Studies on the Detergent Properties of Amylolytic Enzymes and Of Sodium Oleate and Sodium Lauryl Sulfate

Citation preview

DOCTORAL DISSERTATION SERIES

SludieS on fye Detergent Properties of Amijlohjtic Eniymts dnd ofSodium OloAe.

TITLE

tind Sodium JLdlirifl S u lfd it lilid n lin d d A re n t ^Dec.194-2 UNIVERSITY. Thmsylvdnid Stdte College

AUTHOR

DEGREE

.M

-

PUBLICATION NO.

^

UNIVERSITY MICROFILMS

^

A N N ARBOR

.

MICHIGAN

The Pennsylvania State College The Graduate School Department of Chemistry

STUDIES ON THE DETERGENT PROPERTIES OF AMYLOLYTIC ENZYMES AND OF SODIUM OLEATE AND SODIUM LAURYL SULFATE

A Dissertation by Lilian Linda Arent

Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Chemistry

December, 194-2

Approved;

---- -

Head of Department Approved Professor of Textile Cl^m.srtry Date:

Throughout the several years that the experimental work has‘been underway, the author has become indebted to the following people to whom she wishes to express her appreciation and grateful­ ness: To Dr. Pauline Beery Mack for suggesting the problem and for her efforts in checking the logic of the conclusions drawn from the data and the written presentation of the problem; To Dr.

Fred Oesterling for supplying the soiled fab--

rics and the carbon black; also for his suggestions on techniques for certain of the physical tests: To Dr. Esther H. Chapman, Betty L. Fletcher, and Ruth M. Howorth for their invaluable assistance in performing some of the amylolytic enzyme treatments; To Dorothy M. Farris, Barbara K. Webster, and Ruth B. Warner for assistance in calculating and cheeking some of the enzyme data; To W. L. Shetier and H. W. Trapp for the design and con­ struction of the turbidimeter used, and for their helpful suggestions about graphical presentation of data; To T. D. Decker for

the construction of the turbidimeter;

To J. M. Wagner for

the construction of contrivances which

greatly simplified the ensyme treatment procedures?

and

To Edgar W. Clarke, Jr., for his constant encouragement, assistance, and advice without which the problem would not have been completed.

T A B L E

0 F

C O M T E K

TSPage

General Introduction

1

PART I Introduction to Part I, Studies on an Amylolytic Enzyme

3

Method of Procedure

7

Standard Soiled Fabrics

7

Enzyme

7

Starch

8

Preparation of the Buffers

*'

8

Diagrammatic Plan of the Study

10

Enzyme Treatment of Standard Soiled Fabrics

13

Physical Tests

16

Wetting Time of Carbon Black

19

Instantaneous Dispersion

20

Deflocculation

21

Determination of the Amount of carbon in Suspension

22

Presentation of Data

36

Soil Removal Efficiency

39

Physical Tests

54

Discussion

63

Amylolytic Enzyme Treatment of Starched and Unstarched Soiled Fabrics

63

Relationship of pH to Soil Removal

63

Relationship of Time to Soil Removal

70

Table of Contents (Continued)

Page

Relationship

of Temperature to

Relationship

of Enzyme to

Soil Removal

72

Relationship

of Starch to

Soil Removal

73

Relationship of Number of Soil Removal

Soil Removal

Treatments to

Interfacial Tension

75 77

Relationship of pH to Interfacial Tension

77

Relationship of Temperature to Interfacial Tension

79

Relationship of Presence of Starch to Interfacial Tension

79

Relationship of Presence of Enzyme to Interfacial Tension

80

Relationship of Soil Removal to Interfacial Tension

80

Instantaneous Dispersion and Deflocculation

82

Relationship of pH to Instantaneous Dis­ persion and Deflocculation

82

Relationship of the Presence of Enzyme to Instantaneous Dispersion and Defloccu­ lation

84.

Relationship of Starch to Instantaneous Dispersion and Deflocculation

85

Relationship of Soil Removal to Instantaneous Dispersion and Deflocculation

85

Wetting Time of Carbon Black by Enzymes Summary

71

86 87

Table of Contents (Continued)

PART

II. Page

Introduction to Part II, Studies on Sodium Lauryl Sulfate

89

Method of Procedure

91

Soil Removal and Whiteness Retention Determinations

91

Preparation of Solutions for Physical Tests

92

Physical Test Determinations

93

Interfacial Tension

93

Wetting Time of Carbon Black, Instantane­ ous Dispersion and Deflocculation

94-

Presentation of Data

97

Soil Removal

100

Physical Tests

104-

Discussion

120

Summary

126

Bibliography

127

G E N

ER A L

I N T R O D U C T I O N

Any substance which removes soil from a soiled fabric may be classified as a detergent; as a consequence of this broad defini­ tion, substances which are widely different, chemically, may come under the category of detergents. The long chain fatty acid sodium and potassium salts, or the common soaps, and the high mole colar weight sulfated alcohols have oil—water polarity as a common characteristic, and hence they emulsify oil particles and release and suspend the soil bound to the soiled fabric by the oil.

The manner in which this is accomplished

is probably quite analagous for these two types of detergents. In direct contrast to the common soaps and polar compounds of the long-chain sulfated alcohol type are the amylolytic enzymes, the chief function of which is the hydrolysis of starch.

If the

enzymes are allowed to react on starched soiled fabrics, however, it will be found

that the enzymes effectuate the removal of starch from

the fabric and concomittantly of some soil,

'^he method by which this

is accomplished, however, Is undoubtedly quite different from the manner in which the soaps and the gardinols remove soil from a soiled fabric.

Nevertheless, different though the chemical structure and the

soil-removal mechanism of these two types of substances may be, they accomplish the same end purpose - that of soil removal, and’hence both types are detergents .

From previous work by Arent, the author of* this report (1 ) , it was indicated that long-chain polar molecules of the sodium oleate ar>d sodium lauryl sulfate types have a wetting effect upon textile fabric, that they lower the tension of an oil—water interface, and that furthermore they hold up soil

particles in solution.

Hence,

they serve not only to wet a textile fabric and to remove oily soil from its surface, but also to assist in holding the removed soil in suspension until it can be flushed away during the washing process. Moreover, previous work by Arent has likewise indicated amylolytic enzymes have some small soil removal value at pH 7, and that the mechanism of its soil removal activity was worthy of further study. The work upon which the present report is based was there­ fore undertaken in order to find additional data concerning the mechanism of detex'gency in an aqueous medium with the two different types of detergents mentioned - namely, amylolytic enzymes, and long carbon chain compounds of which sodium oleate and sodium lauryl sul­ fate (gardinol) have been chosen as examples.

