%0 Journal Article
%A Pradilla, Diego
%A Subramanian, Sreedhar
%A Simon, Sébastien
%A Sjöblom, Johan
%A Beurroies, Isabelle
%A Denoyel, Renaud
%D 2016
%T Microcalorimetry Study of the Adsorption of Asphaltenes
and Asphaltene Model Compounds at the Liquid–Solid Surface
%U https://acs.figshare.com/articles/journal_contribution/Microcalorimetry_Study_of_the_Adsorption_of_Asphaltenes_and_Asphaltene_Model_Compounds_at_the_Liquid_Solid_Surface/3481745
%R 10.1021/acs.langmuir.6b00816.s001
%2 https://acs.figshare.com/ndownloader/files/5490542
%K Model compound C 5PeC exhibits
%K van der Waals
%K Asphaltene Model Compounds
%K aliphatic end groups
%K acidic polyaromatic asphaltene model compound
%K C 5PeC
%K surface
%K C 6
%K adsorption
%K Δ H z parameter
%X The
adsorption of an acidic polyaromatic asphaltene model compound
(C5PeC11) and indigenous C6-asphaltenes onto the liquid–solid
surface is studied. Model compound C5PeC11 exhibits a similar type
of adsorption with a plateau adsorbed amount as C6-asphaltenes
onto three surfaces (silica, calcite, and stainless steel). Model
compound BisAC11, with aliphatic end groups and no acidic functionality,
does not adsorb at the liquid–silica surface, indicating the
importance of polar interactions on adsorption. The values of the
adsorption enthalpy characterized by the ΔHz parameter (the enthalpy at zero coverage)
indicate that the type of adsorption and the driving force depend
on the surface, a key feature when discussing asphaltene deposition.
The adsorption of C5PeC11 onto silica is shown to be driven primarily
by H bonding (ΔHz = −34.9 kJ/mol), unlike adsorption onto calcite where polar
van der Waals and acidic/basic interactions are thought to be predominant
(ΔHz = −23.5
kJ/mol). Interactions between C5PeC11 and stainless steel are found
to be weak (ΔHz = −7.7 kJ/mol). Comparing C6-asphaltenes and their
esterified counterpart shows that adsorption at the liquid–solid
surface is not influenced by the formation of H bonds. This was evidenced
by the similar adsorbed amounts obtained. Finally, C5PeC11 captures,
to a certain extent, the adsorption interactions of asphaltenes present
at the calcite–oil and stainless steel–oil surfaces.
%I ACS Publications