This research line focuses on the development of smart optical nanomaterials-based coatings and films that enhance visual and thermal comfort while contributing to energy efficiency, solar energy harvesting, and solar energy storage. Our work combines nanotechnology, material science, and sustainable processing to engineer multifunctional coatings that intelligently interact with solar radiation.
All these technologies are based on polymeric nanocomposites incorporating core-shell micro/nanocapsules or oil nanodroplets, which enable the transfer of the optical properties of liquid formulations into robust solid coatings. This encapsulation strategy enhances optical performance, stability, and processability while facilitating scalable and environmentally friendly manufacturing, making these materials highly attractive for practical energy and photonic applications.
Our research is organized into three main areas:
- Smart Modulation of Solar Light Transmittance. We develop stimuli-responsive optical coatings capable of dynamically regulating solar light transmission in response to environmental conditions (light intensity and temperature) or user-controlled electrical stimuli. These systems provide effective photoprotection while improving indoor visual and thermal comfort.
Our research includes the development of photochromic, thermochromic, electrochromic, and multi-stimuli-responsive materials (e.g., photothermochromic systems) with enhanced adaptability to different climatic conditions and geographical regions. Particular emphasis is placed on improving long-term stability, scalability, and sustainability through waterborne coating technologies.
Target applications include architectural glazing, vehicle windows, helmet visors, and ophthalmic lenses, where dynamic solar control can significantly reduce energy consumption associated with lighting and air conditioning. - Solar Light Harvesting, Concentration, and Conversion. We design luminescent nanocomposite coatings capable of filtering, capturing, converting, and concentrating solar radiation through the incorporation of nanoencapsulated fluorophores. These fluorophores absorb incident sunlight and re-emit it at longer wavelengths, while the emitted light is guided by total internal reflection towards the edges of the device.
These luminescent solar concentrators (LSCs) can be coupled with photovoltaic cells positioned at their edges to generate electricity. Additionally, by selectively filtering and downshifting solar radiation, these coatings offer promising opportunities for greenhouse technologies, where the spectral modification of sunlight can promote plant growth.Our research focuses on improving the optical efficiency, photostability, and scalable manufacturing of LSCs through sustainable, aqueous-based fabrication methods enabled by advanced encapsulation strategies.
- Solar Thermal Energy Storage. We develop multifunctional coatings capable of filtering, capturing and storing solar energy through reversible photochemical and thermally driven processes. Solar energy is stored either via the light-induced isomerization of photochromic molecules or through the latent heat associated with the melting and crystallization of phase change materials (PCMs).
By embedding photochromic compounds and PCM micro- or nanoparticles into polymeric coatings, we aim to fabricate solid-state materials with high energy storage and release capacities, enabling passive thermal regulation and energy management, while actuating as photoprotectors.
Key projects
Ongoing
- WINPRINT. Inkjet-printed smart window coatings for energy-savings
Ajuntament de Barcelona – La Caixa, Recerca i innovació, 2025_OVT_280480
