Fluorescence technique for monitoring swelling of PAAm-kappa-carrageenan gel composites

Evingur G. A., Aktaş D., Pekcan O.

4th International Conference on Optical Measurement Techniques for Structures and Systems (OPTIMESS2009), Antwerp, Belgium, 25 - 26 May 2009, pp.151-152 identifier

  • Publication Type: Conference Paper / Full Text
  • City: Antwerp
  • Country: Belgium
  • Page Numbers: pp.151-152
  • Istanbul Technical University Affiliated: Yes


Steady-state fluorescence (SSF) technique was employed for studying swelling of polyacrylamide (PAAm) gels with various content of kappa- carrageenan. Disc shaped composite gels were prepared by free-radical cross/inking copolymerization of acrylamide (AAm) with various amounts of kappa-carrageenan (kappa C) using N, N'- methylenebis (acrylamide) (BIS) as crosslinker in the presence of ammonium persulfate (APS) initiator. Pyranine was introduced as a fluorescence probe. Fluorescence intensity of pyranine was monitored during in situ swelling processes of composite gels. It was observed that fluorescence intensity values decreased as swelling is proceeded. The Li-Tanaka equation was used to determine the swelling time constants tau and cooperative diffusion coefficients D from intensity variations during the swelling processes. It was shown that tau decreased and D increased as the kappa C content in the composites are increased.