3 I N T R O D U C T I O N S T U D I E S

0 N

A U

T 0

P A R T

A M Y L O L T I C

I E N Z Y M E

Although amylolytic enzymes serve very special functions in the textile industry and are used consistently for desizing tex­ tile fabrics, particularly for dyeing, they have never found widespread use in the laundry Industry of this country; yet the majority of cotton clothes are starched, and in some laundries, excessive amounts of chlorine bleach — deterimental to the fabrics themselves - are used in its removal.

Therefore, it was interesting to continue the study

of conditions which are necessary for the removal of soil from starched soil fabrics by amylolytic enzymes, begun by Keeney and con­ tinued by Phillips in this laboratory, and subsequently worked upon by Arent. Phillips (lo) found that the amount of soil removed from starched standard soiled fabrics was not always proportional to the enzyme concentration used; however, his enzyme solutions were not buffered at a constant pH value.

In the study by Arent (l ), it was

found that, if the sheep pancreatic enzyme which vras used, was bufferec at pH 7, the amount of soil and starch removed from the starched standard soiled fabrics was definitely a function of the concentra­ tion of enzyme used* On the other hand, almost all laundry operations are

carried out under more alkaline conditions than pH 7; therefore the present study has included the determination of the degree of alkalinity of the solutions containing the enzyme which would still allow the enzyme to function in its starch- and soil-removing capac­ ity. -

Good soil removal efficiency is ordinarily obtained for

cotton fabrics at pH 11.

This pH value usually does not favor enzyme

activity, however, and yet the question of whether soil could be re­ moved from starched soiled fabrics under conditions where the starch probably would not be removed remained to be answered. It was found in the previous study by Arent (1 ), that, at constant pH 7,

if the starch coating was not removed, there was

likewise no soil removed? however, a pH value of seven is not partic­ ularly favorable to removal of soil from cotton fabrics.

This poses

a question, then, as to whether or not enzymes of an amylolytic type can be made practical in laundry operations, since the best conditions for enzyme activity are found at pH 7, and that for soil removal at pH 11. There was also the question of what would happen to the starched soiled fabrics in acid solutions, where one customarily ex­ pects hydrolysis of starch.

Would there be sufficient hydrolysis of

the starch to free the underlying soil in acid strengths which v/ould not appreciably hydrolyse the fabric also? In the previous study under discussion, three temperatures were compared with respect to enzyme activity - namely, 22 - 27° C.,

38 - 4-3° C.» and 54. - 60° C.

It was rather surprising to find in

tliis study that the lowest temperature studied — namely, 22 - 27° C., favored the activity of the enzyme more than the medium temperature of 38 - 4-3°- C.

The latter temperature Includes, but also exceeds in

value the average body temperature of sheep, which is 39 - 40° C. (ll) j consequently, for the present study, the temperature of the mediumtemperature treatment was lowered by three degrees, so as to include but not exceed the average body temperature of the sheep.

This was

done in an effort to determine whether or not, under these new condi­ tions, the lower temperature still favored greater soil removal efficiency by the enzymes. Becs.use the one-half and one per cent, enzyme solutions showed only slight soil removal efficiency In comparison with the three per cent, enzyme solutions in the constant pH study, it was decided not to include the smaller per cent, enzyme solutions in the present study. The data from certain physical and chemical properties of detergents, such as the lowering of interfacial tension, the in­ stantaneous and long-time suspension of

carbon particles, and the

length of time required to wet all of the carbon particles have been used in recent years to interpret the soil removal efficiency data of detergents.

These properties were not determined in the constant

pH study previously cited.

It is proposed in the present study to

find the relationship between these aforementioned properties and the soil removal efficiency of the enzymes, if such a relationship

6

exists. In the present studyp therefore, soil removal efficiency and response to certain physical tests were made under the following sets of conditions: (1)

At five different pH values;

(2)

At three temperature ranges; and

(3)

At one concentration of enzyme, with a control series in which no enzymes were contained.

7 M E T H O D

0 F

P R O C E D U R E

STANDARD SOILED FABRICS Standard soiled fabrics prepared by the method of Mack and Qesterling (9 ) were used, in these tests.

Standard soiled

fabrics of convenient size for handling in the practical detergency trials and for ascertaining light reflectancy were cut and hemmed to avoid ravelling.

They ranged in weight from 7.60 to 7.77 grams. ENZYME

A commercial preparation of sheep pancreatic amylolytic ft

enzyme, known as Rohm and Haas EnzymolinL, was used in these tests. The pH value for optimum enzyme activity, as commercially described, was the pH value of 7. A weight of enzyme equivalent to three per cent, of the average weight of each series of the test fabrics was used in each trial.

This was made up to a 200 c.c. volume with distilled water in

a volumetric flask.

Of this 200 c.c. of solution, 10 c.c. aliquots

were added to the beakers containing the buffer solutions for treatment of the standard soiled fabrics.

An aliquot of 10 c.c., contained

0.228 grams of enzyme, which is equivalent to three pex* cent, of the weight of standard soiled fabrics used at the lower and the higher temperature series.

For the 36 - 4-0° C. tests, a 10 c.c. aliquot con­

tained 0.2331 grams of enzyme in order to be equivalent to three per cent, of the average weight of the standard soiled fabric used at this temperature.

8 It is a well known fact that the potency of enzymes decrease rapidly upon standing in water solutions ( 12) ; therefore the solutions were made up and the enzyme treatments begun within a period of five to ten minutes.

■STARCH A suspension of 67.5 grams of Argo corn starch in 150 ce. of cold water was made and added to seven and a half liters of boiling water contained in a large copper dye vat.

The suspension

was boiled one-half hour, diluted to nine liters and again brought to a boil. This hot solution of starch was used to starch thirty soiled fabrics at once.

This was accomplished by pinning the fab­

rics with safety pins between two horizontally parallel clotheslines which could be lowered and raised by means of a pulley system. Simul­ taneously, all of the soiled fabrics to be starched were lowered into the starch solution, which was at a temperature between 90 — 95°C., and were allowed to stay 15-20 seconds fully submerged in the hot starch solution.

They were then simultaneously withdrawn from the

hot starch solution.

The starched fabrics were immediately separated

and dried before treatment with the buffered enzyme solutions. PREPARATION OF THE BUFFERS * Fifth molar solutions of orthophosphoric acid and of the di— , mono— , and trisodium phosphates were used in preparing the solutions

9 of different pH values.

