J Colloid Interface Sci. 2021 Mar 2;593:21-31. doi: 10.1016/j.jcis.2021.02.076. Online ahead of print.
ABSTRACT
HYPOTHESIS: The objective is to noninvasively probe the local hydrocarbon dynamics at asphaltene/maltene interfaces to reveal the global characteristics of bitumen at increasing temperatures and under various mechanical constraints.
EXPERIMENTS: We propose multidimensional (1D and 2D) nuclear magnetic relaxation (NMR) experiments to characterize the dynamic properties of hydrocarbons for a set of bitumen from 40 to 180 °C. The convergence towards universal theoretical modelling of NMR relaxation experiments gives a comprehensive understanding of hydrocarbon transport in these very weakly permeable samples. Moreover, a multivariate statistical analysis allows for correlating these NMR relaxation data for all bitumen samples to the main empirical parameters by qualifying the bitumen grading, such as the penetrability, softening and fragility points over a large range of temperatures.
FINDINGS: These new experimental and theoretical multiscale approaches link hydrocarbon interfacial dynamics to the global characteristics of various bitumen types. This is critical for grading these universally encountered materials.
PMID:33730653 | DOI:10.1016/j.jcis.2021.02.076
