surface-charged polymer colloids do ik lee emulsion polymers r&d the dow chemical company...

SURFACE-CHARGED POLYMER COLLOIDS

Do Ik Lee

Emulsion Polymers R&D

The Dow Chemical Company

Midland, Michigan 48674

USA

[email protected]

The 2000 Korean Polymer Society Fall Conference

October 13-14, 2000

Chungnam University

SURFACE-CHARGED POLYMER COLLOIDS

Do Ik Lee

Emulsion Polymers R&D

The Dow Chemical Company

Midland, Michigan 48674

USA

[email protected]

Short Course on Polymer Colloids

National Laboratory for Nanoparticle Technology,

Yonsei University

October 5-6, 2000

Surface-Charged Polymer Colloids

Outline of the Presentation Introduction The Critical Review of Emulsion Polymerization

Mechanisms: Homogeneous and Micellar Particle Nucleations

Preparation of Surface-Charged Polymer Colloids– Ionic Initiators

– Ionic Comonomers

– pH-Dependent Ionogenic Comonomers such as Weak Acids and Bases

– Hydrolysis of Esters

– Post-Reactions

Various Methods of Controlling the Placement of Charge or Functional Groups:– Surface-Modification by Shot Additions– Gradient-Composition by Power-Feed or Computer-Aided Processes– Core-Shell Latexes– Inverted Core-Shell Latexes

Cleaning and Characterization of Surface-Charged Polymer Colloids

General Colloidal and Some Unique Properties Applications Summary and Conclusions

Surface-Charged Polymer Colloids(Continued)

Surface-charged polymer colloids are anionic (negative), cationic (positive), or amphoteric (both negative and positive).

Surface-charged polymer colloids are ubiquitous in both scientific and industrial applications.

Surface charges impart electrostatic stabilization to polymer colloid particles.

Surface-charged polymer colloids are often functionalized in addition to charge groups on the particle surfaces.

Surface-charged polymer colloids are widely used for both scientific and industrial applications.

Introduction

Especially, well-defined, monodisperse surface-charged polymer colloids are widely used as:– Model colloids for basic scientific studies such as crystallization,

self-assembly, colloidal stability / particle interactions, dispersion rheology, packing, etc.

– Calibration standards for electron microscopes, HDC. CHDF, etc.

Surface-charged polymer colloids are quite extensively used for:– Biomedical applications such as diagnostic assays,

immunoassays / cell separation, enzyme immobilization, drug delivery gene therapy, etc.

Introduction(Continue)

Over 10 Million Metric Tons (20 Billion Pounds) of surface-charged polymer colloids are used in industrial applications:– Architectural coatings (Paints): interior and exterior– Paper coatings– Carpet backing: conventional and foam backing– Maintenance and industrial coatings– Textile coatings – Adhesives and Pressure-Sensitive Adhesives– Caulks and Sealants– Inks– Latex foams– Thickeners, etc.

Introduction(Continued)

Current Views on Emulsion Polymerization Mechanisms

Reactions in Aqueous Phase

I2 > 2 I•I• + M > IM•

IM• + (j-1)M > IMj•IMj• + IMj• > IM2jI

(Termination > Water-Soluble Species)IMcrit j•

(Surface-Active)

Entryinto Particle

MicelleFormation

ContinuousPropagation

Current Views on Emulsion Polymerization Mechanisms (Continued)

Entryinto Particle

MicelleFormation

ContinuousPropagation

IMcrit j•(Surface-Active)

IMn•

Entryinto Particle

HomogeneousNucleation

Radical Entryfrom the Aqueous Phase

Reactions in the Particle

Propagation

TerminationTransfer

+ MExit

M

Propagation


Surfactant-Free Emulsion Polymerization– Mainly Homogeneous

Nucleation by the Precipitation of Oligomeric Radicals

– Some Micellar Nucleation In some cases, small amounts of

surfactants will be used for stability.

Conventional Emulsion Polymerization– Mainly Micellar Nucleation

by Monomer-Swollen Micelles

– Some Homogeneous Nucleation

Seeded Emulsion Polymerization– Particle Nucleation Step

Eliminated


Monomer-SwollenMicelles

(5-10 nm)

M

M

M

M

Monomer Droplets(1-10 m)

MM

M

M

M

M

M

M

MM M

M

M

M

M

M M

M

M

M

M

M

MM

MM M

M

M

M

MI2

I2

I2I2

M

Continuous Aqueous Phase

Before Polymerization

M

MM M

MM

MM M

M

M

M

MMMMM

MM M

MM

MM M

M

M

M

MMMM

M

MM M

MM

MM M

M

M

M

MMMM

M

M

: Surfactant

M

M

M

M

Monomer Droplets(1-10 m)

MM

M

M

M

M

M

M

MM M

M

M

M

M

M M

M

M

M

M

M

MM

MM M

M

M

M

MI2

I2

I2I2

M


Interval I: Micellar Particle Nucleation

M

MM M

MM

MM M

M

M

M

MMMM

M

M

MM M

MM

MM M

M

M

M

MMMM

M

Seed ParticleFormation

M

MM M

MM

MM M

M

M

M

MMMM

M

M

M

M

M

Monomer Droplet(1-10 m)

MM

M

M

M

M

M

M

MM M

M

M

M

M

M M

M

M

M

M

M

MM

MM M

M

M

M

MI2

I2

I2I2

M


Interval II: Constant Particle Growth Period

M

M

MM M

MM

MM M

M

M

M

MMMM

M

Seed Particles

M

MM M

MM

MM M

M

M

M

MMMMM

MM M

MM

MM M

M

M

M

MMMM

M

M

M

M

M

M

I2

I2

I2I2


Interval III: Decreasing Monomer Concentrationand Finishing Step

M

M

M

MM

MM

M

M

M

MM

M

M

M

M

M

I2

I2

I2

M

MM

MM

M

M

M

MM

M

M

MM

MM

M

M

M

MM

M

M

MM

MM

M

M

M

MM

M

M

MM

MM

M

M

M

MM

M

M

I2

Anionic Initiators– Persulfate (S2O8

2-) is the most widely used initiator in emulsion polymerization.

– S2O82- > 2 •OSO3

- •OSO3- +

M > •MOSO3- + M > •M2OSO3

- …….. •MjOSO3-

(Surface-active) > Adsorbed onto either monomer-swollen micelles or particles

– Persulfate produces surface-bound sulfate ion groups:

Surface-Charged Polymer Colloids Made with Ionic Initiators

MjOSO3-

In 1970, van den Hul and Vanderhoff* found both sulfate (-OSO3

-)- and hyrdoxyl (-OH)-end groups on persulfate-initiated particles:– •OSO3

- + H2O > •OH + HOSO3-

– Shown by Kolthoff and Miller, especially at low pH’s

– Also, hydrolysis of sulfate-end groups results in hydroxyl groups.

Surface-Charged Polymer Colloids Made with Ionic Initiators (Continued)

* H.J. van den Hul and J.W. Vanderhoff, Br. Polym. J., Vol. 2, 121 (1970).

Schematic Representation of Persulfate-InitiatedPolymer Colloid Particle

H.J. van den Hul and J.W. Vanderhoff, Br. Polym. J., Vol. 2, 121 (1970).

The total number of end-groups was found to be close to two per polymer molecule, when hydroxyl end-groups were added.

In 1965, Matsumoto and Ochi and later in 1970, Kotera, Furusawa, and Takeda studied surfactant-free emulsion polymerizations using potassium persulfate as an initiator.

Then, in 1973, Goodwin, Hearn, Ho, and Ottewill made systematic studies on the effect of various polymerization variables on particle size in surfactant-free emulsion polymerization using potassium persulfate as an initiator:


827.04929

]P[

]M][I[log238.0log

723.1

TD

Persulfate-Initiated Polymer Colloids Leading to Sulfated, Sulfated/Hydroxylated,Hydroxylated, and Carboxylated Polymer Colloids

Persulfate-Initiated Emulsion Polymerization

-OSO

3-

-OSO3-

-OH

-OHHO-

-O3SO-

- O3S

O-HO-

-OSO

3-

-OSO3-

-OSO3

-

-OSO 3--

O3 SO-

-O3SO-

- O3S

O-- O 3

SO-

-OH

-OH

-OH

-OHHO-

HO-H

O-HO-

-CO

O-

-COO-

-COO -

-COO-

-OOC-

-OOC-

- OO

C-- OOC-

High pHsLow pHs

Hydrolysis/OxidationHydrolysis

Hydroxylated Latex Carboxylated Latex

Sulfated/Hydroxylated Latex Sulfated Latex

Hydrolysis

Various anionic Initiator Systems– S2O8

2- + Fe2+ > Fe3+ + •OSO3-

– OSO3- + Fe3+ > Fe2+ + •OSO3

- – S2O8

2- + HSO3- > SO4

2- + •OSO3- + H+ + •SO3

-

– S2O82- + HOCH2SO2

- > SO42- + •OSO3

- + H+ +

•S(CH2OH)O2-

– Also, ter-Butyl Hydroperoxide and Diisopropylbezene Hydroperoxide are used with sodium formaldehyde sulfoxylate (NaHOCH2SO2

-) as a reducing agent at low temperatures.