Actually, the di— and the trisodium phosphates

were saturated solutions in equilibrium with a small amount of the solid undissolved salt, which always settled to the bottom of the car­ boys.

After each preparation of a new carboy lot, the ratios of the

phosphates necessary to obtain pH values of 4-.1, 5.5, 7.0, 8.4-, and 11.0 +_ 0.15 were redetermined.

This was done with a Leeds and Northrup

glass electrode potentiometer, Number 7660. Throughout the course of the experimental work, it was found that the ratio of the phosphates necessary to obtain these aforementioned pH values was not constant.

The average number of cc.

of phosphate solutions needed to make up 300 cc. of undiluted M/5 buffer mixture for the respective pH values was: pH

4.1

4.5 cc. H3PO4/

295.5 cc. NaH2P0^

pH

5.5

6.6 cc. Na2HP0^/ 293.4 cc.

NaH2P0^

pH

7.0

149.4 cc. Na2HP0^/ 150.6 cc.

NaH2P0/+

pH

8.4

3.6 cc. NaHpPO^/ 296.4 cc.

pH

11.0

142.0 cc.

Na2HP0^

Na3P0^/ 158 cc. Na2HP0^

The 300 cc. of M/5 phosphates were diluted to 3000 cc., and the solutions were well shaken before being divided into six equal portions of 500 cc. for the test procedure.

With the ten—fold dilu­

tion just mentioned, the final concentration of phosphates used in the tests became ]V^/50th«

10 The pH values of all of the test solutions employed in a treatment was taken for two different treatments at each temperature in order to determine the variance at each pH value.

From these

determinations, it was found that the variance for pH 11.0 and pH 8.4 was

0.15? whereas, for the other pH values: 4«1* 5.5* and 7.0

an accuracy of +_ 0.10 could he claimed. The ratio of phosphates for pH 8.4 *as difficult to determine experimentally, since only slight amounts of the monosodium phosphate sometimes threw the pH value over the + 0.15 tolerance.

DIAGRAMMATIC FLAM OF THE STUDY

A total of 180 standard soiled fabrics was used in the amylolytic enzyme tests, 60 apiece for each of the three temperatures: 22 - 27°C., 36 - 40°C., and 54 — 60°C.

The following diagrammatic

chart gives the disposition of e ach of 60 standard soiled f abrics at each of the three temperatures used in the study.

11

T A B L E

I

PLAM FOR CONDITION OF SOLUTIONS. USED FOR EACH TEMPERATURE IN THE STUDY

Time of Traatment

pH of Buffers

Treatment of Standard Soiled Fabric

Per cent. Enzyme N-

Starched

• 0$

4.1

Starched

3% 0% 3% 0%

Unstarched

3% 0%

Starched

OA O

Unstarched

5.5 i

va

10

7.0 Unstarched Starched

AA'fcA (no.

Minutes

3% 0%

8.4

Starched

3% 0% 3% 0%

Unstarched

3% o%

Starched

3% 0%

Unstarched

3% 0%

Starched

VIAA r\ o

Unstarched

VI Vi. mo

Unstarched

11.0

4.1 25 Minutes 5.5

II j

T A B L E

Time of Treatment

pH of Buffers

I.

(Continued)

Treatment of Standard Soiled Fabric

Per cent. Enzyme

Starched

3% 0%

Unstarched

3% 0% 3% 0%

7.0

Starched

25 Minutes

8.43% 0% 3% 0%

Unstarched Starched 11.0 Unstarched

3% 0%

Starched

3% 0%

Unstarched

3% 0% 3% 0%

4.1

Starched 5.5

3% 0%

Unstarched

O

Starched

60 7.0

Unstarched Starched

3% 0%

Unstarched

3% 0% 3% 0%

8.4

Starched 11.0 Unstarched

3% 0%

1 j

1 !

■fe&vJ O

Minutes

13 EHZYT/IE TREATMENT OF STANDARD SOILED FABRICS For temperature baths, "two square wooden wasli tubs equipped with steam heat and braised copper racks for holding the liter beak­ ers were used.

One braised rack fitted into each of the tubs, and

was capable of holding 16 beakers well immersed in the water contain­ ed in the tub; this made a- total of 32 beakers which cotild be used at one time.

Of these 32, however, only 30 were used at one time, be­

cause it was found, upon investigation, to be convenient to treat the starched soiled samples, at any one temperature, separately from the unstarched soiled samples, and because there were 30 starched and 30 unstarched soiled fabrics needed for each temperature. A diagrammatic plan of the tubs is given below, showing the arrangement of the beakers: iH '•* CC

a.

6 3 6

o

ir\ »r\ CC

cc

a,

(X

I

:4

U

N

5

Y

I N

3

U

E

s

Y

of

0 /»

M E

0

M

0

o /f °

2

5

M

I

3

%

E

N

Z

U Y

2

5

0

To

M I E N

S z

U Y

O.

I—I *

CO CC

vs

CC

T M

E E

S

T M

E E

T

->■*

« to

CC

CC — Qj-

—

cc £k_

i

ii

i

1 3

0 %

m

I N

:Q U I Y

T M

E E

S

E

S

1 0

0 %

M E

I H

3 5

T M

E E

S

s

M

E E

n cf i /v 60 m

E N Z I M E 10 m 25 m

pH 11

T M

E E

s

0 % 60 m

E N Z i M E 10 m 25 m

oH 11

U Y

u Each "beaker contained 500 cc. of* t-he M/50th buffer solu­ tion.

The water in the tubs and the solutions in the beakers were

brought to the proper temperature; the enzyme solution was added to the beakers; and the soiled samples were introduced into the solution, in this sequence.

The measured time, 10, 25, and 60

minutes began with the last operation mentioned.

During the course

of treatment, at equally spaced intervals, the fabrics treated for 10 minutes received ten vigorous stirs at two different times; the fabrics treated for 25 minutes received 10 vigorous stirs at four different times; whereas the fabrics treated for 60 minutes received 10 vigorous stirs at eight different times.

The stirring was done

manually in as uniform a manner as possible, with a motion simulat­ ing that which occurs in a home washing machine. At the expiration of the respective treatment periods, the fabrics were removed from the reaction beakers and rinsed three times. In the first rinsing each of the fabrics was rinsed separately' in 800 cc. of distilled ,7ater with ten vigorous stirs.

In the second rinse,

the five fabrics treated with enzyme for either the 10, 25, or 60minute periods were rinsed collectively in two and one-half liters of distilled water contained in large salt bottles fitted with screw caps.

The caps were screwed on and the fabrics and rinse water \vere

shaken vigorously ten times.

