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Feb 16th2006

Polymer-SurfactantInteraction

Fadwa OdehDepartment of Chemistry

Clarkson University


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Feb 16th2006 Polymer-Surfactant Interaction

Contents

Introduction

- Surfactants

- polymers

Polymer-Surfactant Interaction and its Effects Importance of these Interactions

ethods Used to study Polymer-SurfactantInteraction

Conclusions

!eferences


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Surfactants

Surfactants "Surface #ctive #$ents% areamphipathic molecules "have a hydrophilic

part and a hydropho&ic part%'

The hydrophilic part

could be anionic (SO3-),

cationic (R3N+) or simply

a polar group (OH)

The hydrophobic part is a long

hydrocarbon chain that (could be

also branched)


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Types of Surfactants

Ionic surfactants

- #nionic Surfactants

# surfactant with a ne$atively char$ed

head $roup such as(Sodium Dodecyl Sulfonate "SDS%


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Ionic Surfactants

- Cationic Surfactants

# surfactant with a cationic $roup such as()enalkonium Chloride

Types of Surfactants(cont.)


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*witterionic "#mphoteric% Surfactants

# surfactant with two oppositely char$ed

$roups such as(

Cocamidopropyl &etain

Types of Surfactants (cont.)


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Types of Surfactants (cont.)

+onionic Surfactants

# surfactant with no char$e $roup

Such as Cetyl alcohol

O,


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Micellization

icelles form when the concentration of the surfactant $oesa&ove a certain limit called critical micelle concentration "cmc%'

he micelles formation is driven &y entropy "&ecause the entropypenalty of surfactants molecules $ather to form a micelle is lessthan the entropy penalty of water molecules "or solvent%$atherin$ to$ether via hydro$en &ondin$ to isolate the

hydropho&ic part in a ca$e like structures%'


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Polymers

Polymers are lon$ chain $iant molecules assem&led from smallerunits "monomers%'

here are natural polymers such as( silk. proteins. ru&&er.car&ohydrates. D+#/'etc'

Synthetic polymers such as( polyurethane. polystyrene. polyvinylchloride/''etc'

yo$lo&in


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Polymers Classification

,omopolymers

"Polypropylene%

#-#-#-#-#-#-#-#- 0 -#n-

Copolymers. could &e- #lternatin$

#-)-#-)-#-)-#-)-#-) 0 -"#)%n-

- !andom

#-#-)-#-)-#-#-#-)-)-#-/''- )lock copolymer

#-#-#-#-#-#-#-#-#-)-)-)-)-)-)-)-)///''


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Polymers are also classified accordin$ tomethod of preparation(

#ddition polymers

Usually the monomers are unsaturated"#lkenes% e1' Polyethylene

Condensation polymers

Usually the monomers have functional $roupslike acids and hydro1yl e1' Polyamides"+ylon%

Polymers Classification


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Effect of Polymer-Surface

Interaction

Polymers induce a$$re$ation


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Polymer-Surfactant Interaction

ypes of interactions(

Electrostatic Interactions "if the polymer and the

surfactant are oppositely char$ed%'

,ydropho&ic Interactions "&etween the hydropho&ic

parts of &oth the polymer and surfactant%'


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#&uin. E' )' and Scaiano. 2' C' Journal of American Chemical Society!"#$. 345. 5678'%

he presence of polymeric

chains induces the

formation of micelles'

he presence of similarities&etween the surfactant

and the polymer attract the

surfactant molecules to

certain positions in thepolymer'


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!ef' 39


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he main attraction forces are still hydropho&icinteractions'

he same mechanism and entropy &alance hold formicelli:ation in presence of polymer

Usually the same a$$re$ate si:e and a$$re$ationnum&er'

he presence of oppositely char$ed species doenhance interaction

Polymer-Surfactant Interaction (cont.)


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he specific viscosity of

4'43 P## with different

de$rees of neutrali:ation. a.

as a function of addedC36#) compared &etween

e1perimental data "filled

sym&ols% and the

predictions "solid lines%'


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Applications of Polymer-Surfactant

Mixtures

Polymers are added to surfactants to(

Control the phase &ehavior " e'$' to solu&ili:e waterinsolu&le polymers%'

Control the interfacial properties "e'$' to sta&ili:esuspensions which depends on a comple1 interplay&etween different pair interactions' #ddition of a polymercan either remove a surfactant from a surface orenhance its adsorption to a surface%'


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o achieve a suita&le rheolo$y "thickenin$ and

$elation effect%'

he polymer induced micelli:ation lead to a lower

surfactant free molecules concentration and activity

"e'$' in skin formulations. free surfactant molecules

cause skin irritation%'

Applications of Polymer-Surfactant

Mixtures


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Techniues !se" to Stu"y

Polymer-Surfactant Interactionshere are several techni=ues to study polymer-surfactant

interactions such as(

Calorimetric easurements

+uclear a$netic !esonance "+!%

Flourescence Conductivity

>el Permeation Chromato$raphy ">PC%

?iscosity easurements

F Infrared Spectroscopy "FI!%

Surface ension easurements @i$ht Scatterin$ echni=ues

Electromotive Force "emf%


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Surface tension measurements are widely

used for studyin$ micelli:ation and

surfactant-polymer interaction'

#ddin$ surfactants reduces surface tension' Even in presence of polymers. the surface

tension reduction still occur'

he effect of the polymer depends on thesurfactant concentration

Surface Tension Stu"ies


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Surface Tension Stu"ies

P?P0poly"vinyl pyrrolidoneSurfactant0 SDS


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Isothermal Titration Calorimetry an"

EM#

!ef'8


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!ef'8

Calorimetric Techniues


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$uclear Ma%netic &esonance'iffusion Measurements

!ef' 5


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$uclear Ma%netic &esonance

'iffusion Measurements

!ef'

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