accordance with adequate ISO standards. Moreover, a unique method for assessing the unevenness of the paper surface and the quality of printing was proposed by using a Python script (RGBreader) for the analysis of RGB colour channels. The modification applied to the paper can serve as a paper security system. The modified paper can act also as a UV radiation indicator.

Made available in DSpace on 2019-10-06T17:04:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-06-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Development and application of a new, simple, inexpensive, and eco-friendly method is presented for the quantification of bumetanide in human urine samples for the detection of doping in sports. The method involves the use of a paper platform and digital image detection and is based on the reaction between bumetanide, p-dimethylaminocinnamaldehyde (p-DAC), and HCl in a methanolic medium, yielding a colored compound in a delimited area on a qualitative filter paper. The concentrations of p-DAC and HCl were optimized by a chemometric experimental design. After the addition of the reagents to the paper, digital images were obtained by scanning in a multifunctional printer and analyzed using the RGB pattern. The linear bumetanide concentration range was 6.90 × 10 −5 –1.37 × 10 −3 mol L −1 with R 2 = 0.993 and the limits of detection (LOD) and quantification (LOQ) were 3.60 × 10 −4 and 1.09 × 10 −4 mol L −1 , respectively. A SPE clean-up step for the samples were required to eliminate the interference of urinary urea. The recoveries obtained varied from 94% to 105%, indicating the absence of significant matrix effects or interferences in urine samples after clean-up step. The proposed method was successfully applied to the analysis of bumetanide in human urine samples. Instituto de Química Universidade Estadual Paulista “Júlio de Mesquita Filho” UNESP, R. Prof. Francisco Degni 55, P.O. Box 355 Instituto de Química Universidade Estadual Paulista “Júlio de Mesquita Filho” UNESP, R. Prof. Francisco Degni 55, P.O. Box 355 CAPES: 001 FAPESP: 2015/21733-1

Nano-sized Sr1−xAgxTiO3 system was prepared using modified Pechini method (x = 0, 0.02, 0.05 and 0.07). XRD, TEM and DRS are utilized for the prepared sample characterization. The doping impact on the structural and the antimicrobials properties was studied. The undoped SrTiO3 has cubic-like perovskite structure while Ag-doped samples have traces of metallic silver in addition to the cubic-like perovskite structure. Doping of SrTiO3 with silver resulted in red shift of the absorption to the visible light range. Antimicrobial properties were detected for nano-sized undoped and Ag-doped SrTiO3, whereas the parent SrTiO3 has not clear zone. Different concentrations of silver were applied in matrices of polymer to be utilized as active coating materials on paper sheets. Physico-mechanical properties of coated paper, thickness, water absorption, tensile, elongation at break and short span, were investigated. Active nanocomposite coating enhanced the mechanical and short span behaviors. Interested throughout assessment was presented for nanocomposites coating and its uses on packaging materials.

