AVS 52nd International Symposium
    Applied Surface Science Thursday Sessions
       Session AS+TF-ThA

Paper AS+TF-ThA3
Laser Processing of Polymer Nanocomposite Thin Films

Thursday, November 3, 2005, 2:40 pm, Room 206

Session: Thin Film Characterization II
Presenter: A.T. Sellinger, University of Virginia
Authors: A.T. Sellinger, University of Virginia
E.M. Leveugle, University of Virginia
G. Peman, University of Virginia
L.V. Zhigilei, University of Virginia
J.M. Fitz-Gerald, University of Virginia
Correspondent: Click to Email
Current biotechnology and sensor research has enhanced the drive to establish viable methods for depositing high quality organic and polymer thin films. In this research, solid targets of polystyrene (PS), poly(methyl methacrylate) (PMMA), and poly-lactic co-glycolic acid (PLGA) were prepared for room temperature pulsed laser deposition (PLD). Likewise, frozen targets consisting of varying concentrations of PS, PMMA, and PLGA dissolved in a volatile matrix material were prepared for matrix assisted pulsed laser evaporation (MAPLE). Carbon nanotubes (CNTs) were subsequently added to both PLD and MAPLE target systems in upwards of 20 wt.% loading for deposition of polymer nanocomposite films. Targets were ablated using a 248 nm KrF laser at fluences ranging from 0.025 J/cm@super 2@ to 1.0 J/cm@super2@. In addition, polymer concentration in MAPLE targets was varied between 1 wt.% and 10 wt.% relative to the matrix solvent. Films were deposited on Si, SiO@sub 2@, and NaCl substrates at room temperature in an Ar atmosphere. The chemical properties of the films deposited by both methods varied significantly from the native, with changes in molecular weight on the order of 75%. While PLD produced films generally showed little observable morphology, MAPLE deposited films typically showed evidence of blistering. A molecular dynamics (MD) program developed to simulate ablation of a frozen target during MAPLE was utilized to model and predict experimental phenomena. Particularly, the ejection of clusters of PMMA and volatile matrix molecules was studied and related to the observed morphology of the deposited films.