ORIGINAL PROPERTIES OF WATER

Transcription

1 ORIGINAL PROPERTIES OF WATER IN NANOCHANNELS Pascale Launois Laboratoire de Physique des Solides, CNRS, Université Paris Sud, Université Paris Saclay, Orsay, France In close collaboration with Erwan Paineau, Stéphan Rouzière & Stéphane Rols Thanks also to S. Dalla Bernardina, J.-B. Brubach, P. Roy, P. Judeinstein

2 OUTLINE Introduction Original properties of bulk water New properties of water confined in carbon nanotubes Our results Water structure during carbon nanotube filling Water dynamics inside carbon nanotubes Alternative nanochannels JMC15 1

3 Introduction

4 WATER Water is the most extraordinary substance! Practically all its properties are anomalous Albert Szent-Györgyi, Nobel Prize in Physiology or Medecine (1937), in The Living State: With observations on Cancer, Academic Press, Inc.: New-York, 1972 Water expands when it freezes! JMC15 2

5 WATER MOLECULE AND WATER STRUCTURE Water electronic structure H bond (HB) ~0.28 nm Ice I h Liquid water nm r = g/cm 3 (0 C) r = g/cm 3 (20 C) n HB = 4 <n HB >~3.6 < 4 JMC15 3

6 CARBON NANOTUBES Single-walled (SW) carbon nanotubes (CNT) Molecule size ~ SWCNT diameter SWCNTs are ideal 1D channels for studying molecular nanoconfinement JMC15 4

7 HYDROPHOBIC CARBON NANOTUBES Graphene-graphitic planar surfaces: hydrophobic Contact angle 90 Taherian et al, Langmuir, 2013 Water spontaneously fills CNTs! o Soaked in liquid water o Exposed to water gas Gogotsi et al, Appl. Phys. Lett., 2001 JMC15 5

8 WHY WATER ENTERS CARBON NANOTUBES PNAS, 2011 Physically, the entropic gain of water in CNT arises from the liberation of water molecules from the tetrahedral frameworks in the bulk, allowing for greater phase space sampling inside the CNTs and therefore greater configurational entropy. Entropic gain from the less constrained water molecules near the wall dominates any enthalpic loss due to a reduced HB (H-bonding), leading to decreased free energies. JMC15 6

9 WATER CARBON NANOTUBES Many simulations studies (> 150) Diameter-dependence: single-file to water layers r t = 0.7 nm JMC15 7

10 H 2 O@CNT: ULTRAFAST WATER TRANSPORT The seminal article (numerical simulations) Nature, 2001 ISI web of Science TITLE: ((Carbon nanotub* AND water) AND (simulation OR theor*)) August 21, 2016 JMC15 8

11 H 2 O@CNT: ULTRAFAST WATER TRANSPORT Strong curvature dependence of the friction coefficient: curvature-induced incommensurability between the water and carbon structures Falk et al, Nano Lett. 10, 4067, 2010 Hydrogen bonding at the interface significantly affects the flow rates Joseph & Aluru, Nano Lett. 8, 452, 2008 Free OH bonds pointing to the wall JMC15 9

12 H 2 O@CNT: ULTRAFAST WATER TRANSPORT Few experimental results Membranes Majumder et al, Nature, 2005; Holt et al, Science, 2006; Noy et al, Nanotoday, 2007 Comparison of the water flux predicted for a polycarbonate (PC) membrane and a Double-Walled (DW) CNT membrane -using Hagen-Poiseuille law - with the flux measured for the DWCNT membrane. Individual nanotubes Qin et al, Nano Letters, 2011 JMC15 10

13 H 2 O@CNT: ULTRAFAST WATER TRANSPORT The phenomenon is not yet fully understood Predictions are strongly dependent of the model/force field used and experimental data are too scarce From Park & Jung, Chem. Society Rev., 2014 JMC15 11

14 H 2 O@CNT: ULTRAFAST WATER TRANSPORT Potential applications JMC15 12

15 H 2 O@CNT A topical issue in fundamental physics with potential applications in energy and environmental fields Lack of experimental results Number of numerical simulations articles 10 x number of experimental articles Improved understanding nanofluidic mechanisms in biological media? Murata et al., Nature, 2000 JMC15 13

