In situ fluorescence study of slow release and swelling processes in gels formed by solution free radical copolymerization

✍ Scribed by Pekcan, Ö.; Yilmaz, Y.; Uğur, Ş.

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 408 KB
• Volume: 44
• Category: Article
• ISSN: 0959-8103
• DOI: 10.1002/(sici)1097-0126(199712)44:4<474::aid-pi843>3.0.co;2-n

✦ Synopsis

A novel method based on steady state Ñuorescence (SSF) measurements is introduced for studying slow release and swelling processes in gels formed by free radical crosslinking copolymerization (FCC) of methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EGDM) in toluene. Gels were prepared at 75¡C with various toluene contents with pyrene as a Ñuo-(P y ) rescence probe. After drying these gels, slow release and swelling experiments were performed in toluene at 50¡C by real-time monitoring of the pyrene Ñuorescence intensity. Li-Tanaka and Fickian type equations were used to obtain swelling and slow release parameters. It was observed that slow release takes place after the gel is swollen. Cooperative and desorption (slow release) di †usion coefficients and D) were measured and found to be 10~6 cm2 s~1 in both cases. (D c