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More than 60% newborns experience hyperbilirubinemia and jaundice within the initial week after birth due to the accumulation of total bilirubin in blood. Left untreated high levels of bilirubin may result in brain impairment. Simple, fast, accurate, low-cost and timely point-of-care (POC) analysis of total bilirubin is an unmet need especially in resource-limited areas. This work introduces a novel sensing device, named a "tape-paper sensor", capable of separating plasma from whole blood and measuring total bilirubin by a colorimetric diazotization method. The tape-paper sensing method overcomes non-homogeneous color distribution caused by the "coffee stain" effect, which improves the accuracy of colorimetric evaluation on paper-based analytical devices. The level of hemolysis in the plasma extracted by the device is evaluated, confirming no interference in the detection of total bilirubin. The accuracy of the tape-paper sensing approach for neonatal blood sample measurement is verified by comparison with the hospital pathology laboratory method. The small volume of samples and reagents, minimal equipment (an office scanner), fast detection (<10 min) and low fabrication cost (~A$ 0.6) reveal the suitability of the device for POC use and in resource-limited settings. The tape-paper sensor is a low-cost, fast, and user-friendly device for measurement of blood total bilirubin levels in neonatal jaundice diagnostics.Copyright © 2020 The Royal Society of Chemistry.

More than 60% newborns experience hyperbilirubinemia and jaundice within the initial week after birth due to the accumulation of total bilirubin in blood. Left untreated high levels of bilirubin may result in brain impairment. Simple, fast, accurate, low-cost and timely point-of-care (POC) analysis of total bilirubin is an unmet need especially in resource-limited areas. This work introduces a novel sensing device, named a "tape-paper sensor", capable of separating plasma from whole blood and measuring total bilirubin by a colorimetric diazotization method. The tape-paper sensing method overcomes non-homogeneous color distribution caused by the "coffee stain" effect, which improves the accuracy of colorimetric evaluation on paper-based analytical devices. The level of hemolysis in the plasma extracted by the device is evaluated, confirming no interference in the detection of total bilirubin. The accuracy of the tape-paper sensing approach for neonatal blood sample measurement is verified by comparison with the hospital pathology laboratory method. The small volume of samples and reagents, minimal equipment (an office scanner), fast detection (<10 min) and low fabrication cost (~A$ 0.6) reveal the suitability of the device for POC use and in resource-limited settings. The tape-paper sensor is a low-cost, fast, and user-friendly device for measurement of blood total bilirubin levels in neonatal jaundice diagnostics.Copyright © 2020 The Royal Society of Chemistry.

Y. Huang, Y. Morishita, K. Uetani, M. Nogi and H. Koga. Cellulose paper support with dual-layered nano–microstructures for enhanced plasmonic photothermal heating and solar vapor generation. Nanoscale Adv., 2020, 2, 2339. https://doi.org/10.1039/D0NA00163E., Plasmonic nanoparticles, such as gold nanoparticles (AuNPs), have been actively applied in solar vapor generation for seawater desalination and water purification, owing to their photothermal heating performances. Such nanoparticles have been frequently anchored within porous supporting materials to ensure easy handling and water absorption. However, there has been limited progress in improving the transport efficiency of light to nanoparticles within porous supports to achieve more effective photothermal heating. Here, we show an enhanced light absorption of AuNPs by supporting on a cellulose paper with tailored porous structures for efficient photothermal heating. The paper consists of AuNP-anchored cellulose nanofibers and cellulose pulp as the top and bottom layers, respectively, which provides dual-layered porous nano-microstructures in the perpendicular direction. Then, the bottom layer with pulp-derived microstructures reflects the transmitted light back to AuNPs within the top layer, which improves their light absorptivity. Thus, under 1 sun illumination, the dual-layered paper demonstrates superior performance in photothermal heating (increases from 28 °C to 46 °C) and solar vapor generation (1.72 kg m-2 h-1) compared with the single-layered AuNP-anchored cellulose nanofiber paper even at the same AuNP content. Furthermore, the water evaporation rate per AuNP content of the dual-layered paper is more than 2 times higher than those of the state-of-the-art AuNP-anchored porous materials under the same light irradiation. This strategy enables the efficient use of precious plasmonic nanoparticles for further development of solar vapor generation.

In this study, we report for the first time few-layered MoS2 nanosheets grown onto graphene dipped cellulose filter paper (M-G-CFP) using a simple hydrothermal method towards efficient adsorption of cationic methylene blue (MB) dye. Detailed morphological and chemical characterization studies of M-G-CFP are performed using FESEM, TEM, XRD and Raman spectroscopy that reveal micro flower-like MoS2 grown onto graphene modified paper with few layers of MoS2 nanosheets and its high purity nature. Due to electrostatic interactions between cationic dye and the anionic adsorbent surface, the hybrid M-G-CFP exhibits ultrafast removal of MB within 2 min with a maximum adsorption capacity of 485.4 mg g-1 which is superior in comparison to other reported MoS2 based adsorbents. This high adsorption capacity is attributed to large accessible active sites on the surface of the hybrid M-G-CFP structure. The adsorption mechanism of MB dye on the MoS2 nanosheets are well described using kinetic and isotherm models with the effects of parameters like pH, contact time and temperature. The kinetic and isotherm study reveals that the adsorption of MB dye follows a pseudo-second order model, indicating the chemisorption and Langmuir model of monolayer adsorption, respectively. Furthermore, this hybrid structure can be efficiently reused for subsequent dye adsorption without compromising on its dye removal efficiency suggesting it is a feasible and promising material towards wastewater treatment applications.

In this study, we report for the first time few-layered MoS2 nanosheets grown onto graphene dipped cellulose filter paper (M-G-CFP) using a simple hydrothermal method towards efficient adsorption of cationic methylene blue (MB) dye. Detailed morphological and chemical characterization studies of M-G-CFP are performed using FESEM, TEM, XRD and Raman spectroscopy that reveal micro flower-like MoS2 grown onto graphene modified paper with few layers of MoS2 nanosheets and its high purity nature. Due to electrostatic interactions between cationic dye and the anionic adsorbent surface, the hybrid M-G-CFP exhibits ultrafast removal of MB within 2 min with a maximum adsorption capacity of 485.4 mg g-1 which is superior in comparison to other reported MoS2 based adsorbents. This high adsorption capacity is attributed to large accessible active sites on the surface of the hybrid M-G-CFP structure. The adsorption mechanism of MB dye on the MoS2 nanosheets are well described using kinetic and isotherm models with the effects of parameters like pH, contact time and temperature. The kinetic and isotherm study reveals that the adsorption of MB dye follows a pseudo-second order model, indicating the chemisorption and Langmuir model of monolayer adsorption, respectively. Furthermore, this hybrid structure can be efficiently reused for subsequent dye adsorption without compromising on its dye removal efficiency suggesting it is a feasible and promising material towards wastewater treatment applications.