Cationic Initiators– Azo-bis(isobutyramidine hydrochloride) (AIBA: 2,2’-

azo-bis(2-amidinopropane) dihydrochloride known as V-50 from Wako Chemicals) is widely used as a cationic initiator:


C C

CH3

CH3

N N C

CH3

CH3

C

NH 2

Cl NH 2

- + -

2H+ClN

N H 2

AIBA 2 C C

CH3

CH3

NH2

Cl NH2

- +

N 2+.

Cationic Initiators (Continued)– In 1979, Goodwin, Ottewill, and Pelton made similar

systematic studies on the effect of various polymerization variables on particle size in surfactant-free emulsion polymerization using AIBA as aninitiators:

– Azo-bis(N,N’-dimethylene isobutyramidine hydrochloride) (ADMBA) is also used.


195.02563

]AIBA[

]M][I[log384.0log

833.0

099.1

TD

Anionic Comonomers– In 1976, Juang and Krieger prepared monodisperse sulfonated

latexes by surfactant-free polymerization of styrene with small amounts of sodium styrene sulfonate (NaSS):

– Chonde and Krieger prepared sulfonated latexes by surfactant-free emulsion polymerization of styrene and sodium vinylbenzyl sulfonate (NaVBS) in the water-menthanol mixtures persulfate as

an initiator.

Surface-Charged Polymer Colloids Made with Ionic Comonomers

46.020.0822

64.0

]M[]OSK[]I[

]NaSS[6.16

D

Anionic Comonomers (Continued)– In 1992, Kim, Chainey, El-Aasser, and Vanderhoff studied the kinetics of the

surfactant-free emulsion copolymerization of styrene and NaSS over a wide range of comonomer compositions:

The polymerization rate increased dramatically in the presence of small amounts of NaSS.

This increas was due to the increased number of particles by a homogenous nucleation.

At low NaSS concentrations, monodisperse latexes were obtained. At high NaSS concentrations, broader and bimodal size distributions were

obtained. This was due to significant aqueous phase polymerization of NaSS. The occurrence of this aqueous phase side reaction made the preparation

of highly sulfonated latexes impossible.

Surface-Charged Polymer Colloids Made with Ionic Comonomers (Continued)

Cationic Comonomers– van Streun, Welt, Piet, and German studied the effect of the

amount of 3-(methacrylamidinopropyl) trimethylammonium chloride (MAD) on the emulsion copolymerization of styrene and MAD using AIBA as a cationic initiator:

MAD accelerated the polymerization and decreased the particle size.

– Declair, Maguet, Pichot, and Mandrand prepared amino-functionalized by emulsion copolymerization of styrene and vinylbenzylamine hdrochloride (VBAH) using AIBA:

The use of divinylbenzene (DVB) improved monodispersity.

Surface-Charged Polymer Colloids Made with Ionic Comonomers (Continued)

Carboxylated Latexes– Carboxylated latexes are the most widely used of all commercial

latexes: They were invented in the 1940s. Their benefits were recognized through the incorporation of MAA, AA, IA,

FA, etc. onto the surface of latex particles. Since then, there has been phenomenal success in developing a variety of

commercial carboxylated latexes for various applications. Thus, carboxylated latexes amount to more than 90% of all the commercial

latexes. The distribution of carboxylic groups, on the particle surface, in the

aqueous phase, and inside the particle, was studied extensively in the 1970s and 1980s.

Surface-Charged Polymer Colloids Made with pH-Dependent Ionogenic Comonomers

Carboxylated Latexes (Continued)– The distribution (on surface, in medium, and within particle) of

carboxylic groups depends on: Type of carboxylic monomers in terms of hydrophilicity: MMA <AA < IA

< FA in order of increasing hydrophilicity The degree of neutralization, that is, the degree of ionization Mode of addition: Early or late addition, continuous addition, shot addition,

etc. The use of more water-soluble comonomers, such as MMA, VCN, etc.,

acting as coupling agents Latex particle size: The smaller particle size, the more carboxylic groups on

the particle surface Ionic strength, etc.

