Fluorescence from poly(N-vinylcarbazole) in uniaxially stretched polymer films

✍ Scribed by Taiji Ikawa; Tohru Shiga; Akane Okada

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 162 KB
• Volume: 66
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19971121)66:8<1569::aid-app18>3.0.co;2-z

✦ Synopsis

Steady-state and time-resolved fluorescence properties of poly( N-vinylcarbazole) (PVCz) dispersed in a polystyrene (PS) cast film were studied under tensile loadings at room temperature. The excited monomer emission of PVCz located around 350 nm decreased with increasing applied tensile strain from 0 to 0.8%. The strain enhanced the emission which was ascribed to the partial-overlap excimer of PVCz in a 360-430 nm region. The emission due to the full-overlap excimer of PVCz between 430 and 500 nm was unchanged by the action of the tensile loadings. The ratio of fluorescence intensities at 375 nm and 345 nm I 375 /I 345 was proportional to the applied strain. The time-resolved fluorescence study indicated that the lifetimes of the excited monomer and of the partial-overlap excimer were not affected by the strain. The obtained results mean that the strain applied to the PS matrix increases the partialoverlap conformation of two adjacent carbazolyl chromophores in a PVCz chain and suggest that PVCz is a useful probe for detecting residual strains in polymer matrices.