Conference Publication Details
Mandatory Fields
Ryder, A.G, Szczupak,B, Rotchev,Y.A, Klymchenko,A.S, Gorelov,A, Glynn,T.J.
OptoIreland 2005, published in: Proc SPIE - Int. Soc. Opt. Eng. vol. 5826
A fluorescence methodology for assessing the polarity and composition of novel thermoresponsive hydrophilic/hydrophobic copolymer system
WOS: 1 ()
Optional Fields
Fluorescence, Polymer, thin-film.
Dublin, Ireland
The use of designed polymer coatings for specific applications such as drug delivery or modifying cell response is a critical aspect of medical device manufacturing. The chemical composition and physical characteristics of thin polymer coatings need to be analysed in-situ and this can present difficulties for traditional analytical methods. For example, changes in the polarity of polymer coatings are typically measured using the contact angle (CA) method. This is a simple process and gives good results however; it cannot be used to measure very hydrophilic polymers, or to analyse features smaller than a couple of mm in size. There is a need for a non-contact method for polarity measurement that issuitable for hydrophilic polymers on a macro- and microscopic scale. 4-diethylamino-3-hydroxyflavone (FE), 5, 6-benzo-4-diethylamino-3-hydroxyflavone (BFE), and 4-diethylamino-3-hydroxy-7-methoxyflavone (MFE) are fluorescence probes based on 3-hydroxyflavone. They respond to environment perturbations by shift and changes in the relative intensity of two well-separated bands in the emission spectra. These bands originate from an excited state intramolecular proton transfer (ESIPT) reaction. We have incorporated FE, BFE, and MFE into a novel thermoresponsive hydrophilic/hydrophobic copolymer system (NIPAM-NtBA) and studied its fluorescence behaviour. The fluorescence emission spectra depend strongly on copolymer composition, with increasing hydrophobicity (greater NtBA fraction) leading to a decrease in the value of log (IN*/IT*). This allows for the noncontact, measurement of the exact composition and surface energy of the copolymer system.
Grant Details
This work was part supported by funding from the National Centre for Biomedical Engineering Science in NUI-Galway as part of the Higher Education Authority Programme for Research in Third Level Institutions, from NUI-Galway in the form of a fellowship to BS, and from Science Foundation Ireland under Grant number (02/IN.1/M231).
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