2024年3月28日发(作者：羊舌冬)

PartII:SurfacePreparation

3SurfaceTensionandItsMeasurement

SinaEbnesajjad

3.1Introduction

Surfacescienceisanimportantbranchof

physicalorganicchemistrythatstudiesthe

behaviorandcharacteristicsofmoleculesator

erfacecanform

betweensolids,liquids,gases,andcombinationsof

xapparatushasbeendevel-

opedtoidentifyandquantifysurfacesandinter-

rsurfacesareofspecialinterestin

industrialandbiologicalapplications;examplesof

thelatterincludedentalimplantsandbodypart

ficationofsurfacesof

thesedevicesallowsformationofcontrolled

interfacestoachievecharacteristicssuchas

bondabilityandcompatibility.

Adhesionisaninterfacialphenomenonthat

occursattheinterfacesofadherendsandadhe-

thefactunderlyingthemacroscopic

understandingoftheforcesthatdevelopthe

interfacesishelpfultotheselectionoftheright

adhesive,propersurfacetreatmentofadherends,

andeffectiveandeconomicalprocessestoform

apterisdevotedtothediscussionof

thethermodynamicprinciplesandworkofadhe-

sionthatquantitativelycharacterizesurfacesof

materials.

3.3SurfaceTension

Themoleculesofaliquidareheldtogetherby

ofallattractiveforceson

anymoleculepresentinthebulkofaliquidaverages

force(alsoknownascohesionforce)on

asurfacemoleculeisanonzeroquantityinthe

directiontowardthebulk(Fig.3.1).Thisistheforce

thatmustbecounteractedtoincreasethesurface

area;theenergyconsumedbythisprocessiscalled

alancedforcesontheinter-

dropletsaresphericalbecauseaspherehasminimum

surfaceareaforagivenvolumeamongallgeometric

ghsurfacetensionandsurfacefree

energyofaliquidareequal,thesameisnottruefor

asolidsurface.

Surfacetensionisdefinedastheworkrequiredto

increasetheareaofasurfaceisothermallyand

etension(g)is

expressedassurfaceenergyperunitareaandalter-

etensionof

liquidscanbemeasureddirectlyandexpressedin

theunitsofworkorenergyperunitarea(erg/cm

2

),

whichisthensimplified(erg/cm

2

¼/cm

2

¼

3.2WhatisanInterface?

Twosolidorliquidphasesincontacthaveatoms/

moleculesonbothsidesofanimaginaryplanecalled

erfacialparticlesdifferener-

geticallyfromthoseinthebulkofeachphasedueto

beingontheboundaryoftherespectivephaseand

compositionandenergyvarycontinuouslyfromone

gion

hasafinitethickness,usuallylessthan0.1mm.

1,2

Figure3.1Liquideliquidinterfaceandbalanceof

forcesonmoleculesofliquids.

HandbookofAdhesivesandSurfacePreparation,:10.1016/B978-1-4377-4461-3.10003-3

Óhtsreserved.

Thischapterhasbeenadaptedfrom‘SurfaceTensionandItsMeasurement’inSurfaceTreatmentofMaterialsforAdhesionBonding,

jjad&jjadÓ2006ElsevierInc.

21

2024年3月28日发(作者：羊舌冬)

PartII:SurfacePreparation

3SurfaceTensionandItsMeasurement

SinaEbnesajjad

3.1Introduction

Surfacescienceisanimportantbranchof

physicalorganicchemistrythatstudiesthe

behaviorandcharacteristicsofmoleculesator

erfacecanform

betweensolids,liquids,gases,andcombinationsof

xapparatushasbeendevel-

opedtoidentifyandquantifysurfacesandinter-

rsurfacesareofspecialinterestin

industrialandbiologicalapplications;examplesof

thelatterincludedentalimplantsandbodypart

ficationofsurfacesof

thesedevicesallowsformationofcontrolled

interfacestoachievecharacteristicssuchas

bondabilityandcompatibility.

Adhesionisaninterfacialphenomenonthat

occursattheinterfacesofadherendsandadhe-

thefactunderlyingthemacroscopic

understandingoftheforcesthatdevelopthe

interfacesishelpfultotheselectionoftheright

adhesive,propersurfacetreatmentofadherends,

andeffectiveandeconomicalprocessestoform

apterisdevotedtothediscussionof

thethermodynamicprinciplesandworkofadhe-

sionthatquantitativelycharacterizesurfacesof

materials.

3.3SurfaceTension

Themoleculesofaliquidareheldtogetherby

ofallattractiveforceson

anymoleculepresentinthebulkofaliquidaverages

force(alsoknownascohesionforce)on

asurfacemoleculeisanonzeroquantityinthe

directiontowardthebulk(Fig.3.1).Thisistheforce

thatmustbecounteractedtoincreasethesurface

area;theenergyconsumedbythisprocessiscalled

alancedforcesontheinter-

dropletsaresphericalbecauseaspherehasminimum

surfaceareaforagivenvolumeamongallgeometric

ghsurfacetensionandsurfacefree

energyofaliquidareequal,thesameisnottruefor

asolidsurface.

Surfacetensionisdefinedastheworkrequiredto

increasetheareaofasurfaceisothermallyand

etension(g)is

expressedassurfaceenergyperunitareaandalter-

etensionof

liquidscanbemeasureddirectlyandexpressedin

theunitsofworkorenergyperunitarea(erg/cm

2

),

whichisthensimplified(erg/cm

2

¼/cm

2

¼

3.2WhatisanInterface?

Twosolidorliquidphasesincontacthaveatoms/

moleculesonbothsidesofanimaginaryplanecalled

erfacialparticlesdifferener-

geticallyfromthoseinthebulkofeachphasedueto

beingontheboundaryoftherespectivephaseand

compositionandenergyvarycontinuouslyfromone

gion

hasafinitethickness,usuallylessthan0.1mm.

1,2

Figure3.1Liquideliquidinterfaceandbalanceof

forcesonmoleculesofliquids.

HandbookofAdhesivesandSurfacePreparation,:10.1016/B978-1-4377-4461-3.10003-3

Óhtsreserved.

Thischapterhasbeenadaptedfrom‘SurfaceTensionandItsMeasurement’inSurfaceTreatmentofMaterialsforAdhesionBonding,

jjad&jjadÓ2006ElsevierInc.

21