Department of Chemistry and Chemical Engineering
Active Carbon Research Group
Research Activities
The existence of an active carbon research group at RMC in support of DND's chemical defence program dates back to the 1950s. As the only group in Canada to specialise in physical adsorption diverse interests have developed, mainly concentrating on activated carbon, but also including other adsorbent systems such as sol-gels, porous polymers and molecular sieves.
The recent activities of the group include both basic and applied research such as fundamental studies on carbon surfaces to reduce ageing problems and the deleterious effects of high humidity on the effectiveness of gas mask carbons. Other investigations include the production, on a laboratory scale, of novel carbons and carbon composites from a variety of precursor materials and the use of porous carbon electrodes in double layer capacitors for the storage of electrical energy.
Carbons are activated and altered using innovative techniques including air-cycling activation and electrochemical oxidation. Two specific studies include attempts to increase the hydrophobicity of active carbons and the production of adsorbents with distinctive pore size distributions optimised for the adsorption of supercritical methane at room temperature.
In the 1990s the group branched out to include the synthesis, characterisation and development of innovative chemically-engineered silica gel structures derived for applications in the catalysis, adsorption, separation and insulation fields.
2001 saw the group host a successful workshop on Gas Storage, which was sponsored by the American Carbon Society. This international meeting attracted participants from fourteen different countries with diverse interests including the storage of hydrogen and natural gas on adsorbents such as activated carbon monoliths, coordination polymers, carbon nanotubes and nanofibers.
The active carbon group, as partners in the Chemical Protection Group, and working in conjunction with the Defence Research Establishment Suffield, has for many years participated in the developmental programmes of the CF in the areas of respiratory protection against toxic vapours and cutaneous protection against vapours and aerosols. This expertise provides a sound base for expansion into the challenges posed by the need to protect against a much wider spectrum of toxic chemicals using a variety of equipment.
Recent research work of the carbon group includes characterisation of carbon fibres, papers, and felts, and adsorption and surface studies. The limitations and shortfalls of the C7 canister and shelf life leading to ammonia release has also been a recent focus, including participation in developing the next generation canister.
Jayne MacDonald was elected to the Advisory Committee of the American Carbon Society for a 6 year term (1999-2005) and joined the Honorary Editorial Advisory Board of the Carbon journal in 2001.
Scanning electron micrograph (SEM) of an aged canister carbon. (2000X) The detrimental effects of humidity are evident in the crystal formation seen on the surface of the metal impregnated carbon.
Novel carbon beads
Scanning electron micrograph (SEM) of uniform carbon beads. (25X)
Scanning electron micrograph (SEM) of the porous carbon surface of an electrode used for electrochemical double layer capacitors. Energy is stored within the capacitor as a result of the separation and accumulation of charge at the interface between an electronically conducting electrode and an ionically conducting electrolyte. The large charge delivered results from the amplification of the double layer over the large surface area of the activated porous carbon.
Scanning electron micrograph (SEM) of activated carbon fibers.
Scanning electron micrograph (SEM) of an activated carbon fiber paper material. (30 and 500X) Uniformly sized fibers are shown here forming an irregular network with some paper bonding material evident.
Scanning electron micrograph (SEM) of an activated carbon felt material. (114X) Uniformly sized fibers are shown here forming an irregular network.
Information: macdonald-j@rmc.ca