16 our results

17 EXPERIMENTAL APPROACHES X-ray scattering (XRS) experiments Electronic density contrast localization and structure of confined water??? Infrared (IR) spectroscopy Inter- and intramolecular vibrations Probing the H-bond network Credit: Martin Chaplin, Water structure and science Website: Brubach et al., J. Chem. Phys., 2005, 122, JMC15 14

18 our results from X-ray scattering experiments

19 PROGRESSIVE FILLING OF SWCNT BY WATER - XRS E. Paineau, P.-A. Albouy, S. Rouzière, A. Orecchini, S. Rols, P. Launois Nano Lett. 13, 1751, 201 The sample Powder of open-ended SWCNT (MER corporation) r t = ± 0.1 nm et 31 tubes/bundles 0.32 nm 2r t j R ij 1 I( Q) F 0 Q N 2 Q J QR ij Q F 2 f r J Qr F CNT C C t 0 ij i t Q C 0.37 atoms/å² f C : X-ray scattering factor of C JMC15 15

20 PROGRESSIVE FILLING OF SWCNT BY WATER - XRS In-situ XRS Under water vapor (Relative Humidity =100%) r hk I Q hk, t I Q hk, t 0 I Q 10, t 0 Paineau et al., Nano Lett., 13, 1751, 2013 JMC15 16

21 PROGRESSIVE FILLING OF SWCNT BY WATER - XRS In-situ XRS r hk = [I(Q hk,t )-I(Q hk,0 )] / I(Q 10,0 ) r hk = [I(Q hk,t )-I(Q hk,0 )] / I(Q 10,0 ) Exp. Model 1 Model Time (h) Under water vapor (Relative Humidity =100%) Time (h) r hk I Q hk, t I Q hk, t 0 I Q 10, t 0 Paineau et al., Nano Lett., 13, 1751, 2013 JMC15 17

22 PROGRESSIVE FILLING OF SWCNT BY WATER - XRS ρ Modelization r t = 0.7 nm 1 I( Q) 0 Q N 2 FCNT Fwater J QRij ij r 1 = r t 0.27 nm r 2 = r nm r 3 = 0.1 nm r 3 r 2 r 1 r 3 r 2 r 1 10 r (Å) F water r J f ( Q) m 1 Qr r r r J Qr r r r J Qr 1 H O H O Q Intensity 0 11 Empty Filled (15.5 w% water) Q (Å -1 ) 21 Paineau et al., Nano Lett., 13, 1751, 2013 JMC15 18

23 PROGRESSIVE FILLING OF SWCNT BY WATER - XRS ρ Fitting of the measured intensity ratios r (Å) Paineau et al., Nano Lett., 13, 1751, 2013 JMC15 19

24 MD simulations Experimental PROGRESSIVE FILLING OF SWCNT BY WATER - XRS Progressive structuration in concentric layers ~ 4% ~ 15% w H2O (%) References 11.3 Maniwa et al., J. Phys. Soc. Jpn. 71, 2863, Kolesnikov et al, PRL, 93, , Paineau et al., Nano Lett., 13, 1751, Maniwa et al., Chem. Phys. Lett., 401, 534, Kyakuno et al., J. Chem. Phys., 134, , Alexiadis et al, Chem. Rev., 108, 5014, 2008 Quintilla et al, PCCP, 12, 902,2010 Nakamura et al, Mater. Chem. Phys., 132, 682, Kyakuno et al, J. Chem. Phys., 134, , Striolo et al, J. Chem. Phys., 122, , 2005 Pascal et al, PNAS, 108, 11794, Kolesnikov et al, PRL, 93, , 2004 Discrepancies between experimental and calculation w H2O for fully hydrated SWCNTs Intermediate layer as a transition zone between higher densities layers: enhanced in-plane translational motions (Pascal et al, PNAS, 2011) Transition from homogeneous water filling to a 3 layers structure Enhanced entropy at the start of the filling? Paineau et al., Nano Lett., 13, 1751, 2013 JMC15 20

