کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5204838 | 1381973 | 2007 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Effect of magnetic nanoparticles on the thermal properties of some hydrogels
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
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چکیده انگلیسی
Magnetic hydrogels (ferrogels) based on poly(vinyl alcohol) (PVA) and poly(hydroxyethyl methacrylate) (PHEMA) with magnetite (Fe3O4) nanoparticles were prepared. PVA ferrogels were synthesised by submitting the aqueous solution of polymer and Fe3O4 to freezing-thawing (F-T) cycles yielding a physical gel. Different samples were prepared by varying (i) the concentration of PVA, (ii) the concentration of magnetite and (iii) the number of F-T cycles applied. PHEMA ferrogels were prepared by a crosslinking polymerization reaction in the presence of magnetite yielding chemical gels. Different samples were prepared by varying (i) the concentration of HEMA, (ii) the concentration of EGDMA and (iii) the concentration of magnetite nanoparticles. All ferrogel samples were first dried before been analysed in a thermogravimetric analyzer. The resulting thermograms showed that the concentration of magnetite nanoparticles does affect the thermal stability of either ferrogels system, a general improvement in comparison with PVA and PHEMA hydrogels, respectively, being observed. The apparent activation energy (Ea) of the thermal degradation for PVA ferrogels was evaluated and calculated applying the Flynn-Wall and the Kissinger methods. Values of apparent Ea increased with the content of Fe3O4 in the ferrogel sample.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer Degradation and Stability - Volume 92, Issue 12, December 2007, Pages 2198-2205
Journal: Polymer Degradation and Stability - Volume 92, Issue 12, December 2007, Pages 2198-2205
نویسندگان
E. Goiti, M.M. Salinas, G. Arias, D. Puglia, J.M. Kenny, C. Mijangos,