Atomic Layer Deposition of Al2O3 Films on Polyethylene Particles

Abstract

Sequential exposures of Al(CH3)3 and H2O at 77 °C were used to encapsulate low-density polyethylene (LDPE) particles with an ultrathin Al2O3 film. FTIR studies revealed that the nucleation of Al2O3 atomic layer deposition (ALD) on the LDPE particles occurred primarily via adsorption of Al(CH3)3 onto the LDPE surface or absorption of Al(CH3)3 into the LDPE particle followed by the reaction with H2O. The FTIR spectra then revealed the progressive switching between AlCH3* and AlOH* species with alternating exposure to Al(CH3)3 and H2O. This nucleation of Al2O3 ALD did not require the existence of specific chemical functional groups on the polymer. The FTIR spectra also demonstrated that the sequential exposures of Al(CH3)3 and H2O led to an increase in Al2O3 bulk vibrational modes. The increase of the absorbance for the Al2O3 bulk vibrational modes was linear with the number of AB cycles. The presence of an Al2O3 film on the LDPE particles was confirmed using transmission electron microscopy (TEM). The TEM i...