Accordingly, the different position of the reactive sites along the polymer chains appears to play a crucial role, resulting in a clear variation of Al2O3 incorporation into the different polymer matrices. More information about the reaction of TMA with these functional groups is necessary to better understand polymer-precursor interactions and investigate the fundamental mechanisms governing inorganic phase growth into a polymer matrix during the SIS process, but this is challenging to elucidate with only experimental techniques and first principles simulations can contribute significantly to growing our understanding of SIS chemistries. In this work, the infiltration of Al2O3 into PMMA and PLA thin films was investigated experimentally and, for the first time, theoretically with first principles density functional theory (DFT) simulations using both non-periodic and periodic models of the TMA-polymer interactions.