Silicon-29 cross-polarization/magic-angle-spinning NMR study of inorganic–organic hybrids: homogeneity of sol–gel derived hybrid gels

Architecture of Silsesquioxanes

“…Experiments can yet be time consuming because of its low natural abundance and large longitudinal relaxation times (T 1 ), which can reach several minutes. In the solid state, the use of cross polarization can definitely help, yet with a possible loss of quantitativity (Komori et al 2005). For solution NMR, the addition of paramagnetic relaxation agents, such as Cr(acac) 3 , and the use of polarization transfer techniques (e.g., DEPT, INEPT) are possible strategies to overcome these drawbacks.…”

Deposition of organic−inorganic hybrid coatings over 316L surgical stainless steel and evaluation on vascular cells

“…1) are dominated by a peak centered at -22 ppm that can be attributed to D 2 species of PDMS molecules. 59 The narrowness of this resonance (0.3 ppm in T 90 P 10 and 0.8 ppm in T 70 P 30 ) indicates high molecular mobility for these silicon groups. There are two additional resonances at -19.7 and -21.5 ppm, both weaker and broader than the main one, corresponding also to D 2 silicon species with low mobility, as usually observed in solid phases.…”

Microheterogeneity in phenyl group modified inorganic/organic hybrid gels after aerosol drying or slow solvent evaporation

“…In the past, cross polarization experiments on sol-gel systems have provided information about the structure [7,8] and homogeneity [9,10] of silica gels. Babonneau and coauthors [8,11] have applied 17 2D 1 H-29 Si correlation NMR spectroscopy to probe the co-condensation and mixing behavior of hybrid sol-gel materials.…”

“…Babonneau and coauthors [8,11] have applied 17 2D 1 H-29 Si correlation NMR spectroscopy to probe the co-condensation and mixing behavior of hybrid sol-gel materials. Komori et al [9] investigated the homogeneity of hybrid gels prepared by co-hydrolysis of different alkoxysilanes-organoalkoxysilane mixtures by 29 Si{ 1 H} CP MAS NMR. Fyfe et al [12] carried out 1 H/ 29 Si heteronuclear correlation NMR spectroscopy on a hybrid gel made from TEOS and methyltriethoxysilane (MTS).…”

“…Various models have been suggested in the literature. Komori et al [9] have used the distribution of T CP to describe the CP dynamics in inorganic-organic hybrid gels. The variation in their T CP is in the range of 2-33 ms, and the authors have suggested a segregation of Q 4 units as the cause of the T CP distribution.…”