Gelation of PAAm-PVP composites: A fluorescence study
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Date
2014
Journal Title
Journal ISSN
Volume Title
Publisher
World Scientific
Abstract
Hybrid hydrogels are a new class of composite materials. Polyacrylamide (PAAm) hydrogels are mainly produced by free radical crosslinking copolymerization (FCC) of AAm in the presence of N N'-methylene bis (acrylamide) (BIS) as the crosslinker. Pyranine doped PAAm-poly (N-vinyl pyrrolidone) (PVP) composite were prepared with different amounts of PVP varying in the range between 0.0015 and 0.1 gr. It was observed that pyranine molecules as a fluoroprobe bind to AAm and PVP chains upon the initiation of the polymerization causing the fluorescence spectra of the bonded pyranines shift to the shorter wavelengths. The sol-gel phase transition and its universality were monitored and tested as a function of PVP contents. Observations around the critical point show that the gel fraction exponent beta agreed with the percolation result for below 0.025 gr PVP contents. However classical result was observed above 0.0125 gr PVP content.
Description
Keywords
Acrylamide, Poly (N-vinyl pyrolidone), Composite gel, Percolation, Critical phenomena, Fluorescence
Turkish CoHE Thesis Center URL
Citation
2
WoS Q
N/A
Scopus Q
Q3
Source
Volume
28
Issue
20