Structural evolution of aging agar-gelatin co-hydrogels

✍ Scribed by S. Santinath Singh; V.K. Aswal; H.B. Bohidar

• Book ID: 104088034
• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 504 KB
• Volume: 50
• Category: Article
• ISSN: 0032-3861
• DOI: 10.1016/j.polymer.2009.09.032

✦ Synopsis

Agar-gelatin co-hydrogel was investigated over a period of z30-days by dynamic light and small angle neutron scattering, and rheology to quantify changes occurring inside the hydrogel. Degree of nonergodicity was extracted as a heterodyne contribution from the measured dynamic structure factor data. From the analysis of the data, we observed two relaxation modes namely fast and slow modes with relaxation times s f and s s whose dependence with aging time, t a fall on a scaling behavior given by power-laws, s f w (t a ) À1/5 and s s w (t a ) 3/5 respectively. Further the analysis showed the heterogeneity size (x SANS ) obtained from SANS also follows power-law behavior, x SANS w (t a ) À1/5 . The data taken together revealed the ''speeding up'' of fast and ''slowing down'' of slow mode relaxation processes.