Thermodynamics of Resonant Infrared Matrix-Assisted Pulsed Laser Evaporation of Luminescent Dendrimers

Abstract

The successful demonstration of resonant infrared laser ablation and deposition of intact polymers and thermally labile organic molecules raises complex questions about the thermodynamics of the process. Here we present results of resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) of luminescent dendrimers, successfully deposited as thin films using cryogenic matrices of chloroform and toluene and analyzed by atomic-force microscopy and nuclear magnetic resonance of the films. The properties of the two matrices have definite effects on the dynamics of the ablation process, resulting in relatively rough films with little damage to the dendrimer for the chloroform matrix, and smoother films with more structural damage to the dendrimer in the case of the toluene matrix. Thermodynamic modeling suggests that RIR-MAPLE in the chloroform matrix proceeds via explosive vaporization, while the ablation process from the toluene matrix is normal boiling and vaporization.