TY - JOUR
T1 - Analysis of the interaction of vinyl and carbonyl silanes with carbon nanofiber surfaces
AU - Nistal, Andrés
AU - Palencia, Cristina
AU - Mazo, Ma Alejandra
AU - Rubio, Fausto
AU - Rubio, Juan
AU - Oteo, José Luis
PY - 2011/4
Y1 - 2011/4
N2 - Carbon nanofibers (CNFs) have been treated with vinyltryethoxy silane (VTS) and 3-metacryloxypropyltrimethoxy silane (MPS). CNF-silane interactions have been analyzed by means of TGA, FTIR-ATR, TEM, HRTEM, SEM and nitrogen adsorption. For similar silane concentration solutions TG analysis has shown that VTS and MPS form one and three silane monolayers, respectively. This has also been corroborated by the presence of an FTIR-ATR band at 1250 cm -1 assigned to Si-O-Si bonds of silica layers. For low silane concentrations, the vinyl group of VTS is bonded to the graphene CNF surface mainly through π-π interactions. However, MPS interacts through the carbonyl group with hydroxyl groups of graphene defect sheets existing probably in micropores. Silanol-CNF hydroxyl interactions are also expected at these silane concentrations. For high silane concentration, when the silica layer is formed, both silanes present vinyl free and carbonyl free groups, as observed by the 1370 and 1686 cm-1 FTIR-ATR bands, respectively. Nitrogen adsorption has shown that while VTS is adsorbed mainly on the defect free graphene surface, MPS is adsorbed on the micropores and, therefore on the hydroxyl defect graphene sites. These results are finally correlated with the dispersion stability of both silanes on water and styrene solutions.
AB - Carbon nanofibers (CNFs) have been treated with vinyltryethoxy silane (VTS) and 3-metacryloxypropyltrimethoxy silane (MPS). CNF-silane interactions have been analyzed by means of TGA, FTIR-ATR, TEM, HRTEM, SEM and nitrogen adsorption. For similar silane concentration solutions TG analysis has shown that VTS and MPS form one and three silane monolayers, respectively. This has also been corroborated by the presence of an FTIR-ATR band at 1250 cm -1 assigned to Si-O-Si bonds of silica layers. For low silane concentrations, the vinyl group of VTS is bonded to the graphene CNF surface mainly through π-π interactions. However, MPS interacts through the carbonyl group with hydroxyl groups of graphene defect sheets existing probably in micropores. Silanol-CNF hydroxyl interactions are also expected at these silane concentrations. For high silane concentration, when the silica layer is formed, both silanes present vinyl free and carbonyl free groups, as observed by the 1370 and 1686 cm-1 FTIR-ATR bands, respectively. Nitrogen adsorption has shown that while VTS is adsorbed mainly on the defect free graphene surface, MPS is adsorbed on the micropores and, therefore on the hydroxyl defect graphene sites. These results are finally correlated with the dispersion stability of both silanes on water and styrene solutions.
UR - http://www.scopus.com/inward/record.url?scp=79551681362&partnerID=8YFLogxK
U2 - 10.1016/j.carbon.2010.12.047
DO - 10.1016/j.carbon.2010.12.047
M3 - Article
AN - SCOPUS:79551681362
VL - 49
SP - 1635
EP - 1645
JO - Carbon
JF - Carbon
SN - 0008-6223
IS - 5
ER -