1、Designation: D 3825 90 (Reapproved 2005)An American National StandardStandard Test Method forDynamic Surface Tension by the Fast-Bubble Technique1This standard is issued under the fixed designation D 3825; the number immediately following the designation indicates the year oforiginal adoption or, in
2、 the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the specificfree energy of a liquid-g
3、as surface a short time after formationof the surface.1.2 It is applicable to liquids with vapor pressures up to 30.0kPa (225 torr) and kinematic viscosities up to 4.0 mm/s (4.0cSt) at the test temperature. Higher viscosities have not yetbeen investigated.21.3 The values stated in SI units are to be
4、 regarded as thestandard. The values given in parentheses are for informationonly.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to consult andestablish appropriate safety and health pract
5、ices and deter-mine the applicability of regulatory limitations prior to use.For specific warning statements, see 7.3, 7.4, and 7.5.2. Referenced Documents2.1 ASTM Standards:3D 1193 Specification for Reagent WaterD 1331 Test Methods for Surface and Interfacial Tension ofSolutions of Surface-Active A
6、gentsE1 Specification for ASTM Liquid-in-Glass Thermometers3. Terminology3.1 Definitions:3.1.1 surface tension (g)the specific surface free energyof a liquid gas interface, millinewton per metre (ergs/cm2).3.2 Definitions of Terms Specific to This Standard:3.2.1 bubble frequency (S)bubbling rate, s1
7、.3.2.2 bubble pressure (DP)difference between maximumpressures for the wide capillary (P1) and the narrow capillary(P2), Pa.3.2.3 dead time (to)time required from start to completionof a bubble, ms.3.2.4 dead time %fraction of a cycle (t + to) in the deadstate, %.3.2.5 surface age (t)time required t
8、o start a new bubble,ms.3.3 Symbols:g = surface tension, millinewtons per metre (dynes/cm)S = bubble frequency, s1to= dead time, mst = surface age, msD = density, kg/m3r = radius, mmDP = difference between maximum pressures, PaP1= maximum pressure for the wide capillary, PaP2= maximum pressure for t
9、he narrow capillary, Pa4. Summary of Test Method4.1 The pressure required for bubble formation at a capillarytip immersed in the liquid is measured at gas flow rates thatprovide a series of bubble frequencies. The pressure and acalibration constant are used to calculate the dynamic surfacetension at
10、 various surface ages.5. Significance and Use5.1 While this test method can be applied to pure liquids, itis especially designed for use with mixtures in which one ormore components migrate to the surface.5.2 Data of this type are needed for the design of equipmentfor processing mixed liquids, such
11、as in distillation towers.6. Apparatus6.1 Bubbler Unit, water-jacketed, as shown in Fig. 1.6.2 Thermostat, circulating water, to hold bubbler at speci-fied temperature.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibili
12、ty of SubcommitteeD02.11 on Engineering Sciences of High Performance Fluids and Solids.Current edition approved June 1, 2005. Published August 2005. Originallyapproved in 1990. Last previous edition approved in 2000 as D 382590(2000).2Kloubek, J., “Measurement of the Dynamic Surface Tension by the M
13、aximumBubble Pressure Method, III,” Journal of Colloid and Interface Science, Vol. 41,October 1972, pp. 716.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the stan
14、dards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.3 Oven, adjustable to 378 K (105C), explosion-proof.6.4 Pressure Transducer, diaphragm-resistive unbondedstrain gage, time constant 25 m
15、s or less, 0 to 2000 Pa, accuracy62%.4,56.5 Bridge Power Supply, for the strain gage.6.6 Oscilloscope, capable of sweep times down to 0.020 s.6.7 Filtered (5-m) Air Supply, with pressure regulatorcapable of 0 to 724 kPa (0 to 105 psig) above ambient.NOTE 1Nitrogen shall be used in place of air if th
16、ere is any problemof oxidizing the liquid.6.8 Thermometer, appropriate range, conforming to Speci-fication E1.7. Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specificati
17、on of the Committeeon Analytical Reagents of the American Chemical Society,6where such specifications are available. Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.7.2 Purit
18、y of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water conformingto Specification D 1193, Type III.7.3 Calibration Liquids, reagent grade, covering a widerange of surface tension.Acetone, toluene, ethanol, and metha-nol have been found satisfactory for thi
19、s purpose.7.3.1 Acetone(WarningExtremely flammable. Vaporsmay cause flash fire. See Annex A1.1.)7.3.2 Toluene(WarningFlammable. Vapor harmful.See Annex A1.6.)7.3.3 Methanol(WarningFlammable. Vapor harmful.See Annex A1.5.)4Razouk, R. “Surface Tension of Propellants,” JPL Quarterly Technical ReviewVol
