TSI Instruments 3480 User manual

method of generating 3-nanometer particles is now
available from TSI. The Model 3480 Electrospray
Aerosol Generator produces stable, monodisperse, sub-
micrometer aerosol in the range from less than 3 to
greater than 100 nanometers. It achieves such small
diameters by moving a conductive liquid solution or
suspension through a capillary and applying an electri-
cal field to the liquid at the capillary tip. The electrical
field draws the liquid from the tip into a conical jet
from which ultrafine charged droplets are emitted. Air
and CO2are merged with the droplets, and the liquid
evaporates while the charge is neutralized by an ioniz-
er. The result is a neutralized, monodisperse aerosol
that is practically free of solvent residue.
A
APPLICATIONS
The successful use of the electrospray method to
generate monodisperse aerosol has been documented in
many publications. Although the basic principles are
well understood, many of the fine details explaining
how different operating parameters affect the electro-
spray method remain to be discovered. Known applica-
tions for this instrument include:
• Instrument calibration
• Studies of nano-aerosols
• Deposition of nanoparticles onto surfaces
• Aerosol analysis in the macromolecular and submi-
crometer range
• Dispersion of nanometer-sized powders for research
applications
• Research involving parameters that influence the
electrospray process
OPERATION
The operator places a standard centrifuge vial
containing a sample solution inside a cylindrical
pressure vessel. The vessel accommodates a capil-
lary and a high-voltage platinum wire, both of
which are immersed in the solution. Maintaining
a differential pressure moves the solution through the
capillary. An electric field induces a charge on the
solution at the capillary tip and acts on the induced
charge to form ultrafine
droplets that are mixed with
clean air and CO2. The gas
Produces particles as small as
3 nm in diameter, in concentrations
as high as 107particles/cm3
P R O D U C T
I N F O R M A T I O N
Model 3480
Electrospray Aerosol Generator
A viewport in the instrument allows you to watch the capil-
lary tip during operation. Three views of the capillary tip are
shown above: (1) no liquid flow, (2) with liquid flow but no
electrical field, and (3) with liquid flow and an electrical
field. The latter view illustrates stable Electrospray operation.
2
13

flow transports the droplets to the neutralization cham-
ber. The highly charged droplets are neutralized by a ra-
dioactive source (Polonium 210), and the liquid evapo-
rates before the aerosol exits the instrument.
SPECIFICATIONS
These specifications include many of the critical parameters that
influence the electrospray process. They include typical values
TSI Incorporated has used and obtained with early
Model 3480 prototypes. Many combinations of parti-
cle materials and solvents are yet to be tested. For
example, methanol and acetonitrile have been found to
be suitable alternative solvents for some applications.
Specifications may change as different particle materi-
als or solvents are used.
Particle type
Aerosol particles as residues from electrosprayed solu-
tions: Water-soluble, nonvolatile solids and liquids may
be used to generate residue particles with diameters from
less than 3 to about 50 nm. Using this approach, every
spray droplet dries to a residue particle that contributes
to the final aerosol, resulting in the highest aerosol con-
centrations obtainable from the Model 3480. The size
distribution of the final aerosol reflects that of the pri-
mary droplet distribution and is, thus, a property of the
Model 3480.
Aerosol particles from aqueous suspensions and emul-
sions: Aerosols of nonsoluble particles, lipid droplets,
or macromolecules are obtained by spraying the corre-
sponding dilute suspensions or emulsions. Proteins as small as 3 nm
and PSL particles as large as 200 nm (that is, somewhat larger than
the spray droplets) have been aerosolized successfully in this way.
Dilution ensures that most droplets contain no more than a single
particle. The size distribution reflects that of the suspended parti-
cles or macromolecules, and the concentration achieved is not as
high as in the solution-residue method.
Particle generation rate: >107particles/cm3
Liquid conductivity: 0.2 S/m nominal
Liquid flow rate: 50 to 100 nL/min
Particle size range: <3 to >100 nm
Initial droplet diameter: 150 nm
Differential pressure: 0 to 5 psi (3.0 psi nominal)
Air flow: 0.2 to 2.5 L/min (1 L/min nominal)
CO2flow: 0.05 to 0.5 L/min (0.1 L/min nominal)
P/N 1930098 Rev A. Copyright © 2001 TSI Incorporated Printed in U.S.A. (091401 -- PDF updated 012902)
Orifice
Plate
Capillary
Tube
Regulated
clean air in
Pressure
Chamber
Top
High-Voltage Wire
Pressure
Chamber
Bottom
(quick-release)
Vial with
particle/liquid
solution
Clean
CO2
in
Clean
air
in
Aerosol out
Droplets
Particles
Ionizer
See "Operation"
on Previous Page
TSI Incorporated
Particle Instruments
P.O. Box 64394
St. Paul, MN 55164 USA
Shipping address:
500 Cardigan Road
Shoreview, MN 55126 USA
Europe:
TSI GmbH
Neuköllner Strasse 4
D-52068 Aachen
Germany
Tel: [phone]
Fax: [phone]
E-mail: [email protected]
Toll Free: 1 800 677 2708
Tel: [phone]
Fax: [phone]
E-mail: [email protected]
Web: www.tsi.com
www.tsi.com
For current information
BIBLIOGRAPHY
Chen D, DYH Pui, and SL Kaufman, Electrospraying of Conduc-
tion Liquids for Monodisperse Aerosol Generation in the 4 nm
to 1.8 µm Size Range, J. Aerosol Science 26:963-977 (1995).
NIST-traceable PSL Mixture†
(73, 102, and 199 nm)
Electrical Mobility Diameter (nm)
Concentration (dN#/cm3)
*Neutralizers are shipped separately. End-user name and address required.
†Emulsifier present below 25 nm.
Specifications subject to change without notice. Model 3480 is covered under U.S.
Patent Numbers 5,076,097 and 5,247,842.
Charger: Po-210, 5 millicurie *
Voltage range: +0.5 to +3.5 kV (2 kV nominal, negative high-
voltage module available)
Current range: 0 to 2000 nA (180 to 320 nA nominal)
Power requirements: 85 to 264 VAC, 50 to 60 Hz,
25 W maximum
Dimensions (LWH): 20.3 cm ×40.4 cm ×25.7 cm
(8.0 in. ×15.9 in. ×10.1 in.)
Weight: 6.8 kg (15 lb)