Standard Test Method for Dynamic Surface Tension by the Fast-Bubble Technique

SCOPE
1.1 This test method covers the determination of the specific free energy of a liquid-gas surface a short time after formation of the surface.  
1.2 It is applicable to liquids with vapor pressures up to 30.0 kPa (225 torr) and kinematic viscosities up to 4.0 mm /s (4.0 cSt) at the test temperature. Higher viscosities have not yet been investigated.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.4  This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific precautionary statements, see 7.3, 7.4, and 7.5.

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31-Dec-1999
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ASTM D3825-90(2000) - Standard Test Method for Dynamic Surface Tension by the Fast-Bubble Technique
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
An American National Standard
Designation:D3825–90(Reapproved 2000)
Standard Test Method for
Dynamic Surface Tension by the Fast-Bubble Technique
This standard is issued under the fixed designation D3825; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2.4 dead time %—fraction of a cycle (t+ t ) in the dead
o
state,%.
1.1 Thistestmethodcoversthedeterminationofthespecific
3.2.5 bubble pressure (DP)—difference between maximum
free energy of a liquid-gas surface a short time after formation
pressures for the wide capillary (P ) and the narrow capillary
of the surface. 1
(P ), Pa.
1.2 Itisapplicabletoliquidswithvaporpressuresupto30.0
3.3 Symbols:
kPa (225 torr) and kinematic viscosities up to 4.0 mm/s (4.0
cSt) at the test temperature. Higher viscosities have not yet
been investigated.
g = surface tension, millinewtons per metre (dynes/cm)
−1
1.3 The values stated in SI units are to be regarded as the
S = bubble frequency, s
standard. The values given in parentheses are for information
t = dead time, ms
o
only.
t = surface age, ms
1.4 This standard does not purport to address all of the
D = density, kg/m
safety concerns, if any, associated with its use. It is the r = radius, mm
responsibility of the user of this standard to consult and DP = difference between maximum pressures, Pa
P = maximum pressure for the wide capillary, Pa
establish appropriate safety and health practices and deter-
P = maximum pressure for the narrow capillary, Pa
mine the applicability of regulatory limitations prior to use.
For specific precautionary statements, see 7.3, 7.4, and 7.5.
4. Summary of Test Method
2. Referenced Documents
4.1 Thepressurerequiredforbubbleformationatacapillary
tip immersed in the liquid is measured at gas flow rates that
2.1 ASTM Standards:
provide a series of bubble frequencies. The pressure and a
D1193 Specification for Reagent Water
calibration constant are used to calculate the dynamic surface
D1331 Test Methods for Surface and InterfacialTension of
tension at various surface ages.
Solutions of Surface-Active Agents
E1 Specification for ASTM Thermometers
5. Significance and Use
3. Terminology
5.1 While this test method can be applied to pure liquids, it
is especially designed for use with mixtures in which one or
3.1 Definitions:
more components migrate to the surface.
3.1.1 surface tension (g)—the specific surface free energy
5.2 Dataofthistypeareneededforthedesignofequipment
of a liquid gas interface, millinewton per metre (ergs/cm ).
for processing mixed liquids, such as in distillation towers.
3.2 Definitions of Terms Specific to This Standard:
−1
3.2.1 bubble frequency (S)—bubbling rate, s .
6. Apparatus
3.2.2 dead time (t )—timerequiredfromstarttocompletion
o
6.1 Bubbler Unit, water-jacketed, as shown in Fig. 1.
of a bubble, ms.
6.2 Thermostat, circulating water, to hold bubbler at speci-
3.2.3 surface age (t)—time required to start a new bubble,
fied temperature.
ms.
6.3 Oven, adjustable to 378 K (105°C), explosion-proof.
6.4 Pressure Transducer, diaphragm-resistive unbonded
This test method is under the jurisdiction of ASTM Committee D02 on
straingage,timeconstant25msorless,0to2000Pa,accuracy
PetroleumProductsandLubricantsandisthedirectresponsibilityofSubcommittee 6,7
62%.
D02.11 on Engineering Science of High Performance Fluids and Solids.
Current edition approved Oct. 26, 1990. Published December 1990.
