Interaction of (3-Aminopropyl)triethoxysilane with Pulsed Ar–O2 Afterglow: Application to Nanoparticles Synthesis

Abstract

The interaction of (3-Aminopropyl)triethoxysilane (APTES) with pulsed late Ar-O 2 afterglow is characterized by the synthesis of OH, CO and CO 2 in the gas phase as main by-products. Other minor species like CH, CN and C 2 H are also produced. We suggest that OH radicals are produced in a first step by dehydrogenation of APTES after interaction with oxygen atoms. In a second step, the molecule is oxidized by any O 2 state, to form peroxides that transform into by-products, break thus the precursor CC bonds. If oxidation is limited, i.e. a low duty cycle, fragmentation of the precursor is limited and produced nanoparticles keep the backbone structure of the precursor, but contain amide groups produced from the amine groups initially available in APTES. At high duty cycle, silicon-containing fragments contain some carbon and react together and produce nanoparticles with a non-silica-like structure.

Plasma Polymerization of 3‐Aminopropyltrietoxysilane (APTES) by Open‐Air Atmospheric Arc Plasma Jet for In‐Line Treatments

“…Moreover, both FTIR and XPS results cannot support the presence of amine groups, but suggest that mostly amide groups were formed. As discussed in the papers of Lecoq et al and Gueye et al, where low pressure microwave argon or nitrogen plasma containing a few percent of O 2 , H 2 , or N 2 were used to polymerize APTES in the post‐discharge, nitrogen atoms and metastables are highly reactive and can easily dissociate the precursor by reacting preferentially with the –CH x groups of the monomer to form CN radicals. Therefore, even nitrogen plasma can efficiently decompose 3‐aminopropyltriethoxysilane and lead to a significant loss of amine groups …”

“…Lachmann et al used atmospheric pressure He/N 2 /H 2 22 kHz DBD with 3‐aminopropyltrimethoxysilane (APTMS) to modify the surface of closed polyolefin bags to enhance cell adhesion properties with amine and silanol groups . Low pressure Ar/N 2 and N 2 /O 2 /H 2 2.45 GHz microwave afterglows were used to synthesize, respectively, nanoparticles and nanocoatings from 3‐aminopropyltriethoxysilane (APTES). Alba‐Elias et al used a commercial PlasmaSpot system from Vito to polymerize APTES from N 2 plasma jet for wear resistant applications .…”

Study of a pulsed post‐discharge plasma deposition process of APTES: synthesis of highly organic pp‐APTES thin films with NH2 functionalized polysilsesquioxane evidences

“…In RP-PACVD processes, the plasma generation and the thin film growth occur in two different areas spatially separated, called discharge chamber, and deposition chamber, respectively. [5,24,35,[43][44][45][46][47][48][49][50] In the discharge chamber, the plasma is generated using non condensable gas whereas charged species are confined. Thank to the gas flow and/or a gradient of pressure, these neutral plasma species are flown in the deposition chamber and can be mixed with a chemical precursor.…”

“…Nevertheless, some previous works based on the use of RP-PACVD have illustrated the difficulty to keep primary amine functional groups with such a process. [35,45,50] Indeed, the primary amine in APTES easily reacts with post-discharge active species, leading to relatively low amine density in the deposited plasma polymers compared to sol-gel methods. [35,36] Another strategy used by different researchers to allow a better retention of the initial structure of the precursor is the use of a pulsed plasma.…”

“…In RP‐PACVD processes, the plasma generation and the thin film growth occur in two different areas spatially separated, called discharge chamber, and deposition chamber, respectively . In the discharge chamber, the plasma is generated using non condensable gas whereas charged species are confined.…”