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The hydrolysis of three alkoxy-silane coupling agents, gamma-methacryloxypropyl trimethoxy silane (MPS), gamma-aminopropyl triethoxy silane (APS), and gamma-diethylenetriaminopropyl trimethoxy silane (TAS), was carried out in ethanol/water solutions (80/20 w/w) at different pH values and followed by 1H, 13C and 29Si NMR spectroscopy. Acidic media were found to stabilize the hydrolyzed forms. As expected, the formation of silanol groups was followed by their self-condensation to generate oligomeric structures, yielding, ultimately, solid homopolycondensated structures, as analyzed by 29Si and 13C high-resolution solid-state NMR. Hydrolyzed MPS in acidic media was then successfully adsorbed onto a cellulose surface and the ensuing substrates submitted to thermal treatment at 110-120 degrees C under reduced pressure, in order to create covalent bonds between cellulose and the coupling agent.

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The hydrolysis of four alkoxysilane agents, g-methacryloxypropyl trimethoxysilane (MPS), g-mercaptopropyl trimetoxysilane (MRPS), octyl trimethoxysilane OS), and N-phenyl-g-aminopropyl trimethoxysilane (PAPS), was carried out in an ethanol/water (80/20) solution under both acid and basic conditions. 1 H, 13 C, and 29 Si NMR spectroscopy were used to provide quantitative analyses of the structural components during hydrolysis and condensation reaction. The analysis revealed that the acidcatalyzed hydrolysis of silane allows the formation of high amount of silanol groups, reduced the selfcondensation reaction among silanol groups and stabilized the proportion of intermediary hydrolyzed species for several days. However, under basic condition, condensation reactions proceed as soon as the hydrolysis reaction started leading to the rapid consumption of silanol groups through selfcondensation and to the growth of three-dimensional high molecular structures. The interaction of MPS and MRPS with cellulose fibers and the evolution of their surface properties were then investigated using adsorption isotherms and contact angle measurement.