Surface-Charged Polymer Colloids Made with pH-Dependent Ionogenic Comonomers (Continued)

The Acid Distribution in the Carboxylated Latexesas a Function of Acid Type and Polymerization pH

Emulsion Polymerization of Nonionic Monomers with Carboxylic Monomers

-CO

OH

-COO-

-COOH

-COOH-OOC-

HOOC-

- OO

C-

HOOC-

High pHsLow pHs

-CO

OH

-COO-

-COOH

-COOH-OOC-

HOOC-

- OO

C-

HOOC-

-CO

OH

-COO-

-COOH-

-COOH-OOC-

HOOC-

- OO

C-

HOOC-

-CO

O-

-COO-

-COO -

-COO-

-OOC-

-OOC-

- OO

C-- OOC-

AA IA and FAMAA MAA, AA, IA and FA

Increasing Hydrophilicity

Acid Distribution inside the Particle

Very LowLowMediumHigh and Uniform

Acid Distribution in the Aqueous Phase

HighHighMediumVery Low

Acid Distribution on the Particle Surface

Very HighHighMediumLow

A Special Class of Carboxylated Latexes: Alkali-Swellable and Soluble Latexes (ASwL’s and ASL’s)– In 1959, Fordyce, Dupre, and Toy invented alkali-soluble latexes.

– In 1966, Muroi established the factors affecting the alkali swelling of carboxylated latexes.

– In 1970, Verbrugge further delineated the properties of alkali-soluble latexes as a function of acid level, backbone hydrophilicity, Tg, molecular weight and crosslinking, etc.

– In 1981, Nishida, El-Aasser, Klein, and Vaderhoff showed that carboxylated latex particles had non-uniform distribution of carboxylic groups: High on the surface and low in the core.


Brief Literature Review of the Alkali-Swelling of Carboxylated Latex Particles

COOHHOOC

COOHHOOC

COOH

COOH

COO-Na+Na+ -OOC

COO-Na+ or NH4+

COO-Na+Na+ -OOC

COO-Na+

H2O

H2OH2O

H2O

H2OAdd Base

Neutralize

The Alkali-Swelling of Carboxylated Latex ParticlesDepends on:

Acid Type and Content (1-3)Polymer Backbone Hydrophilicity (2, 3)

Dissolution Temperature (2) / Polymer Tg (2-3)Molecular Weight (2) / Crosslinking

Degree of Neutralization, pHEtc.

References:

1. D. B. Fordyce, J. Dupre, and W. Toy, Official Digest, 31,

284 (1959).

2. S. Muroi, J. Appl. Polym. Sci., 11, 1963

(1967).

3. C. J. Verbrugge, J. Appl. Polym. Sci., 14,

897 (1970).

A Special Class of Carboxylated Latexes; Alkali-Swellable and Soluble Latexesand Their Swelling Behaviors

Emulsion Polymerization of Nonionic Monomerswith Varying Amounts of Methacrylic Acid at Low pHs

-CO

OH

-COO-

-COOH

-COOH-OOC-

HOOC-- O

OC-

HOOC-

-CO

OH

-COO-

-COOH

-COOH-OOC-

HOOC-

- OO

C-

HOOC-

-CO

OH

-COO-

-COOH

-COOH-OOC-

HOOC-

- OO

C-

HOOC-

Increasing Methacrylic Acid

-CO

O-

-COO-

-COO -

-CO

O-

-OOC-

-OOC-

- OO

C-

- OOC--C

OO

-

-COO-

-COO -

-COO-

-OOC-

-OOC-- O

OC-- OOC-

Neutralization

Unionized carboxylic group

Ionized carboxylic group

Alkali-Soluble LatexAlkali-Swellable LatexConventional Carboxylated Latex

-CO

O -

-COO-

-OO

C-

- OO

C-

- OO

C-

- OOC-

-OOC-

-OO

C- -CO

O-

-COO-

-COO -

-CO

O -

Aminated Latexes– Amine-containing monomers such as dimethyl aminoethyl

methacrylate (DMAEMA), 4-vinylpyridine (VP), etc. can be copolymerized with varous noionic monomers such as styrene, MMA, etc. either by in-situ seeded or seeded emulsion polymerization with either anionic, cationic or nonionic surfactant or by surfactant-free emulsion polymerization using various initiators such as persulfate, azo-bis(isobutyronitrile) (AIBN), and cationic inititiators, depending on the pH of polymerization.


Amphoteric Latexes– Aphoteric latexes can be made by emulsion

copolymerizations of weak acid and weak base monomers with various nonionic monomers either at low pHs or at high pHs.

– Also, amphoteric latexes can be made by emulsion copolymerization of various combinations of cationic monomers and weak acid monomers at low pHs and anionic monomers and weak base monomers at high pHs, with nonionic monomers using appropriate initiators and surfactants.