Submitted by Eduardo Luiz Rossini (eduardo.rossini@unesp.br) on 2020-02-27T15:12:46Z No. of bitstreams: 1 rossini_el_dr_araiq.pdf: 2590313 bytes, checksum: 64d9f340eb5c633e6fa6c028150b8a1b (MD5) Approved for entry into archive by Ana Carolina Gonçalves Bet null (abet@iq.unesp.br) on 2020-03-02T13:10:34Z (GMT) No. of bitstreams: 1 rossini_el_dr_araiq_par.pdf: 703386 bytes, checksum: 96b74b148702167b3e4e332064b9fbf4 (MD5) Made available in DSpace on 2020-03-02T13:10:35Z (GMT). No. of bitstreams: 1 rossini_el_dr_araiq_par.pdf: 703386 bytes, checksum: 96b74b148702167b3e4e332064b9fbf4 (MD5) Previous issue date: 2020-02-14 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) A primeira parte deste trabalho foi desenvolvida no laboratório Fritz Feigl-UNESP/CAr, na qual foi descrito um novo carbon dot (CD) sintetizado a partir de ácido cítrico e tiramina usando uma rota em única etapa por meio de aquecimento por micro-ondas doméstico. O CD sintetizado apresenta emissão no azul quando irradiado com luz UV, que foi suprimida na presença de H2O2 e peroxidase. O CD foi utilizado para desenvolver metodologias para quantificar glicose em amostras biológicas utilizando plataforma de papel. O método desenvolvido foi aplicado em amostras de soro e urina certificadas, e não há diferenças estatisticamente significativas entre os resultados obtidos usando o dispositivo de papel com adição de padrão e as amostras certificadas. Também foram desenvolvidas metodologias utilizando 3D-µPAD com o reagente fluorescente e enzimas oxidase para quantificação de glicose e lactato em amostras de saliva. O preparo de amostra foi simples e rápido e o método foi validada utilizando adição de padrão e recuperação, além de ser aplicado em amostras de soro certificadas, não houve diferenças estatisticamente significativas entre os resultados obtidos e os valores de referência. A segunda parte deste trabalho foi desenvolvida no Badu’s research group na The Ohio State University durante o período sanduiche com bolsa da FAPESP, na qual foi desenvolvida a quantificação direta de agentes dopantes em amostras de urina sem tratamento da amostra por PS-MS. Paper-spray mass spectrometry é um método de ionização em condições ambientes que combina as vantagens das plataformas de papel com a confiabilidade das análises de espectrometria de massas, reduzindo o tempo de análise e o consumo de reagente e de solventes orgânicos. O uso de substâncias ilícitas para aumentar a desempenho de atletas em esportes é proibido e considerado doping. A superfície do papel foi tratada com triclorometilsilano utilizando reação em fase gasosa para aumentar a ionização dos compostos alvo. Essa abordagem foi aplicada para análise de dois agentes anabólicos (trembolona e clembuterol) e dois diuréticos (furosemida e hidroclorotiazida) em amostras de urina. Após a otimização das condições experimentais, os métodos desenvolvidos apresentaram repetibilidade satisfatória e boa correlação linear entre concentração e intensidade absoluta. Foram alcançados limites de detecção na faixa de sub-ng mL-1, abaixo dos níveis de desempenho mínimos requeridos pela WADA, utilizando o método de PS-MS com papel hidrofóbico sem nenhuma etapa de preparo ou clean-up da amostra. Os métodos propostos foram aplicados em amostras de urina fortificadas com os agentes dopantes e se mostraram rápidos, simples, sensíveis, exatos e precisos. The first part of this work was developed on the Fritz Feigl-UNESP/CAr laboratory, in which a novel carbon dot synthesized from citric acid and tyramine was described using a one-step microwave heating route. Under UV irradiation, the CD displayed blue emission that was quenched in the presence of H2O2 and peroxidase. This property was used to develop a method to quantify glucose in biological samples using a paper platform. The method developed was applied in the analysis of certified serum and urine samples, and there were no statistically significant differences between the certified concentrations and the results obtained using the paper device with standard additions. In addition, it was developed method using 3D-µPAD, the CD fluorescence reagent and oxidase enzymes to quantify glucose and lactate in saliva samples. The sample preparation used was simple and fast. The method was validated in saliva samples utilizing standard addition and recovery, and applied in the analysis of certified serum samples, and there were no statistically significant differences between the certified concentrations and the results obtained using the 3D-µPAD. The second part of this work was developed at the Badu’s research group at The Ohio State University during the internship period funded by FAPESP, in which a direct quantification of doping agents in urine samples with no sample preparation by PS-MS was developed. Paper-spray mass spectrometry (PS-MS) is an ambient ionization method that combines the advantages of the paper platform with the reliability of MS analysis, reducing the consumption of time, reagent, and organic solvent. The use of illicit substances to improve enhance athletic performance in sport is forbidden and considered doping. The paper surface was treated with trichloromethylsilane (TCMS) using a gas-phase reaction to increase the target compounds ionization. This approach was applied for the analysis of two anabolic agents (trenbolone and clenbuterol) and two diuretics (furosemide and hydrochlorothiazide) in urine samples. Under optimized conditions, the developed methods presented satisfactory repeatability and a good correlation between concentration and absolute intensity. Highly sensitive detections as low as sub-ng mL 1 which is below the minimum required performance levels (MRPL) proposed by the WADA has been reached using the hydrophobic PS-MS without any pre-concentration and clean-up step. The proposed methods were applied in fortified urine samples with doping agents and showed to be fast, simple, sensitive, accurate and precise. FAPESP n. 2016/20847-6 FAPESP n. 2018/05993-1 CNPq n. 140503/2016-1

A rewritable photonic crystal (PC) paper as an environmentally friendly and low-resource-consuming material for information storage and spreading has gradually become a research hotspot. In this work, a novel rewritable PC paper with inkless writing and double-sided rewritability properties was developed. A double-sided epoxy resin PC paper exhibiting an inverse opal structure and a bright structural color was fabricated using the sacrificial template method. Carbon black was doped into the material to increase color saturation and purity while preventing light transmission and protecting the double-sided structural color from interference. The force of sliding friction and deformation triggered by capillary pressure as well as swelling-triggered recovery of the inverse opal structure led to an easy rewriting of the PC paper. The PC paper exhibited excellent rewritability even after 50 runs of the rewriting process. Given the inkless and double-sided rewriting, this study provides a new method for the preparation of rewritable PC papers.

Made available in DSpace on 2020-12-12T02:09:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-06-03 In this study, the direct analysis of doping agents in urine samples with no sample preparation by a modified paper spray mass spectrometry (PS-MS) methodology has been demonstrated for the first time. We have described a paper surface treatment with trichloromethylsilane using a gas-phase reaction to increase the ionization of target compounds. This approach was applied for the analysis of two classes of banned substances in urine samples: anabolic agents (trenbolone and clenbuterol) and diuretics (furosemide and hydrochlorothiazide). Under optimized conditions, the developed methods presented satisfactory repeatability, and an analysis of variance showed linearity without lack-of-fit. Highly sensitive detections as low as sub-nanogram per milliliter levels, which is below the minimum required performance levels proposed by the World Anti-Doping Agency, have been reached using the hydrophobic PS-MS analysis without any preconcentration and cleanup step. Department of Chemistry and Biochemistry Ohio State University, 100 West 18th Avenue Institute of Chemistry Department of Analytical Chemistry São Paulo State University (UNESP), Rua Professor Francisco Degni 55 ,P.O. Box 355 Institute of Chemistry Department of Analytical Chemistry São Paulo State University (UNESP), Rua Professor Francisco Degni 55 ,P.O. Box 355

Heteroatom (boron) doped reduced graphene oxide (B-rGO) papers were prepared by the simple self-assembly process of graphene oxide through the deoxygenation in argon atmosphere at 400 °C. The phase purity and crystallinity of the B-rGO paper were studied by X-ray diffraction analysis. The wrinkled paper-like morphology was analyzed by scanning electron microscopy (SEM) and the homogeneity by the elemental mapping. The binding energy states of the B-rGO were confirmed by X-ray photoelectron spectroscopy. The shift in zeta potential values also confirms the heteroatom doping in the rGO paper. From the Raman spectra it was observed that the incorporation of boron into the rGO paper exhibits an improved conductivity and mobility. The current-voltage (J-V) characteristics revealed that the B-rGO paper can be effectively used as a hole transport material (HTM) for perovskite solar cells (PSCs). The largest conversion efficiency of 8.96% was achieved for the FTO/TiO2/CH3NH3PbI3/B-rGO/FTO sandwich structure with an active area of 1 cm2.

Large-sized graphene sheets (LG) and doping strategy were employed to fabricate lightweight and flexible graphene paper with exceptional electromagnetic interference (EMI) shielding performance. Compared with the smaller sized ones, LG with fewer defects and more conjugated carbon domain size as well as better alignment result in higher electrical conductivity and strength of graphene paper. The iodine doping further improves the carrier density of LG by formation of triiodide ( I 3 − ) and pentaiodide ( I 5 − ) through charge transfer process without deteriorating the mechanical property, thus leading to superior EMI shielding effectiveness (SE). The EMI SE of iodine doped LG film with thickness of 12.5 μm is up to ∼52.2 dB at 8.2 GHz, which is much higher than that of undoped LG with the same thickness (∼47.0 dB). More important, the improvements in EMI SE is contributed to the SE absorption, while the SE reflection is almost unchanged. The mechanisms of improved EMI shielding performance as well as mechanical property were investigated and discussed. The present study provides a facile way to fully develop graphene in lightweight and flexible EMI shielding materials and devices.

The Fe-N-C nanofibers (NFs) exhibit excellent electro-catalytic activity for oxygen reduction reaction (ORR), which is essential for energy conversion system. Compared with the traditional ink-based electrode, we synthesized the structured Fe-N-C ANFs/CP (activated NFs derived from polypyrrole(PPy) doped with iron atoms in situ grown on carbon paper) by electrochemical polymerization. Herein, we investigate the effect of the iron concentration on the electro-catalytic activity for ORR, revealing that the as-prepared 0.05-Fe-N-C ANFs exhibit superior electro-catalytic activity than 0.01-Fe-N-C ANFs, 0.03-Fe-N-C ANFs as well as 0.10-Fe-N-C ANFs and excellent durability in alkaline solution. It is shown that the better electro-catalytic activity of 0.05-Fe-N-C ANFs for ORR could be ascribing to the fluffy fibrous structure, higher Fe-N x concentration, and well-dispersed catalytic active sites.

In this work, a novel time-resolved ratiometric fluorescent probe based on dual lanthanide (Tb: terbium, and Eu: europium)-doped complexes (Tb/DPA@SiO2-Eu/GMP) has been designed for detecting anthrax biomarker (dipicolinic acid, DPA), a unique and major component of anthrax spores. In such complexes-based probe, Tb/DPA@SiO2 can serve as a stable reference signal with green fluorescence and Eu/GMP act as a sensitive response signal with red fluorescence for ratiometric fluorescent sensing DPA. Additionally, the probe exhibits long fluorescence lifetime, which can significantly reduce the autofluorescence interferences from biological samples by using time-resolved fluorescence measurement. More significantly, a paper-based visual sensor for DPA has been devised by using filter paper embedded with Tb/DPA@SiO2-Eu/GMP, and we have proved its utility for fluorescent detection of DPA, in which only a handheld UV lamp is used. In the presence of DPA, the paper-based visual sensor, illuminated by a handheld UV lamp, would result in an obvious fluorescence color change from green to red, which can be easily observed with naked eyes. The paper-based visual sensor is stable, portable, disposable, cost-effective and easy-to-use. The feasibility of using a smartphone with easy-to-access color-scanning APP as the detection platform for quantitative scanometric assays has been also demonstrated by coupled with our proposed paper-based visual sensor. This work unveils an effective method for accurate, sensitive and selective monitoring anthrax biomarker with backgroud-free and self-calibrating properties.

Cellulose fiber (CF) paper is a low-cost, sustainable, and flexible substrate, which has gained increasing interest recently. Before practical usage, the functionalization of the pristine CF paper is indispensable to meet requirements of specific applications. Different from conventional surface modification or physical mixing methods, we report in situ growth of ultralong hydroxyapatite nanowires (HAPNWs) with lengths larger than 10 μm on the CF paper. HAPNWs are radially aligned on the surface of CFs, creating a micro/nanoscale hierarchical structure. By means of the excellent ion exchange ability of HAP and the hierarchical structure, the functions of the CF paper can be easily customized. As a proof-of-concept, we demonstrate two kinds of functional CF paper: (1) the photoluminescent CF paper by doping Eu3+ and Tb3+ ions into the crystal lattice of HAPNWs and (2) the superhydrophobic CF paper by coating poly(dimethylsiloxane) on the HAPNW hierarchical structure, which can be applied for self-cleaning and oil/water separation. It is expected that an in situ growth of ultralong HAPNWs will provide an instructive guideline for designing a CF paper with specific functions.

The effects of doping of ZnO and Nb2O5 solids with Fe2O3 (1.4 wt%) and Ag2O (1.4 wt%) on its surface and catalytic properties were investigated, as well as its photocatalytic performance on the degradation of a pulp and paper wastewater (PPW). The catalysts were characterized by XRD, SEM, photoacoustic spectroscopy (PAS), NH3-TPD and textural analysis. The results obtained revealed that Fe2O3 doping of Nb2O5 conducted at 500 °C resulted in an increase of about 116% for SBET while Ag2O treatment exerted a decrease of 33% for SBET of the doped adsorbents. Doping ZnO with Fe2O3 or Ag2O led to an increase of 80% for SBET. Iron and silver doping also led to a decrease in band gap energy of at least 6%. The addition of 1.4 wt% Ag2O on ZnO followed by calcination at 500 °C resulted in an increase of 11% in the value of the reaction rate constant (kap) for COD reduction under UV radiation. The treatment of Nb2O5 with 1.4 wt% Ag2O increased by a factor of 2.04 the value of kap for the reaction taking place under VIS radiation. The catalysts partially reduced the organic load and the real colour of the wastewater, allowing the achievement of the specifications for release into rivers, so photocatalysis could be an alternative for pulp and paper wastewater final polishing.

To evaluate the performance of Nanofibrillated cellulose (NFC) modified insulating paper under long term running process, 10 wt. % NFC modified insulating paper and ordinary insulating paper were subjected to accelerate thermal aging for 720 hours in a 130°C thermal aging chamber. The aging characteristics and electrical performance were measured during the aging process. Results show that NFC modification can delaying the thermal aging rate of oil immersed insulating paper and enhancing the electrical strength of oil immersed insulating paper during thermal aging process. NFC makes oil-impregnated insulating paper more compact during thermal aging process, resulting in higher polymerization degree and crystallinity. NFC modification can increase the relative permittivity and dielectric loss of the oil-impregnated paper during thermal aging process slightly. The AC and DC breakdown strength of the NFC modified paper are better maintained than the conventional oil-impregnated paper.

Smart materials that reversibly change color upon light illumination are widely explored for diverse appealing applications. However, light-responsive color switching materials are mainly limited to organic molecules. The synthesis of inorganic counterparts has remained a significant challenge because of their slow light response and poor reversibility. Here, we report a seeded growth strategy for the synthesis of TiO2−x/WO3·0.33H2O hetero-nanoparticles (HNPs) with networked wire-like structure of ∼ 10 nm in diameters that enable the highly reversible light-responsive color switching properties. For the TiO2−x/WO3·0.33H2O HNPs, Ti3+ species self-doped in TiO2−x nanoparticles (NPs) act as efficient sacrificial electron donors (SEDs) and Ti-O-W linkages formed between TiO2−x and WO3·0.33H2O NPs ensure the nanoscale interfacial contact, endowing the HNPs enhanced photoreductive activity and efficient interfacial charge transfer upon ultraviolet (UV) illumination to achieve highly efficient color switching. The TiO2−x/WO3·0.33H2O HNPs exhibits rapid light response ( 180 times). We further demonstrate the applications of TiO2−x/WO3·0.33H2O HNPs in ink-free, light-printable rewritable paper that can be written on freehand or printed on through a photomask using UV light. This work opens an avenue for designing inorganic light-responsive color switching nanomaterials and their smart applications.

Paper plays an important role in various aspects of human life. However, most of the paper materials are vulnerable to both flame and water, which seriously restrict their performance in many applications. Here, we report a new kind of flame-retardant paper with high-temperature-resistant hydrophobicity. This kind of paper was fabricated by vacuum filtration of electrospun fluorinated SiO2 fibers and methyl silicon resin. It is mechanically flexible. Its Young’s modulus is 94 MPa, similar to normal printing paper. The optimized paper demonstrated a water contact angle (WCA) of 151°, which can be maintained as high as 126° even after 30 min of annealing at the temperature of 600 °C. Finally, writing with inorganic ink can be performed on this paper with inhibited ink diffusion. The written paper can maintain its integrity after 5 min of firing by alcohol flame. The flame-retardant and hydrophobic paper here may extend the applications of paper in wide range of fields.

The use of polymer additives is effective for the fabrication of homogeneous single-walled carbon nanotube (SWCNT) films. However, the polymer chains located on the surface of SWCNT bundles act as barriers for electrical transport between SWCNTs and the chemical doping of SWCNTs. In this study, the combustion process of freestanding SWCNT/polymer films for the effective removal of the polymer additive and thermoelectric applications were investigated. By introducing the combustion process, high-performance p-type and n-type thermoelectric buckypapers were fabricated. The combusted and FeCl3-doped buckypapers with excellent electrical conductivity can be used as electrode materials in thermoelectric generators. Furthermore, a paper-based thermoelectric generator three-dimensional stacked for efficient energy harvesting using the vertical temperature difference was demonstrated. The thermoelectric generator with a thermal contact area of 1.2 cm2 exhibited a maximum output power of 2.48 μW with a vertical temperature difference of 30 K.

This paper reports simultaneous modification of graphene oxide (GO) papers by functionalization with MgCl2. The Mg(2+) ions enhance both the interlayer cross-links and lateral bridging between the edges of adjacent GO sheets by forming Mg-O bonds. The improved load transfer between the GO sheets gives rise to a maximum of 200 and 400% increases in Young's modulus and tensile strength of GO papers. The intercalation of chlorine between the GO layers alters the properties of GO papers in two ways by forming ionic Cl(-) and covalent C-Cl bonds. The p-doping effect arising from Cl contributes to large enhancements in electrical conductivities of GO papers, with a remarkable 2500-fold surge in the through-thickness direction. The layered structure and the anisotropic electrical conductivities of reduced GO papers naturally create numerous nanocapacitors that lead to charge accumulation based on the Maxwell-Wagner (MW) polarization. The combined effect of much promoted dipolar polarizations due to Mg-O, C-Cl, and Cl(-) species results in an exceptionally high dielectric constant greater than 60 000 and a dielectric loss of 3 at 1 kHz by doping with 2 mM MgCl2. The excellent mechanical and electrical properties along with unique dielectric performance shown by the modified GO and rGO papers open new avenues for niche applications, such as electromagnetic interference shielding materials.

The preparation and application of heteroatom doped carbons have attracted lots of attention in the past years. In the current work, a facile synthesis of nitrogen doped carbon with filter paper as the carbon source and urea as the nitrogen source was presented. Filter paper was first impregnated with urea solution, and was then carbonized and activated. The carbons’ physical and chemical properties were studied. For the application in CO2 adsorption, impacts from porous characteristics and nitrogen doping were discussed and differentiated. The results suggested that nitrogen doping was beneficial to the improvement of CO2 uptake, but suitable porous properties were the most important factors. Nitrogen doping showed more significant effects on enhancing the adsorption heat and selectivity. The research of carbonaceous CO2 adsorbent should focus on nitrogen doped carbons with high porosity.

A flexible free-standing nitrogen-doped graphene paper (N-GP) is fabricated via a facile hydrothermal approach with doping reaction occurring at the solid/gas interface of graphene oxide and ammonia vapor. Ammonia not only facilitates the doping of oxidized graphene paper efficiently with a nitrogen doping level of ca. 6.81%, but also promotes its reduction. The electrochemical properties of N-GP as an anode of lithium ion batteries (LIB) are evaluated and N-GP delivers almost doubled reversible discharge capacity compared to the undoped graphene paper (GP) as well as a good cyclic stability and rate performance. The proposed strategy to realize simultaneous reduction and nitrogen doping of graphene oxide via hydrothermal approach at the solid/gas interface offers a green and facile solution to modify graphene paper with desired electrochemical performances for LIB application.

Doping attitude is an individual’s subjective evaluation (e.g., good or bad, useful or useless) toward the use of prohibited performance-enhancing substances or methods in sports. Research on doping attitude has traditionally relied on self-report questionnaire methods to measure the construct (Ntoumanis et al., 2014; Chan et al., 2015). However, as doping in sport is illegal (World AntiDoping Agency, 2015) and perceived as socially unacceptable, athletes who hold positive attitudes toward doping are less likely to reveal them to others. As a result explicit measures of doping attitude are susceptible to potential bias as athletes may respond in a socially desirable fashion (Petróczi and Aidman, 2009; Gucciardi et al., 2010). To counter such bias, implicit measures such as the implicit association test (IAT; Greenwald et al., 1998) have been developed to capture individuals’ non-conscious attitudes toward doping (Brand et al., 2014a,b; Schindler et al., 2015). The current paper aims to introduce a paper-and-pen IAT which could potentially serve as alternative method to the traditional computer-IAT for measuring athletes’ doping attitude. peerReviewed