Duration: 01/12/2025-30/11/2027; Partners: Futurechromes, UPC - RESHAPE. Preparation of visible light energy-harvesting polymer nanocomposites based on phase change materials nanostructures containing photoswitching dye/photosensitizer
MICIU, AEI, FEDER, Generación de Conocimiento, PID2024-160803NB-C33
Duration: 01/09/2025-31/08/2028; Partners: ICMAB, UPC - CAPTEN-2. New nanocomposite-based luminescent solar concentrators for efficient solar energy capture, concentration and conversion
Entidad/Tipo de proyecto: AGAUR, Producte, 2024 PROD 00290
Duración: 01/09/2025-31/02/2027
Ended
- Nanocomposite-based luminescent solar concentrators for electric power generation from transparent surfaces
ICN2, MCIU/AEI, Programa Severo Ochoa, valorización tecnológica
Duration: 01/01/2025-31/12/2025 - CAPTEN. Solar energy capture and conversion via nanocomposite-based luminescent solar concentrators
AGAUR, Llavor, 2023 LLAV 00042
Duration: 01/02/2024-31/07/2024 - SOLAR. Development of advanced photochromic materials for solar light autoregulation
MCIN/AEI/10.13039/501100011033, Next GenerationEU/PRTR, Colaboración público-privada, CPP2021-008883
Duration: 01/09/2022-31/08/2025; Partners: Futurechromes, Idonial - SMARTER. Design and development of photoactive SMART nanocomposites self-responding to low-Energy solar Radiation, for energy saving in buildings
MCIN/AEI/10.13039/501100011033, NextGenerationEU/PRTR, Transición ecológica y digital, TED2021-131709B-I00
Duration: 01/12/2022-30/11/2024 - TransWIN. Multistimuli-responsive coatings with transparency modulation for smart windows
AGAUR, Producte, PROD 00190
Duración: 01/11/2022-30/04/2024; Partners: UAB - PCM4Win. Polymer composites of phase change materials for next-generation smart windows
MCIN/AEI/10.13039/501100011033, Next GenerationEU/PRTR, Prueba de concepto, PDC2022-133368-I00
Duration: 01/12/2022 – 30/04/2025; Partners: UAB - NIRGLASS. New generation of chromogenic materials for smart glasses
AGAUR, Innovador, INNOV 00070
Duration: 01/09/2020-28/02/2022 - ADAPTALITE. Pinturas Fotocrómicas en Polvo para su Uso en Arquitectura de Exteriores de Alto Valor Añadido
MICIN/AEI/FEDER, Retos de colaboración, RTC-2014-3128-6
Duration: 09/2014-12/2016; Partners: Adaptacolor
Key technology transfer
Spinoff
- Futurechromes S.L. (2014-present)
Patents
- Nanocomposites for luminescent solar concentrators (LSCs) (WO2026022270)
Priority date: 25/07/2024
Application number: EP24382821.7
Inventors: C. Roscini (ICN2), D. Ruiz-Molina, Alex Parra, L. Vallan
Assignees: UAB, CSIC, ICN2
State: PCT application. - A thermoresponsive composition with tunable light transmittance (WO2024104958A1)
Priority date: 14/11/2022
Application number: EP22383094
Inventors: J. Hernando, J. Otaegui Ramón, C. Roscini (ICN2), D. Ruiz-Molina
Assignees: UAB, CSIC, ICN2
State: Abandoned. - Film made of a polymeric material having thermo-photochromic properties for controlling the colour of glazed surfaces and plastic materials (WO2017191346A1)
Priority date: 03/05/2016
Application number: P201630572
Inventors: C. Roscini (ICN2), A. Julià-López, D. Ruiz-Molina
Assignee: CSIC, ICN2, Futurechromes S. L.
State: Abandoned. - Nanoemulsion optical materials (WO2017105666A1)
Priority date: 14/12/2015
Application number: US201514968586
Inventors: C. Roscini (ICN2), H. Torres-Pierna, D. Ruiz-Molina
Assignees: Futurechromes S. L., ICN2, CSIC, IOTA
State: Granted in USA (US10227527B2), China (CN108770348B), India (201817024314), Brazil (BR112018012014B1), Japan (JP7183365B2), Canada (CA3008601C) - Coating with photochromic properties, method for producing said coating and use thereof applicable to optical articles and glazed surfaces (WO2013132123A1)
Priority date: 08/03/2012
Application number: P201200238
Inventors: J. Hernando Campos, C. Roscini (UAB), N. A. Vázquez Mera, D. Ruiz-Molina
Assignee: CSIC
License: Futurechromes S. L.
