Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Novel insights on swelling and dehydration of Laponite RD   This paper investigates water sorption and dehydration of a model synthetic
clay (Laponite) and highlights the large differences with natural clays
(montmorillonite, hectorite) belonging to smectite family of structure and
composition. Measurements were done by combining for the first time
thermogravimetric analysis and X Ray diffraction methods on Laponite powders
stored in atmospheres with controlled relative humidity. Laponite exhibits a
very good reproducibility of sorption diagram and appears as the most
hygroscopic among smectites. The interlayer space increases from 11 to 20
Angstrom when r = n H2O /n Na increases from 2 to 22 in agreement with recent
numeric simulations by Morrow et al. We show that the desorption process, for 2
< r < 22, in isothermal conditions follow a first order kinetic identifying two
regimes around r* = 7 which is close to the coordination number of Na in
concentrated NaCl solution. Activation energies and frequency factors are
derived for the two regimes of water desorption and discussed in relation with
stability of the cationic complex.

2
The categories of this paper are: math
29
The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat