The Cultural Heritage And Responsive Materials (CHARM) group concentrates in the design of responsive molecules and materials where external stimuli allow control over the direction and outcome of chemical and photochemical reactions and on the science of sustainable conservation of Cultural Heritage. Photochemistry and physical chemistry tools and models and the principles of supramolecular chemistry are applied to:
- The study of a number of photo, electro and thermal induced reactions in a range of responsive materials commercially important for chromogenic displays, DSSCs, luminescent glasses, alternative solvents and luminescent probes.
- The preservation of materials incorporated in Cultural Heritage objects (i.e. from Illuminated Manuscripts to Contemporary Art and Photography) that requires research to determine their original chemical and physical state, and to identify agents and mechanisms of change and degradation.
State of the art analytical instrumentation and expertise from a wide range of disciplines is available for the identification of complex aged materials and to address questions of context and meaning in their use, as well as the impact of previous and contemporary interventions. Innovations for preservation treatments include research and application of Liquid and Supercritical CO2 and Ionic Liquids.
The interdisciplinary environment conveys an integrated approach where state of the art materials and techniques are applied in conservation and the knowledge over how ancient materials have endured inspire the design or development of materials with enhanced properties.
Causes and mechanisms of alteration
- Medieval illuminated manuscripts and polychrome sculpture.
- Amadeo de Souza-Cardoso and 19th century artists’ paints.
- 19th century, Modern & Contemporary Cultural Heritage.
Sustainable innovative methods
- Applications of super critical and liquid CO2
- Applications of ionic liquids.
- New advanced methods of dyes analysis.
Historical reconstructions database
- The book on how to make colours.
- The Winsor & Newton artist materials supplier, 19th century archive.
Anthocyanins and flavylium salts
- Photochromic systems based on anthocyanin family derivatives
- Host-guest systems for improved performance
- New anthocyanin familiy derivatives for DSSCs
Ionic liquids and alternative solvents
- Innovative active pharmaceutical drugs based ionic liquids
- Photochromic Ionic liquids to control rheology with light
- Green electrolytes for electrochromic devices
- Ionic liquids for CO2 capture and conversion
- New organic components for electrochromic devices
- New wet methods for material deposition
- New ITO-free conductive coatings for improved transparence
Luminescent glass materials
- Rare-earth photoluminescence.
- Towards fabrication of quantum-dots in aluminoborosilicate glasses.
- Corrosion mechanisms of glass surfaces and cleaning strategies. Application in stained-glass restoration.
Light activated sensors and actuators
- Multichanel fluorescent sensors for O2, temperature and biologically relevant targets
- Light control over nucleic acid enzimatic polimerization
- Heating through UV/Vis light absorption and non-radiative dumping
- Aggregation induced emission of metalophylic hydrogels
- Lorvão Beatus (1189) UNESCO´s Memory of the World Register
Our team contributed to the interdisciplinary chemical and historical research on the Manuscripts of the Commentary to the Apocalypse (Beatus of Liébana) in the Iberian tradition, which led to the successful entry of 12th century Portuguese Beatus into UNESCO´s Memory of the World Register. Pigment analysis combined with documentary evidence allowed a complete reinterpretation of the color use and depiction of figures in Lorvão Beatus (1189). This research resulted in the codex being recognized as a unique and important contribution to World Heritage.
- Electrochromic Devices
Printed graphics are emerging to the age of interactivity with innovative advanced materials sets allowing the design of smart objects and environments. Electrochromics enables mass producible ultra low-power interactive displays to create the so-called “Internet -of-Things” (IoT). Recently, we have chemically designed semiconductor polymers interactions with carbon nanomaterials and proposed novel electrochromic ionic liquids based on low-cost deep eutectic solvents. As a result, a strong international collaboration with Academia and Industry (e.g., Ynvisible and Sonae Industria de Revestimentos) gave rise to two recent H2020 Projects, bringing together a strong interdisciplinary consortium in 9 different countries, industry and research, that will provide toolkits to introduce printed electrochromics to designers and the printing industry.
- Anthocyanin multistate systems
Anthocyanins are an important family of compounds belonging to the flavonoid group, responsible for the different shades of reds and blues of most flowers and fruits. Besides their role as plant colorants there is evidence that regular consumption of anthocyanins and other polyphenols, reduce the risk of some chronic diseases, due to their anti-oxidant properties. During the last two decades we pioneered work on anthocyanins and related flavylium compounds and a rich experimental and theoretical knowledge has been accumulated, recognized. While there are only six common natural anthocyanins, it is possible to design and prepare bio‐inspired derivatives, more adapted to specific functions. Information systems based on the photochromism within the flavylium network of chemical reactions, able to write‐read‐erase, have been reported, including an illustration of how these system can mimic elementary properties of neurons, and molecular logic gates. The work on anthocyanins provided the seed for contributing to cleaner energy solutions, a societal challenge; anthocyanins were used for building bio‐inspired Dye Sensitised Solar Cells (DSSC), and a DSSC with 3.1% efficiency has been built and the next generation of flavylium compounds for DSSC is under study.
- CO2 Capture and Conversion (CCU) in fuels
Prominent among the technological challenges to be reached is the development of photochemical mechanisms that lead to the efficient production of H2 from water and sunlight. Once produced, H2 may be used directly to power fuel cells or may be further converted into CH4 or fixed into liquid fuels via hydrogenation of CO2 . Our team have contributed to the integration of TiO2 and an Au(I) complex containing a thiocoumarin moiety resulting in a very efficient photocatalyst for the generation of H2 . We have also contributed for Carbon Capture and Utilization (CCU) achievements by the discovery of efficient reversible carbon dioxide capture using bioinspired systems (aminoacids, saccharides, cellulose) in combination with suitable organic superbases, as well as the innovative approaches for catalytic conversion of carbon dioxide in methane using metal nanoparticles/ionic liquid systems.