It is highly desirable to be able to control the placement of functional monomers for designing latexes.

It is generally advantageous to place functional groups on or near the particle surface for various reasons such as colloidal stability, surface functionality, post-reactions, etc.

For this reason, great efforts have been made to maximize the placement of functional monomers.

Special Emulsion Polymerization Techniques for Controlling the Placement of Functional Monomers in

Surface-Charged Polymer Colloids

Some of the Techniques Explored:– Inverted core-shell approaches by Ceska (1974), Lee et al.

(1983), Okubo, Kanaida, and Matsumoto (1987), etc.

– A shot addition by Sakota and Okaya (1976)

– Power feed process to make gradient-composition latexes by Bassett and Hoy (1980, 1981)

– Computer-aided processes of making gradient-composition latexes

– Core-shell approaches

Special Emulsion Polymerization Techniques for Controlling the Placement of Functional Monomers in

Surface-Charged Polymer Colloids (Continued)

Special Emulsion Polymerization Techniques for Controlling the Placement of Functional Monomers in Surface-Charged Polymer

Colloids (Continued)

Inverted Core-Shell Formation D.I Lee and T. Ishikawa, “The Formation of Inverted Core-Shell Latexes”,

J. Polym. Sci., Polym. Chem. Ed., 21, 147 (1983).



M. Okubo, K. Kanaida, and T. Matsumoto, “Preparation of Carboxylated Polymer Emulsion Particlesin Which carboxyl Groups are Predominantly Localized at Surface Layer by Using the Seeded Emulsion

Polymerization Technique”, J. Appl. Polym. Sci., 33, 1511 (1987).

Insi

de

Par

ticl

e

On

Su

rfac

eIn

Ser

umIn

sid

e P

arti

cle

On

Su

rfac

eIn

Ser

um



Functional Monomer Tank



Power Feed Tanks

Power Feed Process

D.R. Bassett and K.L. Hoy, “Nonuniform Emulsion Polymer: Process Description and Polymer Properties”in Bassett, D.R., Hamielec, A.E. (Eds), Emulsion Polymers and Emulsion Polymerization,

ACS Symposium Series 165, Washington, DC, 1981, p. 371-403.

Fitch et al. (1979) prepared polymethy, cyclohexyl, benzyl and -naphtyl acrylate latexes and polymethyl methacrylate latexes snd studied the kinetics of their hydrolysis to form carboxylated latexes.– The acrylate latexes were treated with a mixed bed of

strongly acid and strongly basic ion exchange resins.

– The hydrolysis reactions were measured by conductometric titration.

– Lee et al. (1992, 1996) developed hollow particles by hydrolysis of acrylate cores.

Surface-Charged Polymer Colloidsby Hydrolysis

Lloyd et al. (1962) prepared linear and lightly crosslinked polyvinylbezyl chloride (PVBC) latexes and quaternized them with trimethylamine to form cationic latexes.

Chonde, Liu, and Krieger (1980) prepared a series of latexes with vinylbenzyl chloride (VBC) and carried out nucleophilic displacement of the surface chloride by sulfite ions by reacting them with aqueous sulfite to form anionic sulfonated latexes.

Wessling et al. (1980-1985) prepare cationic latexes by reacting VBC copolymer latexes with tertiary amines.

Kawaguchi et al. (1981) prepared styrene-acrylamide copolymer latex and reacted it with hypochlorite and sodium hydroxide to form amino and carboxyl groups by the Hoffman reaction and competitive hydrolysis of amide groups, respectively.

Ford et al. (1993) prepared monodisperse latexes with styrene (23-98%), VBC (0-75%), DVB (1%), and vinylbenzyl trimethyl ammonium chloride using a cationic initiator and reacted them with trimethylamine.

Surface-Charged Polymer Colloidsby Post-Reactions

Surface Morphology of Charged Polymer Colloid Particles

- Anionic or Cationic Charge Group

Smooth Charged Surface Hairy Charged Surface

Methods of Cleaning In order to remove free and adsorbed surfactants,

water-soluble oligomers and polymers, electrolytes, etc., the following cleaning methods have been used:– Dialysis (Ottewill etal, Fitch et al., etc.)

– Mixed ion exchange (Vanderhoff et al., etc.)

– Continuous hollow dialysis / mixed ion exchange

– Serum replacement (El-Aasser et al., etc.)

– Serum replacement and ion exchange (El-Aasser et al., etc.)

– Ultracentrifugation (Chonde nd Krieger, etc.)

