Stage 1 (2020) Scientific Report Abstract
Several tasks were carried out in LEPDICT’s 1st stage (2020, 2 months): (i) the synthesis / acquisition of precursors, intermediates, monomers with specific optical features; (ii) purification of solvents and reagents, precursors, intermediates, monomers (if necessary); (iii) physico-chemical evaluation of the resulting compounds.
Two organic compounds (and necessary intermediates) were synthesized and will be further used (in the 2nd stage) as monomers/building blocks for the construction of active polymers in the blue color domain: an aromatic oxadiazole derivative with amino terminal groups, and a dibromide-based derivative of fluorene substituted with nitrile end units.
These complex emissive species have undergone the necessary steps of purification and physico-chemical characterization, with emphasis on structural investigation and confirmation, processability (in terms of solubility / compatibility with other complex emissive building blocks and / or preparation methods of envisaged macromolecular compounds) and photo-optical behavior (light emission of a certain color). The evaluation of the luminescent traits confirmed the successful achievement of the main key goal of this stage: the preparation of complex emissive entities capable of emitting blue light, which can be used later in the synthesis of complex macromolecular architectures with photoluminescent activity. Given its difficulty, this task will be continued in the next stage (2021) of the project, to develop other complex emissive components, to serve the same function.
A LEPDICT-dedicated website (https://icmpp.ro/projects/l3 /about.php?id=31) was also created, being hosted on the official website of the coordinating institution (ICMPP). It aims to contribute to LEPDict’s visibility and to be a versatile dissemination tool during and post-implementation.
Stage 2 (2021) Scientific Report Abstract
LEPDICT’s 2nd stage (2021) simultaneously tackled various tasks: (i) the synthesis / acquisition of precursors, intermediates, monomers and / or polymers with specific characteristics (light emission in the green, red, blue, and orange domains); (ii) purification of solvents and reagents, precursors, intermediates, monomers and polymers (if necessary); (iii) optimization of synthetic procedures for the development of chemical species and emitting components (monomers and / or polymers) (if necessary); (iv) the achievement of complex emissive materials by physically blending monochrome luminescent polymers into a single material, in various combinations; (v) optimization of blending process (if necessary); (vi) structural and physico-chemical evaluation of resulting compounds, with emphasis on electro-optical properties and structure-properties correlations; (vii) support activities: dissemination and participation at scientific events.
The synthetic and analytical efforts from this stage were based on the use of chemical engineering (especially the selection of compatible structural elements and identification of optimal experimental conditions) as a productive tool to properly modulate charge transport, manage the color of emitted light and efficiently optimize optical conduct.
Most performed activities focused on identifying the optimal combination of structural building blocks (chemical chromophoric tools) in the same macromolecular architecture to successfully develop polymer-based materials capable of emitting light of a certain color, followed by blending them into a white-light-emitting layer. The latter task also implied a multi-level, extensive optimization process, to achieve a satisfactory degree of the emitted white light in solution and/or in solid-state (as confirmed by chromaticity diagrams’ coordinates).
Four series of complex emissive building blocks (two red-emissive building blocks, six green-emissive building blocks, five blue-emissive building blocks, two orange-emissive building blocks), four series of monochrome luminescent polymers (one red-emissive polymer, two gren-emissive polymers, three- blue-emissive polymers, one orange-emissive polymer-based material) and nine optimized, emissive polymer blends (seven in solution and two in solid-state) were developed in this manner.
Most results obtained throughout Stage 2 were disseminated in the form of three oral presentations and one poster at three international scientific events, and as three papers published in ISI-rated journals (total impact factor: 13.52).
Stage 3 (2022) Scientific Report Abstract
LEPDICT’s 3rd stage (2022) sequentially or concurrently engaged in various tasks: (i) the synthesis / acquisition of precursors, intermediates, monomers and / or polymers with specific characteristics; (ii) purification of solvents and reagents, precursors, intermediates, monomers and polymers (when necessary); (iii) optimization of preparation procedures involved in the development of active chemical species, polymers and materials (when necessary); (iv) structural and physico-chemical evaluation of resulting compounds, with emphasis on electro-optical properties, processability and structure-properties correlations; (v) preparation/acquisition of raw materials and/or auxiliary components for lab-scale PLEDs; (vi) design and fabrication of lab-scale PLED prototypes, with emission in the blue, respectively white range; (vii) physico-chemical assessment of the prototypes, with a focus on their emissive conduct; (viii) building correlations between design/components/fabrication and properties/optical response; (ix) optimization of PLEDs’ preparation process (when necessary) with a focus on enhancing the compatibility between the prototype’s structural elements, increasing efficiency, and tailoring the output color balance; (x) selecting the best performing PLEDs; (xi) support activities: dissemination and participation at scientific events.
