For APTESsilanization process in particular, there have been many studieson the molecular structure,20 type of bonding,21 and surface derivatization conditions30 but the layer formation kinetics hasnot been reported to the authors’ knowledge. Moreover, thesurface coverage of APTES for MNP has not been reported,nor the complete plot of reaction kinetics. The understandingof the kinetics of APTES silanization would help to clarifywhether a monolayer is formed and eventually the qualitycontrol of the layer.11,21In this report, surface functionalization of MNP with APTESis investigated under different reaction conditions in order toreveal the layer formation kinetics, especially the kinetics in theprocess toward saturation. The maximum grafting density andreaction constants are estimated based on the kinetic model.The use of different solvents was carried out in order to assesssolvent effects on the reaction kinetics. The results may help the quality control of the silane layer in terms of reaction time,temperature, and solvent selection.