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SAASA-San Luis 20-02-13

SAASA-San Luis 20-02-13. Measurement of solvent adsorption in mesoporous thin films using spectroscopic and reflectivity methods.

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SAASA-San Luis 20-02-13

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  1. SAASA-San Luis 20-02-13 Measurement of solvent adsorption in mesoporous thin filmsusing spectroscopic and reflectivity methods G.J.A.A. Soler Illiagsoler@cnea.gov.arP. C. Angelomé, M.C. Fuertes, A. Calvo, E.D. MartínezA. Wolosiuk A. Zelcer, M. Bellino, D. Scherlis, M. D. Pérez,F. Roncaroli, M. L. Martínez-Ricci, E. González-Solveyra, P. Y. Steinberg, I. L. Violi GQ-CNEA – Buenos Aires – Argentina DQIAyQF-FCEN-UBA

  2. Summary • Mesoporous Thin Films : structure and architecture • Solvent Adsorption • Ellipsometric Porosimetry (EP) • X-Ray Reflectivity (XRR) • Applications to complex systems • Biofunctionalization • Metallic NP inclusion • Conclusions

  3. 5 nm Sol-gel + Self-assemblyOrganized Mesoporous Materials • OrderedMesopores200 to 1000 m2/g • 2 to 50 nm pores • Controlled periodic structure • Monodisperse • Interesting models! Membranes, sensors, catalysts… Chem. Mater, Special Issue Templated Materials, 2008 Soler-Illia et al. Chem. Rev. 2002, Curr. Opin. Colloid. Interf. Sci. 2003 PeriodicTemplate Creation of a “fossile” oxidemesostructure Template Removal

  4. Mesoporous Thin Films 100 nm • Optical films (100-300 nm) • 200-1000 m2/g accessible pores 2-10 nm

  5. Platform for applications • Ultra-low-k dielectrics (k~2; kSiO2=4) • Optical Applications (lasers, sensors) • Bulk heterojunction Solar Cells • Perm-selective membranes • Fuel Cells (catalysts, membranes) • Heterogeneous Catalysis and photocatalysis • Adsorbents (heavy metals, radionucleides…) • Fixation of biologically active species • Controlled delivery

  6. Im3m MO2 (M,Si)O2 AlPO C Silica P63/mmc Non-silica P6m Crystalline 100 nm Im3m p6m CTAB or ABC Pm3n ABC Sanchez et al, Chem. Mater. 2008 R3m A library of mesoporous frameworks • Dip- or spin-coating under controlled conditions • Post synthesis treatment • Template elimination

  7. O O H H O O n m n C H 3 PEO PPO PEO Example: Mesoporous Titania Films(photocatalysis, photovoltaics, optics) Film Production  Ti(IV) precursors  Nonionic Surfactant templates  Ethanol  Controlled water quantities  Dip-coating (1-5 mm s-1)  Substrate: Si, SiO2, glass...  Temperature 20-35 °C  Controlled Humidity Block Copolymer Templates 0.5 cm Thin Titania filmd=100-300nm(interference) Grosso et al., Adv Mater., 2001 Soler Illia et al., Chem Mater., 2002 Crepaldi et al., J. Am. Chem. Soc., 2003

  8. 2D-SAXS a b z c y x « Pore Crystals » TiO2 Cross section TEM Anisotropic mesopores 100 nm Crepaldi, et al., JACS., 2003 Soler Illia, Innocenzi, Chem Euro J 2006 Im3m Oriented Mesestructurea = 17 nm

  9. a a 2 2 c c a a a a z z x x y y 1 1 Domains in the mesoscale a1= 29.8nm b b a2= 33.4nm a / a = 0,89 1 2 2 Theo [110] = 0,87 Microscopy Characterization [110] face (AFM) [110] Projection (TEM) 100 nm TEM P. BozzanoUAM-CNEA AFM-L. PietrasantaS. Ludueña-UBA

  10. Determination of Porosity in Mesoporous Thin Films • Film properties  Porosity • Pore (and neck) Size • Pore Volume • Surface Area • Accessible Porosity • Characterization Challenges • Very low mass (1mg/cm2) • Pores are anisotropic (uniaxial contraction) • Pore system: interconnected Pores/Necks • Adsorbents (models?) • Solvent sorption: practical applications • Optical or dielectric properties

  11. Ellipsometryoptical properties with high accuracy n(l) and e are obtained

  12. TiO2 350°C Ellipsometric Porosimetry (EP) • Ellipsometry: thickness (e) and index (n(l)) • EP-in the presence of a solvent vapor – adsorption curve - Porosity and mechanical properties (Boissière et al. Langmuir, 2005) Thesis P. C. Angelomé P. Y. Steinberg Fuertes et al, J. Phys. Chem C, 2008

  13. Capillary condensation

  14. Boissiere et al, Langmuir, 2005

  15. Keys: adequate estimation of adsorption energy (contact angle) and pore anisotropy (eccentricity of the ellipsoid), changes in 20% of the value

  16. Pore evolution upon thermal treatment 350°C Necks Pores 500°C TiO2-B58 Si substrate: Type IV H2pores grow, surface decreases Roncaroli et al, J. Phys. Chem. C, submitted 2013

  17. Direct observation of changes in Mesopore shape EPA Soler-Illia et al, Nanoscale, 2012 Violi et al, ACS Appl Mater Interf, 2012 Thesis I. L. Violi

  18. Microscopic behaviour simulations (H2O@TiO2) Thesis E. González-Solveyra (collab D. Scherlis) POSTER P42 E. González-Solveyra et al. J. Phys. Chem C. 2013