Kloubek, J., “Measurement of the Dynamic Surface Tension by the Maximum
Bubble Pressure Method, III,” Journal of Colloid and Interface Science, Vol. 41, Razouk, R. “Surface Tension of Propellants,” JPLQuarterly Technical Review
October 1972, pp. 7–16. Vol 2, 1972, pp. 123–133.
3 7
Annual Book of ASTM Standards, Vol 11.01. Razouk, R. and Walmsley, D., “Surface Tension Measurement by the Differ-
Annual Book of ASTM Standards, Vol 15.04. ential Maximum Bubble Pressure Method Using a PressureTransducer,” Journal of
Annual Book of ASTM Standards, Vol 14.03. Colloid and Interface Science, Vol. 47, 1974, pp. 515–519.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D3825
Tips of b and b8 shall be cut squarely at exactly the same level, and finely
ground (for example, 44 µm S;C (320 mesh S;C).
FIG. 1 Bubbler Unit
6.5 Bridge Power Supply, for the strain gage. 7.3 Calibration Liquids, reagent grade, covering a wide
6.6 Oscilloscope, capable of sweep times down to 0.020 s. range of surface tension.
6.7 Filtered (5-µm) Air Supply, with pressure regulator
NOTE 2—Acetone, toluene, ethanol, and methanol have been found
capable of 0 to 724 kPa (0 to 105 psig) above ambient.
satisfactory for this purpose. Acetone—Warning: Extremely flammable.
Vapors may cause flash fire. See Annex A1.1. Toluene—Warning:
NOTE 1—Nitrogen shall be used in place of air if there is any problem
Flammable.Vaporharmful.SeeAnnexA1.6. Methanol—Warning:Flam-
of oxidizing the liquid.
mable. Vapor harmful. SeeAnnexA1.5. Ethanol—Warning: Flammable.
6.8 Thermometer, appropriate range, conforming to Speci-
Denatured. See Annex A1.4.
fication E1.
7.4 Cleaning Solution, Chromic-sulfuric acid. Warning:
Causes severe burns.Arecognized carcinogen strong oxidizer,
7. Reagents and Materials
contact with organic material can cause fire. Hygroscopic. See
7.1 Purity of Reagents—Reagent grade chemicals shall be
Annex A1.2.
used in all tests. Unless otherwise indicated, it is intended that
7.5 Nitrogen, of purity suitable to avoid reaction with test
allreagentsshallconformtothespecificationoftheCommittee
liquid and less than 100 ppm CO with amines. Warning:
on Analytical Reagents of the American Chemical Society,
Compressed gas under high pressure. See Annex A1.3.
where such specifications are available. Other grades may be
8. Calibration and Standardization
used, provided it is first ascertained that the reagent is of
sufficiently high purity to permit its use without lessening the
8.1 Clean the bubbler with cleaning solution, and rinse with
accuracy of the determination.
water. Warning: Causes severe burns. A recognized carcino-
7.2 Purity of Water—Unlessotherwiseindicated,references
gen. Strong oxidizer, contact with organic material may cause
towatershallbeunderstoodtomeanreagentwaterconforming
fire. Hygroscopic. See Annex A1.2. Condition by soaking in
to Specification D1193, Type III.
water for 48 h followed by a final rinse with water.
8.2 Set up the apparatus as shown in Fig. 2, and bring the
thermostat to the desired temperature.
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
NOTE 3—If a test temperature is not specified, 298 6 0.1 K (25 6
listed by the American Chemical Society, see Analar Standards for Laboratory
0.1°C) is recommended.
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
8.3 Calibrate the transducer and the oscilloscope vertical
and National Formulary,U.S.PharmaceuticalConvention,Inc.(USPC),Rockville,
MD. scale against a suitable timer.
D3825
a—water jacket, b—wide capillary (inside diameter = 2.06 0.1 mm), b8—nar-
row capillary (inside diameter = 0.11 6 0.1 mm), c—inlet manifold, d—pressure
transducer, e—stopcock, f—thermometer, g—vent line, h—bridge supply, i—os-
cilloscope, j—thermostat, k—needle valve, m—pressure reguator, n—filter, 5 µm.
A
Do not use silicone grease on stopcocks or taper joint.
A
FIG. 2 Set-up of Apparatus
8.4 Measure the inner radius (r) of the wide capillary (b)by 9.3.2 Synchronize the sweep circuit so that the pressure
any suitable means to65
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