Conservation of Monuments by a Three-Layered Compatible Treatment of TEOS-Nano-Calcium Oxalate Consolidant and TEOS-PDMS-TiO2 Hydrophobic/Photoactive Hybrid Nanomaterials

Autor: Anastasia Verganelaki, Pipina Dimitriadou, P. Maravelaki-Kalaitzaki, Chrysi Kapridaki
Rok vydání: 2018
Předmět:
Scanning electron microscope
Oxalic acid
02 engineering and technology
lcsh:Technology
01 natural sciences
Nanomaterials
chemistry.chemical_compound
General Materials Science
monuments
limestone
compatible
lcsh:QC120-168.85
conservation
Compatible
Hydrophobic
Limestone
021001 nanoscience & nanotechnology
cement mortars
Photocatalysis
TEOS-nano-Calcium Oxalate
0210 nano-technology
lcsh:TK1-9971
Self-cleaning
self-cleaning
Titanium
Materials science
nanostructured
PDMS-SiO2-TiO2 nanocomposite
hydrophobic
chemistry.chemical_element
Conservation
010402 general chemistry
Oxalate
PDMS-SiO 2 -TiO 2 nanocomposite
Cement mortars
Fourier transform infrared spectroscopy
lcsh:Microscopy
Nanocomposite
lcsh:QH201-278.5
lcsh:T
Monuments
0104 chemical sciences
Chemical engineering
chemistry
lcsh:TA1-2040
lcsh:Descriptive and experimental mechanics
lcsh:Electrical engineering. Electronics. Nuclear engineering
Nanostructured
lcsh:Engineering (General). Civil engineering (General)
Zdroj: Materials, Vol 11, Iss 5, p 684 (2018)
Materials; Volume 11; Issue 5; Pages: 684
Materials
ISSN: 1996-1944
DOI: 10.3390/ma11050684
Popis: Summarization: In the conservation of monuments, research on innovative nanocomposites with strengthening, hydrophobic and self-cleaning properties have attracted the interest of the scientific community and promising results have been obtained as a result. In this study, stemming from the need for the compatibility of treatments in terms of nanocomposite/substrate, a three-layered compatible treatment providing strengthening, hydrophobic, and self-cleaning properties is proposed. This conservation approach was implemented treating lithotypes and mortars of different porosity and petrographic characteristics with a three-layered treatment comprising: (a) a consolidant, tetraethoxysilane (TEOS)-nano-Calcium Oxalate; (b) a hydrophobic layer of TEOS-polydimethylsiloxane (PDMS); and (c) a self-cleaning layer of TiO 2 nanoparticles from titanium tetra-isopropoxide with oxalic acid as hole-scavenger. After the three-layered treatment, the surface hydrophobicity was improved due to PDMS and nano-TiO 2 in the interface substrate/atmosphere, as proven by the homogeneity and the Si-O-Ti hetero-linkages of the blend protective/self-cleaning layers observed by Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM) and Fourier-Transform Infrared Spectroscopy (FTIR). The aesthetic, microstructural, mechanical and permeabile compatibility of the majority of treated substrates ranged within acceptability limits. The improved photocatalytic activity, as proven by the total discoloration of methylene blue in the majority of cases, was attributed to the anchorage of TiO 2 , through the Si-O-Ti bonds to SiO 2 , in the interface with the atmosphere, thus enhancing photoactivation. Παρουσιάστηκε στο: Materials
Databáze: OpenAIRE
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