  19. Solvent adsorption on MOFs ZIF-8 pre-formed NP Transparent Films with double porosity and selective adsorption A. Demesscence et al. J. Mater. Chem. 2010

  20. Angelomé et al., Adv. Mater., 2006 TEM by M.C. Marchi@LNLS F127-TiO2 (cubic 10 nm)on Brij 58-SiO2 (cubic 5 nm) SiO2 TiO2 Mesoporous Bilayers Consolidation 1st Dip-coating 2nd Dip-coating Brij 58-TiO2 (cubic 5 nm)on CTAB-SiO2 (3D Hex 3 nm) Two interconnected pore systems with different spatial chemistry  reactivity

  21. Fuertes et al. J. Phys. Chem. C. 2008 Water adsorption response depends on spatial location of pores TiO2/F127-Im3m SiO2/CTAB-3DHex

  22. X-Ray Reflectometry as a tool todetermine porosity Critical Angle Density Organization X-Ray beam (D10A-XRD2 LNLS) Interference ofbeam reflected at interfaces Penetration abovecritical angle Interferences Thickness-Rugosity Gibaud et al, Thin Solid Films, 2006

  23. Setup of XRR – LNLS – D10A RH% measurement Sample Chamber XRay N2 + H2O Diffractometer (HUBER) Flow Control (0 – 100 RH%) Bubbler

  24. Water Adsorption Isotherms using XRR Intensity / a.u. Brij 58-templated TiO2 • θcmeasured at several RH% • ρfilmobtained • Vads calculated • Advantages: • Separates thickness from ρfilm • θcvery sensitive quantity • Limitations: • Slow measurement • Sensitive setup A. Gibaud et al,App. Surf. Sci., 2006

  25. Inter-Technique comparison dV/dr dV/dr PSD for TiO2 - Brij58EP vs. XRR EP XRR D=5,7nm (Kr 87K)DFT (Thommes) Models! Soler-Illia et al,Nanoscale., 2012

  26. Further Applications of EP and XRR • Enzymes@mesopores • Nanoparticles@mesopores 8 nm 11 nm

  27. Amilasa: 8x4.5x3.5nm3 8 nm 11 nm Bioactive Films Enzyme adsorption leads to stabilization Reusable supported biocatalyst Highly active Difficult to quantify and to assess enzyme hosting 10 nm a-amilasa Bellino et al, ACS Applied Mater Interf., 2010

  28. Bellino et al, ACS Applied Mater Interf., 2010

  29. Size matters F9 100 nm F13-38 10 nm F20 DNA Polymerase (Thermus aquaticus) amylase DNA polymerase (Taq) needs larger poresArchitecture design

  30. Bellino et al, Small2010 F13-38 F15-95 F20 F9 Polymerase Adsorption F13-38 F15-95 F20 F9 PCR with film PCR withsupernatant F13-38 Changes in PSD EP Enzyme is only detected in 38 nm mesopores

  31. Application of XRR to metal/oxide nanocomposites Ag@SiO2 time Intensity (a.u.) Generation of metal NP with well defined spatial location Silver NP generation at nanopores (D10A LNLS):Critical angle shift upon reduction ( r) Fuertes et al, Small, 2009

  32. SiF127 TiB58 SAXS • Ag° fills only the titania pores • XRR: Shift in the critical angle only for TiO2 • SAXS: TiO2 periodicity is disruptedby NP; no difference in SiO2 • Bilayer systems with localized chemical and physical properties Metal NP selectively located Ag+ Selective Reductiononly on Ti(IV) XRR Fuertes et al., Small, 2009

  33. Complex Chemical Systems 1. Surface Charges preconcentrate monomer METAC+ 2. Positive charges of polyelectrolyte preconcentrate AuCl4- Very high NP loading 60-70% XRR determines loading and the remaining porosity A. Calvo et al. Langmuir. 2010 A. Brunsen et al. Langmuir. 2011

  34. Advanced mesoporous Films Patterned NanocompositesMartínez, et al. Appl. Mater. Interf., 2009 Phys. Chem Chem Phys., 2010 « Living » FilmsBellino et al, ACS Applied Mater Interf., 2010 Small, 2010 MEsoporous photonic crystalsFuertes, et al. Adv. Funct. Mater., 2007 J. Phys. Chem C., 2008 Sistemas multicapa con propiedades químicas y físicas localizadas en el espacio

  35. Conclusion EP and XRR are promising tools to determine thin film porosity Need crossed studies! • Pros • Excellent qualitative description • Reproducible qualitative trends • Non-destructive • Fast and simple setup • Very small or localized samples • Real solvents • Real situations “in situ” (catalysis, sensing, biomaterials…) • Cons • Model-dependent • Complex behaviour • Need to develop accurate models • Factors • Pore Anisotropy • Surface interactions • Chemistry • Surface transformations • Understanding interface

  36. Gracias ! Collaborations C. Sanchez (Paris) O. Azzaroni, F. Requejo (La Plata) S. A. Bilmes – D. Scherlis – F. Williams E. Calvo (UBA) P. Innocenzi (Alghero)L. Liz-Marzán (S Sebastián)H. Míguez (Sevilla) H. Amenitsch (Elettra) A. Fainstein - N. Tognalli – H. Troiani (Bariloche) $ - Funding - $CNEA, CONICET, UBA, ANPCyT, Antorchas, MAE, IT/UNSAM, LNLS, ECOS-Sud, ReNAMSI, PAE CINN, FONARSEC, Fundación Bunge y Born

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