Project: Development of novel PHOTOluminescent PROducts .

The aim of the PHOTOPRO project is to develop new photoluminescent pigments coated with silica and formulate these in paints and inks used COly in safety fire protection._x000D_The PHOTOPRO project was submitted to Eurostars Programme (Eurostars Cut-Off 8). The project was positively evaluated, been ranked above the quality threshold. However, as consequence of the score obtained, the project didn’t obtain funding from national funding agency’s. For this reason, we are re-submitting the PHOTOPRO project at Eurostars Cut-Off 9. The consortium has tried to improve the proposal, analyzing the state of the art, research method, technological alternatives and specific market demands._x000D_Making complex formulations or just adding a functional material to a formulation such as a paint, ink or emulsion often gives incompatibility or dispersion problems. Chemical reactivity of the various ingredients or surface energy and polarity differences can make it difficult or even impossible to add a certain material to a certain formulation. This is the case of photoluminescent coatings._x000D_For them, IMPLASER and PINAY have a need for luminescent pigments such as for example Eu doped Sr2MgSi2O7, (1) that are easy to disperse in inks and paints in order to minimize mixing times, increase stability of pigments in the formulation and increase the efficiency of the pigments. Protecting the material of interest by coating or surface modification is a logical strategy that can be used. The coating should of course not influence the activity of the material of interest (2). For example when coating a dye or pigment, one needs to be sure the coating material is transparent for visible light. _x000D_Silica is a cheap, transparent and relatively stable material that can be prepared from liquid precursor solutions (3). Silica can also easily be surface modified by reacting the surface with organo silane molecules (4). A monomolecular layer with desirable surface energy or reactivity can be prepared via self-assembly methods. Silica can be used in composite materials where the silica encapsulates organic or inorganic functional materials (5)._x000D_A silica encapsulation method of composite luminescent particles possibly followed by a surface modification step should yield a type of luminescent pigments that can be made compatible with any formulation. The luminescent pigments should have similar or better luminescent properties compared to the base luminescent material. _x000D_We aim for a production method that can easily be scaled up and that will be industrially and economically interesting. By developing a pigment with the correct surface energy (for every application) we think formulation of the pigments will be easier and cheaper than when the non-coated materials are used. The particle size of the composite pigments should be in the same order as those of the luminescent material or bigger._x000D_The coating process should be compatible with a number of different luminescent materials that vary in absorption and emission wavelength and phosphorescence decay times._x000D_After the luminescent materials have been coated with silica, a second coating step using organosilanes with reactive alkoxide or chloride functionalities may be used in order to, for example, make the pigment hydrophobic, or giving it a reactive type coating (e.g. amine or thiol)._x000D_Luminescent materials are used in many applications ranging from watch handles and glow in the dark toys to safety signs. In this project we will COly focus on the safety sign (passive fire protection) and paint markets. Safety signs need to apply with certain standards that tell how much light needs to be emitted for how long after a certain exposure time. The envisioned pigments will be directly useful for the 2 end-users R&D SMEs in this project. Besides that, the novel pigments can also be interesting for parties outside this consortium._x000D_The consortium consists of 2 R&D SMEs, 1 SME and 2 research institutes. One of them, NANOLOGICA, produces microparticles and will work on the preparation of silica coated luminescent pigments. The other 2, IMPLASER and PINAY will use these pigments in their formulations; paints and inks, to fabricate end-products that will be on the consumer market._x000D_The 2 research institutes, AIDO (subcontracted) and YKI, will perform the CO part of the optical and physical chemical analysis and will also assist in formulation, pigments synthesis and surface modification. The three SMEs will have a direct economic benefit if the project goals are reached._x000D_1. A. A. Sabbagh Alvani et al., Journal of Luminescence 115 (2005) 147–150_x000D_2. M. A. Garcia et al., Journal of Luminescence 93 (2001) 253–259_x000D_3. Wright and Sommerdijk, Sol-Gel Materials chemistry and applications, (2001), Taylor and Francis, London. ISBN: 90-5699-326-7_x000D_4. J. Sagiv et al., J. Colloid Interface Sci., (1984), 100, 465_x000D_5. N. Andersson et al. J. Mater. Chem., (2007), 17, 2700-2705 and N. Andersson et al. J. Mater. Chem., (2005), 15, 3507

Acronym PHOTOPRO (Reference Number: 7827)
Duration 01/10/2013 - 30/09/2015
Project Topic Photoluminescent pigments will be silica coated and, if necessary, surface modified in order to enhance the dispersability of these pigments in inks and paints, thus increasing their performance and bringing down formulation costs.
Project Results
(after finalisation)
During the first year of the project (October 2013 - December 2013) the CO results were:_x000D_- Optical characterization of three photoluminescent pigments._x000D_- Definition of the polymeric binders._x000D_- Definition of the silica coating_x000D_With these results the consortium continued working with the planified work for the second year (January - December 2014). During this period the CO technical results were: _x000D_- The design of the protocols for the spray drying and solution process for the encapsulation of the new photoluminescent pigments. _x000D_- Encapsulation and characterization of the photoluminescent pigments with the two studied processes._x000D_- Formulation of photoluminescent inks and paints with the new pigments. _x000D_- Optimization of the encapsulation process and study of new alternatives to silica spray drying coating with the treatment with fatty acids._x000D_With these results the consortium continued working with the planified work for the third year (January - September 2015). During this period the CO technical results were: _x000D_- Optimization of the encapsulation process with silica and oleic acid. During 2015, within the task 1.5 and task 2.4, the consortium have worked in the introduction of some changes in the protocol that allow an improvement, like the decrease of the amount of water, heat treatments, and changes in the amount in TEOS and oleic acid._x000D_- Complete characterization of the encapsulated pigments and definition of its physical, chemical and optical properties. In the optimization task, the physico-chemical characterization of all the encapsulated pigmets have been done._x000D_- Study and analysis of the Life Cycle Assesment of the new pigments, inks and paints. _x000D_- Formulation of photoluminescent inks and paints, definition of the optimal formulation from the results of mechanical, phisical, chemical and optical tests. It has been obtained a selection of different formulas to select the optimal formulation depending of the results of the printing tests._x000D__x000D_In general terms, silica and oleic acid coating of the pigments offer new functionalities to the pigments. Firstly, silica and oleic acid avoid the hydrolisis from water and avoid the corrosion by external agents like acid rain. The final luminescence is slightly lower but it is agree with the standard UNE 23035 for Fire safety protection and photoluminescent signage. Furthermore, oleic acid allows a better dispersion of the pigment into the inks, so less thinner and energy is needed. _x000D_
Network Eurostars
Call Eurostars Cut-Off 9

Project partner

Number Name Role Country
4 SP, Technical Research Institute of Sweden Partner Sweden
4 Nanologica AB Partner Sweden
4 IMPLASER 99 S.L.L. Coordinator Spain