کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9594192 | 1507518 | 2005 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Evidence of microphase separation in controlled pore glasses
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Evidence of microphase separation in controlled pore glasses Evidence of microphase separation in controlled pore glasses](/preview/png/9594192.png)
چکیده انگلیسی
The phase separation of a mixture of water and isobutyric acid (iBA) confined in the pore space of Controlled Pore Glass (CPG) 10-75 has been studied by 1H NMR relaxometry and 1H-pulsed field gradient (PFG) diffusion measurements. For an acid-rich mixture (mass fraction 54 wt% iBA), evidence of a phase separation process in the pores was obtained, which occurs in a temperature window between 32 and 39 °C, as indicated in the PFG data by an anomalous temperature dependence of the diffusion coefficient and in the relaxation data by a bi-exponential magnetization decay. The phase separation temperature of the mixture in the pore is slightly lower than in the bulk mixture of the same composition (41 °C) and extends over a finite temperature range. A qualitative model of the phase separation process in the pores is developed, which assumes a temperature-dependent domain-like structure of the liquid below the phase transition temperature and a breakdown of these domains upon reaching the transition temperature.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Solid State Nuclear Magnetic Resonance - Volume 28, Issues 2â4, September 2005, Pages 117-124
Journal: Solid State Nuclear Magnetic Resonance - Volume 28, Issues 2â4, September 2005, Pages 117-124
نویسندگان
A. Vyalikh, Th. Emmler, E. Gedat, I. Shenderovich, G.H. Findenegg, H.-H. Limbach, G. Buntkowsky,