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Labeling and Probing the Silica Surface Using Mechanochemistry and 17 O NMR Spectroscopy **
Author(s) -
Chen ChiaHsin,
MentinkVigier Frederic,
Trébosc Julien,
Goldberga Ieva,
Gaveau Philippe,
Thomassot Emilie,
Iuga Dinu,
Smith Mark E.,
Chen Kuizhi,
Gan Zhehong,
Fabregue Nicolas,
Métro ThomasXavier,
Alonso Bruno,
Laurencin Danielle
Publication year - 2021
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202101421
Subject(s) - siloxane , fumed silica , mechanochemistry , spectroscopy , nuclear magnetic resonance spectroscopy , analytical chemistry (journal) , chemistry , materials science , nanotechnology , stereochemistry , organic chemistry , physics , quantum mechanics , polymer
In recent years, there has been increasing interest in developing cost‐efficient, fast, and user‐friendly 17 O enrichment protocols to help to understand the structure and reactivity of materials by using 17 O NMR spectroscopy. Here, we show for the first time how ball milling (BM) can be used to selectively and efficiently enrich the surface of fumed silica, which is widely used at industrial scale. Short milling times (up to 15 min) allowed modulation of the enrichment level (up to ca. 5 %) without significantly changing the nature of the material. High‐precision 17 O compositions were measured at different milling times by using large‐geometry secondary‐ion mass spectrometry (LG‐SIMS). High‐resolution 17 O NMR analyses (including at 35.2 T) allowed clear identification of the signals from siloxane (Si−O−Si) and silanols (Si−OH), while DNP analyses, performed by using direct 17 O polarization and indirect 17 O{ 1 H} CP excitation, agreed with selective labeling of the surface. Information on the distribution of Si−OH environments at the surface was obtained from 2D 1 H− 17 O D‐HMQC correlations. Finally, the surface‐labeled silica was reacted with titania and using 17 O DNP, their common interface was probed and Si−O−Ti bonds identified.