The fabrics were then removed, squeezed

gently with the hand, and the process was repeated for the third time. In the same manner, the five fabrics treated with no enzyme for each separate time interval were rinsed for the second and third rinses.

1-4a

After the third rinse, the fa.brics were centrifuged for three minutes.

The starched standard soiled fabrics were dried be­

fore starching; whereas the unstarched standard soiled fabrics were often treated several times in succession before being dried. DETERMINATION OF SOIL REMOVAL EFFICIENCY The amount of soil removed from the standard soiled fabrics was determined by means of the Hunter Reflectometer.

In making a

determination, the reflectancy of the standard soiled fabric was read at four different places on the fabric, using all three filters; this made a total of twelve readings for each determination.

The cell was

standardized on the green filter only. Six times during the course of the experimentation, the re­ flectancy of every standard soiled fabric was determined! initially, and at the end of the tenth, twentieth, thirtieth, fortieth, and fiftieth treatments.

The fabric must be free from wrinkles in order

to give accurate reflectancy values; yet the heat of a press or iron modifies the soil removal properties of the fabric.

Consequently,

in order that the same samples could be used for all fifty treatments, at the end of every ten treatments the samples were stretched and pinned onto a muslin cloth which was tacked firmly and taughtly onto a wooden frame.

The fabrics so dried v/ere free from wrinkles and gave

reflectometer readings reproducible within one per cent. The per cent, soil removal efficiency was calculated from

15 the following formula; per cent, soil removal _ a - Its efficiency ~ — ----- _2L_ % - Ri

x

100

where. R

=

reflectancy treatment

of standard soiled fabric after

Rl

=

reflectancy

of standard soiled fabric initially

R

—

reflectancy soiling

of the white Indianhead before

W

If the reflectancy of the standard soiled fabric could be read only to an accuracy within one per cent., this means that a variation of 0.6 per cent, in soil removal efficiency was still within experimental error.

(The reflectancy of the white Indianhead

was taken as BA and the reflectancy of the standard soiled fabrics averaged 32,5-

F o t a one per cent, error for a reflectancy reading

between 30 and AO, the expression for per centage soil removal effi­ ciency becomes: 0.3/51.5 x 100, or approximately 0.6 per cent. Soil removal efficiency, as the experimental error).

PHYSICAL TESTS Buffered solutions of distilled water and solutions of starch buffered at the different pH values were used for making the physical measurements, such as interfacial tension against oil, wetting time, instantaneous dispersion, and deflocculation of carbon black, since it was noted visually that the solutions from the enzyme treatments had neither a constant amount of starch nor carbon black removed with successive treatments.

In the initial treatments,

more starch and carbon black were removed during a single operation than were removed in subsequent treatments. The starch solution for the physical tests was made by boiling 2.5 grams of Argo c o m starch in 54-00 cc. of distilled water for one-half hour.

Of this starch solution, 450 cc. were added to

fifty cc. of the buffer solutions, thus making the final concentra­ tion of the starch solution 0.04

cent.

In degree of opalescence

and Intensity of iodine color produced when the latter is added dropwise to the starch solution, the concentration of the solution approxi­ mates that produced by the action of three per cent, enzyme on a starched soiled fabric for an hour at 36 - 40° C. The solutions containing enzyme were made up by filling a 100 cc. volumetric flask to the mark either with the buffered starch or buffered distilled water solutions, and then adding two cc. of the enzyme solution of the same concentration as was used in carrying out the soil removal treatments.

These solutions were placed in the constant temperature baths, and allowed to come to the proper temperature before the following physical measurements were made.

Three baths maintaining

temperatures of 25° C«, 33° C., and 56.5° C., were used.

Each of

these came approximately midway within the temperature range of the practical washing trials.

All physical tests were made at each of

these constant temperatures. INTERFACIAL TENSION MEASUREMENTS A Du Nuoy interfacial tensiometer Number 7054-0 was used for making the interfacial tension determinations. the method of Phillips (10).

It was calibrated by

The scale readings for mixtures of dis­

tilled water and each of the liquids given below were plotted against the known interfacial tension values of these mixtures.

The liquids

used were: carbon disulfide, methyl hexyl ketone, notrobenzene, isobutyl alcohol, benzene aniline, benzaldehyde, ether, chlorobenze, chlo­ roform, and isoamyl alcohol.

The interfacial tension values for these

liquids against water were taken from The International Critical Tables. A variety of hydrogenated cottonseed oil, Mazola Oil, 7/as used with the buffered starch and buffered distilled water solutions. The Mazola Oil and the 100 cc. volumetric flasks containing the buffered solutions were placed in the constant temperature baths until each de­ termination was ready to be made, and then, at the time of the determin­ ation, the oil was added to the buffered distilled water and starch solutions.

13 For the determinations made at 38° G. and 56.5° C., the crystallising dishes holding the solutions were immersed in a larger crystallizing dish containing water hot enough to keep the solutions at the desired temperatures. The six cm. platinum ring used with the Du Miioy instrument was rinsed in steam and 1lamed reading.

twice, successively, between each

Three readings were taken on each solution.

ring was preferentially wetted by the Mazola Oil.

The platinum

WETTING TIME OF CARBON BLACK

A brand of carbon black, Norit C, of average particle size, two to 10 microns, was used for the wetting, instantaneous dispersion, and defloceulation tests.

The method of preparing the Norit for the

physical test is described in detail by Oesterling (9 )• Five tenths grams of this carbon black were weighed out into long test tubes of uniform internal dimensions, 2.2 mm. x 24.4Fifty cc. of the phosphate buffered starch or phosphate buffered dis­ tilled water solutions were entered into the test tube, by holding the latter at a 4.5° angle, and by placing the tip of the pipette on the lower lip of the test tube.

When the solution was added to the tube

in this manner, the carbon black rode on the surface of the liquid. The tube was placed in a wire rack in a constant temperature bath, held at the proper temperature, in order to determine the wetting time, and the instantaneous dispersion and deflocculation values. The wetting time recorded was that interval of time between the entrance of the last drop of the solution into the test tube and the disappearance of the last particle of carbon from the surface of the solution.

The last particle of carbon, however, does not refer

to the film of fine dust which, with hardly an exception, was left on the meniscus of the liquid for an indefinite period.

The distinc­

tion between a particle and a film of dust was easily made by shining the light of a pencil flash light down the tube onto the surface of the solution.

20 With relatively poor wetting agents, such as enzymes, the carbon which was in suspension at the beginning of* the wetting test soon settled to the bottom of the test tube, leaving a transparent grey suspension of carbon.

