Projects / Programmes source: ARRS

Thermo- and Photo-Active Coatings for Windows

Research activity

Code Science Field Subfield
2.03.03  Engineering sciences and technologies  Energy engineering  Renewable resources and technologies 

Code Science Field
T155  Technological sciences  Coatings and surface treatment 

Code Science Field
2.03  Engineering and Technology  Mechanical engineering 
sol-gel technology, thermochromic and photocatalytic coatings, energy efficient window, "green" window, structural, optical and functional properties
Evaluation (rules)
source: COBISS
Researchers (23)
no. Code Name and surname Research area Role Period No. of publicationsNo. of publications
1.  03439  PhD Peter Bukovec  Natural sciences and mathematics    2016 - 2019  543 
2.  16256  PhD Romana Cerc Korošec  Natural sciences and mathematics  Researcher  2016 - 2019  318 
3.  21628  PhD Nataša Čelan Korošin  Natural sciences and mathematics  Researcher  2016 - 2019  60 
4.  34949  PhD Mattia Fanetti  Engineering sciences and technologies  Researcher  2016 - 2019  141 
5.  31463  PhD Dorota Agnieszka Korte  Natural sciences and mathematics  Researcher  2016 - 2019  144 
6.  15804  PhD Irena Kozjek Škofic  Natural sciences and mathematics  Researcher  2016  74 
7.  06699  PhD Roman Kunič  Engineering sciences and technologies  Researcher  2016 - 2019  381 
8.  11873  PhD Urška Lavrenčič Štangar  Natural sciences and mathematics  Principal Researcher  2016 - 2019  521 
9.  37626  Petra Makorič    Technician  2016 - 2018 
10.  33865  PhD Lev Matoh  Natural sciences and mathematics  Researcher  2016 - 2019  48 
11.  33498  PhD Mohor Mihelčič  Engineering sciences and technologies  Researcher  2016 - 2019  121 
12.  13399  PhD Nataša Novak Tušar  Natural sciences and mathematics  Researcher  2016 - 2019  399 
13.  17274  Mojca Opresnik    Technician  2016 - 2019  20 
14.  02565  PhD Boris Orel  Natural sciences and mathematics    2017 - 2019  980 
15.  50323  Olena Pliekhova  Natural sciences and mathematics  Researcher  2018 - 2019  27 
16.  29027  PhD Mojca Rangus  Natural sciences and mathematics  Researcher  2016  105 
17.  22701  PhD Lidija Slemenik Perše  Engineering sciences and technologies  Researcher  2016  380 
18.  14121  PhD Angelja Kjara Surca  Natural sciences and mathematics  Researcher  2016 - 2019  390 
19.  31797  Barbara Šubic  Engineering sciences and technologies  Researcher  2016 - 2019  35 
20.  34546  PhD Andraž Šuligoj  Natural sciences and mathematics  Researcher  2017 - 2019  89 
21.  32016  PhD Aleš Ugovšek  Engineering sciences and technologies  Researcher  2016 - 2018  89 
22.  37518  PhD Nives Vodišek  Engineering sciences and technologies  Junior researcher  2016 - 2017  14 
23.  26472  PhD Suzana Žižek  Natural sciences and mathematics  Researcher  2016 - 2017  86 
Organisations (5)
no. Code Research organisation City Registration number No. of publicationsNo. of publications
1.  0103  University of Ljubljana, Faculty of Chemistry and Chemical Technology  Ljubljana  1626990  22,041 
2.  0104  National Institute of Chemistry  Ljubljana  5051592000  20,972 
3.  0792  University of Ljubljana, Faculty of Civil and Geodetic Engineering  Ljubljana  1626981  25,990 
4.  1540  University of Nova Gorica  Nova Gorica  5920884000  13,237 
5.  2887  M SORA, trgovina in proizvodnja, d.d. (Slovene)  Žiri  2235102  103 
Nowadays, a great amount of energy is consumed for heating and cooling of buildings. Windows remain the weakest point in terms of heat losses and therefore there is a strong need for further improvement of existing windows by applying new coatings that enable smart light and heat management (variable VIS transmittance, low emissivity, IR modulation, UV-cut, glare reduction and self-cleaning features). In this proposal, we will focus on the synthesis of new materials based on transition metal oxides as functional coatings on glazing surfaces to make “green” windows: environmental and energy efficient. To this aim, we formed several research directions to accomplish our goals: (i) preparation of thermochromic coatings on glass and plastics, (ii) preparation of photocatalytic coatings on glass and plastics and UV-protective coatings on wood, (iii) their application in design and modelling of a window, (iv) exploring their physicochemical properties in order to relate them with functional characteristics of a window – illumination and thermal comfort, pollutant removal, self-cleaning, self-sterilizing and anti-fogging surface. Preparation of coatings will be based on a low-temperature sol-gel method and the use of pigment dispersions. For the construction of “green window”, we will originate from a line of windows “Nature Optimo XLS” of M SORA manufacturer while new functional elements will be added to windows. Coatings with a high optical transmission and desired thermochromic (TC) and photochromic (PC) exhibited on a laboratory scale with be used. TC effect will be achieved with coatings based on VO2, which enables modulation of the coatings`s transmittance and reflectance in the near infrared and thermal infrared spectral range, depending on the temperature. The temperature of the phase transition of TC coatings from semiconducting (NIR and IR transmitting state) to metallic state (NIR absorbing and reflecting state) will be adjusted by introducing various dopants to VO2 (W, Mo, etc.), while addition of Mg will increase their transmittance in the visible part of the solar spectrum and the alternation of the whole solar transmission during phase transition. Preparation of the pigment dispersions will be done by milling of VO2 pigments in the presence of