Head

Research focus

Wendelin Stark’s research combines materials with specific functions for medical or industrial use. He has developed nanoparticles for environmental applications i.e. to increase energy efficiency in water and solvent purification, to enable large scale remediation or for more environment-friendly catalytic processes. He has pioneered inherent safety aspects in nanoparticle applications and toxicology during industrial product design.

Market effective research

Six companies have been co-founded by Wendelin Stark: FlamePowders AG made large scale oxide powders (stopped operation in 2006), Turbobeads GmbH made magnetic chemicals (partially distributed by external page Sigma-Aldrich) and diagnostic reagents, external page nanograde AG provides over 1 Million different and customized nanoparticles, external page smartodont GmbH introduces bioactivity to polymer implants, and external page novamem GmbH produces ultrafiltration membranes for water purification and organic solvent nanofiltration. The youngest one, external page Haelixa GmbH uses a high-tech nanotechnology tracer technology developed at FML to provide solutions for industrial tracing, product authentication and liability management.

Selection of Wendelin Stark's achievements

Industrial scale nanoparticle fabrication: From oxide to inorganic salts, glasses, biomaterials and metal nanoparticles

• Multicomponent oxide, salt and metal nanoparticles have become available through modified, scalable flame spray synthesis making classical commodities obtainable as nanoparticles [1], including nano-limestone, nano-gypsum, nano-salt [2] and nano-glass [3]. Making inverted flames running under oxygen deficient conditions, even metal nanoparticles became available as low cost commodity products [4] [5] [6].
• Bioactive glasses and amorphous calcium phosphates today provide a key tool for biomaterials development where the corresponding mineral nanoparticles convey bioactivity (tissue bonding) to virtually any medically useful polymer [7] [8].

Metal nanomagnets with a well-defined, covalently attached chemical surface now enable the use of “magnetic chemical reagents” as powerful tools for accelerating organic synthesis

• In medicine, chemically defined metal nanomagnets enable in vivo extraction of toxic intermediates or compounds out of living blood [9] [10].
• Magnetic catalysts (semi-heterogeneous) and magnetic EDTA for heavy metal removal from highly dilute concentrations.
• Magnetic carbon and ion exchange nanoparticles for ore refining in acidic environment

Pioneering research in nanotoxicology

• Wendelin Stark has developed method and risk evaluation concepts for safe nanoparticles since 2003 and identified key concepts in nanotox, such as the role of particle agglomeration, diffusion and sedimentation [11], solubility, and catalytic activity [12]. His group experimentally pioneered investigations on nanoparticles in wastewater treatment plants [13], exposure of human lung epithelial cells to engineered nanoparticles [14], and during municipal waste incineration at a 200’000 ton per year scale [15].
• Prof. Stark has assisted Swiss Government agencies in developing regulatory evaluation tools for nanoparticle containing products and served as the chairman of the 2nd International Conference in Nanotoxicology. His work has led to fundamental understanding on the behavior of nanoparticles in biological systems and the recognition that persistent nanoparticles should not be used in consumer goods [16].

Living materials combine classical polymers with microorganism and allow “on site” consumption and chemical production of compounds in consumer goods

• Controlled release has enabled fascinating applications in numerous fields. Living materials that include a microorganism as part of a composition, however can tackle even more complex functions, such as “eating” [17], or local production of antibiotics [18].

Organic Synthesis on graphene

• Wendelin Stark has introduced multi-step, covalent and pattern resolved chemical derivatisation of graphene as a basic tool to alter electrical conductivity and as a starting point for the preparation of 2D polymers [19]. Today, this covalent carbon-carbon link provides a chemical design element perpendicular to the graphene base plane and ultimately uses organic chemistry to allow an atom by atom design of function [20].