Search

Large volumes of engineered wood products (EWPs) and paper are routinely placed in landfills in Australia, where they are assumed to decay. However, the extent of decay for EWPs is not well-known. This study reports carbon loss from EWPs and paper buried in landfills in Sydney, Brisbane and Cairns in Australia, located in temperate, subtropical and tropical climates, respectively. The influence of pulp type (mechanical and chemical) and landfill type (municipal solid waste – MSW and construction and demolition – C&D) on decay levels were investigated. Carbon loss for EWPs ranged from 0.6 to 9.0%; though there is some uncertainty in these values due to limitations associated with sourcing appropriate controls. Carbon loss for paper products ranged from 0 to 58.9%. Papers produced from predominantly mechanical pulps generally had lower levels of decay than those produced via chemical or partly chemical processes. Typically, decay levels for paper products were highest for the tropical Cairns landfill, suggesting that climate may be a significant factor to be considered when estimating emissions from paper in landfills. For EWPs, regardless of the landfill type and climate, carbon losses were low, confirming results from previous laboratory studies. Lower carbon losses were observed for EWP and paper excavated from the Sydney C&D landfill, compared with the Sydney MSW landfill, confirming the hypothesis that conditions in C&D landfills are less favourable for decay. These results have implications for greenhouse gas inventory estimations, as carbon losses for EWPs were lower than the commonly assumed values of 23% (US EPA) and 50% (Intergovernmental Panel on Climate Change). For paper types, we suggest that separate decay factors should be used for papers dominated by mechanical pulp and those produced from mostly chemical pulps, and also for papers buried in tropical or more temperate climates. [ABSTRACT FROM AUTHOR]

The surface of paper was treated to control wettability using argon-carbon plasma generated by a direct current-pulsed (frequency: 60 kHz) sputtering device with parallel-arrangement magnets. After plasma treatment, the C–C bond percentage in the C 1s region was inversely proportional to the C–OH bond percentage, while the ratio of C=O and O–C=O bonds only changed slightly. The change ratios for the increase in C–C and the decrease in the C–OH bonds were approximately the same, and the change ratio increased from approximately 5%–11% with an increase in the plasma current. The reduction ratio of the contact angle decreased from 0.945 to 0.182 (°/s) with increasing plasma current. These results indicate that the water resistance of the paper surface was enhanced after the simple plasma treatment, and wettability could be easily controlled by changing the substitution ratio between C–OH and C–C elements, achieved by altering the plasma current. • Papers were plasma-treated using DC-pulsed sputtering with parallel-aligned magnets. • C–C and C–OH bond percentages were inversely proportional after plasma treatment. • Substitution ratio between C–OH and C–C was changed by varying the plasma current. • Contact angle reduction ratio on paper decreased with increase in plasma current. [ABSTRACT FROM AUTHOR]

This article details the study of electrochemical behavior of new carbon electrodes based on pyrolysis of different paper sources to be used in biosensor applications. The resistivity of the pyrolyzed papers was initially used as screening parameters to select the best three paper samples (imaging card paper, multipurpose printing paper, and 3MM chromatography paper) and assemble working electrodes that were further characterized by a combination of microscopy, electrochemistry, and spectroscopy. Although slight differences in performance were observed, all carbon substrates fabricated from pyrolysis of paper allowed the development of competitive biosensors for uric acid. The presented results demonstrate the potential of these electrodes for sensing applications and highlight the potential advantages of 3MM chromatography paper as a substrate to fabricate electrodes by pyrolysis. [ABSTRACT FROM AUTHOR]

Abstract: The commercially available copy papers and pure papers have been adopted to synthesize carbon nanomaterials. It is found that carbon nanocoils (CNCs) are efficiently synthesized on the copy paper substrates using Fe2(SO4)3/SnCl2 catalyst by a thermal chemical vapor deposition method, while only carbon nanotubes (CNTs) are obtained on the pure paper substrate using the same process. It is evidenced that the particles of calcium carbonate existing in copy paper aggregate catalyst and adsorb more sulfur elements which promote the growth of CNCs. In addition, CNCs can successfully grow out from the pure paper by adding calcium carbonate. [Copyright &y& Elsevier]

Abstract: The calculations based on AM1 and PM3 methods suggest that the cycloaddition between the nitrene (HN:) group and (5,5) armchair single-walled carbon nanotube (ASWCNT) produces four isomers, and their thermodynamic stability can be described as follows, V-open >V-closed >S-open >S-closed. The kinetic analysis, however, suggests that the predominant forms are S-open and V-open in the mixture of HN

[Display omitted] • Reproducible sensors using biodegradable substrates and eco-friendly materials. • Use of cost-effective techniques for their fabrication. • Simplified layout for the joint measurement of RH and temperature on the same IDES. Given the increasing number of connected devices as a consequence of the Internet of Things (IoT) revolution, the issue of the removal and recycling of electronics is becoming more and more urgent. In this context, biodegradable electronics is expected to be one of the biggest technological revolutions to tackle this problem. Following this direction, in this work we present the fabrication and characterization of temperature and humidity sensors based on biodegradable materials with the goal of making their removal easier as well as reducing their environmental impact. In particular, these multi-sensing devices were fabricated following a screen-printing process using a carbon-based paste and a conjugated polymer, both on paper and on a water soluble substrate. The results are more than promising and show how with our biodegradable sensors it is possible to obtain a sensitivity of 1 dec/20%RH to moisture content and around 0.04%/°C sensitivity to temperature. It is demonstrated that the simplicity and flexibility of the fabrication approach followed in this work paves the way to a set of new "green" IoT nodes that could be extended to wide range of sensing applications. [ABSTRACT FROM AUTHOR]

Tricolor emissive CDs with multiple-cores@shell structure were synthesized by one-pot hydrothermal route. The surface Aphen moieties endow the as-synthesized AC-CDs with promising pH-sensitive function to prepare fluorescent pH test paper towards qualitative and quantitative detection of pH in the solution. CDs can be used as a cell imaging marker and efficient cellular labelling to detect intracellular pH due to its unique tricolor emission property. • Tricolor emissive CDs with multiple-cores@shell structure were synthesized by one-pot hydrothermal route. • The as-obtained CDs were used to prepare fluorescent pH test paper with promising pH-sensitive feature. • CDs can be used as a cell imaging marker and efficient cellular labelling to detect intracellular pH. • Unique tricolor property of CDs can avoid the fluorescent dyes and protein fluorescence interference for cell imaging. Recently, fluorescent pH test paper has been extensively explored for visual assays due to its easy preparation, low-cost, and portable feature. In addition, intracellular pH also plays important roles in different pathological and physiological processes for understanding cellular functions and providing critical assistance for early disease diagnosis. Herein, the tricolor emission multiple-cores@shell carbon dots (CDs) were synthesized via one-pot hydrothermal method using 5-amino-1,10-phenanthroline (Aphen) and citric acid (CA) as the carbon sources. The fluorescence emission of CDs showed an interesting pH dependence due to the special structure and properties, which can make the CDs to be used as the pH test paper to qualitatively and quantitatively detect pH value in a wide pH range. At the same time, because of good cell compatibility and low toxicity, CDs can be used as a new type of cell imaging marker to detect intracellular pH. The unique tricolor emission property of CDs can well avoid the fluorescent dyes and protein fluorescence interference. [ABSTRACT FROM AUTHOR]