Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Interplay of Physically Different Properties Leading to Challenges in
  Separating Lanthanide Cations -- an Ab Initio Molecular Dynamics and
  Experimental Study   The lanthanide elements have well-documented similarities in their chemical
behavior, which makes the valuable trivalent lanthanide cations (Ln(III))
particularly difficult to separate from each other in water. In this work, we
apply ab initio molecular dynamics simulations to compare the free energies
(Delta G(ads)) associated with the adsorption of lanthanide cations to silica
surfaces at a pH condition where SiO- groups are present. The predicted Delta
G(ads) for lutetium (Lu(III)) and europium (Eu(III)) are similar within
statistical uncertainties; this is in qualitative agreement with our batch
adsorption measurements on silica. This finding is remarkable because the two
cations exhibit hydration free energies (Delta G(hyd}) that differ by >2 eV,
different hydration numbers, and different hydrolysis behavior far from silica
surfaces. We observe that the similarity in Lu(III) and Eu(III) Delta G(ads) is
the result of a delicate cancellation between the difference in Eu(III) and
Lu(III) hydration (Delta G(hyd})), and their difference in binding energies to
silica. We propose that disrupting this cancellation at the two end points,
either for adsorbed or completely desorbed lanthanides (e.g., via
nanoconfinment or mixed solvents), will lead to effective Ln separation.

22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
1
The categories of this paper are: cs
5
The categories of this paper are: gr-qc
19
The categories of this paper are: eess
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th