In this study, we report for the first time few-layered MoS2 nanosheets grown onto graphene dipped cellulose filter paper (M-G-CFP) using a simple hydrothermal method towards efficient adsorption of cationic methylene blue (MB) dye. Detailed morphological and chemical characterization studies of M-G-CFP are performed using FESEM, TEM, XRD and Raman spectroscopy that reveal micro flower-like MoS2 grown onto graphene modified paper with few layers of MoS2 nanosheets and its high purity nature. Due to electrostatic interactions between cationic dye and the anionic adsorbent surface, the hybrid M-G-CFP exhibits ultrafast removal of MB within 2 min with a maximum adsorption capacity of 485.4 mg g-1 which is superior in comparison to other reported MoS2 based adsorbents. This high adsorption capacity is attributed to large accessible active sites on the surface of the hybrid M-G-CFP structure. The adsorption mechanism of MB dye on the MoS2 nanosheets are well described using kinetic and isotherm models with the effects of parameters like pH, contact time and temperature. The kinetic and isotherm study reveals that the adsorption of MB dye follows a pseudo-second order model, indicating the chemisorption and Langmuir model of monolayer adsorption, respectively. Furthermore, this hybrid structure can be efficiently reused for subsequent dye adsorption without compromising on its dye removal efficiency suggesting it is a feasible and promising material towards wastewater treatment applications.

In this study, we report for the first time few-layered MoS2 nanosheets grown onto graphene dipped cellulose filter paper (M-G-CFP) by a simple hydrothermal method towards efficient adsorption of cationic methylene blue (MB) dye. Detailed morphological and chemical characterization studies of M-G-CFP are performed using FESEM, TEM, XRD and Raman spectroscopy that reveal micro flower-like MoS2 grown onto graphene modified paper with few layers of MoS2 nanosheets and its high purity nature. Due to electrostatic interaction between cationic dye and anionic adsorbent surface, the hybrid M-G-CFP exhibits ultrafast removal of MB within 2 min with maximum adsorption capacity of 485.4 mg/g which is superior in comparison to other reported MoS2 based adsorbents. This high adsorption capacity is attributed to the large accessible active sites on the surface of hybrid M-G-CFP structure. The adsorption mechanism of MB dye on MoS2 nanosheets are well described using kinetic and isotherm models with the effects of parameters like pH, contact time and temperature. The kinetic and isotherm study reveals that the adsorption of MB dye follows pseudo-second order model, indicating the chemisorption and Langmuir model of monolayer adsorption, respectively. Furthermore, this hybrid structure can be efficiently reused for subsequent dye adsorption without compromising on its dye removal efficiency suggesting a feasible and promising material towards waste-water treatment applications.

In this study, we report for the first time few-layered MoS2 nanosheets grown onto graphene dipped cellulose filter paper (M-G-CFP) using a simple hydrothermal method towards efficient adsorption of cationic methylene blue (MB) dye. Detailed morphological and chemical characterization studies of M-G-CFP are performed using FESEM, TEM, XRD and Raman spectroscopy that reveal micro flower-like MoS2 grown onto graphene modified paper with few layers of MoS2 nanosheets and its high purity nature. Due to electrostatic interactions between cationic dye and the anionic adsorbent surface, the hybrid M-G-CFP exhibits ultrafast removal of MB within 2 min with a maximum adsorption capacity of 485.4 mg g-1 which is superior in comparison to other reported MoS2 based adsorbents. This high adsorption capacity is attributed to large accessible active sites on the surface of the hybrid M-G-CFP structure. The adsorption mechanism of MB dye on the MoS2 nanosheets are well described using kinetic and isotherm models with the effects of parameters like pH, contact time and temperature. The kinetic and isotherm study reveals that the adsorption of MB dye follows a pseudo-second order model, indicating the chemisorption and Langmuir model of monolayer adsorption, respectively. Furthermore, this hybrid structure can be efficiently reused for subsequent dye adsorption without compromising on its dye removal efficiency suggesting it is a feasible and promising material towards wastewater treatment applications.

H and 13C NMR spectra

H and 13C NMR spectra

Herein we present a novel sensor for the detection of monosaccharides (e.g. glucose, fructose) in solution, using electrical impedance spectroscopy. The sensor is based on carbon interdigitated electrodes, printed on paper using screen printing. The surface of the electrodes was modified with a thin layer of hydrogel containing acrylamide copolymerised with 20 mol% 3-(Acrylamido)phenylboronic acid (PBA). It was observed that the hydrogel layers containing 20 mol% PBA swell considerably in the presence of glucose and fructose. This in turn changes the measured impedance across the electrodes, making it a suitable sensor for the quantitative detection of saccharides. We investigated the impedance and capacitance variations with different concentrations of glucose and fructose (0–5 mM) in aqueous phosphate buffer solutions. Variations in impedance were attributed to changes in the dielectric properties of the hydrogel under an applied electric field, due to swelling of the hydrogel layer induced by uptake and binding of sugar molecules to the boronate species within the gel. Impedance measurements at 1 kHz demonstrated that hydrogel swelling leads to an increased mobility of ions within the swollen hydrogel layer. The impedance decreased with increasing sugar concentration and the relative capacitance curves are markedly different for fructose and glucose, as the hydrogel exhibits greater swelling in the presence of fructose than glucose over the same concentration range. As the proposed sensor was shown to be suitable for the detection of glucose at concentration levels found in human sweat, future work will focus on the incorporation of these modified paper-based electrodes into wearable skin patches for non-invasive sugar monitoring in sweat.

Herein we present a novel sensor for the detection of monosaccharides (e.g. glucose, fructose) in solution, using electrical impedance spectroscopy. The sensor is based on carbon interdigitated electrodes, printed on paper using screen printing. The surface of the electrodes was modified with a thin layer of hydrogel containing acrylamide copolymerised with 20 mol% 3-(Acrylamido)phenylboronic acid (PBA). It was observed that the hydrogel layers containing 20 mol% PBA swell considerably in the presence of glucose and fructose. This in turn changes the measured impedance across the electrodes, making it a suitable sensor for the quantitative detection of saccharides. We investigated the impedance and capacitance variations with different concentrations of glucose and fructose (0–5 mM) in aqueous phosphate buffer solutions. Variations in impedance were attributed to changes in the dielectric properties of the hydrogel under an applied electric field, due to swelling of the hydrogel layer induced by uptake and binding of sugar molecules to the boronate species within the gel. Impedance measurements at 1 kHz demonstrated that hydrogel swelling leads to an increased mobility of ions within the swollen hydrogel layer. The impedance decreased with increasing sugar concentration and the relative capacitance curves are markedly different for fructose and glucose, as the hydrogel exhibits greater swelling in the presence of fructose than glucose over the same concentration range. As the proposed sensor was shown to be suitable for the detection of glucose at concentration levels found in human sweat, future work will focus on the incorporation of these modified paper-based electrodes into wearable skin patches for non-invasive sugar monitoring in sweat.

