also shift the spinodal and binodal lines as compared to the locations of these lines in the phase
diagram for the pure solvent [41]. As a consequence, the solute concentration inﬂuences the hole
nucleation rate. More importantly, the solute particles may also destabilise the dewetting fronts.
As a result, one may ﬁnd strongly ramiﬁed structures in all three systems [23, 25, 40, 42]. A
selection of images exhibiting some of the possible structures is displayed in Fig.1.
For volatile solvents, the contact lines retract even for wetting ﬂuids. It has been found that such
evaporatively receding contact lines may deposit very regular line or ring patterns parallel to the
moving contact line [24, 43]. The deposition of a single ring of colloids from a evaporating
drop of colloidal suspension is well known as the ‘coffee stain effect’ [44]. Detailed investiga-
tions reveal the emergence of rich structures including multiple irregular rings, networks, regular
droplet patterns, sawtooth patterns, Sierpinski carpets, and – in the case of DNA – liquid crys-
talline structures [22, 30, 45–49]. The deposition of regularly spaced straight lines orthogonal to
the moving contact line has also been reported [50]. Droplet patterns may as well be created em-
ploying solvent-induced dewetting of glassy polymer layers below the glass transition temperature
[51–53].
Note that the dewetting of pure volatile liquids has also been studied experimentally [54] and
theoretically [55–58]. In this case, different contact line instabilities have been observed for evap-
orating liquid drops [59, 60].
In the present article we review and preview the experiments and in particular the various mod-
elling approaches for dewetting suspensions of (nano-)particles in volatile partially wetting sol-
vents. After reviewing the basic experimental results in Section II, we discuss in Section III sev-
eral theoretical approaches. In particular, we present a kinetic Monte Carlo model in Section III A,
a dynamic density functional theory in Section III B, and a thin ﬁlm evolution equation in Sec-
tion III C. Finally, we conclude in Section IV by discussing advantages and shortcomings of the
individual approaches and future challenges to all of them.
II. EXPERIMENT WITH NANOPARTICLE SOLUTIONS
We focus on experiments that use monodisperse colloidal suspensions of thiol-passivated gold
nanoparticles in toluene [33, 34, 37–40, 61]. The gold core of 2 – 3 nm diameter is coated by a layer
of alkyl-thiol molecules. The length of the carbon backbone of the thiol used in the experiments
ranges from 6 to 12 carbon atoms ( C6 to C12) [40]. By varying the chain length, one can control
4