TY - JOUR
T1 - Study on swelling of hydrogels (PAAm) at various temperatures by using fluorescence technique
AU - Aktaş, Demet Kaya
AU - Evingür, Gülşen Akin
AU - Pekcan, Önder
PY - 2007/10
Y1 - 2007/10
N2 - 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 64.1 kJ mol-1, respectively.
AB - 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 64.1 kJ mol-1, respectively.
UR - http://www.scopus.com/inward/record.url?scp=34547795813&partnerID=8YFLogxK
U2 - 10.1007/s10853-007-1764-x
DO - 10.1007/s10853-007-1764-x
M3 - Article
AN - SCOPUS:34547795813
SN - 0022-2461
VL - 42
SP - 8481
EP - 8488
JO - Journal of Materials Science
JF - Journal of Materials Science
IS - 20
ER -