U N I M O R E Dipartimento di Scienze
~t'J~6IE~.AT~ ~~,~.~ .) IEl~iL~~ Chimiche e Geologiche
Gottardiite
ctrolyte aqueous
Ryzhikov,b,c Habiba
ience des Malériaux de
1~I'Silà di Messina, j\1essil1~
on) and it can be storce lid interfacial energy b) terial, as a hydrophobi.
or the liquid out of the liqllid system [2J, the thc system disp lays a compunen ts of the Si·
hnological applications 'ion behaviors of thm
and 3M) are compared,
~ framework, struc turai powder diffraction, Thc K04-MSPD beamlinc al Bassèll DA C, exploring
\'olution is concemed,
,'milar pressure values, recognized: i) watcr
~netration of the extra·
iA intruded by NaCI and r.ruded cxtra-framcwork l\lrameters and both ionI
on thc basis of the lini)' determined by the iination of the cation by
ag~·Type Zeosils, J Phys
(2016) lntrusion -cxtrusion wed liquid by in situ high
.-60,
On the crystal-fluid interactions in laumontite
Davide Comboni: G. Diego Gatta", Marco Merlini", Paolo Lotti' , Michael Hanf1andb
" Dipartimenlo di Scienze della Terra, Università degli Studi di Milano. Via Botticelli 23, 20133 Milano, haly,
h ESRF -European Synchrolron Radia/ion Facili/y, 7I Avenue des Martyrs, CS40220, 38043 Grenoble Cedex, France.
Laumontite, I(Ca4.xNa,)Kx(H20)nl [AlgSiI604SL space group C2/m, is one of the most common natura I zeolite occurring in a wide range of geologicaI environments, including sedimentary deposits, deep-sea sediments and in sedimcntary deposits rdated to oil reservoirs. Remarkbly, it is also present in oceanic basalts, as well as in vugs of plutonic and volcanic rocks. Fully hydrated laumontite contains 18 H 20 molecules per formula uniI. If cxposed to air al rclative humidity (RH) < 50%, laumontite can lose up to 4 H 20 molecules per formula unit.
Such a partially-dehydrated laumontite is fonnalJy referred as leonhardite [I). Lee et al. [2J investigated the high-pressure behavior of laumontite up to 7.5 GPa, by in-situ synchrotron powder diffraction with a diamond anvil celi, using the 16:3: l =methanol-ethanol-H20 mix as pressure-transmitting fluid, and observed an instantaneous over-hydration effect at a relatively low pressure
«
0.3 GPa), with a potential additional phase transition at about 3 GPa [2). Others authors have investigated, mainly by in-si/II X-ray powder diffraction, the processes of hydration/dehydration, controlling the RH or submerging samples in pure water or increasing temperature [I, 3).Howcvcr, no expcriments ha ve so far been devoted to the elastic behavior of leonhardite, which both therrnodynamic calculation and geological observations suggest being the stable form of laumontite under diagcnctic and low-gradc metamorphic conditions [4). Furthermore, the bulk modulus K v of leonhardite is a criticaI paramcter necded in order to model the thermodynamic stability of this mineraI in geological environmcnts of economie relevance (i.e., deposits related to oil reservoirs). Moreover, some questions are stilI open about e,g. the single-crystal hydration kinetics in H 20 mixture and the possible phase transition observed by Lee ct al. [2J at about 3 GPa.
In order to unvcil thc open questions, we performed a series of in-si/u single-crystal synchrotron X-ray ditTraction experiments using different pressure-transmitting fluids, as well as in-situ single-crystal X-ray experimcnts at ambicnt prcssure in different H20 rich-mixture. On the basis of these studies, we are were to dcscribc: I) thc hydration mcchanisms and kinetics of laumontite in single crystals, 2) the bonding configuration ofthe adsorbed H20 moleculcs and the structural defonnation of the framework in respanse to the overhydration at ambient pressure; 3) the elastic parameters of leonhardite; 4) the different deformation behavior between Iconharditc and thc fully-hydrated laumontite.
[I J Yama7.aki 1\., Shiraki T., Nishido H., Otsuka R. 1991 , Clay Scienee. Phase change or laumontite under relative humidity-eontrolled conditions, Clay Scicn., H, 79 H6.
121 Lcc Y., Hrilja A.1., Vogt T. 2004. Pressure-induced migration or zeolitic water in laumontite. Phys. Chem. Miner., 31,421-428.
13J Fridriksson T., Aish D,L, Bird D,K 2004. Hydrogen-bonded water in laumontitel: X-ray powder diffraction study of watn site
{l~cupancy and slructural changcs in laumontite during room-tempcraturc isothennal hydration/dehydralion. Am. MineraI., 88, 277- 287.
[41 ,'cuhorr P,S. anJ BirJ D.K. 2001, Partial dehydration of laumontite: lhennodynamic conslrainls and petrogenelic impliealions, MineraI.
Mag., 65, 59-70,
21
••
P6. High-pressure behaviour of B-MFI zeolite in methanol: a preliminary study
P7.Enrico Catizzone: Massimo Migliori," Alfredo Aloise: Girolamo Giordano: Davide Comboni,b Paolo Lo\!, Marco Merlini,b G. Diego Gatta,b
"Dipartimento di Ingegneria per l'Ambiente e il Territorio e Ingegneria Chimica, Università della Calabria, Rende, 1[a.
" Dipartimento di Scienze della Terra, Università degli Studi di Milano, Milano, Italy
The high-pressure (P) behavior of a home-made sample of MFI-zeolite, with chemical forr, Na16B 16Si9440192·nH20, has been investigated by in situ synchrotron powder X-ray diffraction with a dian anvil celi, using silicone oil as a non-penetrating fluid and pure methanol as penetrating fluid [I]. Rietveld ! profile tit was used to obtain the unit-cell. parameters of the investigated sample at varying pressure conditi, The aim of the experiment was to check the occurrence and the effects induced by the intrusion of methanol, the zeolite's structural voids in response to the applied pressure, by compari so n with the behavior in a'
- . ...
,•
o • I •1m
IO
.. .. ,.
'f~j
charuclcritr.:d antiparallcl O
adjaccnl Illy appcars lo be
h ~ IO_ 373n,
penetrating fluido
....
....
-. ... · · · ·
(.)
11
· ·
~'.JM I
. I: :
. ::.::
' o •... .
il. . . . .
....
".. : :
....
1M
.. .. "..., ..
lO.. ..b, ••. •
, b)..
I •• • tti
i
••
....
Figure 1. H
", ( I pressUTe
o evolution of
unit-cell parameters li
. ...
Na-B-Mf. - _ .. ..
zeo/ite in JJ(- .. ..
penetraun,,.rQ.h1 silicone oil
and penetra' methanol (b). The effecl ofpressure on unir-celi volume (c).
The experimental data obtained from the P-ramp in methanol showed that: i) the compressibility of Na-R MFI in methanol is significantly Iower than that in silicooe oil (Fig. le) and ii) the elastic anisotrop; drastically different as well (Figs I a and l b), from which we can infer that the intrusion of the metli;
moJecuIes into the structural voids of investigated sample occUlTed. The P-intruded methanoJ molecuIes H,
"pillars", reducing drastically the voids and then the MFI -t:ype structure compressibility_ Future investigai [II C'Irma .\. 11 will be extending to AI- and Fe-containing MFI-type crystaIs, in order to describe the contro I of the framel 97 2373-242n
components on the crystaJ-f1uid interaction at high pressure. 121 Tcixcira-S
ch'l.ruclCnZU{jun [1] D;IWI)!:lJ S [I] Gatta G.D., Lee Y. (2014) Zeolites al high pressure: a review. MineraI. Mag_, 78,267-291.
V. il17t nlitc hy I 141 Il:J~J1S ~ • TI lOxpcrimcnlal ;md [5] W:.lng . -_ lu 7H 12 7)(20.
42
