Blends of poly (methyl methacrylate) (PMMA) with poly(vinylidene fluoride) (PVF2) are studied by fluorine-enhanced 13C solid-state nuclear magnetic resonance, while spinning at the magic angle (19F-13C CPMAS NMR). Data were acquired under simultaneous proton and fluorine dipolar decoupling. From these experiments it can be concluded that PMMA/PVF2 blends with weight ratios 80/20, 60/40, 40/60, and 20/80 are mixed at the molecular level. The average distance between PMMA C=0 and OCHa carbons and PVF2 fluorines in all blends is found to be between 2.6 and 3.1 Á.

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van de, L. J. M. (1988). On the nature of chemical binding of organic silanes to water-free silica surfaces: a high-resolution solid-state NMR spectroscopic study. Journal of Colloid and Interface Science, 126(2), 604-609. DOI: 10.1016/0021-9797(88) General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Methoxytrimethylsilane (A), dimethoxydimethylsilane (B), and trimethoxymethylsilane (C) were used to silylate porous silica gel, which was very thoroughly dried with thionylchloride. Products were characterized with elemental analysis and by CP/MAS NMR (29Si and ~3C).Under these conditions monofunctional silane A yields monodentate silane-to-surface links (trimethylsiloxysilanes) plus some esterification of silanol sites by methanol, resulting from the main reaction. Bifunctional silane B yields mono-and bidentate silane-to-surface links under the described reaction conditions. Trifunctional silane C also yields mono-and bidentate links. Cross-linked tridentate groups are formed only after exposure to air or reaction with water.

The thermal stability of a number of trialkylsilyl surface modifications has been studied. During heating, weight loss is recorded by thermogravimetry, while evolved gases are simultaneously analysed with mass spectrometry. Changes in the molecular structure on the surface are measured with solid state nuclear magnetic resonance (NMR) and static-SIMS. Degradation mechanisms are proposed and described by a number of reaction equations. The changes in surface chemistry on the internal powder surface as measured with NMR are similar to those observed with static-SIMS on the outer surface of the powder particles.