Gas filling of SBA - 15 silica micropores probed by positron annihilation lifetime spectroscopy (PALS)

• Autorzy: Gorgol M. , Zaleski R. , Kierys A.
• Konferencja: Proceedings of the 40th Polish Seminar on Positron Annihilation PSPA'2012, 13-14 June 2012, Kazimierz Dolny, Poland
• Języki publikacji: EN

Abstrakty

EN

Positron annihilation lifetime measurements were conducted in situ while two gasses (nitrogen and oxygen, respectively) were introduced into the SBA-15 porous silica sample. Slow changes in lifetime spectra were observed during a long lasting gas interaction with the sample. Introduced gases slowly filled the free volumes, starting from the smallest ones, especially small micropores. In the presence of a gas, the rate of change of ortho-positronium (o-Ps) and unbound positron intensity was larger than the rate of change of lifetime. This suggests the existence of an additional process, which reduces the number of ortho-positronium atoms due to the interaction with the gas. Moreover, the process of filling pores with gas was slower than the process of emptying them while the gas was pumped out.

Słowa kluczowe

EN

SBA-15 porous silica; positron annihilation

• Wydawca: Institute of Nuclear Chemistry and Technology
• Czasopismo: Nukleonika
• Rocznik: 2013
• Tom: Vol. 58, No. 1
• Strony: 229--233
• Opis fizyczny: BIbliogr. 18 poz., rys.

Twórcy

autor

Gorgol M.

autor

Zaleski R.

autor

Kierys A.

• Maria Curie-Skłodowska University, Institute of Physics, Department of Nuclear Methods, 1 M. Curie-Skłodowskiej Sq., 20-031 Lublin, Poland, Tel.: [phone], Fax: [phone],

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