Moving toward Smart Cities: Evaluation of the Self-Cleaning Properties of Si-Based Consolidants Containing Nanocrystalline TiO<sub>2</sub> Activated by Either UV-A or UV-B Radiation
This study evaluated the self-cleaning ability and durability of Si-based consolidants (an ethyl silicate consolidant and a consolidant based on nanosized silica) spiked with nanocrystalline TiO<sub>2</sub> activated by either UV-A radiation (spectral region between 340 and 400 nm, and m...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-11-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/12/11/2577 |
| _version_ | 1797549038632960000 |
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| author | José Santiago Pozo-Antonio Daniel Noya-Pintos Patricia Sanmartín |
| author_facet | José Santiago Pozo-Antonio Daniel Noya-Pintos Patricia Sanmartín |
| author_sort | José Santiago Pozo-Antonio |
| collection | DOAJ |
| description | This study evaluated the self-cleaning ability and durability of Si-based consolidants (an ethyl silicate consolidant and a consolidant based on nanosized silica) spiked with nanocrystalline TiO<sub>2</sub> activated by either UV-A radiation (spectral region between 340 and 400 nm, and main peak at 365 nm) or UV-B radiation (spectral region between 270 and 420 nm, and main peak at 310 nm). Granite samples were coated with consolidant, to which nanocrystalline TiO<sub>2</sub> was added at different concentrations (0.5, 1, and 3%, by wt.). Diesel soot was then applied to the coated surfaces, and the samples were exposed to UV-A or UV-B radiation for 1650 h. The surface color changes, relative to the color of untreated granite, were determined every 330 h by color spectrophotometry. Slight color changes indicated a recovery of the reference color due to the degradation of the soot. The final surfaces of both the untreated and treated surfaces were compared by stereomicroscopy and scanning electron microscopy. The main findings were that: (1) In general, the consolidant containing nanosized silica induced the most intense photocatalytic activity. In the more compact xerogel coating formed by the nanosized silica, more TiO<sub>2</sub> nanoparticles were available to interact with the radiation. (2) For all consolidant mixtures, soot degradation remained constant or decreased over time, except with ethyl silicate with 0.5 wt % TiO<sub>2</sub> (no self-cleaning capacity). (3) Soot degradation increased with the concentration of TiO<sub>2</sub>. (4) The UV-B radiation was the most effective in terms of soot degradation, except for the surface coated with the ethyl silicate and 3% wt. TiO<sub>2</sub>. |
| first_indexed | 2024-03-10T15:07:57Z |
| format | Article |
| id | doaj.art-59699cc3eac94299898b82d27c9bd592 |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-10T15:07:57Z |
| publishDate | 2020-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-59699cc3eac94299898b82d27c9bd5922023-11-20T19:33:33ZengMDPI AGPolymers2073-43602020-11-011211257710.3390/polym12112577Moving toward Smart Cities: Evaluation of the Self-Cleaning Properties of Si-Based Consolidants Containing Nanocrystalline TiO<sub>2</sub> Activated by Either UV-A or UV-B RadiationJosé Santiago Pozo-Antonio0Daniel Noya-Pintos1Patricia Sanmartín2Dpto. Enxeñaría dos Recursos Naturais e Medio Ambiente, Escola de Enxeñaría de Minas e Enerxía, Campus As Lagoas-Marcosende, University of Vigo, 36310 Vigo, SpainEscola Superior de Conservación e Restauración de Bens Culturais de Galicia, 36002 Pontevedra, SpainDepartamento de Edafoloxía e Química Agrícola, Facultade de Farmacia, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, SpainThis study evaluated the self-cleaning ability and durability of Si-based consolidants (an ethyl silicate consolidant and a consolidant based on nanosized silica) spiked with nanocrystalline TiO<sub>2</sub> activated by either UV-A radiation (spectral region between 340 and 400 nm, and main peak at 365 nm) or UV-B radiation (spectral region between 270 and 420 nm, and main peak at 310 nm). Granite samples were coated with consolidant, to which nanocrystalline TiO<sub>2</sub> was added at different concentrations (0.5, 1, and 3%, by wt.). Diesel soot was then applied to the coated surfaces, and the samples were exposed to UV-A or UV-B radiation for 1650 h. The surface color changes, relative to the color of untreated granite, were determined every 330 h by color spectrophotometry. Slight color changes indicated a recovery of the reference color due to the degradation of the soot. The final surfaces of both the untreated and treated surfaces were compared by stereomicroscopy and scanning electron microscopy. The main findings were that: (1) In general, the consolidant containing nanosized silica induced the most intense photocatalytic activity. In the more compact xerogel coating formed by the nanosized silica, more TiO<sub>2</sub> nanoparticles were available to interact with the radiation. (2) For all consolidant mixtures, soot degradation remained constant or decreased over time, except with ethyl silicate with 0.5 wt % TiO<sub>2</sub> (no self-cleaning capacity). (3) Soot degradation increased with the concentration of TiO<sub>2</sub>. (4) The UV-B radiation was the most effective in terms of soot degradation, except for the surface coated with the ethyl silicate and 3% wt. TiO<sub>2</sub>.https://www.mdpi.com/2073-4360/12/11/2577self-cleaningTiO<sub>2</sub>consolidantstone preservationphotocatalysissmart city |
| spellingShingle | José Santiago Pozo-Antonio Daniel Noya-Pintos Patricia Sanmartín Moving toward Smart Cities: Evaluation of the Self-Cleaning Properties of Si-Based Consolidants Containing Nanocrystalline TiO<sub>2</sub> Activated by Either UV-A or UV-B Radiation Polymers self-cleaning TiO<sub>2</sub> consolidant stone preservation photocatalysis smart city |
| title | Moving toward Smart Cities: Evaluation of the Self-Cleaning Properties of Si-Based Consolidants Containing Nanocrystalline TiO<sub>2</sub> Activated by Either UV-A or UV-B Radiation |
| title_full | Moving toward Smart Cities: Evaluation of the Self-Cleaning Properties of Si-Based Consolidants Containing Nanocrystalline TiO<sub>2</sub> Activated by Either UV-A or UV-B Radiation |
| title_fullStr | Moving toward Smart Cities: Evaluation of the Self-Cleaning Properties of Si-Based Consolidants Containing Nanocrystalline TiO<sub>2</sub> Activated by Either UV-A or UV-B Radiation |
| title_full_unstemmed | Moving toward Smart Cities: Evaluation of the Self-Cleaning Properties of Si-Based Consolidants Containing Nanocrystalline TiO<sub>2</sub> Activated by Either UV-A or UV-B Radiation |
| title_short | Moving toward Smart Cities: Evaluation of the Self-Cleaning Properties of Si-Based Consolidants Containing Nanocrystalline TiO<sub>2</sub> Activated by Either UV-A or UV-B Radiation |
| title_sort | moving toward smart cities evaluation of the self cleaning properties of si based consolidants containing nanocrystalline tio sub 2 sub activated by either uv a or uv b radiation |
| topic | self-cleaning TiO<sub>2</sub> consolidant stone preservation photocatalysis smart city |
| url | https://www.mdpi.com/2073-4360/12/11/2577 |
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