ASTM_D_1331_-_14.pdf

Designation:D133114Standard Test Methods forSurface and Interfacial Tension of Solutions of Paints,Solvents,Solutions of Surface-Active Agents,and RelatedMaterials1This standard is issued under the fixed designation D1331;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 These test methods cover the determination of surfacetension and interfacial tension of a variety of liquid materials,including but not restricted to paints,solvents,and solutions ofsurface-active agents,as defined in Terminology D459.Fourmethods are covered as follows:Method ASurface Tension by du Noy ring.Method BInterfacial Tension by du Noy ring.Method CSurface Tension by Wilhelmy plate.Method DInterfacial Tension by Wilhelmy plate.1.2 Method A originally was written primarily to coveraqueous solutions of surface-active agents,but is also appli-cable to aqueous paints,nonaqueous solutions(includingpaints)and mixed solvent solutions.1.3 Method B is applicable to two-phase solutions.Morethan one solute component may be present,including solutecomponents that are not in themselves surface-active.1.4 Method C is applicable to surface active liquids and,unlike du Noy ring,no buoyancy corrections are needed andresults are not affected by moderate viscosities(1-10 Pa-sec)ofthe liquid.It is the recommended method for use with paintsand resin solutions.1.5 Method D is applicable to two-phase solutions andmixtures.1.6 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.7 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 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.Material SafetyData Sheets are available for reagents and materials.Reviewthem for hazards prior to usage.2.Referenced Documents2.1 ASTM Standards:2D459 Terminology Relating to Soaps and Other Detergents3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 du Noy ringplatinum wire ring.3.1.2 Wilhelmy plateflat,thin plate made of glass orplatinum.4.Summary of Test Methods4.1 du Noy Ring MethodsThe ring is suspended from atensiometer or balance.The test liquid is brought into contactwith the ring until the latter is covered.For interfacial tensionmeasurements,the ring must be at the interface between thetwo liquids.The ring is then slowly withdrawn until amaximum force is attained,from which the surface or interfa-cial tension may be calculated.4.2 Wilhelmy Plate MethodsThe plate is suspended from atensiometer or balance.The test liquid or interface between twoliquids is brought into contact with the bottom of the plate,causing the plate to be pulled down into the liquid by thesurface tension force.The force applied to the plate from aboveis then increased to bring the bottom edge of the plate levelwith the flat surface of the liquid.The force acting on the plateis measured and used to calculate the surface tension of theliquid or the interfacial tension between two liquid phases.5.Significance and Use5.1 These methods provide data that are useful in evaluatingthe effectiveness of surface active agents in reducing surface1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings,Materials,and Applications and are the directresponsibility of Subcommittee D01.24 on Physical Properties of Liquid Paints&Paint Materials.Current edition approved Dec.1,2014.Published January 2015.Originallyapproved in 1954.Last previous edition approved in 2011 as D1331 11.DOI:10.1520/D1331-14.2For 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 standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 tension.In addition,surface tension data can predict interac-tions between liquids and solid surfaces or other liquids andcan be used to establish wetting properties of paints,solvents,and other liquids.5.2 Anumber of laboratories have found the Wilhelmy plateto be easier to use,easier to clean and generally better for usewith pigmented paints.6.Interferences6.1 The du Noy ring is difficult to clean when used withpigmented paints.Paints high in titanium dioxide have atendency to coat the ring with a layer that is almost impossibleto remove.If left on the ring,this layer of material affects thesurface tension values that are measured.6.2 Paint measurements with the du Noy ring are affectedby viscosity above a level of 10 Poise(1 Pa-sec)