The gelation of sodium alginate with calcium ions studied by magnetic resonance imaging (MRI)

✍ Scribed by Kimberlee Potter; Bruce J. Balcom; T.Adrian Carpenter; Laurance D. Hall

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 754 KB
• Volume: 257
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(94)84112-8

✦ Synopsis

The displacement of the sol/gel interface during the gelation of sodium alginate by calcium ions can be tracked in both one and two dimensions using magnetic resonance imaging . In the one-dimensional gelation experiments, the distance moved by the sol/gel interface was proportional to (time'/ 2), which implies that the gelation process is diffusionlimited . Using the gelation model previously proposed by Smidsrod and co-workers, together with the initial reaction conditions and assuming that the diffusion coefficient of the alginate molecules is extremely small, it was found that the diffusion of calcium ions through the gel network is dependent on the initial concentration of the calcium, the ionic strength of the alginate solution, and the size of pores in the gel which is formed .