A METHOD OF
E'MULSIFYING OILS \I’ITH DIFFERENT
EIVIUISIFIERS

TILES-SI IUII ’I‘IIE IIIGIIIII Ir‘ IIS
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A METHOD
of
EMULSIFYING OILS WITH DIFFERENT EMULSIFIERS

A Thesis Submitted to the Faculty
of
Michigan State College

In Partial Fulfillment of the
Requirements for the Degree
of

Master of Science

7337

G. C. Applebee
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I wish to take this means of eXpressing
my appreciation to Dr. D. T. Ewing, whose
supervision and counsel brought about the

attainment of this thesis.

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Contents

Introduction

Experimental

Apparatus

Procedure

Results

Discussion

Summary

14

17

Introduction

In this thesis, the object is to present
a general method of emulsifying all types of
oil. It is true, that the emulsification of
each oil is an individual problem and by prac-
tics and patience this general method can be
improved upon giving greater stability for
that particular oil.

“An emulsion is a system containing two
liquid phases one of which is dispersed in the
other." Hatscheks Foundation of Colloidial
Chemistry. Holmes states that “Emulsions are
dispersions of minute drOps of one liquid in
another."

From the standpoint of emulsifying oils
in water we can say an emulsion can be de-
scribed as the combination of the desirable
prOperties of both 011 and water. In order
to obtain this combination a third and fourth
material is added which will be called an
emulsifier. In the course of experimentation,
glue, rosin, skimmed milk, cocoanut oil plus

arabic gum, cotton seed oil with arabic gum,

oelic acid with arabic gum, in all cases
emulsions were formed but their stability
varied.

The emulsifier has a two—fold purpose.
(a) the forming of an emulsion.
(b) to give stability.
An excellent way of determining the type of
emulsion devised by Briggs J Physical Chem-
istry 18-34 (1914) stated briefly-~If a film
of an emulsion of oil and water be examined
under a microscOpe, a liquid medium will be
formed and suspended in that medium small
drOplets of the second will be found. If
the medium is oil and the drOplets are water,
it would be a water in oil emulsion. If the
medium is water and the dr0plets are oil, it
would be an oil in water emulsion. An oil in
water emulsion can be readily diluted with
water, while a‘water in oil type can only be
diluted with 011. However, one can be changed
into the other by the addition of .8 grams of
Damar Gum to each liter of the emulsion.

The properties of an emulsifier are of a

two-fold nature:

(a) the drape shall be so small that they will
remain suspended. I

(b) a viscous film or coating should encase
each drop to prevent coalescence.

In order to secure a fine division of
the dispersed liquid homogenizing as well as
mechanical agitation is required during the
preparation of the emulsion.

Clowes J Phys. Chem.--20-403 (1916) states
that an acid or a salt of a fatty acid added
for the following reasons

1. To lower the surface tension so that
the fine spherical dr0ps will be easily formed
and will have a small tendency to recombine.

2. A film is provided around each drOp
and this film separates each particle from the
other, preventing coalescing.

The substances used in this process are
four in number.

(1) The oil to be emulsified

(2) Water

(3) Oelic Acid

(4) Arabic Gum

The oelic acid used is an ordinary C.P.

product.

 

 

 

 

 

 

 

 

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The arabic gum was of the C.P. grade and
always before using "degreased" by grinding in
ethyl alcohol for five minutes, then grinding
in petroleum ether. Krantz and Gordon Colloid
Symposium Monograph found that petroleum ether
treatment of the gum increases the stability.

For the emulsification of vegetable oils
that would be used for food products, cotton
seed or cocoanut oil with Arabic gum, using
ethyl alcohol alone as the degreaser was sub-

stituted.
Experimental

Apparatus-

In the homogenizer (Fig. l), A and B
are one-quart milk bottles while C is a two-
quart milk bottle, glass tubing fused on to a
stop cock connected to bottles A and B. In
the same manner B is connected to the two-
quart milk bottle C. The bottle C is then con-
nected by rubber tubing to the vacuum pump. 0
is drawn to a fine capillary tube. It was found
to be advantageous to have the capillary tube
removable from E. Small particles of arabic

gum often lodge in the fine capillary and more

difficult to remove if tube E is constructed in

a single unit.
Procedure

The emulsion was poured in the reservoir
A, stop cook (a) being closed; then the stOp
cock was Opened and bottle B was evacuated as
much as possible. Then stop cock (a) was Opened
and the emulsion will pass through. When bottle
A was empty, valve (b) was closed and A and B
was interchanged, then repeated.

The purpose of the capillary tube is two-
fold:
(a) The small capillary reduces the size of
the globules.
(b) The globules in turn are hurled against
the sides of the flask. This seems to aid in
emulsification.

An ordinary drink mixer can be used for
an agitator. An improvement can be made to a
great advantage by using two thin discs with
four radii cuts turned up in prOpellor fashion.
One of these discs was placed on the end of
the stirrer and the second disc placed three
inches above the first.

