Thursday, October 24, 2013

Study of Brazilian asphaltene aggregation by Nuclear Magnetic Resonance spectroscopy

Fuel, Available online 21 September 2013, In Press, Uncorrected Proof
Study of Brazilian asphaltene aggregation by Nuclear Magnetic Resonance spectroscopy
Emanuele Catarina da Silva Oliveira (a),
Álvaro Cunha Neto (a), Valdemar Lacerda Júnior (a), Eustáquio Vinícius Ribeiro de Castro (a), Sônia Maria Cabral de Menezes (b)
a Departamento de Química, Centro de Ciências Exatas, Universidade Federal do Espírito Santo, UFES, Avenida Fernando Ferrari 514, Goiabeiras, 29075-910-Vitória, ES, Brazil
b Petrobras/Cenpes/QM, Ilha do Fundão, 21941-598 Rio de Janeiro, RJ, Brazil
Abstract
Using Nuclear Magnetic Resonance, researchers explored the relationship between the structural type (continental or archipelago) and aggregation properties of three distinct asphaltenes: asph_A, asph_B and asph_C. They used diffusion-ordered NMR spectroscopy (DOSY) to study the diffusion coefficients.
They examined the self-diffusion of the asphaltene aggregates in the concentration range of 0.0110% of each asphaltene in deuterated toluene. Data obtained from 1H and 13C NMR suggest that asph_B has a continental type of structure. This contributes to various properties of aggregation. DOSY reveals the presence of three aggregates, with three different diffusion coefficients, called nanoaggregate, microaggregate and macroaggregate.
Full Text Source (Subscription or Fee): http://www.sciencedirect.com/science/article/pii/S001623611300851X

No comments:

Post a Comment