The nematic structuring of cellulose nanofibers (CNFs) is proposed as a nanostructural engineering tool for exploiting the potential of CNFs in conceptually new "transparent papers". The nematic-structured CNF papers exhibit superior mechanical properties, optical transparency, gas-barrier properties, heat transfer properties and electrical resistivity, compared with conventional randomly-structured CNF papers., Non-duplicate with ISI: 000435537702500QC 20180227

Reproduced from Ref. Green Chem., 2016,18, pp. 1117-1124. with permission from the Royal Society of Chemistry., Recent progress in portable and wearable electronics has promoted a growing demand for high-performance and flexible energy-storage devices that are abundant and affordable. Because reduced graphene oxide (rGO), originating from inexpensive graphite, serves as a higher-performance energy-storage electrode than conventional activated carbons and carbon nanotubes, research and development of rGO/polymer composite electrodes for flexible supercapacitors have become a center of attraction. However, the fabrication of rGO-based flexible electrodes frequently requires a long time with high-temperature treatment or toxic chemical treatment, resulting in the lack of scalability and eco-friendliness. Here we show a fast, scalable, and environment-compatible route to fabricate a high-performance rGO/cellulose paper supercapacitor electrode. Single-layer graphene oxide (GO) sheets and recycled waste pulp fibers were successfully fabricated into a paper composite by a well-established scalable papermaking process, followed by a room-temperature, additive-free, and millisecond-timescale flash reduction process. The as-prepared rGO/paper electrode had a high specific capacitance, up to 212 F g-1, for an all paper-based flexible supercapacitor, comparable to those of state-of-the-art rGO-based electrodes, while dramatically decreasing the reduction time of GO from the conventional hour timescale to milliseconds. This work will pave the way for green, flexible, and mass-producible energy-storage paper in future wearable electronics.

© 2016 The Royal Society of Chemistry. This is the first comprehensive analysis of paper-based supercapacitors, P-SCs, that are produced utilising commercially available pencils to draw an interdigitated design upon common household printing paper, developing cheap, green and reliable low profile electrical conductors and electrodes. The P-SCs are optimised in terms of the composition of pencil used, the number of layers and the analysis of single or double sided interdigitated electrode designs; such a comprehensive study is seldom explored in previous literature. A full analysis of the physical and electrochemical properties of the pencil drawn electrodes has been performed, including the application of a new capacitive testing/evaluation circuit applied to charge/discharge measurements/analysis, which provides a revolutionary and unambiguous analysis of the capacitance of the fabricated electrodes; an easy to use experiment guide is presented. The P-SCs are benchmarked using 0.1 M H 2 SO 4 as the aqueous electrolyte. The P-SCs demonstrate a specific capacitance of ∼10.6 μF mg -1 at a charge current of 0.46 A g -1 . The P-SCs are integrated into a novel pouch design, providing a flexible, cheap and easily manufactured supercapacitor, which demonstrates a capacitance of ∼101.4 μF, exhibiting a specific capacitance of ∼42.4 μF g -1 at a current density of 0.46 A g -1 , exhibiting energy and power densities of ∼0.45 J mg -1 (0.125 mW h mg -1 ) and ∼0.03 W mg -1 respectively. The pouch cell, fabricated from P-SCs, utilises five parallel double-sided pencil drawn electrodes, with paper separators, and retains 82.2% of its maximum capacitance, after 5121 charge/discharge cycles at a current density of 0.09 A g -1 . Last, a solid state P-SC is developed utilising a PVA-H 2 SO 4 solid electrolyte, which demonstrates a specific capacitance of 141.8 μF g -1 , at a charging current of 4.33 μA g -1 .

There has been a huge demand for low-cost, eco-friendly, flexible and wearable electronics which find applications in personal health monitoring. Flexible electronics based on plastic substrates have been extensively studied in this regard because of their versatility. However, their fabrication involves energy consuming complex procedures and processing of eco-unfriendly materials which limit their use to certain specific applications. Here we report the fabrication of a flexible all-carbon field effect transistor (FET) using a economically efficient, recyclable and biodegradable cellulose paper as both substrate as well as dielectric and pencil graphite as source, drain, channel and gate without using any expensive, toxic or non-biodegradable materials. The FET transfer characteristics shows ambipolar behavior which can be utilized in analog electronics applications like rectifier, mixer and frequency multipliers and its mobility was found to be very high compared to reduced graphene oxide based FETs. The FET was utilized as a strain sensor which shows excellent sensitivity for very low strains (of both tensile and compressive type) which is comparable to and even better than recently reported carbon nanotube and graphene based strain sensors. The sensitivity of the FET based strain sensor can be modulated by varying the gate voltage under strain. Furthermore, we investigated the performance of the sensor by integrating it with hand gloves to detect human motion. The results indicate that the sensor can be utilized in patients surveillance in healthcare and human-machine interface (HMI) applications. The successful fabrication of this paper based all-carbon transistor using only paper and pencil graphite and its application in human motion detection using strain sensing indicates that this approach can be used for developing highly scalable, low cost, low energy, flexible green electronics for healthcare without using any sophisticated fabrication methods or toxic

There has been a huge demand for low-cost, eco-friendly, flexible and wearable electronics which find applications in personal health monitoring. Flexible electronics based on plastic substrates have been extensively studied in this regard because of their versatility. However, their fabrication involves energy consuming complex procedures and processing of eco-unfriendly materials which limit their use to certain specific applications. Here we report the fabrication of a flexible all-carbon field effect transistor (FET) using a economically efficient, recyclable and biodegradable cellulose paper as both substrate as well as dielectric and pencil graphite as source, drain, channel and gate without using any expensive, toxic or non-biodegradable materials. The FET transfer characteristics shows ambipolar behavior which can be utilized in analog electronics applications like rectifier, mixer and frequency multipliers and its mobility was found to be very high compared to reduced graphene oxide based FETs. The FET was utilized as a strain sensor which shows excellent sensitivity for very low strains (of both tensile and compressive type) which is comparable to and even better than recently reported carbon nanotube and graphene based strain sensors. The sensitivity of the FET based strain sensor can be modulated by varying the gate voltage under strain. Furthermore, we investigated the performance of the sensor by integrating it with hand gloves to detect human motion. The results indicate that the sensor can be utilized in patients surveillance in healthcare and human-machine interface (HMI) applications. The successful fabrication of this paper based all-carbon transistor using only paper and pencil graphite and its application in human motion detection using strain sensing indicates that this approach can be used for developing highly scalable, low cost, low energy, flexible green electronics for healthcare without using any sophisticated fabrication methods or toxic

There has been a huge demand for low-cost, eco-friendly, flexible and wearable electronics which find applications in personal health monitoring. Flexible electronics based on plastic substrates have been extensively studied in this regard because of their versatility. However, their fabrication involves energy consuming complex procedures and processing of eco-unfriendly materials which limit their use to certain specific applications. Here we report the fabrication of a flexible all-carbon field effect transistor (FET) using a economically efficient, recyclable and biodegradable cellulose paper as both substrate as well as dielectric and pencil graphite as source, drain, channel and gate without using any expensive, toxic or non-biodegradable materials. The FET transfer characteristics shows ambipolar behavior which can be utilized in analog electronics applications like rectifier, mixer and frequency multipliers and its mobility was found to be very high compared to reduced graphene oxide based FETs. The FET was utilized as a strain sensor which shows excellent sensitivity for very low strains (of both tensile and compressive type) which is comparable to and even better than recently reported carbon nanotube and graphene based strain sensors. The sensitivity of the FET based strain sensor can be modulated by varying the gate voltage under strain. Furthermore, we investigated the performance of the sensor by integrating it with hand gloves to detect human motion. The results indicate that the sensor can be utilized in patients surveillance in healthcare and human-machine interface (HMI) applications. The successful fabrication of this paper based all-carbon transistor using only paper and pencil graphite and its application in human motion detection using strain sensing indicates that this approach can be used for developing highly scalable, low cost, low energy, flexible green electronics for healthcare without using any sophisticated fabrication methods or toxic

In light of recent interest in the green fabrication of electronics, we report eco-friendly engineered temperature sensors, pH sensors, humidity sensors and passive resistor-capacitor (RC) filters by solventfree processing of graphite on cellulose paper. This was achieved via direct writing of graphite pencil on cellulose paper which involves the deposition of few layers to multi layers of conductive graphene flakes intercalated by clay and wax. The temperature sensor exhibits a negative temperature coefficient of resistance of -4232 ppm K-1, which is comparable to that of conventional temperature sensors (platinum, nickel, and copper) that are fabricated by capital intensive and complex procedures. The dynamic response of the temperature sensor shows its repeatability with excellent response time of 13.5 s. The all-carbon pH sensor could efficiently distinguish acidic, alkaline and neutral solutions with significant sensitivity from 1.77 k Omega pH(-1) to 2.21 k Omega pH(-1). The higher sensitivity of the pH sensor is attributed to the oxygen functional groups present in pencil graphite which undergoes protonation and deprotonation in presence of H+ and OH- ions to alter the conductivity of graphite trace. The interdigitated capacitive humidity sensor shows a linear response to humidity with fast response (1.5-2 s) and recovery times (6-7 s). These fast response and recovery times are due to fast adsorption and evaporation kinetics of water molecules on polar OH groups of cellulose fibers in paper, which depends on porosity of the paper. The versatility of the pencil-on-paper approach was further explored by drawing resistor and interdigitated capacitor in series to fabricate in-plane all-carbon RC filter which demonstrate anticipated functionality with a cut-off frequency of 6 kHz. To the best of our knowledge, no studies have been reported on direct-write graphite on paper based in-plane all carbon passive electronic circuits, pH sensor and humidity sensor. This

There has been a huge demand for low-cost, eco-friendly, flexible and wearable electronics which find applications in personal health monitoring. Flexible electronics based on plastic substrates have been extensively studied in this regard because of their versatility. However, their fabrication involves energy consuming complex procedures and processing of eco-unfriendly materials which limit their use to certain specific applications. Here we report the fabrication of a flexible all-carbon field effect transistor (FET) using a economically efficient, recyclable and biodegradable cellulose paper as both substrate as well as dielectric and pencil graphite as source, drain, channel and gate without using any expensive, toxic or non-biodegradable materials. The FET transfer characteristics shows ambipolar behavior which can be utilized in analog electronics applications like rectifier, mixer and frequency multipliers and its mobility was found to be very high compared to reduced graphene oxide based FETs. The FET was utilized as a strain sensor which shows excellent sensitivity for very low strains (of both tensile and compressive type) which is comparable to and even better than recently reported carbon nanotube and graphene based strain sensors. The sensitivity of the FET based strain sensor can be modulated by varying the gate voltage under strain. Furthermore, we investigated the performance of the sensor by integrating it with hand gloves to detect human motion. The results indicate that the sensor can be utilized in patients surveillance in healthcare and human-machine interface (HMI) applications. The successful fabrication of this paper based all-carbon transistor using only paper and pencil graphite and its application in human motion detection using strain sensing indicates that this approach can be used for developing highly scalable, low cost, low energy, flexible green electronics for healthcare without using any sophisticated fabrication methods or toxic

In light of recent interest in the green fabrication of electronics, we report eco-friendly engineered temperature sensors, pH sensors, humidity sensors and passive resistor-capacitor (RC) filters by solventfree processing of graphite on cellulose paper. This was achieved via direct writing of graphite pencil on cellulose paper which involves the deposition of few layers to multi layers of conductive graphene flakes intercalated by clay and wax. The temperature sensor exhibits a negative temperature coefficient of resistance of -4232 ppm K-1, which is comparable to that of conventional temperature sensors (platinum, nickel, and copper) that are fabricated by capital intensive and complex procedures. The dynamic response of the temperature sensor shows its repeatability with excellent response time of 13.5 s. The all-carbon pH sensor could efficiently distinguish acidic, alkaline and neutral solutions with significant sensitivity from 1.77 k Omega pH(-1) to 2.21 k Omega pH(-1). The higher sensitivity of the pH sensor is attributed to the oxygen functional groups present in pencil graphite which undergoes protonation and deprotonation in presence of H+ and OH- ions to alter the conductivity of graphite trace. The interdigitated capacitive humidity sensor shows a linear response to humidity with fast response (1.5-2 s) and recovery times (6-7 s). These fast response and recovery times are due to fast adsorption and evaporation kinetics of water molecules on polar OH groups of cellulose fibers in paper, which depends on porosity of the paper. The versatility of the pencil-on-paper approach was further explored by drawing resistor and interdigitated capacitor in series to fabricate in-plane all-carbon RC filter which demonstrate anticipated functionality with a cut-off frequency of 6 kHz. To the best of our knowledge, no studies have been reported on direct-write graphite on paper based in-plane all carbon passive electronic circuits, pH sensor and humidity sensor. This

Inkjet printing of functional frequency selective surfaces (FSS) and radio frequency identification (RFID) tags on commercial paper substrates using silver nanoparticle inks sintered using low temperature thermal, plasma and photonic techniques is reported. Printed and sintered FSS devices demonstrate performances which achieve wireless communication requirements having a forward transmission scattering parameter, S21, depth greater than −20 dB at 13 GHz. Printed and plasma sintered RFID tags on transfer paper, which are capable of being mounted on skin, improved read distances compared to previously reported single layer transfer RFID tags fabricated by conventional thermal sintering

The development of a competitive immunoassay system for colorimetric detection on microfluidic paper-based analytical devices (mu PADs) is reported. The mu PADs were fabricated via photolithography to define hydrophilic flow channels and consisted of three main elements: the control and test zones, where target detection was performed, the sample introduction zone, and the competitive capture zone located between the sample introduction zone and the test zone. The chromogenic substrate 3,3', 5,5'-tetra-methylbenzidine (TMB) was deposited at the control and test zones. mu PAD surface modification was performed at the capture zone first via chitosan activation, then the BSA-conjugated target compound was immobilized. The sample solution consisting of the target compound, the peroxidase-conjugated antibody, and the hydrogen peroxide oxidizing agent was introduced into the device and competition occurred at the capture zone, allowing only the target-bound peroxidase-conjugated antibody to travel past the capture zone and into the test zone via capillary action. The developed competitive immunoassay system was successfully demonstrated on the mu PAD detection of biotin as a model compound with a detection limit of 0.10 mu g mL(-1). The applicability of the proposed immunoassay system for point-of-need testing was further demonstrated using aflatoxin B-1, a highly toxic foodborne substance, with a detection limit of 1.31 ng mL(-1). The mu PAD with the competitive immunoassay format showed promising results for practical applications in point-of-need testing involving small molecular weight targets in food and water safety and quality monitoring, environmental analysis, and clinical diagnostics.

The combination of a microfluidic paper-based analytical device (mu PAD) and digital image analysis is widely used for quantitative analysis with mu PADs because of its easy and simple operation. Herein, we have demonstrated a quantitative analysis based on multiple color changes on a mu PAD. The CIE L*a*b* color system was employed to analyse the digital images obtained with the mu PAD. We made pH measurements using a universal pH-indicator showing multiple color changes for various pH values of aqueous test solutions. The detectable pH range of this method was wider than the typical grayscale-based image analysis, and we succeeded in the measurements for a wide pH range of 2-9.

The development of a competitive immunoassay system for colorimetric detection on microfluidic paper-based analytical devices (mu PADs) is reported. The mu PADs were fabricated via photolithography to define hydrophilic flow channels and consisted of three main elements: the control and test zones, where target detection was performed, the sample introduction zone, and the competitive capture zone located between the sample introduction zone and the test zone. The chromogenic substrate 3,3', 5,5'-tetra-methylbenzidine (TMB) was deposited at the control and test zones. mu PAD surface modification was performed at the capture zone first via chitosan activation, then the BSA-conjugated target compound was immobilized. The sample solution consisting of the target compound, the peroxidase-conjugated antibody, and the hydrogen peroxide oxidizing agent was introduced into the device and competition occurred at the capture zone, allowing only the target-bound peroxidase-conjugated antibody to travel past the capture zone and into the test zone via capillary action. The developed competitive immunoassay system was successfully demonstrated on the mu PAD detection of biotin as a model compound with a detection limit of 0.10 mu g mL(-1). The applicability of the proposed immunoassay system for point-of-need testing was further demonstrated using aflatoxin B-1, a highly toxic foodborne substance, with a detection limit of 1.31 ng mL(-1). The mu PAD with the competitive immunoassay format showed promising results for practical applications in point-of-need testing involving small molecular weight targets in food and water safety and quality monitoring, environmental analysis, and clinical diagnostics.

The combination of a microfluidic paper-based analytical device (mu PAD) and digital image analysis is widely used for quantitative analysis with mu PADs because of its easy and simple operation. Herein, we have demonstrated a quantitative analysis based on multiple color changes on a mu PAD. The CIE L*a*b* color system was employed to analyse the digital images obtained with the mu PAD. We made pH measurements using a universal pH-indicator showing multiple color changes for various pH values of aqueous test solutions. The detectable pH range of this method was wider than the typical grayscale-based image analysis, and we succeeded in the measurements for a wide pH range of 2-9.

Colorimetric detection methods that produce results readable by eye are important for diagnostic tests in resource-limited settings. In this work, we have compared three main types of colorimetric methods – enzymatic reactions, silver deposition catalyzed by gold nanoparticles, and polymerization-based amplification – in a paper-based immunoassay for detection of Plasmodium falciparum histidine-rich protein 2, a biomarker of malarial infection. We kept the binding events in the immunoassay constant in order to isolate the effect of the detection method on the outcome of the test. We have highlighted that the optimal readout time in a test can vary significantly – ranging from immediately after addition of a visualization agent to 25 minutes after addition of a visualization agent – depending on the colorimetric method being used, and accurate time keeping is essential to prevent false positives in methods where substantial color develops over time in negative tests. We have also shown that the choice of a colorimetric method impacts the calculated limit-of-detection, the ease of visual perception of the readout, and the total cost of the assay, and therefore directly impacts the feasibility and the ease-of-use of a test in field settings., Massachusetts Institute of Technology (Jonathan Whitney Fund), Massachusetts Institute of Technology (Haas Family Fellowship in Chemical Engineering), Massachusetts Institute of Technology (Charles E. Reed Faculty Initiative Fund)

This paper describes a simple and instrument-free screen-printing method to fabricate hydrophilic channels by patterning polydimethylsiloxane (PDMS) onto chromatography paper. Clearly recognizable border lines were formed between hydrophilic and hydrophobic areas. The minimum width of the printed channel to deliver an aqueous sample was 600 mu m, as obtained by this method. Fabricated microfluidic paper-based analytical devices (mu PADs) were tested for several colorimetric assays of pH, glucose, and protein in both buffer and artificial urine samples and results were obtained in less than 30 min. The limits of detection (LODs) for glucose and bovine serum albumin (BSA) were 5 mM and 8 mu M, respectively. Furthermore, the pH values of different solutions were visually recognised with the naked eye by using a sensitive ink. Ultimately, it is expected that this PDMS-screen-printing (PSP) methodology for mu PADs can be readily translated to other colorimetric detection and hydrophilic channels surrounded by a hydrophobic polymer can be formed to transport fluids toward target zones.

This paper describes a simple and instrument-free screen-printing method to fabricate hydrophilic channels by patterning polydimethylsiloxane (PDMS) onto chromatography paper. Clearly recognizable border lines were formed between hydrophilic and hydrophobic areas. The minimum width of the printed channel to deliver an aqueous sample was 600 mu m, as obtained by this method. Fabricated microfluidic paper-based analytical devices (mu PADs) were tested for several colorimetric assays of pH, glucose, and protein in both buffer and artificial urine samples and results were obtained in less than 30 min. The limits of detection (LODs) for glucose and bovine serum albumin (BSA) were 5 mM and 8 mu M, respectively. Furthermore, the pH values of different solutions were visually recognised with the naked eye by using a sensitive ink. Ultimately, it is expected that this PDMS-screen-printing (PSP) methodology for mu PADs can be readily translated to other colorimetric detection and hydrophilic channels surrounded by a hydrophobic polymer can be formed to transport fluids toward target zones.

