SPEAKER PROFILE |
 Prof. Alke Fink BioNanomaterials, Adolphe Merkle Institute, University of Fribourg Switzerland |
Nanoparticles and their interaction with wood
Abstract
Among many materials used in construction currently, wood excels because it is renewable and thus green. However, its ability to degrade may pose risks to wood used for construction in areas with high humidity or soil-contact. To prevent decay, wood can be protected by thermal or chemical modification, or impregnation of a wood-treating agent. One example of the latter are formulations containing nano/micro particles together with additional co-biocides. Ideally the submicron-sized particles can enter the wood structure and serve as a reservoir for a continuous protection, aspects like size, material, shape or charge may have a huge impact on the impregnation behaviour.
In a systematic study using model particles, we pressure-impregnated various engineered nanoparticles into wood samples to assess penetration depth as a function of wood species and particle size. Based on these results we extended the study and surface functionalized those particles to additional expose hydrophobic and hydrophilic surfaces in different solvents to samples of pine and beech wood. We could narrow down important parameters to improve particle impregnation: wood-dependent size, particle charge and dispersant were important factors. It was shown that already known limitations to the maximum particle size of 400 to 600 nm were reduced even further to a size of maximum 140 nm for pine.
In a systematic study using model particles, we pressure-impregnated various engineered nanoparticles into wood samples to assess penetration depth as a function of wood species and particle size. Based on these results we extended the study and surface functionalized those particles to additional expose hydrophobic and hydrophilic surfaces in different solvents to samples of pine and beech wood. We could narrow down important parameters to improve particle impregnation: wood-dependent size, particle charge and dispersant were important factors. It was shown that already known limitations to the maximum particle size of 400 to 600 nm were reduced even further to a size of maximum 140 nm for pine.
Bio
Prof. Alke Petri-Fink received her Ph.D. in Chemistry from the University of Ulm, Germany in 1999. After a post-doctoral stay at the University of Gainesville, Florida, she joined the Institute of Materials Science at the École Polytechnique Fédérale de Lausanne (EPFL), first as a post-doctoral researcher, then as a senior scientist. She became an Associate Swiss National Science Foundation Professor in the Department of Chemistry at the University of Fribourg in 2009, and Full Professor in 2011 at the Adolphe Merkle Institute, Switzerland. Her research focuses on inorganic nanoparticles, their synthesis, surfaces, and interactions with biological cells.