Poly(dimethylsiloxane) as a room-temperature solid solvent for photophysics and photochemistry

Area of Science:

• Materials Science
• Photochemistry
• Polymer Science

Background:

• Medium viscosity influences solvated species dynamics and excited-state deactivation.
• Poly(dimethylsiloxane) (PDMS) is a transparent, moldable, elastic polymer with applications in microfluidics.
• PDMS swelling in organic solvents limits its use with non-aqueous fluids.

Purpose of the Study:

• Demonstrate the utility of PDMS as a room-temperature solid-state medium for optical spectroscopy.
• Investigate the effect of PDMS on the photophysical properties of molecular rotor dyes.
• Gain mechanistic insights into excited-state deactivation pathways in a solid-state environment.

Main Methods:

• Optical spectroscopy of molecular rotor dyes.
• Utilizing poly(dimethylsiloxane) (PDMS) as a solid matrix.
• Characterizing fluorescence quantum yield and excited-state lifetimes.

Main Results:

• Transferring molecular rotors to PDMS induced orders-of-magnitude enhancement in fluorescence quantum yield.
• Excited-state lifetimes of molecular rotors were significantly increased in PDMS.
• Reversible swelling of PDMS facilitated sample loading into the solid matrix.

Conclusions:

• Poly(dimethylsiloxane) (PDMS) shows unexplored potential as a solid solvent for optical applications.
• The enhanced photophysical properties in PDMS provide mechanistic insights into excited-state deactivation.
• PDMS offers a versatile platform for optical spectroscopy, overcoming limitations of traditional liquid solvents.