Polydimethylsiloxane at the interfaces of fumed silica and zirconia/fumed silica

Chemisorption and thermally induced transformations of polydimethylsiloxane on the surface of nanoscale silica and ceria/silica

“…Previous studies have shown that the thermal decomposition of polydimethylsiloxane occurs through two main pathways e oxidation to SiO 2 , CO 2 and H 2 O (Scheme 1a); and depolymerization via the release of volatile cyclic siloxanes (Scheme 1b) [16,41,42]:…”

“…The specifics of the thermal decomposition of polydimethylsiloxanes adsorbed on silicas modified by ZrO 2 , Al 2 O 3 , TiO 2 , V 2 O 5 , ZnO, Cr 2 O 3 and SnO depend on the acidebase properties of the oxides [16].…”

“…According to the literature, the decomposition of polysiloxanes in air proceeds through oxidation to SiO 2 , CO 2 and H 2 O [16,42], although formation of formaldehyde, formic acid, methanol, and CO is also possible [16]. However, Camino et al [42] state that oxidation to SiO 2 , CO 2 and H 2 O mostly takes place by reactions in the gas phase between the oxygen and volatile oligomers formed during thermal degradation.…”

Relaxation phenomena in poly(vinyl alcohol)/fumed silica affected by interfacial water

“…These values suggest strong hydrogen bonding in the systems. For instance, in the case of poly(dimethylsiloxane) (PDMS) adsorbed onto fumed silica, the activation energy is much smaller [66] because of weak bonds between molecules (T g = 156 K).…”

A New Route for Preparation of Hydrophobic Silica Nanoparticles Using a Mixture of Poly(dimethylsiloxane) and Diethyl Carbonate

“…However, due to high reactivity and moisture sensitivity of above-mentioned modifying agents, purification is often critical for these hydrolyzable precursors. Poly(dimethylsiloxanes) provide a viable and environmentally benign alternative to the chemical functionalization of oxides as they are characterized by high carbon content, hydrophobic properties, thermal stability, chemical inertness, and they are noncorrosive reagents, and generate only water as a byproduct [9][10][11][12][13][14][15][16][17][18][19][20][21]. Despite this fact, the chemisorption of the simplest methylsiloxanes-hexamethyldisiloxane (H 3 C) 3 SiOSi(CH 3 ) 3 on fumed silica surfaces requires the use of very high temperatures (>350 • C) [19,[22][23][24].…”