It was thereby possible, by transmitting

light through the suspension at right angles to the test tubes, which were in a vertical position, to watch the chunks of carbon fall from the under surface of the meniscus to the bottom of the test tube. Even after all of the carbon had been wetted, and the surface of the liquid had become free from carbon, as much as one-half to one-fourth of the total carbon might still cling to the tinder surface of the liquid; by the time the last particle of carbon on the surface of the liquid had been wetted, however, the last flake of carbon particles to fall spontaneously from the under side of the meniscus had dropped to the bottom of the tube...

INSTANTANEOUS DISPERSION After the last particle of carbon had been wetted, a five cc. aliquot of the 50 cc. of liquid was taken from the lower third of the test tube. It was not always possible to take the aliquot for instan­ taneous dispersion determinations immediately after the wetting of the last carbon particle, because, as was mentioned previously, carbon still clung to the under surface of the meniscus of the liquid in some instances; and, when the meniscus of the solution was pierced with the

21 five cc. pipette, the carbon clinging to the under surface of the meniscus would fall in large particles to the bottom of the tube.

If

the aliquot were withdrawn immediately, abnormal values would often be obtained, because one or more of these falling aggregates of carbon had been sucked into the pipette.

After these large particles ceased

to fall, the aliquot for instantaneous dispersion was withdrawn and emptied into a small weighing bottle containing five cc. of a dilute gardinol solution.

Gardinol was used rather than soap because it is

an effective dispersing agent in acid as well as in alkaline media. The amount of carbon in these aliquots was determined by means of a turbidimeter which will be described in detail later in this report.

DEFLOCGULATION After the aliquots had been withdrawn for the instantaneous dispersion tests, the test tubes were tightly corked, tilted back and forth 20 times in order to insure a uniform suspension of the carbon in the liquid; the corks were released to allow liquid which had collect­ ed around them to flow back to the main body of liquid; and the tubes were placed in the racks of the constant temperature baths, held at the proper temperatore.

They were allowed to stand for an hour.

At the

expiration of this time, five cc. aliquots were withdrawn from the lower third of the test tube.

The aliquots were handled in the same fashion

as were the aliquots for the instantaneous dispersion tests.

22 DETERMINATION OF THE M O U N T OF CARBON IN SUSPENSION A "turbidimeter designed by W. L. Shetler and H* D. Trapp of the Ellen H. Richards Institute and constructed by T. D. Decker of the Physics Shop was used to determine the amount of carbon in the instantaneous dispersion and deflocculation aliquots* Photographs of the instrument appear in Figures I and II and drawings to scale appear* on Figures III, IV, and V.

23

KEY TO FIGURE

I

Wedge Microammeter Instrument panel light Filter control Oil cup Vent Air line to motor Opening to wedge scale Absorption cell Light switch for scale light Lamp switch Motor switch Adjustment screw for wedge

Figure

I

Exterior view of turbidimeter used in measurements of instantaneous dispsx-sion and deflocculation. Key to the lettering is given on the page opposite.

KEY TO FIGURE

II

Transformer Reflector

Lamp Lamp holder Lens Prism for deflecting wedge geam Rotating Sector Stator Oil line to sector Motor Filter Wedge Prism for deflecting absorption cell beam Photo-electric cell Microammeter Scale on wedge Light to illuminate scale Instrument panel light

Interior view of turbidimeter looking down from tbs top with the cover resioved. See opposite page for the key to the lettering.,

27

KEY TO FIGURE: III

%

•A

Transformer

B

Reflector

C -jl

Lamp

C2

Lamp Holder

D

Lens

E

Prism for deflecting wedge beam

Fx

Rotating Sector

F2

Stator

H

Motor

J

Wedge

K

Prism for deflecting

L

Photo—electric. cell

M

Microsmmeter

absorption cell beam

P

Instrument panel light

S

Vent

U

Opening to Wedge S cale

V

Absorption cell

Z

Adjustment screw for wedge

L A T E R A L V I E W OF T U R B I D I M E T E R .

F ig u r e

nn

HALF SIZE

KEY TO FIGURE IV

A

Transformer

B

Reflector

C]_

Lamp

Cp

Lamp Holder

D

Lens

E

Prism for deflecting wedge beam

F^

Rotating sector

F2

Stator

H

Motor

J

Wedge

K

Prism for deflecting absorption cell beam

L

Photo—Electric cell

M

Microammeter

N

Scale on V'/edge

0

Light to illuminatescale

P

Instrument Panel Light

V

Absorption cell

Z

Adjustment screw for

wedge

TOP

V IE W

OF T U R B I D I M E T E R

W ITH

FIGURE

TOP

m.

REM O VED.

5CALE-HALF SHE

T U R B I D I M E T E R . S E G M E N T DETAILS S C A L E - H A L F SIZ.E

ROTOR

STATOR

Tf

45

y th^ Liso catio n of c e n te r i*> . not c r itic a l F ric tio n d r i v e )

Hole f o r S h a f t . S iz e to b e d e te rm in e d . B e a r i n g s and B e a r in g M o u n t in g n o t

shown

F ig u r e V

M

32 The instrument works on the null principle; it is unique, however, in that one photo-electric cell replaces the paired photo­ electric cells commonly found in the null instruments* In the ordinary null instrument, the

of light is split

and one-half of the beam, after passing through a standard filter or wedge, shines continuously on one of the paired photo-electric cells; the other half of the light beam, after passing through the solution of unknown strength, shines continuously on the other cell.

When the

instrument is in balance, the galvanometer (which is connected to the paired photocells) comes to rest at zero. In this particular turbidimeter, each of the split beams of light is intercepted intermittently by a rotating sector,so that once during a revolution of the sector the beam of light passing through the standard wedge shines alone on the photo-electric cell; and once during a single revolution of the sector the beam of light which passes through the suspension of carbon shines alone on the same photo-electric cell.

The sector rotates with sufficient speed that, when the depth

of the wedge does not match the darkness of the suspension, a succession of wide, rapid deflections of the microarametar needle are obtained; the microammeter, of course, is connected to the photo-electric cell.

When

the instrument is in balance, and the two light beams striking the photo-electric cell are of equal intensity, the microammeter needle deflects only slightly* The beam of light is obtained from a 50-candle power automoHLe

33 headlight operating at nine volts from a stepdown transformer.

The

headlight lies in the focal plane of a concave reflector and a convex lens.

By means of a right-angled prism which covers half the area

of the lens, the "beam of light coming from the lens is split.

The

half-beam deflected by the right-angled prism is directed downwards, where it strikes another right-angled prism so situated that the light beam leaves this prism travelling parallel to the other half of the original beam of light.

