Organic-Inorganic (O-I) Interfaces. Materials

Transcription

1 Chimie de la Matière Condensée de Université Pierre et Marie Curie - CNRS (France) NMR Characterisation of rganic-inorganic Interfaces in Hybrid Materials N. Baccile, G. Laurent, T. Azaïs, C. Bonhomme, F. Babonneau M. Wong-Chi-Man 2, B. Alonso 2, D. Avnir 3 LCMCP, UPMC - Univ 06 and CNRS,, France 2 ICG Montpellier, UMII-CNRS-ENSCM-UMI, Montpellier, France 3Dept of Chemistry, Hebrew Univ. Jerusalem, Israel rganic-inorganic (-I) Interfaces I Covalent interactions I Weak interactions Electrostatic interactions Van der Walls interactions H-bonding I NMR : S I S? 29, 27 Al, 3 P, 23 Na, 5 V... H H, 3 C, 3 P, 5 N...

2 Through-space vs. through-bonds interactions.through-bond interaction : J coupling J( 3 C- H) 0 Hz Dipolar Spin-Spin interactions Covalent bonds between I and I S I S 2.Through-space interaction : D coupling γ D I- proportionnal to I.γ r I- 3 D( 3 C- H) 0 khz Proximity between I and Highest γ I value : H I -I interfaces : some examples. Surfactant templated silicas and organosilicas N. Baccile, G. Laurent, F. Babonneau (,, France) C. Teixeira, M. Linden (Åbo University, Finland) H. Amenitsch (Austrian Academy of Sciences, Graz, Austria) 2. Composite particles of 2 H. Elimelech, D. Avnir (Hebrew Univ, Jerusalem) 3. Self-assembled -I systems through H-bonding C. Bonhomme (,, France) M. Wong Chi Man, B. Alonso (ENSCM/CNRS, Montpellier, France 4. Host-guest interactions in porous silicas N. Baccile, T. Azais (,, France) 2

3 Inorganic materials through templating self-assembly process Faujasite R R N R Diatom Radiolaria R Zeolites : Molecular Templating agents Pore size nm Quaternary ammonium salt: cationic surfactant Mesoporous silicas : Micellar Templating agents Pore size 2-0 nm Surfactant-templated templated silicas - 2 precursor : (Et) 4 (TES) - Cationic Surfactant : Geometry of polar head group Hydrophobicity - Catalyst : H +, H - - Counter-Ion X - : Br -, Cl - N+ N CH + 3 CH CH3 CH 2 CH N + CH 2 3 CH 2 CTAB CTEAB CH CH 2 3 CH2 CH N + 2 CTPAB CH 2 CH X - X - N CH + 3 Interface model CH N + N + CH 2 CH3 MMG 3

4 CTAB-templated silicas : NMR study Intensity 0 ab d 0 d d θ T 4 khz Q 2 : 3% Q 3 : 56% Q 4 : 4% 0.6 H/ H 7.05 T 4 khz -(CH 2 ) n - N( ) 3 -CH 2 N H? B 0 =7 T ν=4 khz (ppm) (ppm) Q 4 Q 3 -H -H Head N+ CTAB Chain H 29 t CP dec. Acquisition Heteronuclear Correlation (HETCR) based on CP sequence Contact time t 2 lica-cta + interfaces : 29 - H proximities { H} 29 HETCR experiment With variable contact times Q 3 Q 4 Q 3 -H -H Head N+ CTAB Chain Q 3 Q4 B 0 =7 T ν=4 khz 29 Q 4 29 Head Group Head Group Chain -H -H H t = 500 µs H t = 5 ms N. Baccile al. C.R. Chimie 9 (2006)

5 H 29 H Double Cross-Polarization (CP) ) 29 H: t CP -H N CH + 3 B 0 =7 T ν=4 khz -H N+ N + CTAB 2) 29 H : t CP2 H Selective Detection of protons close to the surface H 29 H (ppm) N. Baccile et al. Chem. Mater. 9 (2007) H 29 H Double CP : acidic versus basic conditions CTAB/H t CP = 3 ms H Head: N( ) Chain: N-CH 2 -CH 2 lica-cta + interfaces Basic Conditions CTAB/HCl t CP = 3 ms B 0 =7 T ν=4 khz H---H 2 Head: N( ) Chain: N-CH 2 -CH 2 Acidic Conditions 5

6 lica-surfactant interfaces : acidic versus basic conditions Chem. Mater. 9 (2007) Basic conditions : - Few -H - Short distance between -- and polar head group H - Acidic conditions : - -H rich surface - Presence of interfacial H-bonded water molecules - Longer distance between -- and polar head group - Counter-ion? H + -I interfaces : some examples. Surfactant templated silicas and organosilicas N. Baccile, G. Laurent, F. Babonneau (,, France) C. Teixeira, M. Linden (Åbo University, Finland) H. Amenitsch (Austrian Academy of Sciences, Graz, Austria) 2. Composite particles of 2 H. Elimelech, D. Avnir (Hebrew Univ, Jerusalem) 3. Self-assembled -I systems through H-bonding C. Bonhomme (,, France) M. Wong Chi Man, B. Alonso (ENSCM/CNRS, Montpellier, France 4. Host-guest interactions in porous silicas N. Baccile, T. Azais (,, France) 6