Conductometric titration Potentiometric titration Electrophoresis (Potential Measurement) Turbidometric titration with a cationic surfactant Viscosity Particle swelling Etc.

Characterization

Conductometric Titration

Conductometric Titration ofPersulfate-Initiated Latex

Amount of NaOH Solution Added

Con

duct

ance

Con

duct

ance


Conductometric Titration ofPersulfate-Initiated/Carboxylated Latex

Potentiometric Titration

Conductometric Titration ofPersulfate-Initiated Latex

Conductometric Titration ofPersulfate-Initiated/Carboxylated Latex


pHpH


Electrophoresis - Potential Measurement

0 642 8pH

Zet

a

P

oten

tial

, mv

Zeta Potential of Amphoteric Colloids Vs. pH

U = C()cU

for RCfor RC

10-4 M NaCl

10-3 M NaCl10-2 M NaCl

General Colloidal Propertiesof Surface-Charged Polymer Colloids

Most importantly, surface-charged polymer colloids are electrostatically stabilized by surface charges.

Their colloidal behaviors are strongly affected by the ionic strength of aqueous phase.

Their stability is generally governed by the Schulz-Hardy Rule: The effect of counter-ion valency.

Industrially, surface-charged polymer colloid particles are often combined with nonionic steric stabilizers to achieve electrosteric (both electrostatic/steric) stabilization.

Industrially, they are often modified with a variety of functional groups.

Some Unique Properties of Surface-Charged Polymer Colloids - Iridescence

Monodisperse Polyvinyl Toluene LatexR.M. Fitch, “Polymer Colloids: A Comprehensive Introduction”, Academic Press, New York, 1997.

Some Unique Properties of Surface-Charged Polymer Colloids - Order-Disorder Behaviors

Monodisperse Polymethy Acrylate Latex Showing Three Phases at EquilibriumR.M. Fitch, “Polymer Colloids: A Comprehensive Introduction”, Academic Press, New York, 1997.

Some Unique Properties of Surface-Charged Polymer Colloids - Ordered Packing

Ordered Packing of Monodisperse Polystyrene Latex Particles“An Introduction to Polymer Colloids”, Ed. F. Candau and R.H. Ottewill, Kluwer Academic Publishers, 1990.

Some Unique Properties of Surface-Charged Polymer Colloids - Cell Separation

Latex Particle-AntibodyConjugate

Antibody

CarboxylatedLatex Particle

Carbodiimide Method for Antibody Conjugation (Fitch et al.)

Latex Particle with Antibody Molecules on Surface

Some Unique Properties of Surface-Charged Polymer Colloids- Immunoassay

Antigen-CoatedLatex Particle Antibody

Antigen-CoatedLatex Particle

AgglutinatedLatex Particle

Latex Agglutination

In addition to their use for various scientific studies, surface-charged polymer colloids are widely used in industrial applications such as: – Architectural coatings (Paints): interior and exterior– Paper coatings– Carpet backing: conventional and foam backing– Maintenance and industrial coatings– Textile coatings – Adhesives and Pressure-Sensitive Adhesives– Caulks and Sealants– Inks– Latex foams– Thickeners, etc.

Applications of Surface-ChargedPolymer Colloids

Summary and Conclusions Surface-charged polymer colloids can be prepared to be anionic,

cationic or amphoteric using ionic initiators, ionic comonomers, pH-dependent weak acid and base monomers, hydrolysis or post-reactions.

The placement of charge groups can be effectively controlled by inverted core-shell, shot addition, power feed, computer-aided feed or core-shell approaches.

Smooth and hairy charged surfaces are two extreme particle surface morphologies.

Surface-charged polymer colloids can be cleaned by dialysis, ion exchange, serum replacement or ultracentrifugation, and then subsequently characterized by conductometric and potentiometric titrations, electrophoresis or turbidometry.

Particle surface charges provide electrostatic stabilization. The colloidal properties of surface-charged polymer colloids

are highly affected by the amount and valency of counter ions. Additionally, monodisperse surface-charged particles have

unique properties such as iridescence, order-disorder behaviors, ordered packing, etc.

Surface-charged polymer colloids are widely used in both scientific studies and industrial applications.

The control of surface-charges on polymer colloid particles is one of the most important pillars

for latex technologies.

Summary and Conclusions (Continued)

References For Emulsion Polymerization Mechanisms:

– Gilbert R G, “Emulsion Polymerization: A Mechanistic Approach”, Academic Press, London 1995

For Persulfate-Initiated Latexes:– van den Hul H J, Vanderhoff J W, British Polym. J., 2, 121 (1970).

