کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5189720 | 1381190 | 2007 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Nanostructural features in silica-polyvinyl acetate nanocomposites characterized by small-angle scattering
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Small-angle scattering (SAS) experiments were carried out on nanocomposites of poly(vinyl acetate) (PVAc) and fumed silica nanoparticles with different surface areas and chemical treatment, in the wave-vector (Q) range: 0.0002-1Â Ã
â1 . SAS data on composites with matrices of two different molecular weights indicate that the particle aggregation is independent of the molecular weight of the matrix for a fixed filler concentration and surface treatment. Particle size distributions derived from the SAS data suggest that particle aggregation is reduced when the native surface hydroxyl groups are blocked by various surface treatments, which also reduce the bonding strength to the polymer matrix. The unified exponential/power-law analysis of the SAS data shows three levels of hierarchy in the organization of silica particles. The first level consists of small aggregates of silica particles. At the second level we observe polydispersed aggregates resembling mass-fractal objects that is corroborated by TEM. The polydispersed aggregates further associate to form agglomerates at the third level. The relevance of these findings to the mechanism of nanofiller reinforcement of linear amorphous polymers above Tg is discussed.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 48, Issue 19, 10 September 2007, Pages 5734-5741
Journal: Polymer - Volume 48, Issue 19, 10 September 2007, Pages 5734-5741
نویسندگان
R. Aravinda Narayanan, P. Thiyagarajan, Ai-Jun Zhu, Benjamin J. Ash, M.L. Shofner, Linda S. Schadler, Sanat K. Kumar, S.S. Sternstein,