Study on swelling of hydrogels (PAAm) at various temperatures by using fluorescence technique
Yükleniyor...
Dosyalar
Tarih
2007-10
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Springer US
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
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, tau(c) and cooperative diffusion coefficients, D-c from intensity, weight and volume variations during the swelling processes. It is observed that swelling time constants, tau(c) decreased and diffusion coefficients, D-c increased as the swelling temperature is increased. The swelling activation energies, Delta E were measured from the intensity, weight and volume variations and found to be 10.7, 32.2 and 64.1 kJ mol(-1), respectively.
Açıklama
Anahtar Kelimeler
Poly(methyl methacrylate) gels, Phase-transitions, Kinetics, Shrinking, Gels, Hydrogels, Polyacrylates, Phase transition, Activation energy, Copolymerization, Diffusion, Fluorescence, Free radicals, Pyrene, Swelling, Swelling process, Swelling temperature, Tanaka equation
Kaynak
Journal of Materials Science
WoS Q Değeri
Q2
Scopus Q Değeri
Q1
Cilt
42
Sayı
20
Künye
Kaya Aktaş, D., Akın Evingür, G. & Pekcan, M. Ö. (2007). Study on swelling of hydrogels (PAAm) at various temperatures by using fluorescence technique. Journal of Materials Science, 42(20), 8481-8488. doi:10.1007/s10853-007-1764-x
