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

hν Ο2 Various free radicals formed by homolytic bond scission and/or reaction with oxygen Complex, crosslinked polymer structures

O Si Si CH3 H CH3 H3C CH3 H

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

• f oxygen.

These changes probably due to loss of small organic molecules.

Direct vs cross polarization

CP DP DP CP CP

Si O Si O Si H3C CH3 O Si Si H3C CH3 H Si O Si O Si H3C H O Si O H O O Si O H3C O O Si O O O

Spectral assignment

• Comp. study - oxygen exposure

All 150 sccm TMDS and 4kW hν

2kW 4kW 5.4kW All: 400 sccm O2 150 sccm TMDS

Fresh sample Approx. 7 months

• ld sample