Zinātniskās darbības atbalsta sistēma
Latviešu English

Publikācija: Thick Silica Foam Films through Combined Catalytic Decomposition of H2O2 and Sol–Gel Processes

Publikācijas veids Zinātniskais raksts, kas indeksēts Web of science un/vai Scopus datu bāzē
Pamatdarbībai piesaistītais finansējums Nav zināms
Aizstāvēšana: ,
Publikācijas valoda English (en)
Nosaukums oriģinālvalodā Thick Silica Foam Films through Combined Catalytic Decomposition of H2O2 and Sol–Gel Processes
Pētniecības nozare 2. Inženierzinātnes un tehnoloģijas
Pētniecības apakšnozare 2.5. Materiālzinātne
Autori Martin Timusk
Agnes Kuus
Kathriin Utt
Triin Kangur
Andris Šutka
Martin Järvekülg
Māris Knite
Atslēgas vārdi Silica foam, Low-density material, Closed-cell porosity, Sol–gel, Hydrogen peroxide, Manganese dioxide
Anotācija A novel method for the preparation of thick silica foam films is reported that combines an alkoxide-based hydrolytic sol–gel process and in situ catalytic decomposition of hydrogen peroxide on a catalyst-coated support. A hydrogen peroxide/nitric acid aqueous solution was used to carry out acid-catalysed hydrolysis of tetramethoxysilane. Complete stability of H2O2 in the resulting silica sols over extended periods (N120 min) was demonstrated by in situ Raman spectroscopy. The H2O2-loaded sols were sprayed on MnO2-coated substrates, resulting in heterogeneous catalytic decomposition of H2O2 and effective foaming and simultaneous gel formation due to oxygen gas and water formation. Silica foam films with a well-defined closed-cell porosity were annealed at 600 °Cwithout any damage to the closed-cell porous filmmorphology. Up to 530 μmthickfilms were prepared with macropore sizes in the range of 29–47 μm, exceptionally thin macropore wall thicknesses of 16–50 nm and a bulk density as low as 64 kg/m3, comparable to that of the aerogels. The lowest measured thermal conductivity of the prepared foams was 0.018±0.001 W/(m∗K), which is also similar to silica aerogels, enabling the prepared foams to be used as efficient thermal insulation materials.
DOI: 10.1016/j.matdes.2016.08.092
Hipersaite: http://www.sciencedirect.com/science/article/pii/S0264127516311558 
Atsauce Timusk, M., Kuus, A., Utt, K., Kangur, T., Šutka, A., Järvekülg, M., Knite, M. Thick Silica Foam Films through Combined Catalytic Decomposition of H2O2 and Sol–Gel Processes. Materials and Design, 2016, Vol.111, 80.-87.lpp. ISSN 0264-1275. Pieejams: doi:10.1016/j.matdes.2016.08.092
Papildinformācija Citējamību skaits:
ID 23083