Bancroft (Applied Colloid P. 357 Second
Edition) calls this method the “Soap Method."

It can be used to emulsify the majority of min-
eral and vegetable oils. With this method all
of the oils used did not show a separation
within two days. Furthermore dilution with
water withstood separation.

In general, the composition of the emulsion
studied was as follows:

85 parts of oil (by weight)

10 parts of C.P. Oelic Acid (by weight)

5 cc of "Degreased" Arabic Gum.

This method of forming the emulsion was
always used:

Place in the agitator 18 parts of the oil
and the 5 cc of arabic gum and agitate for 5
minutes or until thoroughly ground together.

The oelic acid was added and agitated un-
til thoroughly mixed, then the remainder of the
oil was added in three equal parts during the
10 minutes of agitation.

It was run through the homogenizer twice.

There was placed an equal amount of hot
water in the agitator, and while agitating,
the prepared oils were poured in small amounts
during the process of agitation. The emulsion
should be creamy white.

It was run through the homogenizer twice

and agitated for five minutes.

For Vegetable Oils

The following method proved to give
greater stability when either cotton seed or
cocoanut oil was substituted for the oelic
acid. Either cocoanut oil or cotton seed
oil was used for food products, while oelic
acid would not be suitable on account of the
taste as well as the toxicity effect.

The composition of the product to be
emulsified was:

85 parts of oil

9 parts of cottonseed oil

10 cc of arabic gum

or

83 parts of oil

12 parts of cocoanut oil

10 cc of arabic gum
In container No. l was placed:

Cotton seed or cocoanut oil

5 cc of gum
In container No. 2 was placed:

011

5 cc of gum

Each container was agitated three minutes

three different stirrings (intermittent stir-

ring). The contents of each container were
poured into an equal volume of hot water under
agitation, small amounts of one and then the
other were added. Time of stirring, 10 min-
Iutes. It was homogenized twice, then stirred
5 minutes.

The gum solution was, for mineral oils,
prepared in the following manner:

25 grams of finely arabic gum were
weighed out, 10 cc of Ipt'eltwleum ether and 20
cc of benzene'was added; agitated for five
minutes. This formula could be made in any
amounts provided the same proportions were
used.

For Foods Products.

20 grams of powdered arabic gum was weighed
out and was agitated five minutes with 30 cc of
pure ethyl alcohol. I

In both cases gum was always shaken before
using and was added during the process of agi-

tation.

011 Phase

Oil

85 parts

Oelic acid 10 parts

Gum

9;;
Castor
Chinawood.
Cocoanut

Corn

Lemon grass

Lemon
Olive
Peanut
Cottonseed
Peppermint
Soy bean
Turpentine
Kerosene
Juniper

(Cheap)
Linseed

Oelien
Neetsfoot
Paraffin

5 parts

Viscosity

 

same
same
heavier
heavier
same
same
heavier
same
heavier
same
same
same
same

same

same
same
same

same

Table I

011 phase

70%

Water phase 30%

Color Stability, Remarks..

white
white
white
white
green
white
white
cream
white
cream
white
white
white
white

yellow

coffee

cream

white

2

Ca (3 (fl QR 09 F4 I“ #7 0a [U

u
6
a

days
days
weeks
weeks
week
week
weeks
weeks
weeks
weeks
weeks
weeks
weeks

weeks

weeks
week
weeks

weeks

slight

very slight at
separation

no separation

slight

slight

slight

no separation

slight

no separation

slight

slight

slight

slight

slight

slight
partial separation
slight

very slight

 

_Qil_ Viscosity
Petrol same
Petrolatum same
Scale same
Verdol same
Sesame same
Sperm same
Stymax same
Engine same
Raw linseed same
Boiled
linseed same

Linalool same
Rape seed same
Turkey Red same
Creosite same
Polarine same
Petroleum same
Benz

aldehyde same
Lanolin heavier

Color

white
white
cream
cream
white
white
white

yellow

cream

cream
white
cream

brown

Stability

8
8
6
6

1
1
3
3
3

3

weeks
weeks
weeks
weeks
week

week

weeks
weeks

weeks

weeks

10

Remarks

very slight

no separation

very slight
very slight
complete

complete

very slight
very slight
very slight

none

36-48 hrs.complete
48 hrs.
48 hrs.

red-brown 1 week

cream

white

white

cream

3
3

3
2

weeks

weeks

weeks

weeks

complete
complete
slight

very slight
very slight

none

none

Table II
The Effect of Dilution

Oelic gum process

 

Time of
Q11 320 Stability
$90 parts 10 parts 8 weeks
66 parts 34 parts 8 weeks
Olive
33 parts 67 parts 8 weeks
5 parts 95 parts 7 weeks
90 parts 10 parts 6 weeks
66 parts 34 parts 6 weeks
Scale

oil 33 parts 67 parts 5 weeks
5 parts 95 parts 5 weeks
90 parts 10 parts 8 weeks
66 parts 34 parts 8 weeks