The synthetic and analytical efforts from this stage were based on the use of fine organic synthesis, polymer chemistry and physics, and materials science (centered on the design and selection of compatible structural elements, identification of the most favorable blueprint and experimental conditions related to synthesis, design, fabrication, and optimization of PLEDs with specific optical response) as productive instruments to finely tune the proportion and interactions between emissive species, manage the color of emitted light and optimize the optical behavior at both (macro)molecular and PLED level.
Most of the performed activities focused on: (i) identifying the optimal combination of active structural building blocks (chromophoric structural segments) in the same macromolecular medley to successfully develop polymer-based materials able to emit light of a certain color, (ii) testing and validating active polymeric materials in PLED prototypes. The two development directions pursued in this stage also involved an extensive, multi-level optimization process to achieve a light emission with a satisfactory degree of purity both in the developed active materials as well as in the PLED prototypes built from them.
Two series of luminescent polymer materials (one active polymeric material incorporating emissive species in the red, green, and blue range, respectively; two active polymeric materials incorporating emissive species in the blue and orange range, respectively) and three sets of PLED prototypes (two lab-scale, PLED prototypes with emission in the blue range; 13 lab-scale PLED prototypes, with emission in the white range, 9 of which were then optimized) were developed and tested in this fashion.
Some of the results obtained throughout the project were disseminated in Stage 3 in the form of 4 presentations at 2 international scientific events, and as 1 national patent application.
2 Short training stages were also carried out for 2 of the team members (1 PhD student member).
Publications
- Pavel Nitschke, Bozena Jarzabek, Andra-Elena Bejan, Mariana-Dana Damaceanu. Effect of protonation on optical and electrochemical properties of thiophene-phenylene-based schiff bases with alkoxy side groups. Journal of Physical Chemistry B, 125, 30, 8588-8600 (2021) https://doi.org/10.1021/acs.jpcb.1c05390
- Catalin-Paul Constantin, Mihai Asandulesa, Cristian Varganici, Violeta Melinte, Maria Bruma, Andrzej Jankowski, Aleksandra Wolinska-Grabczyk, Mariana-Dana Damaceanu. Exploring the potential of thin films made from poly(imide-amide-sulfone)s for engineering applications. Materials Science & Engineering B, 270, 115217 (2021) https://doi.org/10.1016/j.mseb.2021.115217
- Irina Butnaru, Adriana-Petronela Chiriac, Codrin Tugui, Mihai Asandulesa, Mariana-Dana Damaceanu. The synergistic effect of nitrile and jeffamine structural elements towards stretchable and high-k neat polyimide materials. Materials Chemistry Fontiers, 5, 7558-7579 (2021) https://doi.org/10.1039/D1QM00643F
Conferences
- Mariana-Dana Damaceanu, Catalin-Paul Constantin, Radu-Dan Rusu. Insights into some organic light-emitting materials based on a donor-acceptor system for OLEDs. 13th International Conference on Physics of Advanced Materials ICPAM-13, September 24 – 30, 2021, Sant Feliu de Guixols, Spania.
- Radu-Dan Rusu. Fluorene-based chemical tools for light-emitting materials. 13th International Conference on Physics of Advanced Materials ICPAM-13, September 24 – 30, 2021, Sant Feliu de Guixols, Spania
- Mariana-Dana Damaceanu, Catalin-Paul Constantin. Phenoxazine-based polymers with blue and green light emission in solid state for light-emitting diode applications. New trends and strategies in the chemistry of advanced materials with relevance in biological systems, technique and environmental protection, 13th Edition, online, October 7 – 8, 2021, Timisoara, Romania.
- Irina Butnaru, Cristian Logigan, Mariana-Dana Damaceanu. Study of new imines containing a phenanthroline chromophore. Progress in Organic and Macromolecular Compounds, 28th Edition, International Conference, MacroIasi 2021, October 7 – 9, 2021, Iasi, Romania.
- Radu-Dan Rusu. Organic polymeric blends for solution-processed white organic light-emitting diodes. 14th International Conference on Physics of Advanced Materials ICPAM-14, September 8 – 15, 2022, Dubrovnik, Croatia
- Catalin-Paul Constantin. Tailorable photophysiscal behavior of Schiff base polymers containing electron donor and acceptor segments. 14th International Conference on Physics of Advanced Materials ICPAM-14, September 8 – 15, 2022, Dubrovnik, Croatia
- Radu-Dan Rusu. Optimization of polyfluorene synthesis towards reliable blue light emission. 1st Baltic Symposium on Polymer and Biomaterials Science – Baltic Biomat, September 22 – 23, 2022, Szczecin, Poland
- Trofin Ioana-Alexandra, Catalin-Paul Constantin, Rusu Dan-Radu. Organic polymeric blends for solution and solid-state white light emission. 1st Baltic Symposium on Polymer and Biomaterials Science – Baltic Biomat, September 22 – 23, 2022, Szczecin, Poland
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