Functional Polymer Nanocomposites by Gas Aggregation Cluster Source and Initiated Chemical Vapor Deposition

Functional metal-polymer nanocomposites are required for highly tailored surface properties and coatings. However, past approaches like cosputtering, physical evaporation, or plasma polymerization can not retain the functionality of the polymer matrix or produce tailored nanoparticles. A new kind of codeposition of nanocomposite polymer thin films is presented via the combination of a gas aggregation cluster source (GAS) and initiated chemical vapor deposition (iCVD) in a common GAS+iCVD vacuum system. iCVD delivers ultraprecise and defect-free polymer thin films on the nanoscale while a GAS creates nanoparticles that form in the gas phase and can be tuned in size and composition. Using the GAS+iCVD system, nanocomposites of well-defined Ag nanoparticles in a chemically intact PTFE polymer thin film are prepared. The deposited nanocomposite proved applicable in antibacterial applications by decreasing the colony-forming units of Enterococcus faecalis by 38%. Antiviral SARS-CoV-2 Spike-ACE-2 binding inhibition reaches 65% of pure silver nanoparticles. The nanocomposite improves the apoptotic gene expression for liver cancer cells compared to pure thin films. This new kind of codeposition paves the way for the fabrication of functional nanocomposite thin films combining the advantages of the iCVD polymer palette with a large variety of nanoparticles that can be prepared by GAS.