Nanoporous materials

Molecular polymer imprinting is a highly elegant and efficient method of producing functional materials equipped with selective identification characteristics. Using the lock-and-key principle, selective materials can be produced for different applications, such as sensors, purification of mixtures or enrichment.

Advantages and applications

Molecularly imprinted polymers (MIPs) are produced by synthesizing highly cross-linked polymers in the presence of template molecules. In a self-organizing process, the growing polymer skeleton adapts to the molecular model, forming a type of imprint of the molecular template. The geometric adaptation of the polymer and the interactions of the functional groups, for example the formation of hydrogen bonds, make the polymer selective for the template, which means that it can be applied as a selective sensor coating.

At Fraunhofer ICT, MIPs are being developed as sensor coatings for the detection of explosives, and as particles for the enrichment of semi-volatile compounds. Various coating technologies such as nanoplotting, spin coating, screen printing and various synthesis methods (UV polymerization, suspension polymerization, core-shell particles are used. Possible analytes range from explosives or toxic substances, such as herbicides and pesticides, to natural substances such as steroids.

Our offer

• Synthesis of MIP materials for customer-specific target molecules for enrichment / extraction or as selective sensor coatings
• Adjustment or development of coating processes for various sensor surfaces
• Characterization of surface properties and particle size distributions
• Characterization of the adsorption properties of the template used

Metal-organic frameworks (MOFs) form a new class of microporous materials that are characterized by extremely large specific pore volumes (up to 3.60 cm³/g) and large specific surfaces (> 7000 m²/g) that substantially exceed those of established porous materials like silicates or activated carbon.

Structure

MOFs are composed of metallic clusters such as Zn, Cu, Fe and Zr, connected by organic linkers (e. g. terephthalate, imidazolate). They offer an infinite array of compositional possibilities, generating a wide variety of MOF substances with very different properties. MOF materials can therefore be used in very different areas of application, in particular gas storage, separation techniques, sensor development, drug delivery, environmental restoration and catalysis.

Synthesis and scale-up

Fraunhofer ICT carries out applied and industry-oriented research in the area of metal-organic frameworks. Emphasis is placed on economical synthesis routes for MOF compounds and their scale-up to the kilogram range, which forms the basis for future product developments. Synthesis protocols originally obtained through fundamental research are further optimized on the basis of reaction engineering concepts. The major goal is to simplify the synthesis processes and significantly reduce their costs. Here, questions pertaining to the economical use of resources and energy, waste reduction, product quality, space/time yield, safety and future up-scaling play an important role.

Fraunhofer ICT uses screening procedures that are conducted either continuously or batch-wise in parallel reactor set-ups, in order to identify promising synthesis routes at a very early stage during the exploration of new MOF materials. Modern analytical methods are available for characterizing the synthesis products, in particular the structure, specific surface, adsorption behavior and chemical and thermal stability of the porous materials.

MOF applications

The main research priorities at Fraunhofer ICT are currently product developments in the areas of reactive gas storage, selective sensing of hazardous substances and liquid-phase catalysis using MOFs. Starting with MOF substances known from literature we develop strategies to optimize functionality, for instance by modifying linker molecules or by post-functionalization of the entire MOF compound. As part of a strategic partnership with five other Fraunhofer institutes (Fraunhofer IWS, IKTS, IGB, ISE, and UMSICHT), further MOF applications in the areas of gas storage, heat storage, gas separation and sensor technology are explored. In addition, processes for the shaping and manufacturing of MOF semi-finished products as well as new characterization techniques are currently being developed.

Our offer

• We provide our customers and project partners with rapid and comprehensive access to the diverse applications of metal-organic frameworks.
• We offer a broad range of R&D services ranging from feasibility studies and expertise to product and process developments.
• We develop, analyze and optimize MOF syntheses and MOF processes for customer-specific tasks in all areas from the laboratory to production scale.