Polysilane application

Polysilane application

• 1.
  ADVANCED APPLICATION OF POLYSILANES
• 2.
  POLYSILANES  High molecularweight polymer with silicon in their backbone  Differ from inorganic polymers like polysiloxane and polyphosphazene .  The exclusive Si-Si bond allows sigma delocalization  Electrical and Optical properties and other Siloxanes Polyphosphazene Polysilanes
• 3.
  • Solubility canbe tuned with varying attached group • Thermal Resistant upto 573 K • Sigma electron delocalization along the Si- Si chain • Low Sigma-sigma* excitation • The bond can be broken by UV light Properties of Interest
• 4.
  APPLICATION HISTORY  FirstSynthesized in 1920  No application till 1970  Yajima et al formation of polydimethysilane to Silicon Carbide  Discovery of electronic properties by west et al  Two fold:  Application based on the reactivity  Aplication based on the electrical properties
• 5.
  APPLICATIONS BASED ONTHE REACTIVITY OF POLYSILANES Precursor to Silicon Carbide • Prolysis of a mixture of Polysilanes and Polycarbosilanes at 1670 K • Silicon Carbide uses-  Structural Material  Automobile Parts  Heating Material  Steel Production
• 6.
  PHOTOINITIATOR IN RADICALREACTION  Homolytic Cleavage on exposure to UV light form free silyl radical  Can react with olefinic monomer to initiate free radical Polymerization  Polymerization of styrene and several acrylate polymers
• 7.
  APPLICATIONS BASED ONTHE PHOTOPHYSICAL AND ELECTRONIC PROPERTIES OF POLYSILANES  Hole transporting materials  In electronic devices, such as organic light emitting diodes (OLEDs) and organic photovoltaics (OPV).
• 8.
  APPLICATION BASED ONELECTRICAL PROPERTIES  Polysilanes in OLEDs  Polysilanes can be employed as hole transporting materials or emitters in OLED  The basic design of a polymer OLED is devices, more specifically in polymer OLEDs. • OLED in Display and other Electronic devices.
• 9.
  POLYSILANES AS PHOTOVOLTAIC Polysilane in Photo voltaic  Polysilanes can be part of the active layer or, such as in multi-layered OLEDs,  serve as a hole transporting hole transporting material in organic solar.
• 10.
  OTHER AREAS  Fabricationof Microlens Arrays  Coatings  Polysilanes as Photoresists in Microelectronics  And more……
• 11.
  CONCLUSION  Application ofPolysilanes are numerous  Commercialization has not happened  Some reason: difficulties in  controlling their synthesis with regard to molecular weight, PDI and impurities as  well as the high costs of these elaborate methods and the purification processes involved.
• 12.
  REFERENCES  A. Rahimi,Iran. Polym. J., 13, 149 (2004).  A. Rahimi and P. Shokrolahi, Int. J. Inorgan. Mater., 3, 843 (2001).  J. E. Sheats, Jr., Ch. E. Carraher, Jr., Ch. U. Pittmann, and M. Zeldin, Macromol.  K. Matyjaszewski, Polym. Mater. Sci. Eng., 64, 104 (1991).  Book Inorganic Chemistry by James E Mark and Harry E Allock  Modern Synthetic and Application Aspects of Polysilanes: An Underestimated Class of Materials? A. Feigl, A. Bockholt, J. Weis