caa a22 4500 463223489 CHVBK 20180405153219.0 cr unu---uuuuu 170326e20071001xx s 000 0 eng 10.1007/s10853-007-1764-x doi (NATIONALLICENCE)springer-10.1007/s10853-007-1764-x Study on swelling of hydrogels (PAAm) at various temperatures by using fluorescence technique [Elektronische Daten] [Demet Aktaş, Gülşen Evingür, Önder Pekcan] Steady-state fluorescence (SSF) technique was employed for studying swelling of polyacrylamide (PAAm) hydrogels. Disc-shaped gels were prepared by free-radical crosslinking copolymerization of acrylamide (AAm) with N, N′- methylenebis (acrylamide) (BIS) as crosslinker in the presence of ammonium persulfate (APS) as an initiator. Pyranine was introduced as a fluorescence probe. Fluorescence intensity of pyranine was measured during in situ swelling process at various temperatures and it was observed that fluorescence intensity values decreased as swelling is proceeded. Li-Tanaka equation was used to determine the swelling time constants, τc and cooperative diffusion coefficients, D c from intensity, weight and volume variations during the swelling processes. It is observed that swelling time constants, τc decreased and diffusion coefficients, D c increased as the swelling temperature is increased. The swelling activation energies, ΔE were measured from the intensity, weight and volume variations and found to be 10.7, 32.2 and 64.1kJmol−1, respectively. Springer Science+Business Media, LLC, 2007 Aktaş Demet Department of Physics, Istanbul Technical University, Maslak, 34398, Istanbul, Turkey aut Evingür Gülşen Department of Physics, Istanbul Technical University, Maslak, 34398, Istanbul, Turkey aut Pekcan Önder Department of Physics, Isık University, Kumbaba-Şile, 34980, Istanbul, Turkey aut Journal of Materials Science Springer US; http://www.springer-ny.com 42/20(2007-10-01), 8481-8488 0022-2461 42:20<8481 2007 42 10853 https://doi.org/10.1007/s10853-007-1764-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10853-007-1764-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Aktaş Demet Department of Physics, Istanbul Technical University, Maslak, 34398, Istanbul, Turkey aut NATIONALLICENCE 700 1- Evingür Gülşen Department of Physics, Istanbul Technical University, Maslak, 34398, Istanbul, Turkey aut NATIONALLICENCE 700 1- Pekcan Önder Department of Physics, Isık University, Kumbaba-Şile, 34980, Istanbul, Turkey aut NATIONALLICENCE 773 0- Journal of Materials Science Springer US; http://www.springer-ny.com 42/20(2007-10-01), 8481-8488 0022-2461 42:20<8481 2007 42 10853 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer