Stationary interphases with extended alkyl chains: A comparative study on chain order by solid-state NMR spectroscopy

Spherical and lamellar octadecylsilane hybrid silicas

“…In the literature, many studies reported the use of this technique in the characterization of alkyl-modified silica gel in many situations such as evaluation of the synthetic route, [27,39] of the support, [40] of the chain length, [41] of the coating content, [42] and of the effect of the temperature on the conformation of the chemical species on the surface. [39][40][41] The chemical shift of the central methylene groups in an alkyl chain in a 13 C CP-MAS NMR spectrum depends on the conformation of the chains on the solid surface, i. e., on the γ (gauche) conformation.…”

Synthesis, Characterization and Enhanced Selectivity in RP-HPLC of Polar Carbonyl Group Embedded Poly (Vinyl Octadecanoate) Grafted Stationary Phase by Simple Heterogeneous "Graft from" Technique

“…36 The suspension state 1 H NMR of Sil-2 is thus measured from 20 to 50 o C and it was apparent that alkyl chain mobility is high enough irrespective of temperature variation. Relative NMR intensities of long alkyl chain was measured according to the formula described elsewhere 32 and it was shown that alkyl chain intensity increases steadily with increase of temperature.…”

Synthesis and characterisation of silica nanoparticles bearing different functional groups obtained via a two‐stage method

“…For the amine, nitrile and phenyl-functionalised nanosilica, two particle sizes were detected: One in the nanometric and the other in the micrometric range, the former being the most abundant in all cases but one (3c). Si CP/MAS NMR spectroscopy [16], where even the covalent bonding between the organic moiety and the silane can be observed. …”