Inorganic Materials and Environmental Remediation Chemistry

Materials Design

            High surface area nanoporous oxides are a promising class of compounds with potential applications for the adsorption and/or detoxification of environmental pollutants. Various synthetic strategies can be used to prepare chemically functionalized materials with controlled pore structures ranging in size from 4 to 50 Å.

1. Pillared layered oxides. The introduction of a functional molecule (pillar) in between the oxide sheets of layered minerals (such as clays) produces microporous materials (pore size between 4 and 10 Å) whose chemical properties are determined by the nature of the pillaring group.

2. Mesoporous molecular sieves. These are a newly discovered class of oxides which possess very high surface areas (800 to 1400 m2/g) and contain pore channels of uniform diameter in the size range of 20 to 50 Å. Chemical species can be anchored to the surface of these pore channels, producing highly functionalized materials.

Materials Characterization

            The structure and chemical composition of the new functional materials can be elucidated by a variety of analytical methods, including X-ray diffraction, surface area analysis by N2 adsorption, FTIR, thermal analysis, X-ray fluorescence, AAS, ICP and other techniques. Obtaining accurate structural and chemical information on new materials is crucial in order to understand and predict their reactivity.

Environmental Applications

The preparation of functionalized nanoporous materials capable of remediating contaminated environments is the ultimate goal of this research program. Specific areas of interest include:

• the preparation of high capacity adsorbents for the selective removal and recovery of heavy metal ions from water.

• the design of hydrophobic adsorbents with controlled pore dimensions for the selective removal of organic contaminants from water.

• the synthesis of nanoporous catalysts for the decomposition of specific pollutants in both water and air environments.

Publications:

Beaudet, L., Pitre, R., Robillard, L., and Louis Mercier
Structural Perturbations in Mesoporous Silica Microspheres Prepared using Cationic Organosilanes.
Chem. Mater., 21: 5349-5357. (2009) (PDF)

Abughusa, L. Amaratunga and L. Mercier . 
Extraction of Precious Metal Ions from Simulated Mine Effluents Using a Nanostructured Absorbent.      
Can. Metallurg. Quarterly, (2006) (Abstract) 

R. Sawicki and L. Mercier
Evaluation of mesoporous cyclodextrin-silica nanocomposites for the removal of pesticides from aqueous media.
Environ. Sci. Technol., 40: 1978-1983. (2006)

A. Abughusa, L. Amaratunga and L. Mercier
The recovery of rhodium ions at ultra-low concentrations using nanostructured adsorbents. 
Stud. Surf. Sci. Catal., 156: 957-962. (2005) 

A. Bibby and L. Mercier
Adsorption and separation of water-soluble aromatic molecules by cyclodextrin-functionalized mesoporous silica.
Green Chemistry, 5(1), 15-19. (2003)

R. Richer & L. Mercier
Direct synthesis of functional mesoporous silica by neutral pH non-ionic surfactant assembly: factors affecting framework structure and composition
Chem. Mater., 13 (9); 2999- 3008. (2001) [PDF]

Huq, R.; Mercier, L.; Kooyman, P. J.
Incorporation of Cyclodextrin into Mesostructured Silica.
Chemistry of Materials, 13(12), 4512-4519. (2001)

J. Brown, R. Richer, & L. Mercier. 
One-step synthesis of high capacity mesoporous Hg2+ adsorbents by non-ionic surfactant assembly.
Micropor. Mesopor. Mater. 37: 41-48. (2000)

L. Mercier &T.J. Pinnavaia
Direct synthesis of hybrid organic-inorganic nanoporous silica by a neutral amine assembly route: structure-function control by stoichiometric incorporation of organosiloxane molecules
Chem. Mater. 12: 188-196. (2000)

J. Brown, L. Mercier, & T.J. Pinnavaia. 
Selective adsorption of Hg2+ by thiol-functionalized nanoporous silica.
J. Chem. Soc., Chem. Commun., 1999: 69-70. (1999)

L. Mercier & T.J. Pinnavaia.
Heavy metal ion adsorbents formed by the grafting of thiol functionality to mesoporous silica molecular sieves: factors affecting Hg2+ uptake.
Environmental Science and Technology, 32: 2749-2754. (1998)

L. Mercier & T.J. Pinnavaia.
A function-alized porous clay heterostructure for heavy metal ion (Hg2+) trapping.
Micropor. Mesopor. Mater., 20: 101-106. (1998)