|
|
Photocatalytic concrete screeds with self-cleaning and antimicrobial function
Bíbová, Hana ; Šubrt, Jan ; Pližingrová, Eva ; Jakubičková, M. ; Sázavská, T. ; Dohnálek, P. ; Hykrdová, Lenka ; Jirkovský, Jaromír
Photocatalytic concrete screeds with self-cleaning and antimicrobial function have been developed and tested. These building materials contain sand grains with deposited composite TiO2/SiO2 layers. Two types of the screeds, grey and white, were prepared and their photoactivity and material characteristics were compared. Commercial TiO2 photocatalysts from several manufacturers were employed. Effects of different parameters, such as temperature of the coated sand calcination, humidity, and surface abrasion, were followed. Mechanical properties of the screeds were analyzed by SEM/XRD microscopy. Photocatalytic activity was tested by means of NOx oxidation (ISO norm 22197-1/2007). Antibacterial activity was evaluated by modified ISO norm 27447/2009 with Bacillus subtilis as a model organism.
|
|
|
Photocatalytic active coatings-environmental way to improve quality and durability of buildings
Sázavská, T. ; Jakubičková, M. ; Jirkovský, Jaromír ; Šubrt, Jan ; Peterka, F.
Transparent coatings of TiO2-SiO2 nanocomposite were developed to be applied on building facades in order to prevent growth of microorganisms and thus to improve urban building sustainability. Structure and texture characteristics of the prepared nanocomposites were determined by electron microscopy (SEM, TEM + EDS), their photocatalytic activity was quantified by testing self-cleaning ability and antimicrobial activity. The self-cleaning properties were evaluated according to the standard ISO method based on photocatalytic degradation of methylene blue. The TiO2-SiO2 nanocomposite coatings were applied on various types of substrates commonly used in building industry. The antimicrobial activity was mainly investigated for algae because these microorganisms are often responsible for facades ageing. According to the laboratory tests the prepared TiO2-SiO2 nanocomposites are highly efficient. This fact was already proved by first applications in real conditions. The transparent SiO2-TiO2 nanocomposites represent an ecological and noninvasive way how to keep nice appearance of buildings for a long time. It is due to their permanent photocatalytic activity causing self-cleaning and algicidal effects. Such coatings may significantly reduce ageing processes on facades of buildings that are caused by microbiological pollution and smog exhalations.
|
|
| |
|
| |
|
|
Application of photocatalysis on TiO2 for pesticide removal
Krýsa, J. ; Jirkovský, Jaromír
Pesticides contaminate surface water mainly by washing from fields and crop-plant and by wind during aerial spraying. They may discrupt biologic equilibrium in streams due to their toxic effect on biocenosis. They can also unfavorably influence the self-cleaning ability of water, its odour and taste. Surface water is still treated and distributed as drinking water to more than half of the population in the Czech Republic supplied from public water conduits.
|
|
| |
|
| |
|
| |
|
| |
|
| |
host ::
RSS.