– van den Hul H J, Vanderhoff J W, in Fitch R M (Ed), Polymer Colloids, Plenum Press, New York 1971, p 1

– Kotera A, Furusawa K, Takeda Y, Kolloid-Z. u. Z. Polymere, 239, 677 (1970)

– Matsumoto T, and Ochi A, Kobunshi-Kagaku (Tokyo), 22, 481 (1965)

– Goodwin J W, Hearn J, Ho C C, Ottewill R H, Br. Polym. J., 5, 347 (1973).

– Goodwin J W, Hearn J, Ho C C, Ottewill R H, Colloid Polym. Sci., 252, 464 (1974).

For Cationic Initiator-driven Latexes:– Goodwin J W, Ottewill R H, Pelton R H, Colloid Polym. Sci., 257, 61 (1979).

For Surfactant-Free Emulsion Polymerization:– Matsumoto T, and Ochi A, Kobunshi-Kagaku (Tokyo), 22, 481 9 1965).

– Kotera A, Furusawa K, Takeda Y, Kolloid-Z. u. Z. Polymere, 239, 677 (1970).

For Acid Distributions in Latexes:– Greene B W, J. Colloid Interface Sci., 43, 449 (1973).

– Greene B W, J. Colloid Interface Sci., 43, 462 (1973).

– Hen J, J. Colloid Interface Sci., 49, 425 (1974).

– Ceska GW, J. Appl. Polym. Sci., 18, 427 (1974).

– Ceska G W, J. Appl. Polym. Sci., 18, 2493 (1974).

– Vijayendran B R, J. Appl. Polym. Sci., 23, 893 (1979).

References (Continued)

For Controlled Placement of Functional Groups:– Ceska G W, J. Appl. Polym. Sci., 18, 2493 91974).– Okubo M, Kanaida K, Matsumoto T, J. Appl. Polym. Sci., 33, 1511 (1987).– Lee D I, Ishikawa T, J. Polym. Sci., Polym. Chem. Ed., 21, 147 (1983).– Muroi S, Hoshimoto H, Hosoi K, J. Polym. Sci., Polym. Chem. Ed., 22, 1365 (1984).– Cho I, Lee K W, J. Appl. Polym. Sci., 30, 1903 (1985).– Lee D I, Kawamura T, Stevens E F, in El-Aasser M S, Fitch R M (Eds), Future Directions in Polymer Colloids, NATO

ASI Series, Series E: Applied Sciences - No. 138, Martinus Nijhoff, Dordrecht 1987, p 47– Hoy K L, J. Coat. Technol., 51 (651), 27 (1979).– Bassett D R, Hoy K L, in Bassett D R, Hamielec A E (Eds), Emulsion Polymers and Emulsion Polymerization, ACS

Symposium Series 165, Washington DC 1981, p 371

For Alkali-Swelling of Carboxylated Latexes:– Fordyce D B, Dupre D, Toy W, Ind. Eng. Chem., 51, 115 (1959).– 70 Fordyce D B, Dupre D, Toy W, Off. Dig. Fed. Soc. Paint Technol., 31, 284 (1959).– 71 Muroi S, J. Appl. Polym. Sci., 10, 713 (1966).– 72 Muroi S, Hosoi K, Ishikawa T, J. Appl. Polym. Sci., 11, 163 (1967).– 73 Verbrugge C J, J. Appl. Polym. Sci., 14, 897 (1970).– 74 Verbrugge C J, J. Appl. Polym. Sci., 14, 911 (1970).– 75 Nishida S, El-Aasser M S, Klein A, Vanderhoff J W, in Bassett D R, Hamielec A E (Eds), Emulsion

Polymers and Emulsion Polymerization, ACS Symposium Series 165, ACS, Washington, DC 1981, p 29.

References (Continued) For Hydrolysis and Post-reactions:

– Lloyd W G, Vitkuske J F, J. Appl. Polym. Sci., 6(24), S56 (1962).– Lloyd W G, Durocher T E, J. Polym. Sci., 7, 2025 (1963).– Lloyd W G, Durocher T E, J. Polym. Sci., 8, 953 (1964).– Chonde Y, Liu L-J, Krieger I M, J. Applied Polym. Sci., 25, 2407 (1980).– Wessling R A, Yats L D, Meyer V E, Organic Coatings Plast. Chem., 42, 156 (1980).– Wessling R A, in Poehlein G W, Ottewill R H, Goodwin J W. (Eds), Science and Technology of Polymer Colloids, Vol. II, Martinus Nijhoff Pub, The

Hague, The Netherlands 1983, p 393– Wessling R A, Yats L D, Makromol. Chem., Suppl., 10/11, 319 (1985).– Kawaguchi H, Hoshino H, Ohtsuka Y, J. Appl. Polym. Sci., 26, 2015 (1981).