Rotational microfluidic platforms have attracted swiftly growing interest over the last decade due to their suitability for integration and automation of sample preparation and detection. Valving is of pivotal importance on these compact “Lab-on-a-Disc” (LoaD) platforms as all liquids are exposed to the same centrifugal field. A number of valving technologies have been developed to coordinate timing of serial and / or parallel multi-step / multi-liquid assay protocols comprising of laboratory unit opera-tions (LUOs) such as the release, metering and mixing of sample and reagents. So far these valving techniques could be broadly categorised into rotationally controlled or externally actuated schemes. Only recently a new, “event-triggered” flow control has been introduced. In this approach, a valve is opened upon arrival of a liquid at a defined destination on the disc; this innovative mechanism for the first time permits the cascading of LUOs independent of the spin rate. In one technology, dissolvable films (DFs) are configured with a pneumatic chamber to offer function akin to an electrical relay. Dissolving one DF, termed the control film (CF), results in the release of liquid at a distal location through a so-called load film (LF). In this paper, a new method for temporal control of actuating DF-based, event-triggered CFs which are serially aligned at defined distances along a paper strip is introduced. Liquids are transported through the paper strip at a given velocity, thus setting well-defined intervals between subsequent LUOs, e.g. incubation steps. As a proof-of-concept, we present a disc with inte-grated metering and mixing which can perform a prototypical, 4-fold serial dilution; a common function in bioanalytical protocols. Imbibition of the paper strip sequentially opens five valves for serial dilution and mixing. To illustrate an unprecedented level of on-disc automation, this is followed by a branched cascade of 17 event-triggered valves (for a total o

Diagnostic tests in resource-limited settings require technologies that are affordable and easy to use with minimal infrastructure. Colorimetric detection methods that produce results that are readable by eye, without reliance on specialized and expensive equipment, have great utility in these settings. We report a colorimetric method that integrates a paper-based immunoassay with a rapid, visible-light-induced polymerization to provide high visual contrast between a positive and a negative result. Using Plasmodium falciparum histidine-rich protein 2 as an example, we demonstrate that this method allows visual detection of proteins in complex matrices such as human serum and provides quantitative information regarding analyte levels when combined with cellphone-based imaging. It also allows the user to decouple the capture of analyte from signal amplification and visualization steps., Bill & Melinda Gates Foundation (Award 51308), United States. Defense Advanced Research Projects Agency (HR0011-12-2-0010), National Science Foundation (U.S.). Graduate Research Fellowship, Burroughs Wellcome Fund (Career Award at the Scientific Interface)

Porous MgO-CaO-SnOx nanocubes (crystalline SnOx and amorphous MgO/CaO) were synthesized to implant firmly and uniformly onto in situ formed carbon paper by a facile route including a template-free growth process and calcining treatment. Low-cost filter paper was used to realize the part implantation of cubes as well as a source of carbon paper. The mechanistic analysis demonstrates that Mg2+/Ca2+ ions and ammonium hydroxide played important roles in the formation of the cubic phase precursor. This MgO-CaO-SnOx-nanocubes/carbon paper could be directly applied as a binder-free film electrode for lithium-ion batteries eliminating conventional electrode fabrication processes, and an average capacity contribution of ~719 mA h g-1 for MgO-CaO-SnOx nanocubes through 40 cycles was achieved. The facile synthesis strategy combines the material synthesis, dispersion and electrode fabrication, which further opens a new avenue for the application of nano-architectures in energy storage. © 2014 the Partner Organisations.

Successful research efforts, in either academe or industry, require an awareness of the state of the art. This is necessary in order to identify previous research, to develop an understanding of the research problem, and to avoid unnecessary duplication of work. In addition, maintaining an on-going awareness of current literature in your area of chemistry, is crucial to career advancement. This is true for graduate students, whose theses must be based on unique research results, as well as for senior researchers who are able to secure grant funding and pursue exclusive technology rights only for original work.

In this paper, we provide experimental evidence to indicate that the polyanionic Mo132O372 cage with a hydrophobic inner nanospace has a unique capability to participate in anion-pi interactions by showing a preference for electron-deficient mono-substituted benzenes over non-electron-deficient guests in inclusion.

type:Paper, Extracts of Eurycoma longifolia Jack (EL) and Eurycoma harmandiana Pierre (EH) contain numerous bioactive compounds and varying matrices that are challenging to separate using chromatographic techniques. Herein, micellar liquid chromatography (MLC) was used to analyze canthin-6-one alkaloids contained in these extracts, and the achieved performance was compared with that of a conventional high-performance liquid chromatography (HPLC) method. The optimal mobile phase of MLC corresponded to 15 : 85 (v/v) acetonitrile : water (pH 3) containing 110 mM sodium dodecyl sulfate and 10 mM NaH_2PO_4. The retention times of canthin-6-one-9-O-b-D-glucopyranoside, 9-hydroxycanthin- 6-one, canthin-6-one, and 9-methoxycanthin-6-one were 4.78/15.42, 17.64/24.11, 32.84/38.27, and 39.04/39.86 min, respectively, in the cases of isocratic MLC and conventional HPLC. In both cases, the analyte resolution exceeded 1.5. The MLC elution behavior of the examined analytes was largely determined by their hydrophobicity and ionization. The sensitivity, precision, accuracy, and per-run acetonitrile consumption of the MLC method were comparable to those of the conventional HPLC method. However, the latter method exhibited higher performance for application to EL and EH samples, particularly those with low analyte concentrations and varying sample matrices. Overall, the analysis of canthin-6-one alkaloids using MLC was limited to trace analytes due to interference by the matrix.

type:Paper, The ionization and fragmentation processes for pentachlorobenzene were examined using a femtosecond laser emitting at 400, 800, and 1200 nm. A molecular ion was clearly observed in the mass spectrum, since the molecule can be directly ionized from the singlet electronic exited state before relaxation to triplet levels, because the pulse width of the laser is shorter than the lifetime of the excited state. Fragmentation was minimal at 1200 nm, in contrast to ionization at 800 and 400 nm. Indeed, a doubly-charged molecular ion was prominent at 800 nm, owing to the absorption band of the singly-charged molecular ion at this wavelength. Fragmentation was further enhanced at 400 nm, which can be explained by the dissociation of the doubly-charged molecular ion having a larger absorption band at 400 nm. Fragmentation was strongly affected by the absorption character of the ionic species, i.e., singly- and doubly-charged molecular ions, appeared in the process of multiphoton ionization.

MXenes are emerging sensing materials due to their metallic conductivity and rich surface chemistry for analytes; they, however, suffer from poor stability. Incorporation with functional polymers can largely prevent the performance decay and enhance the sensing performance. Herein, we demonstrate a core–shell composite, Ti₃C₂Tₓ@croconaine (poly(1,5-diaminonaphthalene-croconaine), PDAC) prepared by a facile in situ polymerization reaction, suitable for NH₃ detection. Compared to pristine Ti₃C₂Tₓ, the sensor made of a Ti₃C₂Tₓ–polycroconaine composite exhibits a significantly enhanced sensitivity of 2.8% ppm⁻¹ and an estimated achievable limit of detection of 50 ppb. The improved sensing performance could be attributed to the presence of PDAC facilitating the adsorption of NH₃ and changing the tunneling conductivity between Ti₃C₂Tₓ domains. Density functional theory (DFT) calculations reveal that the adsorption energy of NH₃ on PDAC is the highest among the tested gases, which supports the selectivity of the sensor to this analyte. Benefiting from the protection conferred by the PDAC shell, the composite has a reliable operation period of at least 40 days. In addition, we demonstrated a flexible paper-based sensor of the Ti₃C₂Tₓ@PDAC composite, without attenuated performance upon mechanical deformation. This work proposed a novel mechanism and a feasible methodology to synthesize MXene–polymer composites with improved sensitivity and stability for chemical sensing.