Pepper-
mint 33 parts 67 parts 8 weeks
5 parts 95 parts 8 weeks
90 parts 10 parts 8 weeks
66 parts 34 parts 8 weeks

Cocoanut
33 parts 67 parts 7 weeks
5 parts 95 parts 6 weeks

11

no separation
no separation
no separation
very slight
no separation
no separation
very slight
very slight
slight

slight

no separation
no separation
no separation
no separation

slight

(slight

12

Table III

011 85 parts
Cottonseed oil 10 parts

Oil phase 70%
Water phase 3Q%~

 

Arabic gum 5 parts
Separation

Oi Viscosity Color in

Corn heavier white 1 week

Cocoanut heavier white 4 weeks

Cottonseed plastic white

Olive heavier white 4 weeks

Peanut heavier creamy 4 weeks

Castor heavier creamy 24 hours slight

Peppermint heavier creamy 3 weeks

Soy bean plastic creamy 3 weeks

Paraffin same white 48 hours slight

Sperm same white 10 hours slight

Stymax same white 5 days slight

Scale same tan 24 hours complete

Verdol same creamy 10 hours complete

Corn heavier white 8 days

Castor heavier white 12-24 hrs.

Cottonseed plastic white 3+weeks agitation
emulsified again

Olive heavier white 3~Weeks agitation
emulsified again

Peanut heavier creamy 3 weeks agitation
emulsified again

Peppermint heavier creamy 3 weeks agitation

emulsified again

9;;

Soy bean
Paraffin
Sperm
Stymax
Scale

Renown
Engine

W
plastic
same
same
same

same

same

9212:.
creamy
white
white
white

tan

yellow

13

Separation
in

3 weeks agitation
emulsified again
48—60 hours

24 hours
6 days
10 hours

2 hours

14

Discussion

Colloidial theory indicates that in general
any type of oily material, insoluble in water
and that can be liquified under 100° C can be
emulsified. In this work approximately thirty dif-
ferent oils were chosen at random and fair results
were obtained. Castor, oelien, sesame, china wood
had a life of about 48 hours while others remained
free from separation for 8 to 10 weeks. In no case
was the separation so marked that it could not be
returned to the same creamy emulsion by a hand shak-
ing of one or two minutes. Separation would not
take place again for about 48 hours. These emul—
sions were heated to 8 70Land dropped to “3°C—
without any marked separation, that could not be
removed by simply shaking by hand one or two min-
utes.

As previously stated, each oil is a special case
and it is merely a problem of securing the correct
ratio between the oelic acid, arabic gum and the
oil to be emulsified. The same is probably true
with the mineral oils with the use of either cot-
ton seed or cocoanut oil as the emulsifier. The
correct ratio between cotton seed oil and the oil

to be emulsified was not determined. In the case

15

of the vegetable oils, the ratio was more nearly
correct and the emulsions were far more stable.

The various other single emulsifiers used
evidently required a second emulsifier for a suc-
cessful emulsion. Glue, rosin, skimmed milk acting
as a single emulsifier produced only one or two
semi-permanent emulsions out of a group of thirty
oils.

If a poorly made emulsion is allowed to stand,
separation takes place almost immediately. An emul-
sion can be made using the correct ratio of oil
and emulsifier, this same emulsion in a container
containing a film of grease will break almost im-
mediately. Bancroft (Applied Colloid Chemistry,
Page 352) states "when free 011 comes in contact
with the film around the oil drops it tends to
make it bend in the Opposite direction, thereby
cracking the emulsion." Grease in this case seemed
to act the same way, that is, the grease destroyed
the film, which in turn destroyed the emulsion.

All containers in this work were cleaned by
boiling with dilute caustic soda and then rinsing
with hot distilled water.

The method of diluting emulsions is important.
The required amount of hot water should be added

gradually to the emulsion under agitation. The

16

time of agitation should be about fifteen minutes;
after the water has been added allow to agitate
five minutes longer.

If gum is ground with alcohol the water will
wet it immediately, while water alone fails to
peptize it. Benzene, ether or any organic liquid
with a low vaporization point can be substituted
for the alcohol.

The action of the alcohol upon the gum is to
remove the grease or foreign substances that encase

the particles of gum.

17

Summary

A permanent emulsion (48 hours or longer)
could not be made by using inorganic metallic
salts as emulsifiers.

Powdered iron, aluminum, magnesium were used
as emulsifiers; a heavy plastic mass was formed
which separated in a few hours.

Technique plays a very important part, es-

’ pecially intermittent stirring, also vessels free
from grease are as important as the emulsifiers
themselves.

Future experimental work with this method
will be carried on in the following fields:

(a) Acid Emulsions-~such as nitro benzene with

sulphuric acid.

(b) Emulsions of waxes and semi-solids.

(0) Pharmaceutical emulsions.

(d) Soluble Oils.

 

 

 

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