The redirected beam of light ultimately

passes through a gelatin wedge of the type used in a Hecht Adaptometer

(3y+) ; whereas the other beam passes through a Cenco Number 12336 absorption cell which contains the suspension of unknown carbon content. For descriptive convenience the beam which passes through the wedge will be designated as beam W, and that which passes through the cell will be called beam C.

Lying between the first set of prisms

and the absorption cell or the wedge is a rotating sector which has two open areas, arc-shaped, lying opposite to each other, as shown in the diagram (Figure 5) «■

During one revolution of the sector there are

four phases of changes in the light which reaches the photocell.

In

the first phase, only beam W strikes the photo-electric cell; in the second phase, the light from beam W decreases and that from beam C increases; in the third phase only beam C strikes the photo-electric cell; and in the fourth phase the light from beam C decreases and that from beam W increases.

The sector rotates about 150 R.P.M., although

its speed is not critical.

After beam C has passed through the cell, it

is turned downward by a right-angled, prism, and passes through a filter

34 made of photographic negative before it strikes another right-angled prism which covers one—half of the area of the photo-electric cell. The latter right-angled prism restores the direction of the light to a horizontal path. Both beams of light are now travelling horizontally and side by side.

Under such circumstances they alternately hit a Weston photo­

electric cel.1 which is connected to a microammeter. The instrument was calibrated by plotting the vernier scale readings of the wedge, for suspensions of known quantities of carbon black, against the mgs. of carbon per lOO cc. in these suspensions. The instrument must be recalibrated whenever the lamp is replaced; it is desirable, however, to adjust the new lamp’s position horizontally and vertically in order to give the maximum deflection of the microammeter needle before making the calibration.

It is likewise

desirable to check the calibration curve after the rubber tubing on the motor drive shaft, which revolves the sector, has been replaced. Although the instrument was sensitive to concentrations of carbon ranging from zero mgs. per 100 cc. to 50 mgs. per 100 cc., it was found convenient to dilute those samples having a concentration greater than 25 mgs. carbon per 100 cc., in order that the final con­ centration of the diluted solution might lie somewhere between five and 25 mgs. of carbon.

Within this range the calibration curve was linear

and the zero reading of the microammeter needle could easily be detected. These

dilutions were made either by adding distilled water to the aliquot

35 by means of a pipette, or by diluting the aliquot to the desired volume in a volumetric flask. About 50 determinations were required before detection of the minimum deflection of the microammeter needle came easily or readily. It was found advisable to take several readings for a single determin­ ation, and to approach the end point from both directions.

After each

of the readings for a single determination, the absorption cell was re­ moved, the small glass lid supplied with every Cenco absorption cell was placed on the cell, and the cell was shaken to insure a uniform suspension.

I>uring the time that the suspension was being shaken, the

switches for the motor and the lamp were turned off.

This was done to

prevent the motoi' or the apparatus case from becoming too warm, and further to avoid ultimate deterioration of the gelatin wedge.

Other

precautions were also taken to keep the motor and the apparatus ease cool.

A stream of air was passed through the motor and a vent was

placed over the headlight bulb.

The vent provided exit for the heat of

the lamp, but did not admit escape of the light.

36 PRESENTATION OF DATA

Tables II and III give "the soil removal efficiencies for three per cent, enzyme and no enzyme, respectively, on starched and unstarched soiled fabrics at 22-27° C.

The data appear graphically

in Figures Via, VIb, and Vic. Tables IV and V present the soil removal efficiencies for three per cent, enzyme and no enzyme, respectively, on starched and unstarched soiled fabrics at 36-4-0° C.

The data in these tables are

shown graphically in Figures Vila, VTIb, and VIIc. In Tables VI and VII, the 3oil removal efficiencies for three per cent, enzyme and no enzyme, respectively, on starched and unstarched soiled fabrics at 54-60° C. are recorded.

Graphical presentation of

these data is given in Figures Villa, Vlllb, and VTIIc. It will be noted that the soil removal efficiency data have been plotted on single cycle, semi-logarithm paper.

Because it was

impossible to plot the logarithms of negative numbers a constant has been added to each value for percentage of soil removal efficiency, thus making every number a positive number. number 30 was arbitrarily chosen.

For this purpose, the

This means that any value below 30

represents a fabric which is darker than it was before treatment was begun; however, this can not be construed to mean that there was no soil removed from the fabric at all.

This point will be elaborated further

in the section of this report devoted to discussion. Conversely, any value greater than 30 indicates that the fabric vias lighter at the end of the treatments than it was before the treatments were begun; it also indicated that soil was unquestionab ly removed from the soiled fabric. Smoother curves were obtained when the soil removal efficiency data plus the constant 30 were plotted on a log paper than were obtained when the actual soil removal efficiency figures themselves were plotted on plain coordinate paper.

The interfacial tensions of three per cent, and zero per cent, amylolytic enzyme in distilled water and in 0.04 per cent, starch solu­ tion against Mazola Oil at 25° C. are given in Table VIII, along with the wetting time of carbon black and the instantaneous dispersion and the deflocculation values for carbon black given by these solutions. The interfacial tension values appear in graphical form in Figure IX; whereas the instantaneous dispersion and deflocculation values appear in graphical form in Figure XII. Table IX presents data for the interfacial tension against Mazola Oil, wetting time, instantaneous dispersion, and deflocculation of carbon black values for three per cent, and zero per cent, amyloly­ tic enzyme, respectively, in distilled water and In 0.04 per cent, starch solution at 33° C,

Graphical depiction of these interfacial

tension values is given in Figure X, and that for instantaneous

38 dispersion and deflocculation is given in Figure XII. The interfacial tension values of three per cent, enzyme and no enzyme in distilled water and in 0.04 P®** cent, starch against Mazola Oil at 56. 5° C. are given in Table X, and they are presented graphically in Figure XI.

The instantaneous dispersion and defloccu­

lation of carbon black by these enzyme solutions at 56.5° C. are likewise given in Table X and presented graphically in Figure XIV. The physical test data have been graphed on single cycle, semi-logarithm paper, in a manner similar to that for soil removal efficiency.

Here, however, the data would ordinarily be plotted on

double cycle semi—logarithm paperj yet the curves produced by adding a constant, namely ten, to the interfacial tension, the instantaneous dispersion, or the deflocculation values are better curves on single cycle semi-logarithm paper than those produced either when the data are plotted on plain coordinate paper or on double cycle, semilogarithm paper.

SOIL REMOVAL EFFICIENCIES FOR STANDARD SOILED FABRICS TREATED WITH THREE PER CENT, SNZIME, BUFFERED AT DIFFERENT pH VALUES, at 22-27°C.