various dispersants, following already known routes. PC effect will be obtained with TiO2 based coatings, which under solar illumination catalyze pollutants degradation and enhance their removal due to photoinduced superhydrophilicity on the surface of the semiconductor. Synthesis route is based on the preparation of the acidic aqueous sol with a silicate binder. UV-protection effect for wooden window frame will be based on preparation of pigment dispersions from UV absorbers, such as TiO2, CeO2 or ZnO. Solution or dispersion formulation will be optimized for three types of surface. When using plastic surfaces, possible degradation of the substrate will be prevented with additional intermediate protecting layer or with deposition of a gradient coating. Structural, mechanic and functional properties of the prepared coatings will be determined with different methodologies, mastered among project partners. An understanding the role of glazing components on window light transmittance and heat balance will be obtained by computer modelling. Model calculations will be compared with experimental results of Uw value determination on a test wall (MSR-ECO-500 IFT Rosenheim). The testing wall enables us to define thermal transmittance through the window and to measure local temperatures on the window considering different climatic conditions. Collaboration of four different Slovenian research institutions (UNG, KI, FKKT, FGG), foreign research groups and Slovenian window manufacturer M SORA d.d. gives a solid base for a successful execution of the project tasks with the aim to produce even more energy efficient “green” window.
Significance for science
Sol-gel coatings have not reached state of development, which should allow their wide spread applications and mostly coatings based on organic polymers are used. Practical use of coatings with embedded well defined nanoparticles are also not widely spread, since they are hindered by the fact that agglomeration and flocculation of the nanoparticles are difficult to prevent without using effective dispersants. This project proposal therefore represents a step towards application of sol-gel technology in an important area of energy efficient building elements. Furthermore, sol-gel coatings with the incorporated nanoparticles will be derived from the water-borne systems. The outcomes of the proposed project will be easily transferable to other fields and applications, where thin, durable, optically transparent coatings are needed. Typical examples are glazing for solar thermal collectors, photovoltaic modules, etc.
Significance for the country
In Slovenia, total turnover in windows industry annually reaches impressive 350 mil Euros. This amount of money is obtained by selling relatively simple, standardized windows made of plastic or wooden frames and glass panels. Even though windows standards in Slovenia increase, we may even say that in worldwide scale we are on the top. 80% of customers are still buying standardized windows; wooden windows with 68 mm thick window profile with triple glazing (Ug ( 0,7 W/m2K). Worldwide, these characteristics represent superior and low energy windows. Because of customers' demands for intelligent windows solutions, each year quality level of windows is increasing. Competition of European companies causes classical windows getting hard to sell. Slovenian companies are on the top of European windows production industry, and for high windows quality production they use latest materials and technology. We are aware of the fact that only with development and investment in the new solution and improvement of each window component we can maintain market share and full production in the future. Efficient cooperation among different laboratories and industry represents an important factor for development of practically used products with high added value originating from development of new functional materials based on nanoscience. Undoubtedly, this is what we will achieve in this project; UNG, KI and FKKT focus on fundamental research, development of materials, their characterization and production of functional nanostructured coatings. Knowledge of using functional coatings as active layers in windows construction will be obtained by model calculations created at FGG. Collaboration of these partners will ensure proper knowledge and materials background for M SORA company, for building lighter and more energy efficient windows, which will provide intelligent control of the light flow inside the building (and heat in the opposite direction) and at the same time will have self-cleaning ability. Synthesis of different nanostructured materials in a big extent is foreseen, and it will be done in order to enable production of coatings in sufficient amount (fine chemical syntheses) for production of smart glazing which will be used in M SORA normal sized windows at the final phase of this project. Successful development of self-cleaning and other nanostructured coatings is a big step forward in use of intelligent and transparent surfaces on buildings envelope. That will enable better and easier use for the customer. Coatings of high potential should attract major manufacturers of glasses in Slovenia and Europe. Epilogue of the project will be short presentation of products to at least five glass manufacturers in Europe, and gaining their feedback on the products could lead to new industrial projects and cooperation.
Most important scientific results Interim report, final report
Most important socioeconomically and culturally relevant results Interim report, final report
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