Sıvı asfaltların ve bunlardan elde edilen asfaltenlerin süspansiyonlarında dinamik nükleer polarizasyon
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Date
1999-07-08
Authors
Çimenoğlu, Mehmet Akif
Journal Title
Journal ISSN
Volume Title
Publisher
Uludağ Üniversitesi
Abstract
Bazı kolloidal asfalt ve asfalten süspansiyonlarını incelemek için 1,437 mT 'lık zayıf manyetik alanda Nükleer Manyetik Rezonans (NMR) ve Overhauser Etkisi (OE) tipi Dinamik Nükleer Polarizasyon (DNP) kullanıldı. Bu yöntemde, difüzyona uğrayan çözgen moleküllerindeki çekirdek spinleri ile asfalten misellerinde bulunan çiftlenmemiş elektron spinleri manyetik olarak etkileşirler. Kullanılan asfalt, İzmit Tüpraş petrol rafinerisinden sağlanan, Libya kaynaklı, MC-30 sıvı petrol asfaltıdır. Asfalten, sıvı petrol asfaltının benzende çözündürülüp, petrol eterinde çökeltilmesiyle elde edildi. Saf çözgen ortam olarak, benzen, toluen, mesitilen, etilbenzen, tetralin, nitrobenzen, klorobenzen, piridin, kinolin ve tiyofen kullanıldı. Karışık çözgen ortamlar için, karbon tetraklorür (CCI4) ve karbon disülfür (CS2) sırasıyla toluen, benzen ve piridin ile sabit oranda karıştırıldı. Her bir çözgen ortam için üç farklı konsantrasyonda örnekler hazırlandı ve zayıf alan çift rezonans NMR spektrometresinde deneylere tabi tutuldu. ESR frekansına bağlı sinyal büyüme faktörleri ölçülerek asfalt için tek çözgen ortamda üç EPR spektrumu elde edildi. Başlıca DNP parametreleri bulunarak sonuçlar tartışıldı.
Nuclear Magnetic Resonance (NMR) and the Overhauser Effect (OE) type Dynamic Nuclear Polarization (DNP) have been used to study some colloidal asphalt and asphaltene suspensions in a weak magnetic field of 1,437 mT. In this method, diffusing nuclear spins in the solvent interact with unpaired electron spins in the asphaltene micelles. The asphalt used in this study is the MC-30 liquid petroleum asphalt from Libyan originated that supplied from rafinery of Tüpraş in İzmit. The asphaltene have been obtained by dissolving in benzene and precipitating in petroleum ether from liquid asphalt. Benzene, toluene, mesitylene, ethylbenzene, tetralin, nitrobenzene, chlorobenzene, pyridine, quinoline, and thiophene have been used as the pure solvent medium. For the mixed solvent media, CCI4 and CS2 have been mixed in constant ratio with toluene, benzene and pyridine respectively. For every solvent medium, the samples have been prepared in three different concentration and investigated experimentally in weak field double resonance NMR spectrometer. By measuring signal enhancement factors which depend on ESR frequency, three EPR spectra in the single solvent medium for asphalt have been obtained. Major DNP parameters have been also obtained and results have been discussed.
Nuclear Magnetic Resonance (NMR) and the Overhauser Effect (OE) type Dynamic Nuclear Polarization (DNP) have been used to study some colloidal asphalt and asphaltene suspensions in a weak magnetic field of 1,437 mT. In this method, diffusing nuclear spins in the solvent interact with unpaired electron spins in the asphaltene micelles. The asphalt used in this study is the MC-30 liquid petroleum asphalt from Libyan originated that supplied from rafinery of Tüpraş in İzmit. The asphaltene have been obtained by dissolving in benzene and precipitating in petroleum ether from liquid asphalt. Benzene, toluene, mesitylene, ethylbenzene, tetralin, nitrobenzene, chlorobenzene, pyridine, quinoline, and thiophene have been used as the pure solvent medium. For the mixed solvent media, CCI4 and CS2 have been mixed in constant ratio with toluene, benzene and pyridine respectively. For every solvent medium, the samples have been prepared in three different concentration and investigated experimentally in weak field double resonance NMR spectrometer. By measuring signal enhancement factors which depend on ESR frequency, three EPR spectra in the single solvent medium for asphalt have been obtained. Major DNP parameters have been also obtained and results have been discussed.
Description
Keywords
Asfalt, Asfalten, Asphaltane, Asphalt, Difüzyon, Dinamik nükleer polarizasyon, Manyetik rezonans spektroskopi, Diffusion, Dynamic nuclear polarization, Magnetic resonance spectroscopy
Citation
Çimenoğlu, M. A. (1999). Sıvı asfaltların ve bunlardan elde edilen asfaltenlerin süspansiyonlarında dinamik nükleer polarizasyon. Yayınlanmamış doktora tezi. Uludağ Üniversitesi Fen Bilimleri Enstitüsü.