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pramolecular chemistry with a fundamental concept of molecular
self-assembly without guidance or management from an outside
source. In self-assembly all final nanostructures are “encoded” in
the shapes and properties of the molecules that are empoloyed. The
particular desired structures of suspended supramolecular
nanoparticles may be realised by subtle changes of macroscopic
system parameters, e.g. system’s composition, as illustrated in the
phase diagram of Fig. 2 (from Ref. 13).
In turn, phase changes in evolving nanocolloids may notably
affect macroscopic properties of the bulk nanofluid. In petroleum,
the majority of self-assembling molecules belong to the solubility-
defined fraction of “asphaltenes”.
14-17
Colloidal Suspensions and Association
Nanocolloids in Petroleum
Specialists in the subject may argue that there is no novelty in im-
portance for petroleum properties of native colloids (either mi-
crometer- or nanometer-sized). Indeed, this importance has been
emphasized several decades ago, firstly with respect to bitu-
men.
18,19
Later, it was recognized that any petroleum medium
represents a colloid system with dispersed colloidal phase consti-
tuted predominantly of asphaltenes. The details of asphaltene col-
loid characterization have been reported in numerous references.
The important milestones in this research were publications of a
book based on materials of 1993 International Symposium on the
Characterization of Petroleum Colloids
20
and of a Russian-
language book on disperse systems in petroleum.
21
However, neither earlier, nor more recent models of asphal-
tene colloids in petroleum include a concept of asphaltene self-
assembly into a variety of (nano)colloidal configurations with a
well-structured phase diagram.
In most models (cf. Ref. 22 and multiple references therein),
asphaltenes from the start are regarded as solid (quasispherical)
colloidal particles with diameters of 2–10 nm. Under evolving con-
ditions these colloids may coagulate/flocculate via diffusion- or re-
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