20、 2, 1972, pp. 123133.5Razouk, R. and Walmsley, D., “Surface Tension Measurement by the Differ-ential Maximum Bubble Pressure Method Using a Pressure Transducer,” Journal ofColloid and Interface Science, Vol. 47, 1974, pp. 515519.6Reagent Chemicals, American Chemical Society Specifications, AmericanC
21、hemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC),
22、Rockville,MD.Tips of b and b8 shall be cut squarely at exactly the same level, and finelyground (for example, 44 m S;C (320 mesh S;C).FIG. 1 Bubbler UnitD 3825 90 (2005)27.3.4 Ethanol(WarningFlammable. Denatured. SeeAnnex A1.4.)7.4 Cleaning Solution, Chromic-sulfuric acid. (WarningCauses severe burn
23、s. A recognized carcinogen strong oxidizer,contact with organic material can cause fire. Hygroscopic. SeeAnnex A1.2.)7.5 Nitrogen, of purity suitable to avoid reaction with testliquid and less than 100 ppm CO2with amines. (WarningCompressed gas under high pressure. See Annex A1.3.)8. Calibration and
24、 Standardization8.1 Clean the bubbler with cleaning solution, and rinse withwater. (WarningCauses severe burns.Arecognized carcino-gen. Strong oxidizer, contact with organic material may causefire. Hygroscopic. See Annex A1.2.) Condition by soaking inwater for 48 h followed by a final rinse with wat
25、er.8.2 Set up the apparatus as shown in Fig. 2, and bring thethermostat to the desired temperature.NOTE 2If a test temperature is not specified, 298 6 0.1 K (25 60.1C) is recommended.8.3 Calibrate the transducer and the oscilloscope verticalscale against a suitable timer.8.4 Measure the inner radius
26、 (r) of the wide capillary (b)byany suitable means to 65%.8.5 Half-fill the bubbler with water; then connect it tothermostat and equilibrate it until the test temperature isreached.8.6 Pass gas through the narrow capillary (b8) at a rate togive S = 0.5 s1and record the pressure maximum as P2.(Warnin
27、g Compressed gas under high pressure. See AnnexA1.3.)8.7 Open the stopcock (e) to the wide capillary and recordthe pressure as P1.8.8 Empty the bubbler and dry in the oven.8.9 Half-fill the bubbler with ethanol or methanol and repeat8.5-8.8.8.10 Repeat 8.9 with three other calibration liquids.8.11 C
28、alculate the calibration constant (A) for each of thefive liquids by:A 5g/DP 1 1 675 rD/DP! (1)Average the results.8.11.1 In general, handbook values of D are satisfactory.However, the true value of g for each supply of each calibra-tion liquid must be known; if it is not available from otherrecords
29、, then test in accordance with Test Method D 1331 orequivalent.9. Procedure9.1 Clean the bubbler as in 8.1 and dry in the oven.9.2 Half-fill the bubbler with the test liquid, connect to thethermostat and equilibrate.9.3 Close the stopcock (e) on the wide capillary.9.3.1 Pass dry gas through the narr
30、ow capillary as in 8.6 andrecord P2.9.3.2 Synchronize the sweep circuit so that the pressuretraces superimpose without drift, and record the sweep rate asS.NOTE 3To avoid synchronizing at 2S or 3S, observe the bubblesvisually.9.3.3 Open the stopcock and record P1.awater jacket, bwide capillary (insi
31、de diameter = 2.06 0.1 mm), b8nar-row capillary (inside diameter = 0.11 6 0.1 mm), cinlet manifold, dpressuretransducer, estopcock, fthermometer, gvent line, hbridge supply, ios-cilloscope, jthermostat, kneedle valve, mpressure reguator, nfilter, 5 m.ADo not use silicone grease on stopcocks or taper
32、 joint.FIG. 2 Set-up of ApparatusAD 3825 90 (2005)39.4 Close the stopcock and increase the flow rate by meansof the needle valve (k), to give S = 1.0 s1and record S and P2.Open the stopcock and check P1.9.5 Continue to double the gas flow rate, recording S and P2at each step, until evidence of dead
33、time appears at theright-hand side of the display as idealized in Fig. 3. From thenon it is necessary to record toor % dead time based on thehorizontal scale of the display. Record P1at each step.NOTE 4For a similar apparatus, an empirical equation was devel-oped:7to5 31.9 2 0.25S (2)This can be use
34、d as a guide for observability of to, but not for calculationof results since unevaluated differences in dimensions exist.9.6 Continue to double the gas flow rate, recording S, P2, to,and P1at each step, until regular bubbling breaks down, asshown by a sudden increase in P2.NOTE 5Breakdown depends o
35、n g and viscosity, and on some equip-ment factors.2The highest rate obtained2was S = 50, with water plussurfactant. The lowest rate to show breakdown was S = 20, with the mostviscous liquid (aniline with a viscosity of 4 mm2/s (4 cSt).9.7 Reduce the gas flow rate to the initial value S = 0.5within 6
36、1 %, and redetermine both P2and P1. If the differenceDP is changed by more than 62 % from that in 9.3, record thatfact as evidence that the properties of the sample have beenaltered during the test.10. Calculations10.1 Calculate the surface age for each flow rate by thefollowing equation:t 5 1000/S!