State: Granted in USA (US9885808B2), Japan (JP6151725B2), Israel (IL234381B), Europe (EP2823883B1), China (CN104394980B)
Key publications
- Weather-Resistant Thermoresponsive UV-Curable Smart Window Composites Based on Paraffin Particles
ACS Appl. Mater. Interf., 2026, 0:e73786
M. Villabona, L. Vallan, D. Ruiz-Molina, C. Roscini, J. Hernando
DOI: https://doi.org/10.1021/acsami.6c04877 - Energy Transfer in Nanodroplet-Based Luminescent Solar Concentrators
Small, 2026, 0:e73786
L. Vallan, J. W. Mikurenda, A. Parra Sánchez-Camacho, M. Lili, S. J. M. Robben, S. C.J. Meskers, M. G. Debije, C. Roscini
DOI: https://doi.org/10.1002/smll.73786 - Cost-effective paraffin particles-based thermochromic composites for smart windows and greenhouses
Small Struct., 2025, 2500250
L. Vallan, J. Otaegui Rabanal, D. Ruiz-Molina, J. Hernando, C. Roscini
DOI: https://doi.org/10.1002/sstr.202500250 - Enhanced Electrochromic Smart Windows Based on Supramolecular Viologen Tweezers
Chem. Mater., 2025, 37, 2220–2229
J. R. Otaegui, S. Mena, J. M. Dorsainvil, G. Guirado, D. Ruiz-Molina, J. Hernando, J. C. Barnes, C. Roscini
DOI: https://doi.org/10.1021/acs.chemmater.4c03174 - Light phase modulation with transparent paraffin-based phase change materials
Adv. Opt. Mater., 2024, 2401008
J. R. Otaegui, Y. Bertschy, L. Vallan, F. Schmidt, A. Vasista, J. Garcia-Guirado, C. Roscini, R. Quidant, J. Hernando
DOI: https://doi.org/10.1002/adom.202401008 - Multistimuli-responsive smart windows based on paraffin-polymer composites
Chem. Eng. J., 2023, 463, 142390
J. R. Otaegui, D. Ruiz-Molina, J. Hernando, C. Roscini
DOI: https://doi.org/10.1016/j.cej.2023.142390 - Highly transparent and tunable fast-responsive photochromic materials based on nanoemulsion
Mater. Horiz., 2020, 7, 2749–2759
H. Tórres-Pierna, D. Ruiz-Molina, C. Roscini
DOI: https://doi.org/10.1039/D0MH01073A - Solid materials with tunable reverse photochromism
ACS Appl. Mater. Interfaces, 2019, 11, 11884–11892
A. Julià-López, D. Ruiz-Molina, J. Hernando, C. Roscini
DOI: https://doi.org/10.1021/acsami.8b22335 - Photochromism of dihydroazulene-based polymeric thin films
Dyes Pigm., 2017, 145, 359–364
H. Torres-Pierna, C. Roscini, A. Vlasceanu, S. Broman, M. Jevric, M. Cacciarini, M. B. Nielsen, D. Ruiz-Molina
DOI: https://doi.org/10.1016/j.dyepig.2017.06.015 - Temperature-Controlled Switchable Photochromism in Solid Materials
Angew. Chem., Int. Ed., 2016, 128, 15268–15272
A. Julià-López, J. Hernando, D. Ruiz-Molina, P. González-Monje, J. Sedó, C. Roscini
DOI: https://doi.org/10.1002/ange.201608408 - Liquid-Filled Valence Tautomeric Microcapsules: A Solid Material with Solution-Like Behavior
Adv. Funct. Mater., 2015, 25, 4129–4134
N. A. Vázquez-Mera, C. Roscini, J. Hernando, D. Ruiz-Molina
DOI: https://doi.org/10.1002/adfm.201501166 - Liquid-Filled capsules as fast responsive photochromic materials
Adv. Opt. Mater., 2013, 1, 631–636
N. A. Vázquez-Mera, C. Roscini, J. Hernando, D. Ruiz-Molina
DOI: https://doi.org/10.1002/adom.201370054
Key private collaborators
Futurechromes, Idonial, Novogenio, Ariño Duglass
Key collaborators
Prof. Jonathon Beves (University of New South Wales, Australia – Singlet fission/FRET in solid films), Prof. Kerui Li (State Key Laboratory of Advanced Fiber Materials, College of Materials Science, China – Smart windows), Prof. Michael Debije (Technology University of Eindhoven, The Netherland – Luminescent solar concentrators), Prof. Jonathan Barnes (Washington University, USA – Smart windows), Prof. Martina Cacciarini (Florence University, Italy – Solar thermal energy storage), Prof. Mogens Brøndsted Nielsen (University of Copenhaguen, Denmark – Solar thermal energy storage), Prof. Loredana Latterini (Perugia University, Italy – Photon energy upconversion), Dr. Joaquim Romaní Picas (Institut de Recerca en Energia de Catalunya, IREC – Smart windows), Dr. Mariano Campoy (Instituto de Ciencia de Materiales de Barcelona, ICMAB – luminescent solar concentrators), Prof. Emilio J. Juárez-Perez (Instituto de Nanociencia y Materiales de Aragón, INMA – Smart windows), Prof. David Amabilino (Instituto de Ciencia de Materiales de Barcelona, ICMAB – Solar thermal energy storage), Prof. Kasper Moth-Poulsen, Universidad Politécnica de Cataluña, UPC – Solar thermal energy storage), Dr. Amador Menéndez (Fundación Idonial – Smart Windows), Prof. Jordi Hernando Universitat Autonoma de Barcelona – Smart Windows).