5 research outputs found
Interaction of (3-Aminopropyl)triethoxysilane With Late Ar-N 2 Afterglow: Application to Nanoparticles Synthesis
International audienceFrom results of in situ FTIR absorption and optical emission spectroscopy, the interaction of (3âaminopropyl)triethoxysilane (APTES) with late Ar-N2 afterglow is shown to occur mainly with N atoms. They react preferentially with carbon from CHx groups in the precursor, leading to the synthesis of CN bonds. No production of NH radical is observed, demonstrating the lack of direct reaction between active nitrogen and APTES. The -NH2 group is not affected by the afterglow. One of the C-C bonds of the propylamine group in the APTES is likely broken. These nanoparticles present secondary amides due to reactions with active nitrogen. They are amorphous and react in air to produce a salt
Caractérisation par infrarouge à transformée de Fourier des réactions chimiques entre post-décharges et précurseurs organosiliciés : cas du 3-aminopropyltriethoxysilane (APTES)
The present work deals with the characterization by Fourier transform infrared spectroscopy (FTIR) and by optical emission spectroscopy of chemical reactions between a post-discharge and an organosilicon precursor: the 3-aminopropyltriethoxysilane (APTES). The aim is to keep the highest retention of amine functions -NH2 in coatings or in the synthesized nanoparticles. First, a state of the art of Ar-N2 and Ar-O2 post-discharges and their applications is presented as well as the kinetics of the interaction of APTES in these post-discharges, highlighting the role plasma gases on the decomposition of the precursor and the nature of the deposited films. Then, the study of the decomposition of APTES in an Ar-N2 post-discharge is carried out. Analysis by optical emission spectroscopy (OES) and in situ FTIR show the role of the nitrogen atoms N in the formation of various main by-products, namely HCN, CO and C=O. The synthesized nanoparticles contain few primary amines, and have a significant concentration of nitrogen in the form of secondary amide. In the case of interaction APTES with pulsed Ar-O2 afterglow, there is one main trend: the nanoparticles synthesized in the gas phase when the duty cycle increases have a composition that decreases in nitrogen and carbon but increases in oxygen. The -NH2 groups are efficiently converted into amide groups. The nanoparticles synthesized with high duty cycle exhibit compositions that are different from those of thin films deposited on the walls, the latter being close to silica because of the etching by atomic oxygen, which affects them more. The specific behavior of oxygen and nitrogen atoms in post-discharge makes difficult the retention of a high level of amines in plasma polymers. Finally, we finished with a study of the hydrodynamics in the case of the interaction of acetylene with an Ar-O2 post-discharge and proved the key role of the flow for any approach aiming at getting time-resolved FTIR measurementsLes travaux prĂ©sentĂ©s dans ce mĂ©moire concernent la caractĂ©risation par infrarouge Ă transformĂ©e de Fourier (FTIR) et par spectroscopie dâĂ©mission optique (SEO) des rĂ©actions chimiques entre post-dĂ©charges et prĂ©curseurs organosiliciĂ©s, avec comme exemple le cas du 3-aminopropyltriĂ©thoxysilane (APTES). Le but est dâobtenir la rĂ©tention la plus Ă©levĂ©e possible de fonctions amine -NH2 dans les revĂȘtements ou dans les nanoparticules synthĂ©tisĂ©es. Tout dâabord, un Ă©tat de lâart des post-dĂ©charges Ar-N2 et Ar-O2 et leurs applications est prĂ©sentĂ© ainsi que la cinĂ©tique dâinteraction de lâAPTES dans ces post-dĂ©charges, mettant en Ă©vidence le rĂŽle des mĂ©langes plasmagĂšnes sur la dĂ©composition du prĂ©curseur et sur la nature des films dĂ©posĂ©s. Ensuite lâĂ©tude de la dĂ©composition de lâAPTES dans une post-dĂ©charge Ar-N2 est rĂ©alisĂ©e. Les analyses par SEO et par FTIR in situ montrent le rĂŽle des atomes dâazote N dans la formation des diffĂ©rents sous-produits, Ă savoir HCN, CO et C=O. Les nanoparticules synthĂ©tisĂ©es contiennent peu dâamine primaire, et prĂ©sentent une concentration non nĂ©gligeable dâazote sous forme dâamide secondaire. Dans le cas de lâĂ©tude de la dĂ©composition de lâAPTES dans la post-dĂ©charge Ar-O2 en mode pulsĂ©, une tendance se dessine : les nanoparticules synthĂ©tisĂ©es en phase gazeuse lorsque les rapports cycliques augmentent ont une composition qui sâappauvrit en azote et en carbone mais sâenrichit en oxygĂšne. Les groupements NH2 initiaux sont fortement convertis en groupement amide. Les nanoparticules synthĂ©tisĂ©es avec des rapports cycliques Ă©levĂ©s ont des compositions diffĂ©rentes de celles des films minces dĂ©posĂ©s sur les parois, plus proches de la silice et ce en raison de la gravure par lâoxygĂšne atomique qui les affecte davantage. Le comportement spĂ©cifique des atomes dâoxygĂšne et dâazote en post-dĂ©charge rend difficile la rĂ©tention des amines dans les polymĂšres plasmas. Enfin nous avons terminĂ© par une Ă©tude de lâhydrodynamique dans le cas de lâinteraction entre lâacĂ©tylĂšne et une post-dĂ©charge Ar-O2 et Ă©tabli lâimportance de lâĂ©coulement sur toute approche visant Ă faire des mesures FTIR rĂ©solues temporellemen
Characterization by Fourier transform infrared spectroscopy of chemical reactions between post-discharge and organosilicons precursors : case of 3-aminopropyltriethoxysilane
Les travaux prĂ©sentĂ©s dans ce mĂ©moire concernent la caractĂ©risation par infrarouge Ă transformĂ©e de Fourier (FTIR) et par spectroscopie dâĂ©mission optique (SEO) des rĂ©actions chimiques entre post-dĂ©charges et prĂ©curseurs organosiliciĂ©s, avec comme exemple le cas du 3-aminopropyltriĂ©thoxysilane (APTES). Le but est dâobtenir la rĂ©tention la plus Ă©levĂ©e possible de fonctions amine -NH2 dans les revĂȘtements ou dans les nanoparticules synthĂ©tisĂ©es. Tout dâabord, un Ă©tat de lâart des post-dĂ©charges Ar-N2 et Ar-O2 et leurs applications est prĂ©sentĂ© ainsi que la cinĂ©tique dâinteraction de lâAPTES dans ces post-dĂ©charges, mettant en Ă©vidence le rĂŽle des mĂ©langes plasmagĂšnes sur la dĂ©composition du prĂ©curseur et sur la nature des films dĂ©posĂ©s. Ensuite lâĂ©tude de la dĂ©composition de lâAPTES dans une post-dĂ©charge Ar-N2 est rĂ©alisĂ©e. Les analyses par SEO et par FTIR in situ montrent le rĂŽle des atomes dâazote N dans la formation des diffĂ©rents sous-produits, Ă savoir HCN, CO et C=O. Les nanoparticules synthĂ©tisĂ©es contiennent peu dâamine primaire, et prĂ©sentent une concentration non nĂ©gligeable dâazote sous forme dâamide secondaire. Dans le cas de lâĂ©tude de la dĂ©composition de lâAPTES dans la post-dĂ©charge Ar-O2 en mode pulsĂ©, une tendance se dessine : les nanoparticules synthĂ©tisĂ©es en phase gazeuse lorsque les rapports cycliques augmentent ont une composition qui sâappauvrit en azote et en carbone mais sâenrichit en oxygĂšne. Les groupements NH2 initiaux sont fortement convertis en groupement amide. Les nanoparticules synthĂ©tisĂ©es avec des rapports cycliques Ă©levĂ©s ont des compositions diffĂ©rentes de celles des films minces dĂ©posĂ©s sur les parois, plus proches de la silice et ce en raison de la gravure par lâoxygĂšne atomique qui les affecte davantage. Le comportement spĂ©cifique des atomes dâoxygĂšne et dâazote en post-dĂ©charge rend difficile la rĂ©tention des amines dans les polymĂšres plasmas. Enfin nous avons terminĂ© par une Ă©tude de lâhydrodynamique dans le cas de lâinteraction entre lâacĂ©tylĂšne et une post-dĂ©charge Ar-O2 et Ă©tabli lâimportance de lâĂ©coulement sur toute approche visant Ă faire des mesures FTIR rĂ©solues temporellementThe present work deals with the characterization by Fourier transform infrared spectroscopy (FTIR) and by optical emission spectroscopy of chemical reactions between a post-discharge and an organosilicon precursor: the 3-aminopropyltriethoxysilane (APTES). The aim is to keep the highest retention of amine functions -NH2 in coatings or in the synthesized nanoparticles. First, a state of the art of Ar-N2 and Ar-O2 post-discharges and their applications is presented as well as the kinetics of the interaction of APTES in these post-discharges, highlighting the role plasma gases on the decomposition of the precursor and the nature of the deposited films. Then, the study of the decomposition of APTES in an Ar-N2 post-discharge is carried out. Analysis by optical emission spectroscopy (OES) and in situ FTIR show the role of the nitrogen atoms N in the formation of various main by-products, namely HCN, CO and C=O. The synthesized nanoparticles contain few primary amines, and have a significant concentration of nitrogen in the form of secondary amide. In the case of interaction APTES with pulsed Ar-O2 afterglow, there is one main trend: the nanoparticles synthesized in the gas phase when the duty cycle increases have a composition that decreases in nitrogen and carbon but increases in oxygen. The -NH2 groups are efficiently converted into amide groups. The nanoparticles synthesized with high duty cycle exhibit compositions that are different from those of thin films deposited on the walls, the latter being close to silica because of the etching by atomic oxygen, which affects them more. The specific behavior of oxygen and nitrogen atoms in post-discharge makes difficult the retention of a high level of amines in plasma polymers. Finally, we finished with a study of the hydrodynamics in the case of the interaction of acetylene with an Ar-O2 post-discharge and proved the key role of the flow for any approach aiming at getting time-resolved FTIR measurement
Study of a pulsed postâdischarge plasma deposition process of APTES: synthesis of highly organic ppâAPTES thin films with NH 2 functionalized polysilsesquioxane evidences
International audienceThis article reports the use of pulsed remote Ar-O 2 microwave plasma assisted chemical vapor deposition with an âNH 2 containing organosilicon precursor ((3-Aminopropyl)triethoxysilane: APTES). It is shown that modifying the plasma pulses duration (t on) and the plasma off duration (t off) allows to finely tune the deposited layer composition. In addition, the results of this work demonstrate that an important film growth occurs during t off , which results in an increased âNH 2 density. Besides, high resolution MALDI-ORBITRAP Mass spectrometry analysis clearly points out that APTES oligomers up to eight base units, including silsesquioxanes (cages), and cyclosi-loxanes (rings) molecules with intact âNH 2 groups are embedded into the as grown pp-APTES thin film. K E Y W O R D S microwave discharges, plasma-enhanced chemical vapour deposition (PECVD), plasma polymerization, pulsed discharges, remote plasma processes