For Latex Cleaning:– Ottewill R H, Shaw J N, Kolloid-Z. u. Z. Polymere, 218, 34 (1967).– Shaw J N, Marshall M C, J. Polym. Sci., Part A1, 6, 449 (1968).– van den Hul H J, Vanderhoff J W, J. Colloid Interface Sci. 1968, 28, 336 (1968).– Vanderhoff J W, van den Hul H J, Tausk R J M, Overbeek J Th G, in Goldfinger G (Ed), Clean Surfaces: Their Preparation and Characterization for

Interfacial Studies, Marcel Dekker, New York 1970, p 15– El-Aasser M S, in Poehlein G W, Ottewill R H, Goodwin J W. (Eds), Science and Technology of Polymer Colloids, Vol. II, Martinus Nijhoff Pub, The

Hague, The Netherlands 1983, p 422– Ahmed S M, El-Aasser M S, Pauli G H, Poehlein G W, Vanderhoff, J W, J. Colloid Interface Sci., 73, 388 (1980).– Labib M E, Robertson A A, J. Colloid Interface Sci., 67, 543 (1978).– Labib M E, Robertson A A, J. Colloid Interface Sci., 77, 151 (1980).– Wilkinson M C, Hearn J, Cope P, Chaney M, British Polymer J., 13, 82 (1981).– Chonde Y, Krieger I M, J. Colloid Interface Sci., 77, 138 (1980).– Fitch R M, Polymer Colloids: A Comprehensive Introduction, Academic Press, New York 1997, p 132-133

References (Continued) For Characterization:

– van den Hul H J, Vanderhoff J W, J. Colloid Interface Sci., 28, 336 (1968).– van den Hul H J, Vanderhoff J W, British Polym. J., 2, 121 (1970).– Vanderhoff J W, van den Hul H J, Tausk R J M, Overbeek J Th G, in Goldfinger G (Ed), Clean Surfaces: Their Preparation and Characterization

for Interfacial Studies, Marcel Dekker, New York 1970, p 15– van den Hul H J, Vanderhoff J W, in Fitch R M (Ed), Polymer Colloids, Plenum Press, New York 1971, p 1– Ottewill R H, Shaw J N, Kolloid-Z. u. Z. Polymere, 218, 34 (1967).– Kotera A, Furusawa K, Takeda Y, Kolloid-Z. u. Z. Polymere, 239, 677 (1970).– Saxton R, Daniel Jr K H, J. Appl. Polym. Sci., 8, 325 (1964).– Fitch R M, Polymer Colloids: A Comprehensive Introduction, Academic Press, New York 1997, p 148-149– Krieger I M, Eguiluz M, Trans. Soc. Rheol., 20, 29 (1976).– Buscall R, Goodwin J W, Hawkins M W, Ottewill R H, J. Chem. Soc. Faraday Trans. I, 78, 2873 (1982).– Bergenholtz J, Willenbacher N, Wagner N J, Morrison B, van den Ende D, Mellema J J, Colloid Interface Sci., 202, 430 (1998).– Hoy K L, J. Coat. Technol., 51 (651), 27 (1979).– Bassett D R, Hoy K L, in Bassett D R, Hamielec A E (Eds), Emulsion Polymers and Emulsion Polymerization, ACS Symposium Series 165,

Washington DC 1981, p 371– Ottewill R H, in El-Aasser M S, R. Fitch M (Eds), Future Directions in Polymer Colloids, NATO ASI Series, Series E: Applied Sciences - No.

138, Martinus Nijhoff, Dordrecht 1987, p 253– Ottewill R H, in Candau F, Ottewill R H (Ed), Scientific Methods for the Study of Polymer Colloids and Their Applications, NATO ASI Series,

Series C: 303, Kluwer Academic, Dordrecht 1990, p 349– Fitch R M, Polymer Colloids: A Comprehensive Introduction, Academic Press, New York 1997, p 120-128– Fitch R M, Su L-S, Tsaur S-L, in Candau F, Ottewill R H (Ed), Scientific Methods for the Study of Polymer Colloids and Their Applications,

NATO ASI Series, Series C: 303, Kluwer Academic, Dordrecht 1990, p 373– Banthia A K, Mandal B M, Palit S R, J. Polym. Sci., Polym. Chem. Ed., 15, 945 (1977).

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