270 likes | 562 Views
Chemical Modification ( 化学修飾 ) of Graphene. Tobe Lab. M1 Kosuke Hada. Contents. Graphene Self-assembly of Molecules My Work. Graphene Self-assembly of Molecules My Work. Graphene. Graphite. Graphene. Graphene. Graphene was isolated by using adhesive tape.
E N D
Chemical Modification (化学修飾)of Graphene Tobe Lab. M1 KosukeHada
Contents • Graphene • Self-assembly of Molecules • My Work • Graphene • Self-assembly of Molecules • My Work
Graphene Graphite Graphene
Graphene Graphene was isolated by using adhesive tape. Novoselov and Geim won the Nobel Prizein 2010. Graphene Novoselov, K. S. et al. Science2004, 306, 666-669.
Graphene • Properties of Graphene • ・Strength • ・Zero BandGap • ・Ultrahigh Carrier Mobility Zboril, R. et al. Chem. Rev. 2012, 112, 6156−6214. Touch Screens Sensor New Material Solar Cell
Chemical Modification (化学修飾) of Graphene ・Adding molecule having useful propertiesto graphene We can add useful property to graphene ・Changing double bonding of graphene to single bonding double bonding: strong bonding single bonding : weak bonding • Carbon having double bonding: conductive • Carbon having no double bonding : non-conductive We can control strength and conductivity of graphene
Example of Chemical Modification of Graphene 1. N2H4・H2O, pH 10 80 ゜C, 24 h 2. , rt, 1 h Graphene Oxide 酸化グラフェン R = Cl, NO2, OCH3, Br ←Photographs of supernatant N,N′-dimethylformamide(DMF)solutions (上澄み) obtained from dispersions of (a) graphene and (b) R = Br, (c) R = Cl, (d) R = NO2, and (e) R = OCH3after centrifugation (遠心分離) for 15 min at 3200 rpm Tour, J. M. et al. J. Am. Chem. Soc. 2008, 130, 16201-16206. Graphene modified can be dispersed (溶ける) in polar solvent such as N,N′-dimethylformamide (DMF)
Functionalization With Diazirine of Graphene (高反応性) (付加反応) TEM Image of Functionalized Graphene Carbene Addition Workentin, M. S. et al.Langmuir2011, 27, 13261–13268.
Problem of Chemical Modification of Graphene Non-regularmodification We can’t precisely control the property Regular modification is needed to control precisely the property
Contents • Graphene • Self-assembly of Molecules • My Work
Construction of Nano Structure on Surfaces Top-down approach (photolithography) Bottom-up approach (molecular self-assembly) light = molecules = photoresist Self-assembly = substrate = substrate About 100 nm scale 1~10 nm scale
Tunneling current Mechanism of Scanning Tunneling Microscopy (STM)
electron STM Ji (tunneling current) Ji = Aexp(-Bd) Largechange Ji : tunneling current A, B : constant d : distance Tip Tunneling current d (distance) Smallchange Sample Tip Sample
Example of 2D Molecular Self-assembly STMImage of 2D Molecular Self-assembly at Alkanoic Acids/Graphite Interface Lackinger, M.; Griessl, S.; Heckl, W. M.; Hietschold, M.;Flynn, G. W.; Langmuir, 2005, 21, 4984.
Honeycomb Structureof Dehydrobenzo[12]annulene (DBA) at the Liquid/Graphite Interface DBA = STM Imageof DBA on Graphite Self-Assembly at the Liquid/Solid Interface
Honeycomb Structureof Dehydrobenzo[12]annulene (DBA) at the Liquid/Solid Interface Van der Waals Force between the Molecules and the Solid DBA Van der Waals Force between the Molecules = Self-Assembly at the Liquid/Solid Interface
Honeycomb Structureof Dehydrobenzo[12]annulene (DBA) at the Liquid/Graphene Interface DBA = STM Imageof DBA on Single-Layer Graphene on Cu
Characters of DBA = DBA • We can change the size of DBA and holes • Holes catch the another molecules Sensor
Contents • Graphene • Self-assembly of Molecules • My Work
Purpose of MyWork Carbene Diazirine Diazirine • Chemical stability of diazirine • Precursor of carbene • Photo-reaction under long wavelength Carbene • High reactivity • Labeling of biomolecules • Adding to graphene
Purpose of MyWork = Diazirine Self-Assembly Graphene
Purpose of MyWork hv Graphene
Purpose of My Work Regularmodification We can precisely control the property
STM Image of DBA at the Phenyl Octane/Graphite Interface Solvent : phenyloctane STM Imageof DBA 1 on Graphite 7.2 × 10-7 mol/L
Summary • Graphene is considered as a prospective material because of its unique properties. • Chemical modification is used to control the properties of graphene and functionalize it • Self-assembly by non-covalent interactions is used to construct the ordered structures at the solid surface. • A purpose of my work is to establish an unique approach which makes periodic functionalization of graphene possible based on self-assemblies of molecules at the liquid/graphene interface and following the addition to the graphene.