Nanostructured Polymers and Composites

The Department focuses on the research of smart materials based on nanostructured polymers and polymer nanocomposites, often using the synergistic combination of both concepts. Our research consists in design, synthesis, and in elucidation of structure/property relationships in novel multifunctional materials with tailored properties. Click chemistry, self-assembly and nano-phase separation are the approaches often exploited in our syntheses. In the area of rigid nanofillers, our research focuses on their structure-directing potential in multi-phase polymer systems, as well as on their effect in ‘macro-composites’, for example in-situ generated fibrillar reinforcement in composites. The studied materials include stimuli-responsive-, self-healing-, and shape-memory systems, but also biodegradable waterborne polyurethanes.

Topics

Advanced polymer nanocomposites with enhanced and functional properties

A wide range of systems based on both polymer thermoplastics, thermosets as well as biodegradable polymers is studied, and different types of nanofillers, with geometry of 0D (well-defined nanoblocks), 1D (CNT, CF, halloysite nanotubes), 2D (clay, graphene) and 3D type (in situ generated nanostructures), both of inorganic and organic nature, are incorporated. Synthesis and characterization of organized and self-assembled systems undergoing ordering of nanodomains in a polymer matrix at a supramolecular level is carried out as well. An important aspect is the highlighting of the complex effect of platelet-like and tubular nanoelements on the performance of multicomponent systems, and of micro/nano-reinforced microfibrillar composites. The controlled incorporation of graphite nanoplatelets led to the preparation of novel dually reinforced biocompatible materials, as well as of macroscopic fibers with unique properties. Very promising results have been achieved in thermoplastic and thermoset systems modified with bimodally grafted graphene oxide.

Fig. 1 Unique complex effect of bimodally grafted graphene on performance of a ductile/brittle system.

Carbohydrate Polymers (2020), Composites Part B: Engineering (2018), Polymer Testing (2020), Polymer Testing (2017), RSC Advances (2017)

Smart hydrogels with fast or very-fast stimulus response

This research is dedicated to the imitation of processes in living systems and to the design of corresponding synthetic smart materials. Super-porous nanocomposite gels reinforced with in-situ-formed nano-silica are able of ultra-fast volume response to temperature, and of very fast water uptake from the fully dried state. These gels were modified to be pH-responsive as well. As an alternative system, non-porous monolithic gels intercalated by starch were synthesized, which achieved surprisingly fast one-way responsivity to T and pH with potential applications in actuators and in drug release. A different non-porous alternative system are hydrogels crosslinked physically by clay nano-platelets, which are interesting due to their excellent mechanical and tensile properties.

Fig. 2 Monolithic non-porous PNIPA hydrogels intercalated by starch: materials with a tunable very fast to moderately slow one-way response to pH and temperature – potential actuators or drug release materials.

Soft Matter (2019), European Polymer Journal (2019), Sensors and Actuators B: Chemical (2017), Polymer International (2017), Soft Matter (2017)

Smart solvent-free materials based on self-assembled polymers

As a solvent-free alternative of the above-mentioned smart hydrogels, the reversible elastomers and smart oils based on LC copolymers are studied: Supra-molecularly assembled liquid-crystal (LC) copolymers with highly flexible chain segments were synthesized, which are crosslinked entirely physically, by interactions of the LC units. The temperature-sensitive behavior of the LC crosslinks makes possible switching between rubbery, plastic rubbery, viscoelastic and thin melt state. The reversible nature of the physical crosslinks also enables self-healing behavior. These smart polymers are of interest for potential applications in soft robotics, 3D printing, or as energy-absorbing materials. A different self-assembled material, which was found to display distinct internal self-healing, are the ultra-extensible solvent-free polyacrylate elastomers physically crosslinked by clay nano-platelets.

Fig. 3 Supra-molecularly assembled elastomeric networks based on liquid-crystalline copolymers – potential smart elastomers or liquids for soft robotics.

Journal of Applied Polymer Science (2021), European Polymer Journal (2020), Polymers (2020a), Polymers (2020b)

Cooperation

The Department cooperates with several Czech and foreign research teams, namely with:

Charles University (Prague)
Institute of Chemical Technology (Prague)
University of West Bohemia (Plzeň)
Institute of Physics of Materials (Brno)
Rzeszow University of Technology (Rzeszow, Poland)
Pierre and Marie Curie University (Paris, France)
Institut National des Sciences Appliquées (Lyon, France)
Institute of Composite and Biomedical Materials CNR (Portici, Italy)
University of Milano-Bicocca (Milan, Italy)
University of Novi Sad (Novi Sad, Serbia)
Central Leather Research Institute (Chennai, India)
University of Rio Grande do Sul (Brazil)

Recent Projects

EU- COST (HINT): MP1202: Rational design of hybrid organic-inorganic interfaces: the next step towards advanced functional materials, 2013–2016
Czech Science Foundation (GAČR): GA19-06065S: Upgrade of thermoset composites via self assembled structures based on modified carbon Nanoplatelets, 2019–2021
Czech Science Foundation (GAČR): GA19-04925S: Advanced smart and self-healing nanocomposite hydrogels sensitive to external stimuli, 2019–2021
Czech Science Foundation (GAČR): GA18-03932S: Polyurethanes with integrated inorganic/organic blocks and controllable hydrolytic stability, 2018–2020
Czech Science Foundation (GAČR): GA17-13103S: Advanced smart and self-healing polymer nanocomposites, 2017–2019
Czech Science Foundation (GAČR): GA16-03194S: Effect of modified graphene oxide on performance of multiphase polymer systems, 2016–2018
Czech Academy of Sciences: Programme for support of international cooperation (with CNR Italy): M200501203: Smart nanostructured polymers, 2013–2016
Czech Science Foundation (GAČR): GA13-15255S: Self reinforced polymer-polymer composites upgraded by nanofillers of various geometry, 2013–2016
Czech Science Foundation (GAČR): GA13-06700S: Multifunctional highly elastic polymer materials with controlled biodegradability, 2013–2016
Czech Science Foundation (GAČR): GA13-06700S: Multifunctional highly elastic polymeric materials with controlled biodegradability, 2013–2016