Materials Chemistry

Members

M. Vamvakaki,   G. Armatas,   K. Velonia,  C. Stoumpos

Research Topics

• Synthesis and characterization of responsive and biocompatible polymer brushes on flat and curved surfaces for biomedical and photonic applications
• Synthesis, characterization and applications of responsive core-shell microgel particles
• Metal and semiconducting nanoparticle formation within polymer matrices for use in catalysis, sensors and imaging applications
• Biocompatible surfaces and 3D structures for cell culture
• Preparation of mesoporous metal-oxides and mixed metal-oxides (e.g. spinels, perovskites) with tailorable composition and textural properties
• Synthesis of periodically order mesoporous composite materials formed by metal-oxide and heteropoly acid compounds
• Synthesis of nanomaterials for photocatalysis and solar energy conversion
• Mesoporous semiconductors

Organic and Hybrid Materials

Our research interests focus in the area of functional and stimuli-responsive polymeric materials known as “smart” materials which are able to undergo significant changes in their physicochemical properties in response to applied stimuli leading to polymer self-assembly and the formation of complex hierarchical structures. Organic polymers are developed in a vast range of functionalities and architectures and exhibit an unprecedented variety of attractive properties in bulk, in solution and on a surface. We apply “living” and/or controlled polymerization techniques to prepare functional polymeric materials with control over the polymer structure and architecture and thus the structure-properties-applications relationship. “Smart” polymers are studied in terms of their responsive behavior to variations of different external stimuli, i.e. temperature, pH, ionic strength, the application of UV or visible light radiation, and others. Organic-inorganic hybrids which combine the properties of the inorganic material (electronic, optical, magnetic, and/or catalytic) with those of the polymer (solubility, film formation, and chemical activity) are also developed using the functional polymer templates. Organic-inorganic hybrid material precursors which can be photostructured by non-linear optical microstructuring leading to complex 3D components and systems with resolution below 100 nm are investigated. The unique characteristics of these functional materials have attracted great scientific interest and render them ideal candidates for numerous technological uses in our everyday life (coatings, adhesives, thickeners, etc.) as well as for advanced applications in biotechnology, environmental science, colloidal chemistry, microelectronics and in the fabrication of 3D photonic crystals and devices.

Inorganic Materials

Nanowires consisting of multicrystalline Cr₂O₃ and 12-phosphomolybdic acids adopt a hexagonal p6mm mesostructureOur research work utilizes liquid-crystal templating from amphiphilic surfactants and hard templating (nanocasting) approach to assemble complex one- or multi-dimensional architectures with controllable composition and textural morphology. In general, we apply “button-up” procedures to construct large scale superstructures and nanoporous frameworks. Efforts are primarily focused on specific interactions evolved between the inorganic or organic components and the surface of templates in order to achieve control in manipulation and precise positioning of nanoscale building blocks into complex large scale superstructures. The self-assembly or assisted-assembly of inorganic or organic functional units into periodically order mesostructures can contribute further to the design of novel nanomaterials. These materials offer coexistence of regular mesoporosity with a catalytic, semiconducting and magnetic property in host framework as a unique combination not available in individual components. Systems that blend these disparate features are of considerable scientific interest and for practical applications in redox- and photo-catalysis, magnetism, solar energy conversion, environmental remediation, bio-assaying and optoelectronic.

High-surface-area cubic mesoporous Co₃O₄/H₃PW₁₂O₄₀ composite materialWe combine organic and inorganic synthetic chemistry with a wide range of analytical techniques in solution and in the solid-state in order to elucidate the structure – properties relationship of these materials. The main techniques applied for characterization include gel permeation chromatography, infrared and ultraviolet-visible spectroscopy, X-ray diffraction, dynamic light scattering, high-resolution transmission electron microscopy, scanning electron microscopy, atomic force microscopy, thermal analysis, ellipsometry, contact angle measurements and adsorption analysis.

Further information: Lab of Materials Chemistry

Laboratory of Synthetic Biomaterials — Supramolecular Chemistry

The Laboratory of Synthetic Biomaterials – Supramolecular Chemistry (Prof. Velonia) focuses on the construction of bioconjugates and polymer-protein conjugates which are programmed to self-assemble into multifunctional nanoarchitectures and aimed at biotechnological and biomedical applications. In recent years, the laboratory has focused on the development of novel bioconjugation approaches able to afford such biomacromolecular chimeras in high yields while preserving the integrity of the biological component. The lab is currently focusing on the development of new biocompatible and/or biodegradable protein- polymer conjugates bearing proteins with unique structural or catalytic properties, the programmed assembly of multi-enzyme nanoreactors, and the study of the interaction of such multifunctional nanostructures with biological entities (such as bacterial cells). The lab is engaged in several collaborations for the development and integration of chimeric biomaterials into functional nanoscale devices.