Fluorescence of Aminophtalimide (AP) in Poly(vinylalcohol) (PVA) and Poly(vinylacetate) (PVAc)”.

B. C. BARJA; P. F. ARAMENDÍA

Ascochinga, Córdoba. Argentina

Simposio; 12thIAPS Conference. Inter-American Photochemical Symposium; 2001

Time resolved and steady state fluorescence emission of aminophtalimide (AP) was mwasured in thin films of poly(vinylalcohol) (PVA) and of poly(vinylacetate) (PVAc) as a function of temperature. Steady state spectra have a maximum at 434 nm in PVAc and at 458 nm in PVA at room temperature. This maximum shifts to the blue with increasing temperature. The difference in emission maxima between the two polymers is explained by the stabilizing ability oh H-bonds of the excited state of AP. The hypsochromic shift with temperature is due to ordering capacity of the axcited state on the environment. Time resolved spectra show a red shift of the maximum with time in all cases. After spectral relaxation the emission maximum is red shifted compared to the corresponding steady state spectrum. The time constant of thie red shift is dependent on the temperature an on the polymer matrix. On the other side, the total fluorescence decays monoexponentionally  with a temperature independent lifeteime of 25 ns in PVAc and 20 ns in PVA. Environment change due to probe-polymer reorientation during excited stste lifetime is responsible for the red shift of the spectra.