NMR Studies on Plasmainduced Organosilicon Polymers Prof. Oleg - PowerPoint PPT Presentation

NMR Studies on Plasmainduced Organosilicon Polymers Prof. Oleg Antzutkin and Mats Lindberg, PhD Luleå University of Technology Prof. Hans Griesser and M.A. Ponnusamy Thirunavakkarasu Ian Wark Research Institute University of South Australia

Plasma Induced Polymerisation

TMDS polymerization H 3 C O CH 3 Si Si H CH 3 H CH 3 h ν Ο 2 Various free radicals formed by homolytic bond scission and/or reaction with oxygen Complex, crosslinked polymer structures

Properties - composition relationship Hardness - Increases with increasing power (2 - 8 kW) of the microwave irradiation as well as an increased oxygen flow (300 - 500 sccm) Composition - Ratio of silicon to carbon increased with increasing power. Oxygen content nearly constant. Si:C ratio increases on increased oxygen flow - as is the content of oxygen. These changes probably due to loss of small organic molecules.

Direct vs cross polarization CP DP DP CP CP

Spectral assignment O O O O Si Si Si Si H 3 C H H O O O O O Si Si Si Si O O H 3 C O Si H 3 C CH 3 O O H 3 C O Si Si H CH 3

All 150 sccm TMDS Comp. study - oxygen exposure and 4kW h ν

All: 2kW 400 sccm O 2 150 sccm TMDS 4kW 5.4kW

Approx. 7 months old sample Fresh sample