25 our results from Infra-Red spectroscopy

26 H 2 O@CNT: H-BOND NETWORK BY IR SPECTROSCOPY Nanotubes sample Powder of open-ended SWCNT (NanoAmor) D = nm (from Raman spectroscopy; R. Le Parc and J.-L. Bantignies, LCC, Montpellier) Thermodynamic origin of water filling SWCNT An entropy (rotational and translational) stabilized phase of water for small SWCNTs (D = nm) An enthalpy stabilized, ice-like phase for medium-sized SWCNTs ( nm) A liquid phase stabilized by increased translational entropy in larger SWCNTs Pascal et al, PNAS, 2011 Filling of SWCNT with water Many simulations studies (> 150) Diameter-dependence: single-file to water layers Water-vapor adsorption isotherms Progressive filling as a function of P/P 0 Filling of smaller diameter CNTs begins first D~1nm 2nm Ohba et al, Langmuir, 2013 JMC15 21

27 H 2 O@CNT: H-BOND NETWORK BY IR SPECTROSCOPY S. Dalla Bernardina, E. Paineau, J.-B. Brubach, P. Judeinstein, S. Rouzière, P. Launois, P. Roy J. Am. Chem. Soc., Articles As Soon As Publishable (DOI: /jacs.6b02635) IR/THz Absorbance difference log I : I 0 substraction of the dry state + water vapor Various water relative humidity: RH = 9-100% JMC15 22

28 H 2 O@CNT: H-BOND NETWORK BY IR SPECTROSCOPY Spontaneous filling of hydrophobic SWCNTs with water THz measurements Libration band Bending band Stretching band Dalla Bernardina et al., JACS, 2016 JMC15 23

29 H 2 O@CNT: H-BOND NETWORK BY IR SPECTROSCOPY The stretching band is very sensitive to intermolecular interactions: the oscillator strength of water molecules decreases when its coordination number n HB increases n HB =4 n HB =3 n HB =0-2 Brubach et al, J. Chem. Phys. 122, (2005) Bergonzoni et al, PCCP 16, (2014) Dalla Bernardina et al., JACS, 2016 JMC15 24

30 H 2 O@CNT: H-BOND NETWORK BY IR SPECTROSCOPY RH = 30% 1D water chains in narrowest SWCNTs with D ~ 0.8 nm RH = 100% External water layer with free OH bonds for liquid H 2 O in larger SWCNTs (D > 1.4 nm) Hummer et al., Nature, 2001 Ice-like water in SWCNTs with D ~ nm Joseph & Aluru, Nano Lett., 2008 Moshizuki & Koga, PNAS, 2015 Dalla Bernardina et al., JACS, 2016 JMC15 25

31 H 2 O@CNT: H-BOND NETWORK BY IR SPECTROSCOPY Tentative assignation of the low frequency mode Translational Density of State of water in a SWCNT with D = 0.8nm RH=100% RH=55% RH=30% RH=9% Dry state Wavenumber (cm -1 ) Kumar et al., J. Chem. Phys., 2011 Dalla Bernardina et al., JACS, 2016 JMC15 26

32 our results Conclusion

33 H 2 O@CNT FROM XRS AND IR SPECTROSCOPY Filling of nanotubes with D~1.4 nm From an homogeneous to a layered water structure with increasing filling rate Enhanced entropy: a key to understand spontaneous water filling of SWCNT Three different structures for water depending on the CNT diameter 1D structure in small diameters SWCNTs (0.8 nm) Ice-like organization in medium nanotubes ( nm) External layer with OH dangling bonds for larger nanotubes (> 1.2 nm) Loosely bonded water molecules First experimental evidence More than 50% of the stretching intensity, even at RH = 100% Modification of the H-bond network of water in SWCNTs has to be taken into account to explain its properties, as it is done by several authors to explain ultralow friction Refinement of force fields used in simulations JMC15 27

34 Alternative nanochannels

35 ~ 1.8 nm ~ 2.4 nm ALTERNATIVE NANOCHANNELS Disentangle curvature and water-wall interactions effects Imogolite metal-oxide nanotubes Amara, Paineau et al, Chem. Mater., 2015 Hydrophilic or hydrophobic concave nanochannels Hydrophilic convex nanochannels JMC15 28

36 THANK YOU FOR YOUR ATTENTION