Abstract
This paper reports the static and dynamic fluorescence emission of pyrene sorbed onto the surface of 6 different polyamides classified in two categories: AB (polyamide-6 and -11) or AABB (polyamide-6,6, -6,9, -6,10 and -6,12). Pyrene is a well known fluorescent probe for the polarity evaluation of different media for which the ratio of intensities of the vibronic bands ( I 1/ I 3) decreases in less polar medium and the fluorescence decay from the singlet electronic excited state increases with decreasing polarity. The steady-state vibronic ratio I 1/ I 3 of the pyrene fluorescence emission decreases with decreasing polarity for polyamides AB but for polyamides AABB, this ratio undergoes a significant decrease for polyamides-6,9 compared with -6,6 but remains almost constant for polyamides-6,10 and -6,12. This shows that the steady-state fluorescence of pyrene is only sensitive to the polarity of sorption sites whose dimensions are similar to the van der Waals radius of the molecule. In contrast, fluorescence decays decrease with decreasing polarity of the polyamide from τ F = 250 ns for polyamide-6,6 to τ F = 310 ns for polyamide-6,12 and thus this parameter is always sensitive to the polarity of the medium. We also discuss the advantages of these spectroscopic methodologies that include their applicability to samples without any further sample manipulation and which is independent of their form, powder, pellet or film, and of their thicknesses and sizes.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.