Growth behavior and surface topography of different silane coupling agents adsorbed on the silicon dioxide substrate (0001) for vapor phase deposition

The surface topography and growth behavior of self-assembled monolayers (SAMs) formed from vinyltriethoxysilane (VTES) at a constant temperature (20°C) on silicon dioxide substrates were investigated using atomic force microscopy (AFM). Two methods for silanization were introduced: vapor phase deposition and deposition from a solution. The influence of deposition conditions on the topography of silane films was also studied. The property of modified SiO2substrates surface was characterized by static water contact angle measurements. The experimental results revealed that the silane films deposited from the solution method grew via islands, whereas this is not the case for vapor phase deposition. The roughness of the layers deposited via solution method first decreased and then increased with the VTES concentration increasing, while the roughness of the layers deposited via vapor phase increased straight. Furthermore, the adsorption types for silane being adsorbed on SiO2substrates were also investigated. The results indicated that there were two adsorption types in both deposition processes: physisorption and chemisorption.

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Functionalization of Porous Clay Heterostructures with Silane Coupling Agents

Materiale Plastice ◽

10.37358/mp.17.2.4847 ◽

2017 ◽

Vol 54 (2) ◽

pp. 341-344

Author(s):

Anda Ionelia Mihai (Voicu) ◽

Sorina Alexandra Garea ◽

Eugeniu Vasile ◽

Cristina Lavinia Nistor ◽

Horia Iovu

Keyword(s):

Pore Volume ◽

Total Pore Volume ◽

Coupling Agents ◽

Silane Coupling Agents ◽

Porous Clay Heterostructures ◽

Bet Analysis ◽

Silane Coupling ◽

Ftir Spectrometry ◽

Textural Parameters ◽

Epoxy Groups

The goal of this paper was to study the modification of porous clay heterostructures (PCHs) with various silane coupling agents. Two commercial coupling agents (3-aminopropyl-triethoxysilane (APTES) and 3-glycidoxypropyl-trimethoxysilane (GPTMS)) with different functional groups (amine and epoxy groups) were used as modifying agents for the PCHs functionalization. The functionalization of PCH with APTES and GPTMS was evaluated by Fourier transform infrared (FTIR) spectrometry, thermogravimetric analysis (TGA), X-Ray Diffractions (XRD) and BET Analysis. FTIR spectra of modified PCHs confirmed the presence of characteristic peaks of silane coupling agents. TGA results highlighted an increase of weight loss for the modified PCHs that was assigned to the degradation of silane coupling agents (APTES and GPTMS) attached to the PCHs. The XRD results showed that the structure of modified PCHs was influenced by the type of the silane coupling agent. The functionalization of PCHs with silane coupling agents was also confirmed by BET analysis. Textural parameters (specific surface area (SBET), total pore volume (Vt )) suggested that the modified PCHs exhibit lower values of SBET and a significant decrease of total pore volume than unmodified PCHs.

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