electrospray deposition graziano magnano nanoscience group school of physics & astronomy...

Electrospray deposition

Graziano Magnano

Nanoscience groupSchool of Physics & Astronomy

University of Nottingham

Berlin - 1st October 07

• Instrument: principles and settings

• Results:

• Deposition of PEO on Si(111)

• Deposition of C60 on Au(111)

• Deposition of C60 onto PTCDI / Melamine on Au(111)

• Ongoing and Future work

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Overview

Electrospray is widely used in mass spectrometry (MS) as an ionisation source for non-volatile molecules and molecules which break down upon heating.

It’s possible to create gas phase ions directly from a solution of the molecules of interest.

Electrospray ionisation

Especially in MS, electrospray works on large molecules:

• To determine the molecular weight and distribuition of polymers and biomolecules, e.g. DNA.

• To analyse the sequence of proteins or oligonucleotides.

• To analyse drugs, pesticides, carbohydrates or fatty acids with long chains.

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Ion production in an electrospray ionisation source has three steps:

Electrospray ionisation: principles

• Aerosol formation;

• Desorbed ion formation;

• Migration to the sample.


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Solvent evaporation Coulombic explosion






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S.J. Gaskell, J.Mass Spectrom. 32 (1997) 667





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Recently, aside from mass spectrometry, novel applications of electrospray have been used to create:

New Deposition Techniques

Applications

Surface coatings

Functional films

Biological arrays

Electrode coatings

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We have developed an electrospray deposition system in which the spray occurs

Instrumentation

In vacuum

At atmospheric pressure

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10-2 torr 10-5 torr

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In vacuum

Carbon Nanotubes (CNTs)

Electrospray deposition in vacuum: Swarbrick,J.C; Taylor, J.B.; O’Shea, J.N.

Appl. Surf. Sci. (2006) 252, 5622

Polymer (PEO)

Electrospray deposition of carbon nanotubes in vacuum:O’Shea J.N., Schulte K. et al.

Nanotechnology (18) 035707 (2007)

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In vacuum

E

P1 P2 P3

S

ca. 70 cm

Solution

Air ~10 Torr-7

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10-7 torr

water-methanol solution

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Deposition of PEO on Si(111)

E

P1 P2 P3

S

ca. 70 cm

Solution

Air ~10 Torr-7

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Deposition of C60 on Au(111)

J. A. Theobald, et al., Langmuir, 21, 2005.L. M. A. Perdigão , et al., J. Phys. Chem. B, 110 (25), 2006

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Deposition of C60 onto PTCDI / Melamine on Au(111)

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2 minutes deposition from a ~ 1mg/ml C60 soln. in Tol:MeCN (3:1)

+1.80V, 0.03nA, 102.3nm x 75.3nm

A – reduced order area

B – Dimers trapped in parallelogram network

C – Heptamers in hexagonal network with 2nd layer growth

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A

+1.80V, 0.03nA, 51.0nm x 33.7nm +1.80V, 0.03nA, 23.9nm x 23.9nm

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B

+1.80V, 0.03nA, 51.2nm x 40.6nm

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+1.80V, 0.03nA, 49.8nm x 30.3nm

C

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• Deposition of:

• Nanotubes,

• PbS,

• P3HT, DMP (Soluble Pentacene Precursors),

• C60O, Porphyrin, N@C60.

Ongoing and Future work

• Line of Sight Mass Spectrometry of Electrospray

• Detailed inventory of species in electrospray beam• Attempt to deflect using a biased target could give idea of impact energy

• New housing for spray generation

• Inert atmosphere (Nitrogen)• Precise tip positioning during operation• Heated drying gas

Acknowledgements

• Dr. James O’ Shea• Chris Satterley, Louise Mayor and Anna Rienzo

Funding

• EC Marie-Curie Early Stage Researcher Training NetworkProgram MONET: MOLECULAR NETWORKS AT PHASE BOUNDARIES

…Thank you for your attention

Graziano Magnano


electrospray deposition graziano magnano nanoscience group school of physics & astronomy...

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