Catalytic performance of carbonaceous materials in the esterification of succinic acid

Mesoporous carbonaceous materials have outstanding potential in many different applications such as adsorption, medicine and catalysis. We have recently reported the synthesis of a new form of mesoporous carbon, named Starbon((R)), obtained after low temperature carbonization of expanded starch. Such starch-derived mesoporous materials have several tunable properties including surface energies (ranging from hydrophilic to hydrophobic surfaces), which can be easily controlled by the degree of carbonization (from 200 to 700 degrees C). Due to the diversity of surface functional groups, Starbons((R)) can be easily chemically modified. Treatment of Starbon((R)) materials with sulfuric acid gave a solid acid that has promising properties as heterogeneous catalyst. Comparative catalytic studies with some other similar commercial carbonaceous materials such as DARCO((R)) and NORIT (R), as well as phosphorous-containing microporous carbons, are reported. (c) 2008 Elsevier B.V. All rights reserved

Scientific Note: Update on the establishment of birch leafminer parasitoids in western Canada

submitted as scientific note, no abstract

The Impact of Domestic Violence in the Workplace: Results from a Pan-Canadian Survey

When workers experience domestic violence (DV) at home, impacts are felt in the workplace; however, little research is available on this topic. Methods: We conducted an online survey regarding the impacts of DV at work. Results: A total of 8429 people completed the survey. More than a third of respondents reported experiencing DV; among them, more than a third reported that DV affected their ability to get to work, and more than half reported that it continued at or near work. Most reported that DV negatively affected their performance. Almost all respondents, regardless of DV experience, believed that it impacts victims\u27 work lives. Conclusions: This research identifies the scope and impact of DV on workers and workplaces. The data should assist governments, unions, and employers to enact and evaluate proactive practices to address the impact of DV in the workplace

Post-polymerisation modification of bio-derived unsaturated polyester resins via Michael additions of 1,3-dicarbonyls

Post-polymerisation modification of α,β-unsaturated polyesters (UPEs) is useful to deliver polymers with tuneable properties and applications different from their parent backbone. Bio-derivable itaconate unsaturated polyesters, with a range of co-monomers, were modified via a heterogeneously catalysed microwave-assisted Michael addition of pendants, acetylacetone (Hacac) and dimethyl malonate (DMM), to the polymer backbones with very short reaction times. Differential scanning calorimetry analysis showed an increase in the glass-transition temperatures of most of the saturated polyesters considered. Solubility and complexation studies demonstrated metal chelating abilities of the acetylacetone pendant can be retained, even following tethering to a polyester backbone. Additionally, it is demonstrated for the first time that Michael addition with Hacac and DMM can be used to reverse Ordelt saturation, an unwanted side-reaction in the synthesis of UPEs

Work-hardening Photopolymer from Renewable Photoactive 3,3’-(2,5-Furandiyl)bisacrylic Acid

The design of a photopolymer around a renewable furan-derived chromophore is presented herein. An optimised semi-continuous oxidation method using MnO2 affords 2,5-diformylfuran from 5-(hydroxymethyl)furfural in gram quantities, allowing the subsequent synthesis of 3,3’-(2,5-furandiyl)bisacrylic acid in good yield and excellent stereoselectivity. The photoactivity of the diester of this monomer is confirmed by reaction under UV irradiation, and the proposed [2+2] cycloaddition mechanism supported further by TD-DFT calculations. Oligoesters of the photoreactive furan diacid with various aliphatic diols are prepared via chemo- and enzyme-catalysed polycondensation. The latter enzyme-catalysed (Candida antarctica lipase B) method results in the highest Mn (3.6 kDa), suggesting milder conditions employed with this protocol minimised unwanted side reactions, including untimely [2+2] cycloadditions, whilst preserving the monomer's photoactivity and stereoisomerism. The photoreactive polyester is solvent cast into a film where subsequent initiator-free UV curing leads to an impressive increase in the material stiffness, with work-hardening characteristics observed during tensile strength testing

Synthesis and application of tuneable carbon-silica composites from the microwave pyrolysis of waste paper for selective recovery of gold from acidic solutions

Microwave pyrolysis bio-oil from waste paper and K60 silica gel has successfully been utilised to synthesise mesoporous carbon-silica composites with uniquely tuneable surface properties, where functionality and structural characteristics can be altered and even enhanced by curing at different temperatures. This temperature-dependence resulted in composites ranging from highly oxygenated polymerised bio-oil composites at 300 °C to aromatic carbonaceous materials covering the silica surface at 800 °C, making them attractive materials for gold recovery from mining wastewater. The composite materials exhibit exceptional ability and selectivity to recover gold from dilute solutions. Metal adsorption on the surface of these composites proceeded via both chemisorption and physisorption leading to the reduction of Au(iii) to Au(0), resulting in high recovery capacities for gold. Composite material prepared at 500 °C demonstrated the optimum combination of surface functionality and porosity, allowing for an adsorption capacity of 320 mg g-1 of gold and with 99.5% removal being achieved at concentrations mimicking those of real-life mine tailing wastes. All materials pioneered in this research display great potential as selective adsorbents for the recovery of gold from acidic media. This journal i

Torrefied fuel pellets from solid waste of sugar industry

The preparation of fuel pellets from the filter cake waste from the sugar industry was studied. Pelletization by a hydraulic press at a pressure of 20 to 50 bar (2 to 5 MPa) was used to produce fuel pellets with a diameter of 1 cm and height of 1. 25 cm. Energy efficiency of the resulting pellets was improved by thermal treatment called “torrefaction”. During this process, the samples were heated to between 200 and 300°C for 0.5 to 2 h under a nitrogen atmosphere. The properties of fuel pellets including calorific value, bulk density, pellet density, proximate analysis, and compressive strength were characterized. The results demonstrated that the minimum pressure needed to produce the pellets without binder was 30 bar. The calorific value was between 13,954–14,468 kJ/ kg for the resulting fuel pellet, which was significantly higher than that of the unpelletized raw material (11,197 kJ/ kg). The fuel pellets had bulk density and pellet density of between 300–440 kg/m3 and 720–890 kg/m3, respectively. Increasing the time and temperature of torrefaction resulted in the lower yields of pellets. Fuel pellets maintain their shape and did not break under the applied torrefaction conditions. Torrefied pellets resulted in higher calorific value of 16,552–22,642 kJ/kg, higher carbon content, lower pellet and bulk densities compared to the fuel pellet without thermal treatment. The compressive strength of torrefied pellets decreased due to the delicate nature of the sample. The suggested conditions for optimal torrefied pellet in thermal and physical properties are 300°C and 1 h. The prepared fuel pellets showed comparable heating values to other fuels, and had properties in agreement with Thailand standards. Therefore, filter cake as a solid waste from production process of sugar has potential as raw material for the production of solid fuel pellets

Scientific Note: Update on the establishment of birch leafminer parasitoids in western Canada

submitted as scientific note, no abstract