Hybrid silica materials synthesis

Synthesis of Hybrid Silica Materials Using an Anionic Surfactant... 

The synthesis was the same as the one presented above but without the use of surfactant. TEOS was added to a P-CDAPS solution (in a water-ethanol mixture with molar ratio 9 1) in varying proportions. The resulting mixture was stirred Ih at ambient temperature and then kept statically for 2 days at 373 K. The precipitate obtained was hltered and the powder dried under vacuum at 333 K. The initial molar composition was 0.5 TEOS x P-CDAPS 180 H O 20 EtOH where x is equal to 0.5, 0.25 or 0.1. The obtained hybrid silica materials were designated Tbn, where n= 1, 2 and 3 corresponds to x = 0.5, 0.25 and 0.1 respectively. 

Tab. 3.1 Polysaccharides and proteins involved in the synthesis of hybrid silica nanocomposite materials.

Templated mesoporous silica materials have been discovered by Kresge et al. in 1992 [ 1,2]. S ince then, efforts have been made to produce by direct co-condensation synthesis hybrid materials functionalized by different types of reactive groups. 

Characterization of the XMo,-Si02 materials indicated that the synthesis produced three-dimensional ordered macroporous materials with highly dispersed polyoxometalates covalently incorporated within the wall structures. IR, UV/DRS, solid-state MAS NMR spectra confirmed that the polyoxometalates remained intact in the hybrid macroporous silica materials. At first, three solid XMOu-SiOj materials all exhibited two absorptions with maxima at ca. 200 and 260 nm, respectively (Figure 1). The former is stronger and... 

For all these reasons, the guanine building blocks and the sol-gel chemistry were used as molecular precursor to conceive hybrid chiral materials at nanometric and micrometric scales. Our efforts involved the synthesis and the self-assembly of a guaninesiloxane monomer Gsi (Fig. 3) in the G-quartet and G-quadruplex supramolecular architectures (Fig. 6), which are fixed in a hybrid organic-inorganic material by using a sol-gel transcription process, followed by a second inorganic transcription in silica, by calcination. 

The high-quality crystal of SBA-1 and other materials with Pm3n structure (e.g., hybrid silica HMM-3[141]) can be obtained by varying synthesis conditions. Figure 8.25 shows two examples HMM-3 (BTME as silica source and C TMA as template) and SBA-1 (synthesized at —5°C).[142]... 

Ahmad, S. Zafar, F. Sharmin, E. Garg, N. Kashif, M. (2012). Synthesis and Characterization of Corrosion Protective Polyurethanefattyamide/ Silica Hybrid Coating Material. Progress in Organic Coatings, Vol. 73, No. 1, Qanuary 2012), pp.ll2- 117,ISSN 03009440... 

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