Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Particle monolayer assembly in evaporating salty colloidal droplets   Ring-shaped deposits can be often found after a droplet evaporates on a
substrate. If the fluid in the droplet is a pure liquid and its contact line
remains pinned during the process, the mechanism behind such ring-shaped
deposition is the well-known coffee-stain effect. However, adding small amounts
of salt to such a droplet can change the internal flow dramatically and
consequently change the deposition mechanism. Due to an increase of surface
tension in the contact line region, a Marangoni flow arises which is directed
from the apex of the droplet towards the contact line. As a result, particles
arrive at the contact line following the liquid-air interface of the droplet.
Interestingly, the deposit is also ring-shaped, as in the classical
coffee-stain effect, but with a radically different morphology: particles form
a monolayer along the liquid-air interface of the droplet, instead of a compact
three-dimensional deposit. Using confocal microscopy, we study
particle-per-particle how the assembly of the colloidal monolayer occurs during
the evaporation of droplets for different initial concentration of sodium
chloride and initial particle dilution. Our results are compared with classical
diffusion-limited deposition models and open up an interesting scenario of
deposits via interfacial particle assembly, which can easily yield homogeneous
depositions by manipulating the initial salt and particle concentration in the
droplet.

28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
5
The categories of this paper are: gr-qc
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex