Пожалуйста, используйте этот идентификатор, чтобы цитировать или ссылаться на этот ресурс: https://elar.usfeu.ru/handle/123456789/8777
Название: Electrosurface Properties of Nanostructured Silica Assessed by EPR of Molecular pH Labels
Авторы: Kovaleva, E. G.
Molochnikov, L. S.
Osipova, V. A.
Stepanova, D. P.
Reznikov, V. A.
Дата публикации: 2015
Издатель: Springer-Verlag Wien
Библиографическое описание: Kovaleva, E. G. Electrosurface Properties of Nanostructured Silica Assessed by EPR of Molecular pH Labels / E. G. Kovaleva, L. S. Molochnikov, V. A. Osipova [et al.] // Applied Magnetic Resonance. – 2015. – Vol. 46. – Iss. 12. – P. 1367-1382.
Аннотация: Three techniques of spin labeling have been applied to nanostructured SiO2 and have been tested by electron paramagnetic resonance spectroscopy of pH-sensitive nitroxide radicals (NRs). The best technique was based on preliminary interaction of the pH-sensitive NR bromomethyl-2,2,3,5,5-pentamethylimidazoline-1-oxyl with aminopropyltriethoxy-silane (APTES) in the presence of trioctylamine and further treatment of the nanostructured SiO2 with the hydrolyzed product and acetic anhydride. It was found that there are two types of location of the pH-sensitive NRs (spin labels) on the surface of nanostructured silica. The spin labels of the first type located near the surface of nanostructured SiO2 (“slow-motional” NR) have been used to measure near-surface electrical potential at the site of NR N–O• fragment location, q equal to −90 mV. The NR molecules of the second type which were positioned well far from the nanostructured SiO2 surface (“fast-motional” NRs) were employed to establish the regularities of mutual changes in the NR form and nanoparticle surface charge with variations in pH of external bulk solution (pHext). The pH-sensitive NRs covalently attached to the SiO2 surface were successfully employed for the study of surface charge in the drying process with a rise of temperature up to 375 K. A negative surface charge was shown to decrease due to reducing an ionization degree of the surface silanol groups. This process was found to be reversible at re-adsorption of water molecules. © 2015, Springer-Verlag Wien.
Ключевые слова: ELECTRON SPECTROSCOPY
MAGNETIC RESONANCE
MOLECULES
PARAMAGNETIC RESONANCE
PH SENSORS
SILICA
SURFACE CHARGE
ADSORPTION OF WATER
ELECTRICAL POTENTIAL
ELECTRON PARAMAGNETIC RESONANCE SPECTROSCOPY
ELECTROSURFACE PROPERTIES
HYDROLYZED PRODUCTS
NANOPARTICLE SURFACE CHARGE
NANOSTRUCTURED SILICA
NEGATIVE SURFACE CHARGES
ELECTRON SPIN RESONANCE SPECTROSCOPY
URI: https://elar.usfeu.ru/handle/123456789/8777
DOI: 10.1007/s00723-015-0704-1
SCOPUS: 2-s2.0-84946489057
WoS: WOS:000364504700005
РИНЦ: 24969178
Располагается в коллекциях:Научные публикации, проиндексированные в SCOPUS и WoS CC

Файлы этого ресурса:
Файл Описание РазмерФормат 
2-s2.0-84946489057.pdf487,3 kBAdobe PDFПросмотреть/Открыть    Request a copy


Все ресурсы в архиве электронных ресурсов защищены авторским правом, все права сохранены.