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Use of Bipolar Electrochemistry to Control Nanofluidics Applications
Bradley Group:Sundar Babu (postdoc)
Patrick Ndungu (graduate student)Guzeliya Korneva (graduate student)
Jillian Tromp (undergraduate)Eric Moore (undergraduate)
1. Bipolar Electrochemistry Concepts2. Bipolar Electrodeposition onto nanofibers, MWNT’s3. Preparation and Bipolar Electrodeposition onto CVD Nanopipes4. Contactless Nanosyringe
Bradley, J.-C.; Ma, Z. Contactless Electrodeposition of Palladium Catalysts, Angew. Chem. Int. Eng. Ed. 1999, vol. 38, 1663.
Toposome prepared by bipolar electrodeposition of Pd and Au on graphite powder
Spatially Coupled Bipolar Electrochemistry
(SCBE)
Bradley, J.-C.; Chen, H.-M.; Crawford, J.; Eckert, J; Ernazarova, K.; Kurzeja, T.; Lin, T.; McGee, M.; Nadler, W.; Stephens, S.G. Nature, 1997, vol. 389, 268.
Exploitation of particle aspect ratio to carry out bipolar electrochemistry at sub-micron scale
2r
L
sphere Emin = Vc
2r
Emin = Vc
Lgeneral
E
F
H
G
D
A
B
C
0 s
10 s
20 s
40 s
80 s
120 s
240 s
480 s
E = 3000 V/cm
Bipolar Electrodeposition of Pd onto Carbon Nanofibers
Bipolar Electrodeposition of Cobalt on Nanotubes Supported on Polyester Membranes 1, Jean-Claude Bradley, P Ndungu, S Babu.
ChemWeb Preprint Server, CPS:chemistry/0304002, 2003, http://preprint.chemweb.com/chemistry/0304002
Figure 11: SEM micrograph Cobalt deposited on one tip of MWNT (commercially obtained) by contact less method.Field properties: Intensity 10 kV/cm, ton = 1ms, toff = 24 ms, field time = 25 min
Bipolar Electrodeposition of Co onto a MWNT
Bipolar electrodeposition of nickel on nanotubes supported on polyester membranes 1, Jean-Claude Bradley, P Ndungu, S Babu.
ChemWeb Preprint Server, CPS:chemistry/0304001, 2003, http://preprint.chemweb.com/chemistry/0304001
Figure 12: SEM micrograph of Nickel deposited on one tip of MWNT (commercially obtained) by contact less method.Field properties: Intensity 10 kV/cm, ton = 1ms, toff = 24 ms, field time = 25 min
Bipolar Electrodeposition of Ni onto a MWNT
Figure 10: SEM micrograph Cadmium deposited on one tip of MWNT (commercially obtained) by contact less method.Field properties: Intensity 10 kV/cm, ton = 1ms, toff = 24 ms, field time = 60sec
Bipolar Electrodeposition of Cadmium onto one tip of a Carbon Nanotube, Jean-Claude Bradley, P Ndungu, S Babu, J Tromp, N Hackett.
ChemWeb Preprint Server, CPS:chemistry/0311001, 2003, http://preprint.chemweb.com/chemistry/0311001
Bipolar Electrodeposition of Cd onto a MWNT
CVD Carbon Nanopipe Synthesis
670oC
Arg
on
30
% C
2H
4 +
70
% H
e
Effluent
Programmable high temperature furnaceQuartz tubes to hold the alumina membrane
Alumina membranes stacked between two short quartz
tubes
SEM micrographs of CVD nanopipe obtained by CVD of 30%C2H4 + 70% He at 670oC inside the pores of alumina membrane. The Alumina template was removed by sonicating the membrane in 1M NaOH for 90 min.
Nanotube Synthesis Using Alumina Template (a4), Jean-Claude Bradley, S Babu, P Ndungu, A Nikitin, Y Gogotsi.
ChemWeb Preprint Server, CPS:chemistry/0303002, 2003, http://preprint.chemweb.com/chemistry/0303002
CVD Carbon Nanopipes
Figure 8: SEM micrograph Tin deposited on one tip of nanopipe by contact less method.Field properties: Intensity 10 kV/cm, ton = 1ms, toff = 24 ms, field time = 10sec
Bipolar Electrodeposition of Tin onto one tip of a Carbon Nanotube 1, Jean-Claude Bradley, P Ndungu, S Babu, J Tromp, N Hackett.
ChemWeb Preprint Server, CPS:chemistry/0309001, 2003, http://preprint.chemweb.com/chemistry/0309001
Bipolar Electrodeposition of Sn onto a CVD nanopipe
Figure 9: SEM micrograph of Zinc deposited on one tip of nanopipe by contact less method.
Field properties: Intensity 6 kV/cm, ton = 1ms, toff = 24 ms, field time = 40sec
Bipolar Electrodeposition of Zinc onto one tip of a Carbon Nanotube 1Jean-Claude Bradley, P Ndungu, S Babu, G Korneva, J Tromp, E Moore.
ChemWeb Preprint Server, CPS:chemistry/0312002, 2003, http://preprint.chemweb.com/chemistry/0312002
Bipolar Electrodeposition of Zn onto a CVD nanopipe
Figure 13: SEM micrograph of Cadmium sulfide deposited on one tip of nanopipe.
Field properties: Intensity 9 kV/cm, ton = 1ms, toff = 24 ms, field time = 20 sec
Bipolar Electrodeposition of Cadmium Sulfide onto one tip of a Carbon Nanotube 1, Jean-Claude Bradley, P Ndungu, S Babu, J Tromp, N Hackett, E Moore.
ChemWeb Preprint Server, CPS:chemistry/0312001, 2003, http://preprint.chemweb.com/chemistry/0312001
Bipolar Electrodeposition of CdS onto CVD nanopipes
(c) (d)
(b)(a)
Bipolar electrodeposition of polypyrrole onto carbon nanotubes 1, Jean-Claude Bradley, P Ndungu, S Babu, J Tromp, N Hackett.
ChemWeb Preprint Server, CPS:chemistry/0308001, 2003, http://preprint.chemweb.com/chemistry/0308001
Bipolar Electrodeposition of Polypyrrole onto a CVD Nanopipe
(a) (b)
(c)
Bipolar Electrodeposition of Polypyrrole onto both ends of a Carbon Nanotube 1, Jean-Claude Bradley, P Ndungu, S Babu, J Tromp, N Hackett.
ChemWeb Preprint Server, CPS:chemistry/0308002, 2003, http://preprint.chemweb.com/chemistry/0308002
Bipolar Electrodeposition of Polypyrrole onto a CVD Nanopipe
(b)(a)
Nuclepore Membrane (pore size 200 nm)
Platinum Electrodes(5mm inter-electrode gap)
Carbon Nanopipes
(c)Polypyrrole deposited after field application
(d)
Polypyrrole deposited after reversing the
polarity
+
-
-
+
+
-
Contactless Nanosyringe: Step 1 – Introduction of Polypyrrole
4.9 Torr 5.2 Torr
5.3 Torr4.9 Torr
Polypyrrole Mediated Injection of Water into a Nanopipe
Condensation of Water into a Nanopipe without Polypyrrole