ASTM_D_3849_-_14a.pdf

Designation:D384914aStandard Test Method forCarbon BlackMorphological Characterization of CarbonBlack Using Electron Microscopy1This standard is issued under the fixed designation D3849;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 This test method covers(1)the morphological(forexample,size and shape)characterization of carbon black fromtransmission electron microscope images which are used toderive the mean particle and aggregate size of carbon black inthe dry(as manufactured)state,from CAB chip dispersion orremoved from a rubber compound and(2)the certification ofmean particle size using a correlation based on statisticalthickness surface area measurements.1.2 The values stated in SI units are to be regarded as thestandard.The values in parentheses are for information only.1.3 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.2.Referenced Documents2.1 ASTM Standards:2D3349 Test Method for Absorption Coefficient of EthylenePolymer Material Pigmented with Carbon BlackD6556 Test Method for Carbon BlackTotal and ExternalSurface Area by Nitrogen Adsorption3.Terminology3.1 Definitions:3.1.1 General:3.1.1.1 carbon black particlea small spheroidally shaped,paracrystalline,non-discrete component of an aggregate;it canonly be separated from the aggregate by fracturing;carbonblack particle size is a distributional property;therefore,theterm particle size implies the mean value from multiplemeasurements.3.1.1.2 carbon black aggregatea discrete,rigid colloidalentity that is the smallest dispersible unit;it is composed ofextensively coalesced particles;carbon black aggregate size isa distributional property;therefore,the term aggregate sizeimplies the mean value from multiple measurements.3.1.1.3 statistical thickness surface area(STSA)the exter-nal specific surface area of carbon black that is calculated fromnitrogen adsorption data using the de Boer theory and a carbonblack-specific model.3.1.1.4 glow dischargea plasma of ionized gas that isformed in a high-voltage field at pressures of about 3 to 20 Pa(25 to 150 10-3torr);an alternating current(a-c)glowdischarge using air is effective in cleaning and oxidizing thesurface of carbon substrates to improve the wetting character-istics of polar vehicles containing pigment dispersions.3.1.1.5 substratea thin film that is used to support electronmicroscope specimens;evaporated carbon films are commonlyused because of relatively good mechanical strength,stability,and conductivity.3.1.2 Aggregate Dimensional Properties from Image Analy-sis:3.1.2.1 area(A)the two-dimensional projected area of thecarbon black aggregate image.3.1.2.2 perimeter(P)the total boundary length of anaggregate.3.1.2.3 volume(V)an estimate of the volume of the carbonblack aggregate using stereological principles.3.1.3 Image Analysis:3.1.3.1 dilationthe converse of erosion;this process isaccomplished by changing any OFF pixel to ON if it hasgreater than a preset minimum of ON neighbors,causing imagefeatures to grow in size,which fills in small breaks in features,internal voids,or small indentations along the feature surface.3.1.3.2 erosionthe process by which image features arereduced in size by selectively removing pixels from theirperiphery;it consists of examining each binary pixel andchanging it from ON to OFF if it has greater than a presetminimum of neighbors that are OFF;it serves a number ofuseful functions,such as smoothing feature outlines andseparating features touching each other.1This test method is under the jurisdiction of ASTM Committee D24 on CarbonBlack and is the direct responsibility of Subcommittee D24.81 on Carbon BlackMicroscopy and Morphology.Current edition approved Nov.1,2014.Published November 2014.Originallyapproved in 1980.Last previous edition approved in 2014 as D3849 14.DOI:10.1520/D3849-14A.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 3.1.3.3 featureareas within a single continuous boundarythat have gray-level ranges that allow them to be distinguishedfrom the background area outside the feature via thresholding.3.1.3.4 thresholdingselecting a range of brightness suchthat discrimination is possible between the feature and thebackground;the gray levels within carbon black imagesbecome lower with decreas