A growing interest in sustainable polymer composites as potential alternatives to petroleum-based products has created a demand for new metrology capable of assessing composite performance non-destructively. This requires development of measurement tools that are able to quantify fundamental structure-property relationships (e.g. characteristic of components at the interface) at multiple length-scales. The National Institute of Standards and Technology (NIST) recently developed a new fluorescence imaging method to reveal the interface in polymer nanocomposites. This was done by employing F�rster resonance energy transfer (FRET) through confocal microscopy to probe nanoscale-interactions at the interface of a coumarin (donor dye) dispersed polymer and 5-(4,6-dichlorotriazinyl)-aminofluorescein (DTAF, acceptor dye) labeled nanofibrillated cellulose (NFC) composite. However, coumarin was not covalently attached to the matrix, and this hindered the extension of this model system to other polymers, due to free dye diffusion. Switching donor-acceptor dye pair to DTAF/rhodamine enables DTAF, attached to the NFC, to be used as the donor. We have investigated the differences between these two FRET pairs. In this work, a primary amine containing rhodamine spirolactam (RS), acting as the acceptor to enable FRET measurements of a NFC-epoxy composite, was synthesized for covalent attachment to an epoxy matrix. Introduction of a photoactivatable fluorescent dye in the epoxy matrix reduces dimerization and self-quenching, which can cause low FRET efficiency. FRET measurements were accomplished using both fluorescence lifetime imaging (FLIM) and conventional intensity based measurements.

Preparation of a photoactivatable fluorescent dye labeled epoxy monomer and its application in FRET measurements of sustainable nanocomposites

247th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.