7 Composite Particles of lica Emulsion of Polymer and TES In basic EtH/water solution With surfactant as stabilizer J. Am. Chem. Soc. 2007, 29, MAS-NMR Low Density (ppm) Highly condensed silica network Composite Particles of PE@ 2 Q 3 (-H) Q 4 ( 2 ) 29 PE : CH 2 -CH 2 PEG : CH 2 - -H H Physically interprenetrating networks Presence of PE-b-PEG at interface 7

8 -I interfaces : some examples. Surfactant templated silicas and organosilicas N. Baccile, G. Laurent, F. Babonneau (,, France) C. Teixeira, M. Linden (Åbo University, Finland) H. Amenitsch (Austrian Academy of Sciences, Graz, Austria) 2. Composite particles of 2 H. Elimelech, D. Avnir (Hebrew Univ, Jerusalem) 3. Self-assembled -I systems through H-bonding C. Bonhomme (,, France) M. Wong Chi Man, B. Alonso (ENSCM/CNRS, Montpellier, France 4. Host-guest interactions in porous silicas N. Baccile, T. Azais (,, France) Bioinspired hybrid materials biomolecular assembly hydrolysis H-bonding Inorganic pillars 8

9 rgano-silicas based on Adenine and Thymine assemblies Thymine (T) --> C n -Thymine Adenine (A) --> C n -Adenine Homo-assembly (A/A or T/T) Hetero-assembly (A/T) rgano-silicas based on Thymine (T) (T) T-T homo-assemblies 2-2 (ppm) 2δ 2 H H 2 δ +δ 2 2δ - -2 H H 2 δ δ 2 (ppm) H Double Quanta G. Arrachard et al. J. Mater. Chem. (2008) 9

10 rgano-silicas based on Thymine/Adenine Pairs H DQ NMR 750 MHz 33 khz Adenine : A (CH 2 ) n Thymine : T A-T T-T Direct evidence for the formation of A-T hetero-assemblies in organosilica networks G. Arrachard et al. J. Mater. Chem. (2008) -I interfaces : some examples. Surfactant templated silicas and organosilicas N. Baccile, G. Laurent, F. Babonneau (,, France) C. Teixeira, M. Linden (Åbo University, Finland) H. Amenitsch (Austrian Academy of Sciences, Graz, Austria) 2. Composite particle of 2 H. Elimelech, D. Avnir (Hebrew Univ, Jerusalem) 3. Self-assembled -I systems through H-bonding C. Bonhomme (,, France) M. Wong Chi Man, B. Alonso (ENSCM/CNRS, Montpellier, France 4. Host-guest interactions in porous silicas N. Baccile, T. Azais (,, France) 0

11 Host-guest interactions in porous silica powders Drugs, pollutants... - Physical state of guest molecules - Host-guest interactions? H H Encapsulated molecules in porous silica : H MAS NMR Pollutant : 4-chloro--methoxyphenol Drug : Ibuprofen H H NMR H NMR 7 T MAS : 4 khz Aromatic T MAS : 33 khz CH Crystalline Ibuprofen H Surfactant High RT Aromatic Alkyl Ibuprofen in silica δ (ppm) δ (ppm) N. Baccile et al. Microp. Mesop. Mater. (in press) T. Azais et al. Chem. Mater. 8 (2006)

12 Model compound : Benzoic acid in porous silica { H}- 3 C HETCR experiment : D coupling Aromatic No CH H K 298K C= H C= Aromatic 278K K -H 258K K CH(o,p) CH(m) Chemical shift (ppm) 2 238K 238 K 0-2 -H -H H C Conclusion rganic-inorganic Materials Complex in compositions and nanostructures Importance of -I Interfaces Solid State NMR techniques based on Dipolar coupling Heteronuclear interaction : X-Y proximities H-X HETCR experiment H-X- H Double CP experiment Homonuclear interaction : X-X proximities X-X Double Quanta experiment Variable temperature measurements : Dynamics 2

13 Merci LCMCP Thierry AZAIS Laure BNHMME Christel GERVAIS Christian BNHMME Guillaume LAURENT Jocelyne MAQUET Next ISGS summer school Alghero (Sardegna-Italy) August Sol-gel in small dimensions: particles and thin films Next ISGS Sol-Gel Conference Bahia (Brasil) August ISGS Journal J. of Sol-Gel Science and Technology New : Fast-track Communications Board of Directors Florence BABNNEAU (France), President; Christophe BARBE (Australia), Vice-President; Michel PRASSAS (France), Chairman of the Board; Eric BESCHER (USA), Treasurer; Guido KICKELBICK (Austria), Secretary; Plinio INNCENZI (Italy); Kazuki NAKANISHI (Japan); Gunnar WESTIN (Sweden); Philippe BELLEVILLE (France) 3