STARCHED STANDARD SOILED FABRICS UNSTARCHED STANDARD SOILED FABRICS Length of pH of Per cent. soil removal efficientoies at the Per cent, soil removal efficiencj.es at the Reaction Buffer end of the foilowing muTiber of ;reatments end of the fol] owing muliber of ti’eatments Time 10 10 40 20 30 50 1 20 30 40 50

10 Minutes

25 Minutes

4-1 5.5 7.0 8.A 11,0

- 9.3 - 7.0 - 0.4 - 1.3 -11.9

-12,6 -11.6 - 3.5 - 1.7 -15.6

1o ^ -Joo -12.0 - 2.0 - 1.1 -15.4

-15.3 -13.9 - 4.9 - 2.6 -18.8

-15.3 -13.7 - 5.5 - 2.0 -17.9

(+ -

3.2 2.3 1.2 0.4 0.7

+ -

3.0 1.9 0,8 1,4 1.0

+ -

3.4 oc 1, 1.6 0.8

- 3*6 - 1.6 - 1.0 + 2.7 + 0.6

- 3.2 - 2.3 - 1.0 + 3.2. + 0.6

4.1 5.5 7,0 8.4 11.0

+ + -

-12.1 - 8,1 + 3.8 + 8.3 - 3.9

-12.1 - 8.1 + 7.0 + 9.7 - 4.1

-14.6 - 9.1 + 7.0 +10.7 - 6,5

-13.8 - 8.9 + 8.2 +10.9 - 5.7

+

1.7 1.3 0.6 0.8 2.4

+

1.7 1.5 0.6 0.4 2.6

+

2.4 2,2 0.9 0.4 3.4

+ + +

" °’9 I*,1 + 0.4 + 1.4 + 6.0 ,......

8.1 5.6 3.6 7.1 3.5

1.1 1*3 0.7 1.2 5*6

....

60 Minutes

4.1 5.5 7,0 8.4 11.0

+ * +

7.1 3.0 6.8 6.0 2.0

-10.6 - 3.8 + 8.1 + 6.4 - 0.8

-11.0 - 2.2 +10,6 + 8.5 + 2.0

-11.8 - 3.2 + 9.5 ..+ 7.6 - 0.4

-11.8 + 0.6 +11.2 +10.1 + 1.0

- 1,2 0.0 | - 0.2 + 2.7 + 6.3

+ + + +

1.0 0.8 1.3 5.0 8.5

+ + + +

1.2 1.2 1.9 6.7 9.9

0.0 + 3.3 + 4*0 + 9.2 +12,8

+ 0.6 + 3.7 + 4.6 +10.5 +13*2

U)

sD

M

TABLE

III

SOIL REMOVAL EFFICIENCIES FOR STANDARD SOILED FABRICS TREATED WITH JO ENZYME YET BUFFERED AT DIFFERENT pH VALUES, at 22-27°C. STARCHED STANDARD SOILED FABRICS Length pH of Per cent. soil reiEovsl efficiencies at the of Reaction Buffer end of the foliowing numher of treatments 40 50 20 10 30 Time

10 Minutes

25 Minutes

60 Minutes

4.1 5.5 7.0 3.4 11.0

4«1 5.5 7*0 8.4 11.0

4.1 5.5 7.0 8.4 11.0

[ UNSTARCHED STANDARD SOILED FABRICS i !Per cent . soil removal efficiency es at the |end of the following number of trsatments i 20 20 | 30 I 40 50 1 - 1.3 - 1,6 ’ - 0.4 - 0.4 ! - 1.5 - 3.6 - 3.6 i - 2.3 - 3.2 - 4.3 0.0 - 0.5 - 1.1 - 0.9 - 1.3 - 2.5 - 2.5 - 1.9 - 2.3 - 3.1 - 0.2 0.0 + 0.2 + 2.4 + 2.6 t— -----

-

8.4 9.2 8.3 6.6 8.1

-11.6 -12.7 -13.2 -12.3 -12.3

-11.0 -12.9 -12.4 -12.1 -11.9

-13.3 -15.1 -14.0 -12.8 -13.3

-13.3 -15.3 -13.8 -13.4 -13.5

-

7.6 7.9 4.0 6.5 7.9

- 9.7

- 9.5

-10.7 - 8.3 - 9.6 -11.4

-10.7 - 7.4 - 9.4 -11.2

-12.2 -12.4 -10.0 -11.7 -13.2

-12.6 -12.6 - 9.4 -11.4 -12.6

: +

2,4 2.6 1.3 3.0

+

3.6 3.0 3.0 1.6 4*6

+

5.1 3.2 3.2 1,48.4

- 3.4 - 1.7 - 1.3 - 2.6 +12,0

- 3.3 - 1,5 - 2,4 - 0.6 +13.7

-

6.2 6.7 6.6 4*1 1.8

-10.1 - 9.3 - 7.9 - 6.1 - 3.3

-12.3 -10.0 - 8.7 - 5.6

-13.3 -12,1 - 9.6 - 6.1 - 3.3

-14.1 -13.2 - 8.5 - 5.0 - 2.0

+

2.5 2.0 1.3 0.8 1.9

+

2.5 2.2 1.6 0,6 4*2

+

2.7 1.4 0.8 0.2 9.3

+ 1,3 + 0.2 -f- 1,0 + 1.6 +14.9

“ 0.3 - 0.4 - 0,6 + 1.9 +16.6

■ * “ O•f^C

- 2*6

4>O

SOIL REMOVAL EFFICIENCIES FOR STANDARD SOILED FABRICS TREATED WITH THREE PER CENT. EMZYME, BUFFERED AT DIFFERENT pH VALUES, at 36-4Q°C. UNSTARCHED STANDARD SOILED FABRICS STARCHED STANDARD SOILED FABRICS pH of Per cent„ soil r3soval e:?ficienc;Les at the Per cent , soil r9moval efficiencies at the Reaction Buffer end of t le followdng muniDer of ta-eatments end of the foliowing nuraber of treatments 10 20 30 40 20 40 50 50 10 30 Cime .engih

