Free and Encapsulated (TiO 2 ) 2 Dimers into Carbon Nanotubes Presented by Prof. TANGOUR Bahoueddine University of Tunis-El Manar, Tunisia S. Dargouthi, S. Boughdiri, B. Tangour ICMCC2015 JUNE TORONTO - CANADA
1- Introduction to Nanotechnology
Nanotechnologies are concerned with: Controlledproduction, design, characterization and application of structures, devices, and systems presenting size and shape at the nanometer scale and exhibiting at least one novel/superior characteristic or property. ICMCC2015 JUNE TORONTO - CANADA3
The nanometer scale Humanhair fragment and a network of single-walled carbon nanotubes. ICMCC2015 JUNE TORONTO - CANADA4
The gold color ICMCC2015 JUNE TORONTO - CANADA5
2- Phenomenological Description of Single Walled Carbon nanotubes (SWNT) 6
ICMCC2015 JUNE TORONTO - CANADA SWNT are conceptuallyconsidered as rolled-up graphite sheet even it does not related to the real fabrication way. 7
Schematic description ICMCC2015 JUNE TORONTO - CANADA8
Different types of Carbon SWNT Chiral Θ ≠ 0 and 30° (n,m) type Semi-conductor Gap = [2-4] eV Achiral θ=30° Armchair (n,n)type Semi-metallic Gap = [0,2 - 1,4] eV Achiral θ=0° Zigzag (n,0) type Metallic 9
3- Confined molecules inside carbon nanotubes ICMCC2015 JUNE TORONTO - CANADA10
fullerenes encapsulated into CNT Nanotubes offer a unique opportunity for investigation of physical and chemical processes in confined systems ICMCC2015 JUNE TORONTO - CANADA11
Release of carboplatin from CNT. ICMCC2015 JUNE TORONTO - CANADA Representative HRTEM pictures were shown after incubation of CNT-Carboplatin A) 30min B) 24h in cell culture medium at 37°C. NanomedicineNanomedicine April 2008, Vol. 3, No. 2, Pages
4- THEORETICAL CALCULATIONS CONFINED TiO 2 SPECIES into CNT noted
ICMCC2015 JUNE TORONTO - CANADA Calculation details DFT B3LYP calculations Different basis sets 6-311G and 6-311G (d). Hundreds of atoms Thousands of basis functions 14
TiO 2 ICMCC2015 JUNE TORONTO - CANADA R Ti-O (Å)=1.629 (exp. =1.704) O-Ti-O (°)=111.4 (exp.=113.0) TiO 2 molecule is only detected into noble gas matrix at very low temperature of some Kelvin. 15 CNTs with different diameters
TiO ICMCC2015 JUNE TORONTO - CANADA16
Different Confinement interactions Chemical Interactions Physical Interactions Without confinement effect Energy Variation (in arbitrary units) CNT Diameter in Á ICMCC2015 JUNE TORONTO - CANADA17
TiO (8,0) D=6.267 Å Stabilisation of the molecule by roughly 50 kcal/mol ICMCC2015 JUNE TORONTO - CANADA R Ti-O (Å)=1.612 (1.629 in free molecule) O-Ti-O (°)=94.6 (111.4 in free molecule ) Confinement of TiO 2 molecule will help its manipulation at room temperature 18
3 possible Dimers (TiO 2 ) 2 ICMCC2015 JUNE TORONTO - CANADA Trans DIMER (T) Cis DIMER (C) Tetrahedron/ Pyramidal DIMER (T/P) 19 Optimized Structures
Stabily Comparison ICMCC2015 JUNE TORONTO - CANADA 20
CONFINED DIMERS
T- (TiO 2 ) ICMCC2015 JUNE TORONTO - CANADA 22 Few and non signifiant changes Before Confinement After
C- (TiO 2 ) ICMCC2015 JUNE TORONTO - CANADA 23 Few and non signifiant changes Before Confinement After
T/P- (TiO 2 ) ICMCC2015 JUNE TORONTO - CANADA 24 T/P transforms in Trans Before Confinement After
Separated Dimers
Parallele position (P) ICMCC2015 JUNE TORONTO - CANADA26 Transitory specie
Orthogonal position (O) ICMCC2015 JUNE TORONTO - CANADA 27 Transitory specie
Confined (P) Dimer ICMCC2015 JUNE TORONTO - CANADA 28 (P) Transforms in (O) and stays in iteraction with CNT’s edge Before Confinement After
Confined (O) Dimer ICMCC2015 JUNE TORONTO - CANADA 29 The dimer keeps his structure when confined so Stabilizing of the transitory species (TiO2)2 by encapsulation into carbon nanotubes. Before Confinement After
Stabilisation by confinement ICMCC2015 JUNE TORONTO - CANADA 30 Dargouthi Sarra a, Boughdiri Salima and Tangour Bahoueddine, 2015 Acta Chimica Slovenica, 61, in press
THANK YOU FOR YOUR ATTENTION ICMCC2015 JUNE TORONTO - CANADA31