Cu-doped zinc oxide (Cu–ZnO) nanostructure was prepared using Whatman filter paper as a template by combustion method. For the synthesis of porous Cu–ZnO nanostructures the stoichiometric amount of precursors were impregnated in the filter papers and processed, thermally. The formation of wurtzite phase having crystallite size in the range of 20–24 nm was confirmed by X-ray diffraction (XRD) analysis. The morphological study by field emission scanning electron microscopy (FESEM) and field emission transmission electron microscopy (FETEM) shows size of nanoparticles in the range of 25–50 nm. The optical study shows red shift i.e. extended absorbance in the visible region due to Cu doping. The photoluminescence study of Cu–ZnO results quenching in the photoluminescence peak as effect of Cu doping in ZnO lattice. Considering the extended band gap in the visible region of as synthesized Cu–ZnO, the photocatalytic dye degradation activity of methylene blue (MB) was executed in presence of sunlight irradiation. The effect of salt concentration and PH on dye degradation activity also studied. The highest photocatalytic activity was observed for Cu–ZnO with 4% doping as compared with other Cu–ZnO and ZnO nanostructure. The photocatalytic performance of Cu–ZnO shows complete degradation of MB dye within 30 min for 4% Cu–ZnO nanostructure. The photocatalytic activity obtained is much higher as compare to earlier reports. The synthesis of Cu doped ZnO by paper templated method and its photocatalytic activity is hitherto unattempted.

As good alternatives for conventional rigid piezoelectric materials, piezoelectric nanocomposites combining piezoelectric materials and flexible polymer matrix demonstrate great potential for flexible nanogenerators. Rational design of the hybrid structure is important for performance optimization of piezoelectric nanocomposite. Here, we designed a hybrid piezoelectric paper through uniform assembly of vanadium doped ZnO (V-ZnO) mircoflowers in bacterial cellulose (BC) matrix by a in situ synthesis method. Different from pure ZnO where the c-axis of crystalline need to be oriented in order to get improved piezoelectric output, V-ZnO demonstrate ferroelectric property, which is prerequisite for poling with external high voltage in enhancing the output performance. The resultant hybrid paper demonstrated excellent flexibility and was used to fabricate flexible piezoelectric nanogenerators (PENGs). With excellent mechanical strength and durability, the V-ZnO/BC hybrid paper-based PENGs can work as self-powered motion sensors, which are capable of monitoring page-turning motions when integrated with pages of books. The V-ZnO/BC hybrid paper based PENGs are lightweight and inexpensive, which demonstrate promising applications for self-powered sensor networks and wearable electronics.

It is shown that the composition of the investigated alloy is nearly identical to the commercially available alloy MP35N (35Co-35Ni-20Cr-10Mo, wt%). However, the thermomechanical treatment of the experimental alloy is quite different from that used for the commercial one which consists of using cold work followed by annealing at temperatures below the recrystallization temperature. Here, depending on the amouunt of cold work, a tremendous hardening effect occurs, due to Suzuki hardening which allows to tune the mechanical properties in a range much larger than obtainable by the strategy used by the High Entropy Community by creating hierarchical microstructures.

The facile and sensitive strategies for detections of nitroaromatic explosives are highly desirable in many challenging environments, especially for homeland security against terrorism. Here, we inkjet printed polyethylenimine (PEI)-coated Ce, Tb co-doped NaGdF4 nanorods (NaGdF4:Ce/Tb NRs) onto common filter paper to construct test paper for visual and instant detections of a typical explosive 2,4,6-trinitrophenol (TNP). Polyethylenimine molecules not only facilitate the formation of uniform NaGdF4 nanorods but also provide specific recognized sites for TNP by the acid-base pairing interaction. The resultant TNP bound at the surface of PEI-coated NaGdF4:Ce/Tb NRs can strongly quench the phosphorescence with a remarkably high quenching constant by the charge transfer mechanism from NaGdF4:Ce/Tb NRs to TNP. By printing of the probe on a piece of filter paper, trace amounts of TNP can be visually detected by the appearance of a dark color against a bright green background under a UV lamp. This test paper can detect TNP as low as 0.45 ng mm(-2) by the naked eye, which provides a potential application in the rapid, on-line detections of explosives.