Staff directory Jaume Ramón Otaegui Rabanal

Jaume Ramón Otaegui Rabanal

Visiting Doctoral Student
Universitat Autònoma de Barcelona (UAB)
Nanostructured Functional Materials



  • Multistimuli-responsive smart windows based on paraffin-polymer composites

    Otaegui, JR; Ruiz-Molina, D; Hernando, J; Roscini, C Chemical Engineering Journal; 463: 142390. 2023. 10.1016/j.cej.2023.142390.


  • Multimodal Fluorescence Switching Materials: One Dye to Have Them All

    Otaegui J.R., Carrascull-Marín A., Ruiz-Molina D., Hernando J., Roscini C. Advanced Optical Materials; 2022. 10.1002/adom.202200083.

    Off/on, on/off, and on1/on2 fluorescence switching systems find application in a variety of areas, for each of which a particular dye or dye-switch tether must be specifically designed and synthesized. Herein it is demonstrated that such tight requirement can be avoided by using easily prepared mixtures of readily available emitters and phase change materials (PCMs). By proper selection of the PCM and, if needed, additives, thermo- and photothermoresponsive materials showing all classes of emission switching modes can be prepared from a single dye and without chemical modifications. This strategy can be generalized to distinct emitters and, thanks to the facile and versatile printability of dye–PCM mixtures, it can be used for the fabrication of fluorescent patterns showing complex (photo)thermal responses with direct applicability in sensing and anti-counterfeiting. © 2022 The Authors. Advanced Optical Materials published by Wiley-VCH GmbH.

  • Tunable Thermofluorochromic Sensors Based on Conjugated Polymers

    Bellacanzone C., Otaegui J.R., Hernando J., Ruiz-Molina D., Roscini C. Advanced Optical Materials; 10 (10, 2102423) 2022. 10.1002/adom.202102423. IF: 9.926

    Even though thermofluorochromic materials are eternal candidates for their use in multiple applications, they are still limited as they require complex synthetic strategies to accomplish tunable optical properties and/or provide optical changes only over a very wide temperature range. By taking advantage of the high sensitivity of the optical properties of conjugated polymers and oligomers to the external environment, herein phase change material (PCM)-based thermofluorochromic mixtures are created, where the solid-to-liquid transition of the PCM host triggers a sharp fluorescence color change of the dispersed polymers/oligomers. Fluorophore conjugation length, concentration, and PCM nature can be used to vary the spectral properties of the resulting materials along the visible region, covering a large part of the CIE 1931 color space. For the preparation of functional devices, this behavior can be directly transferred to the solid state by soaking or printing cellulose papers with the obtained thermofluorochromic mixtures as well as by structuring them into solid lipid particles that can be dispersed within polymer matrices. The resulting materials show very promising features as thermal sensors and anticounterfeiting labels. © 2022 The Authors. Advanced Optical Materials published by Wiley-VCH GmbH.


  • Thermoresponsive multicolor-emissive materials based on solid lipid nanoparticles

    Otaegui J.R., Ruiz-Molina D., Latterini L., Hernando J., Roscini C. Materials Horizons; 8 (11): 3043 - 3054. 2021. 10.1039/d1mh01050f. IF: 13.266

    Despite the recent advances in the field of thermofluorochromism, the fabrication of thermoresponsive multicolor-emissive materials in a simple, low-cost and versatile manner still remains a challenge. Herein we accomplish this goal by expanding the concept of matrix-induced thermofluorochromism, where a sudden two-state variation of dyes' emission is promoted by the solid-liquid transition of a surrounding phase change material (e.g., paraffins). We demonstrate that this behavior can be transferred to the nanoscale by the synthesis of dye-loaded solid lipid nanoparticles, different types of which can then be combined into a single platform to obtain multicolor thermofluorochromism using a single type of emitter. Because of the reduced dimensions of these particles, they can be utilized to prepare transparent nanocomposites and inkjet-printed patterns showing complex thermoresponsive luminescence signals and applications ranging from smart displays to thermal sensing and high-security anti-counterfeiting. © 2021 The Royal Society of Chemistry.


  • Color-Tunable White-Light-Emitting Materials Based on Liquid-Filled Capsules and Thermally Responsive Dyes

    Vázquez-Mera N.A., Otaegui J.R., Sánchez R.S., Prats G., Guirado G., Ruiz-Molina D., Roscini C., Hernando J. ACS Applied Materials and Interfaces; 11 (19): 17751 - 17758. 2019. 10.1021/acsami.9b02169. IF: 8.456

    Color-tunable white-light-emitting materials are currently attracting much attention because of their potential applications in artificial lighting, sensing, and imaging. However, preparation of these systems from organic emitters is often cumbersome due to the interchromophoric interactions occurring upon solvent drying in the final solid materials, which can be hardly predicted and may lead to detrimental effects. To circumvent these obstacles, we have developed a new fabrication methodology that relies on dye encapsulation within liquid-filled capsules, thus enabling direct transfer of the luminescent properties from solution to the solid state and as such, rational design of miniaturized white-light-emitting materials. By introducing a thermally responsive chromophore into the capsules, these materials are further endowed with color tunability, which does not only allow ample modulation of the emitted color but also facilitate external fine control of the system so as to ensure precise realization of white light at the desired temperature and excitation wavelength. © 2019 American Chemical Society.