37、 1 2 % to/100! (3)t 5 1000/S! 2 to(4)10.2 Calculate the surface tension for each flow rate by thefollowing equation:g5ADP1 1 675rD/DP! (5)10.3 Plot the values of g versus those of t, and interpolatefor the value of g at t = 25 ms, or any other specified surfaceage.11. Report11.1 Report g and t for a
38、ll flow rates (usually 6 or 7).11.2 Summary reports may consist of g for t = 2000 ms asstatic surface tension and for t = 25 ms, or other specified time,for dynamic surface tension.11.3 If the DP measured in the check test 9.7 differsappreciably from that measured originally in 9.3, report that thel
39、iquid changed during the test by mN/m or ergs/cm2difference.12. Precision and Bias12.1 Committee D02 has no immediate plan at this time todevelop precision and bias statements for this test method.13. Keywords13.1 dynamic surface tension; tension (tensile) properties/tests; surface tension7Austin, M
40、., Bright, B. B. and Simpson, E. A., “The Measurement of theDynamic Surface Tension of Manoxol OT Solutions for Freshly Formed Surfaces,”Journal of Colloid and Interface Science, Vol 23, 1967, pp. 108112.FIG. 3 Idealized Oscilloscope Display at About S=16D 3825 90 (2005)4ANNEX(Mandatory Information)
41、A1. WARNING STATEMENTSA1.1 AcetoneWarningExtremely flammable. Vapors may cause flashfire.Keep away from heat, sparks, and open flame.Keep container closed.Use with adequate ventilation.Vapors may spread long distances and ignite explosively.Avoid build-up of vapors and eliminate all sources ofigniti
42、on, especially nonexplosion proof electrical apparatus andheaters.Avoid prolonged breathing of vapor or spray mist.Avoid contact with eyes and skin.In case of spillage absorb and flush with large volumes ofwater.In case of fire use water, dry chemical, CO2, or foam.A1.2 Chromic Acid (Cleaning Soluti
43、on)WarningCauses severe burns. A recognized carcinogen.Strong oxidizercontact with other material can cause fire.Hygroscopic.Do not get in eyes, on skin, on clothing.Avoid breathing vapor or mist.Keep container closed.Use with adequate ventilation.Do not take internally.Wash thoroughly after handlin
44、g.In case of spillage soak up with excess sodium carbonate andflush with plenty of water.A1.3 Compressed Gases, NitrogenWarningCompressed gas under high pressure. Gas re-duces oxygen available for breathing.Keep container closed.Use with adequate ventilation.Do not enter storage areas unless adequat
45、ely ventilated.Always use a pressure regulator. Release regulator tensionbefore opening cylinder.Do not transfer to cylinder other than one in which gas isreceived. Do not mix gases in cylinders.Do not drop cylinder. Make sure cylinder is supported at alltimes.Stand away from cylinder outlet when op
46、ening cylindervalve.Keep cylinder out of sun and away from heat.Keep cylinders from corrosive environment.Do not use cylinder without label.Do not use dented or damaged cylinders.For technical use only. Do not use for inhalation purposes.A1.4 Ethanol or Ethyl AlcoholWarningFlammable. Denatured canno
47、t be made non-toxic.Keep away from heat, sparks, and open flame.Keep container closed.Use with adequate ventilation.Avoid prolonged breathing of vapor or spray mist.Avoid contact with eyes and skin.Do not take internally.A1.5 Methanol (Methyl Alcohol)WarningFlammable. Vapor harmful.Can be fatal or c
48、ause blindness if swallowed or inhaled.Cannot be made nonpoisonous.Keep away from heat, sparks, and open flame.Keep container closed.Avoid contact with eyes and skin.Avoid breathing of vapor or spray mist.Use with adequate ventilation.Do not take internally.A1.6 TolueneWarningFlammable. Vapor harmfu
49、l.Keep away from heat, sparks, and open flame.Keep container closed.Use with adequate ventilation.Avoid breathing of vapor or spray mist.Avoid prolonged or repeated contact with skin.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.T