In this paper, we provide experimental evidence to indicate that the polyanionic Mo132O372 cage with a hydrophobic inner nanospace has a unique capability to participate in anion-pi interactions by showing a preference for electron-deficient mono-substituted benzenes over non-electron-deficient guests in inclusion.

Conductive polymers represent the next generation of soft, flexible electronics. Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is among the most widely used of these, despite having a relatively low conductivity when deposited in the standard form with no additional chemical dopants. This is often mitigated through chemical doping, but this is associated with changes in processing easy, mechanical stability, or compatibility. This paper reports a laser micro-annealing process for PEDOT:PSS, including process optimisation, investigation of the underlying mechanism, and application in organic electronics. The laser micro-annealing increases the material conductivity from 1 S cm(-1) to around 360 S cm(-1) without any additive or post-deposition chemical treatments. This process is used, along with a laser ablation step, to fabricate organic electrochemical transistors (OECTs). These show comparable performance to material fabricated with common additives, while allowing rapid production of myriad devices. The additive and photolithography free processes enables simple fabrication of devices without the processing complications introduced by the use of additional chemicals. Following process optimisation, detailed study of the material properties suggests the dominant mechanism for this conductivity enhancement is the agglomeration of PEDOT cores within the film, facilitated by the moderate local heating action of the laser., Vodivé polymery představují novou generaci měkké, flexibilní elektroniky. Poly(3,4-ethylendioxythiofen):poly(styrensulfonát) (PEDOT:PSS) patří mezi nejpoužívanější z nich, přestože má relativně nízkou vodivost, když je nanesen ve standardní formě bez dalších chemických příměsí. To je často zmírňováno chemickým dopingem, ale to je spojeno se změnami ve snadnosti zpracování, mechanické stabilitě nebo kompatibilitě. Tento článek popisuje proces laserového mikro-žíhání pro PEDOT:PSS, včetně optimalizace procesu, zkoumání základního mechanismu a aplikace v organické elektronice. Laserové mikro-žíhání zvyšuje vodivost materiálu z 1 S cm(-1) na přibližně 360 S cm(-1) bez jakýchkoli aditivních nebo post-depozičních chemických úprav. Tento proces se používá spolu s krokem laserové ablace k výrobě organických elektrochemických tranzistorů (OECT). Ty vykazují výkon srovnatelný s materiálem vyrobeným s běžnými přísadami a zároveň umožňují rychlou výrobu řady zařízení. Procesy bez aditiv a fotolitografie umožňují jednoduchou výrobu zařízení bez komplikací při zpracování, které přináší použití dalších chemikálií. Po provedené optimalizaci procesu, podrobné studium vlastností materiálu naznačuje, že dominantním mechanismem pro toto zvýšení vodivosti je aglomerace PEDOT jader ve filmu, umožněné mírným lokálním ohřevem s pomocí laseru.

type:Paper, Extracts of Eurycoma longifolia Jack (EL) and Eurycoma harmandiana Pierre (EH) contain numerous bioactive compounds and varying matrices that are challenging to separate using chromatographic techniques. Herein, micellar liquid chromatography (MLC) was used to analyze canthin-6-one alkaloids contained in these extracts, and the achieved performance was compared with that of a conventional high-performance liquid chromatography (HPLC) method. The optimal mobile phase of MLC corresponded to 15 : 85 (v/v) acetonitrile : water (pH 3) containing 110 mM sodium dodecyl sulfate and 10 mM NaH_2PO_4. The retention times of canthin-6-one-9-O-b-D-glucopyranoside, 9-hydroxycanthin- 6-one, canthin-6-one, and 9-methoxycanthin-6-one were 4.78/15.42, 17.64/24.11, 32.84/38.27, and 39.04/39.86 min, respectively, in the cases of isocratic MLC and conventional HPLC. In both cases, the analyte resolution exceeded 1.5. The MLC elution behavior of the examined analytes was largely determined by their hydrophobicity and ionization. The sensitivity, precision, accuracy, and per-run acetonitrile consumption of the MLC method were comparable to those of the conventional HPLC method. However, the latter method exhibited higher performance for application to EL and EH samples, particularly those with low analyte concentrations and varying sample matrices. Overall, the analysis of canthin-6-one alkaloids using MLC was limited to trace analytes due to interference by the matrix.

In this paper, we provide experimental evidence to indicate that the polyanionic Mo132O372 cage with a hydrophobic inner nanospace has a unique capability to participate in anion-pi interactions by showing a preference for electron-deficient mono-substituted benzenes over non-electron-deficient guests in inclusion.

Molecular doping can increase the conductivity of organic semiconductors and plays an increasingly important role in emerging and established plastic electronics applications. 4-(1,3-Dimethyl-2,3-dihydro-1H-benzimidazol-2-yl)-N,N-dimethylaniline (N-DMBI-H) and tris(pentafluorophenyl)borane (BCF) are established n- and p-dopants, respectively, but neither functions as a simple one-electron redox agent. Molecular hydrogen has been suggested to be a byproduct in several proposed mechanisms for doping using both N-DMBI-H and BCF. In this paper we show for the first time the direct detection of molecular hydrogen in the uncatalysed doping of a variety of polymeric and molecular semiconductors using these dopants. Our results provide insight into the doping mechanism, providing information complementary to that obtained from more commonly applied methods such as optical, electron spin resonance, and electrical measurements.

Angle resolved XRF (AR-XRF) is an analytical technique in which the sample is analyzed at different angles of detection or irradiation. The change in the geometry affects the intensity of the elemental characteristic emission from the sample, which depends on the in-depth distribution of analyte. In this paper, for the first time, we apply AR-XRF to gilding samples that mime real cultural heritage ones. The samples analysed, also investigated with scanning electron microscopy, present small lateral inhomogeneities and a rough surface. Moreover, we illustrate how to analyze AR-XRF data, from the collection of XRF spectra to the creation of AR-XRF profiles and the fitting of data using Sherman's equation. Using AR-XRF combined with the fundamental parameters method we calculate the massive thickness of laboratory made layered samples.

In this paper, we provide experimental evidence to indicate that the polyanionic Mo132O372 cage with a hydrophobic inner nanospace has a unique capability to participate in anion-pi interactions by showing a preference for electron-deficient mono-substituted benzenes over non-electron-deficient guests in inclusion.

