Nanotechnology: A Novel Approach to Prevent Biocide LeachingEPA Grant Number: GR832371
Title: Nanotechnology: A Novel Approach to Prevent Biocide Leaching
Investigators: Heiden, Patricia , Dawson-Andoh, Benjamin , Matuana, Laurent
Institution: Michigan Technological University , Michigan State University , West Virginia University
EPA Project Officer: Carleton, James N
Project Period: July 1, 2008 through August 30, 2009
Project Amount: $333,130
RFA: Greater Research Opportunities: Research in Nanoscale Science Engineering and Technology (2004) RFA Text | Recipients Lists
Research Category: Nanotechnology , Safer Chemicals
The primary objective of this proposal is to develop a practical and effective approach to prepare biocide-loaded nanoparticles (organic and copper-based biocides) that can be efficiently introduced into wood to reduce or eliminate biocide leach into sensitive environments. Preventing biocide loss to leach is also expected to increase the useful lifetime of wood products while using less biocide. To accomplish this objective the nanoparticle must be constructed to serve as a protective reservoir for the biocide that prevents its loss by leach or by degradation, but that also releases biocide into the wood in a controlled manner at a rate that maintains the minimal amount of biocide required within the wood for wood preservation.
A new nanoparticle preparation method is being developed to prepare hydrophobic nanoparticles that serve as a biocide reservoir and will moderate the biocide release rate. The nanoparticles will be stabilized in water so that they may be delivered into wood using a conventional modified full pressure-treatment method. American Society for Testing and Materials (ASTM) and American Wood Preservers’ Association (AWPA)-approved methods respectively will be used to determine the biological efficacy of treated sapwood of pine and birch against the brown rot fungus Gloeophyllum trabeum and the white rot fungus Trametes versicolor and the leach rates of biocide from the nanoparticle-treated wood. Wood controls will be prepared by treatment with the same amount of biocide introduced by conventional solution or emulsion methods and evaluated in the same tests in side-by-side studies. All results will be compared and assessed for statistically significant differences.
This project will demonstrate the environmental benefits of introducing biocide into wood using hydrophobic nanoparticles as a delivery vehicle and controlled release device for organic and inorganic biocides. The primary benefits expected from use of nanoparticles as controlled release devices for biocide in wood are an increased service life of wood and a reduction of biocide loss to leach, which is expected to allow wood to be effectively protected with lesser amounts of biocide than is used now. These benefits are expected to be realized by using a new and more efficient nanoparticle preparation to give a slow biocide release rate coupled with good nanoparticle stability in aqueous suspensions These features will allow the nanoparticles to be delivered efficiently into wood, but once in wood maintain a slow release rate. Successful completion of this project will benefit all ecosystems containing preserved wood. Even greater benefits are expected for wetlands and other moist ecosystems through reduction of biocide contamination, and in forest ecosystems harvested for wood by extending the service life of preserved wood and wood products.