Co-precipitation of Ni0.8Co0.1Mn0.1(OH)₂ (NCM811) and Mg-doped (0.25 wt% and 0.5 wt%) NCM811 precursors is carried out from concentrated metal sulphate solutions. In this paper, the aim is to study the role of magnesium dopant in the co-precipitation step of NCM811, the cathode active material and further the Li-ion battery cell performance. Based on the results, magnesium was fully co-precipitated in the NCM811 precursors, as expected from thermodynamic calculations. The presence of magnesium in these precursors was also confirmed by several characterization methods and magnesium was evenly distributed in the sample. It was observed that tapped density decreased and surface area increased with an expected increase in Mg content. Surprisingly, Mg doping did not improve the cyclability of coin cells, due to the stable crystal structure of NCM811. However, a slight improvement in cyclability was seen in pouch cells after 1000 cycles. A washing effect was clearly seen in lattice parameters and washing also decreased the capacity retention after 62 cycles for all samples.

This paper introduces a new mathematical model that is used to compute either the interfacial tension of quiescent axisymmetric pendant/sessile drops and pendant/captive bubbles. This model consists of the Young–Laplace equation, that describes interface shape, together with suitable boundary conditions that guarantee a prescribed volume of drops/bubbles and a fixed position in the capillary. In order to solve the problem numerically, the Young–Laplace equation is discretized by using numerical differentiation and the numerical solutions are obtained applying the well-know Newton method. The paper contains a validation of the new methodology presented for what theoretical bubble/drops are used. Finally, some numerical results are presented for both drops and bubbles of water as well as several surfactant solutions to demonstrate the applicability, versatility and reproducibility of the proposed methodology

Coronene (C24H12), a charge transfer complex with low-cost and high-performance energy storage, has recently attracted attention as a model molecule of graphene nano-flakes (GNFs). The stacking structures of the trimer radical cation correlate strongly with the conduction states of the GNFs. In the present paper, the structures and electronic states of the monomer, dimer and trimer radical cations of coronene were investigated by means of density functional theory calculations. In particular, the proton hyperfine coupling constants of these species were determined. The radical cation of coronene(+) (monomer) showed two structures corresponding to the (2)A(u) and B-2(3u) states due to the Jahn-Teller effect. The (2)A(u) state was more stable than the B-2(3u) state, although the energy difference between the two states was only 0.03 kcal mol(-1). The dimer and trimer radical cations took stacking structures distorted from a full overlap structure. The intermolecular distances of the molecular planes were 3.602 angstrom (dimer) and 3.564 and 3.600 angstrom (trimer). The binding energies of the dimer and trimer were calculated to be 8.7 and 13.3 kcal mol(-1), respectively. The spin density was equivalently distributed on both coronene planes in the dimer cation. In contrast, the central plane in the trimer cation had a larger spin density, rho = 0.72, than the upper and lower planes, both with rho = 0.14. The proton hyperfine coupling constants calculated from these structures and the electronic states of the monomer, dimer, and trimer radical cations of coronene were in excellent agreement with previous ESR spectra of coronene radical cations. The structures and electronic states of (coronene)(n)(+) (n = 1-3) were discussed on the basis of the theoretical results.

In this paper, we investigated the effects of the Ga loading amount and H-2 treatment temperature for the reductive solid-state ion-exchange reaction on the generated Ga species in Ga-exchanged MFI zeolites (Ga-MFIs) as well as their catalysis for ethane dehydrogenation (EDH). For the formation of isolated Ga hydrides in the zeolites, [GaH](2+) ions were preferentially formed in the low-loading Ga-MFI (Ga/Al = 0.3) treated with H-2 at 550 degrees C, corresponding to the conventional preparation conditions, (Ga-MFI-0.3(550)), while the high Ga loading (Ga/Al = 1.0) and high-temperature H-2 treatment (800 degrees C) (Ga-MFI-1.0(800)) induced the formation of [GaH2](+) ions as the major Ga hydrides, as revealed by in situ Fourier transform infrared spectroscopy including the isotope experiment using D-2. In the context of other Ga species, such as Ga+ cations and partially reduced Ga oxides (GaOX), Ga+ cations and GaOX coexist in Ga-MFI-0.3(550), as indicated by pyridine adsorption experiments. On the other hand, GaOX was hardly observed and a larger amount of Ga+ cations was formed in Ga-MFI-1.0(800). The remaining Bronsted acid sites (BASs) were also characterized by the NH3 adsorption experiment. In the EDH reaction, Ga-MFI-1.0(800) exhibited high selectivity owing to low coke formation, resulting in the highest durability among the series of Ga-MFIs tested. Under the optimized conditions, Ga-MFI-1.0(800) exhibited the highest C2H4 formation rate among previously reported Pt-free catalysts. Based on the combined results of characterization, catalyst tests, and kinetic studies, the high selectivity and durability of Ga-MFI-1.0(800) can be ascribed to the low amount of the remaining BASs by isolated Ga species ([GaH](2+), [GaH2](+) ions and Ga+ cations) as well as the major formation of [GaH2](+) ions among isolated Ga hydrides.

This review is a summary of the most up-to-date knowledge regarding assessment of atmospheric deposition of reactive nitrogen (Nr) pollutants across complex terrain in the UK. Progress in the understanding of the mechanisms and quantification of Nr deposition in areas of complex topography is slow, as no concerted attempts to measure the components of Nr in complex terrain have been made in the last decade. This is likely due to the inherent complexity of the atmospheric processes and chemical interactions which contribute to deposition in these areas. More than 300 studies have been reviewed, and we have consulted with a panel of international experts which we assembled for that purpose. We report here on key findings and knowledge gaps identified regarding measurement and modelling techniques used to quantify deposition of Nr across complex terrain in the UK, which depending on definition, may represent up to 60% of land coverage across Great Britain. The large body of peer reviewed papers, reports and other items reviewed in this study has highlighted both the strengths and weaknesses in the tools available to scientists, regulators and policy makers. This review highlights that there is no coherent global research effort to constrain the uncertainties in Nr deposition over complex terrain, despite the clearly identified risk of N deposition to ecosystems and water quality. All evidence identified that enhanced Nr deposition across complex terrain occurs, and magnitude of the enhancement is not known; however, there are major uncertainties particularly in the differences between modelled and measured wet deposition in complex terrain and representing accurate surface interactions in models. Using simplified estimates for Nr deposition, based on current understanding of current measurement and model approaches, an enhancement across UK complex terrain in the range of a factor of 1.4–2.5 (i.e. 40–150% larger than current estimates) is likely over complex upland ter

In this paper, we address the unique nature of fully textured, high surface-to-volume 3C-SiC films, as produced by intrinsic growth anisotropy, in turn generated by the high velocity of the stacking fault growth front in two-dimensional (111) platelets. Structural interpretation of high resolution scanning electron microscopy and transmission electron microscopy data is carried out for samples grown in a hot-wall low-pressure chemical vapour deposition reactor with trichlorosilane and ethylene precursors, under suitable deposition conditions. By correlating the morphology and the X-ray diffraction analysis we also point out that twinning along (111) planes is very frequent in such materials, which changes the free-platelet configuration.