10 Minutes

25 Minutes

60 Minutes

4.1 5.5 7.0 8.4 11.0

+ + -

3.4 2.8 1.5 2.7 2.4

+ + -

4.1 3.9 1.5 1.1 4.1

-4*6 - 4.3 + 3.9 + 3.3 - 2.7

- 6.0 - 4.3 + 6.5 + 6,5 - 1.7

+ + -

9.0 7.6 2.8 3*0 3.4

+ + + + +

2.5 2.4 3.6 3.4 4*6

+ + + + +

1.9 0.9 2.9 2.9 5.5

+ + + + +

1*4 0.2 2.2 2,5 4«9

+ 1.5 0.0 + 2,7 + 3.0 + 4*7

+ + + + +

1.4 0.7 2.9 3*4 4*2

4.1 5.5 7.0 8*4 11.0

+ + -

3.2 1.3 3.6 5.0 3.6

t + -

5.4 3.0 6,0 6.5 5.2

+ + -

6.0 2.8 7.5 9.6 2.5

- 5.6 - 2.2 +10.0 +12.2 - 0.5

+ + -

9.7 5.0 7,3 9.4 3.4

+ + + + +

3.5 3.4 2,4 2.9 3.9

+ 0.7 + 2.0 +1.3 + 2.3 + 4.2

+ + + + +

0.4 1.6 0.4 2.7 6.3

+ + + +

+ + + +

0.2 1.8 0.7 4.5 7.7

4.1 5.5 7.0 8.4 11.0

- 2.0 -2.6 + 5.5 + 7.2 - 4.1

+ + -

3.0 4.2 8.5 8.0 5.0

- 2.3 - 1.8 +13.3 +14.0 0.0

- 2.7 - 0.2 +16.6 +17.1 + 4*1

- 5.7 - 1.9 +14.3 +16.2 + 2.1

+ + + + +

1.4 2.8 2.5 3.2 7.4

+ 0.4 + 1.7 + 2.7 + 4*3 +10.5

+ 0.2 + 2.4 + 3.6 + 5.6 +12.9

0.2 1.8 0.4 3.4 6.3

+ 0.5 + 1.3 + 4*3 + 5.9 +12.5

+ 0.9 + 2.3 + 6.1 + 6.8 +13.5

SOIL REMOVAL EFFICIENCIES FOR STANDARD SOILED FABRICS TREATED WITH NO ENZYME, YET BUFFERED AT DIFFERENT pH VALUES. at 36-4-0°C» .. - - -— .......... UNSTARCHED STANDARD SOILED FABRICS STARCHED STANDARD SOILED FABRICS Length ’emoval efficiencies at tne pH of Per ceni soil i•emoval efficiencies at the Per ceni soil 1 of die folicwing nunfoer of treatments Reaction Buffer end of i,he folicwing nunfber of treatments end of • 50 40 30 20 10 50 40 20 10 30 Time

10 Minutes

25 Minutes

60 Minutes

4-.1 5.3 7.0 8.4 11.0

-

5.4 6.0 5.7 3.8 5.3

~ -

7.5 7.8 7.9 6.3 7.3

-

8.3 8.2 3.3 5.7 6,5

~

3.7 9.1 9.0 6.1 5.1

-12.7 -13.0 “11.4 -8.3 - 7.4

+ + + + | +

1.1 1.3 2.1 1.9 5.9

+ + + +

0.4 0.9 0.9 1.6 7.5

- 1.4 0.0 + 0.5 + 1.4 + 8.6

- 1.9 - 0.4 + 0.5 + 1.1 +10.7

- 1.9 + 0.9 + 1.4 + 1.6 +12.3

4*1 5.5 7.0 8.411.0

-

4.6 5.8 3.3 4.8 6.0

-

7.6 8.1 .9 5.9 8.1

-

7.2 8.3 4.3 4*6 5.6

-

6.5 9.4 3.6 4.8 4.0

-11.5 -12.5 - 7.2 - 7.0 - 5.2

! + + + + +

2.1 1.7 1.8 2.4 7.1

+ 1.8 + 1.9 + 0.2 + 2.8 +11.8

+ 0.7 + 0.3 0.0 + 2.4 +15.7

+ 0.7 + 1.3 - 0.4 + 4*1 +17.7

+ 0.9 + 1.7 - 0.8 + 4*7 +19.3

4.1 5.5 7.0 8.4 11.0

-

7.7 7.9 4.3 7.6 1.6

-10.1 - 9.9 - 5.7 - 9.6 - 1.7

+

9.5 9.7 4.4 3.2 0.3

-10.7 - 7.9 - 4.1 - 6.9 + 5.5

-13.5 -11.6 - 6.8 - 9.2 + 2.1

+ + + + +

3.2 3*1 3-4 3.1 7.9

+ 2.3 + 2.7 + 2.8 + 3.3 +14.3

+ 1,1 + 1.6 + 2*2 + 4*0 +17.3

+ 1.6 + 1.6 + 2.6 + 3*6 +19.7

+ 1.6 + 0.9 + 2.8 + 4*6 +22.1

*• 70

M

SOIL REMOVAL EFFICIENCIES FOR STANDARD SOILED FABRICS TREATED PITH THREE PER CENT. ENZYME. BUFFERED AT DIFFERENT pH VALUES, at 54-60°C. ! UHSTARCKED STANDARD SOILED FABRICS STARCHED STANDARD SOILED FABRICS pE of Per cent, soil removal efficiencies at the iPer cent. soil removal efficiencies at the 3f Reaction Buffer end of the foliowing number of treatments 1end of t ie following number of treatments 40 50 20 10 30 40 50 20 30 10 Time

10 Minutes

25 Minutes

60 Minutes

7.5 5.9 6.9 9.9 8.1

-10.1 _7 0 - 3.7 -10.9 - 8.3

-10.1 - 6.3 - 3.3 - 9.7 - 7.1

-10.3 - 7.1 - 7.9 - 9.5 - 5.4

- 7.8 - 7.3 3.9 7.5 - 3.7

- 8.4 - 8.2 9.3 9.7 - 7.9

-10,2 - 9.4 — 10 , * 4 -10.1 - 3.5

- 9.4 ^! — w .4. 9.3. 8.8 - 6.2

- 9.0 8,4 3.9 7,3 4.8

— 4«4 - 6.9 4.1 4*4 - 2.8

- 7.4 - 3.2 5.3 4.0 - 2.2

- 6,8 9.9 5.9 3.0 - 0.4

- 8,2 8.4 5.3 1.6 + 2.6

- 7.3 7.1 4.1 + 0*6 + 3.7

4.1 5o 7.0 S.4 11.0

-

4.1 5.5 7.0 8.4 11.0

4.1 5.5 7.0 8.4 11.0

6.9 5.6 6.9 8.9 6.9

-

0.8 0.7 1.3 2,4 3.5

-0.4 + 0.7 + 0.8 + 2.0 + 2.5

+ + + +

- 1.2 1.0 0.4 + 0.4 + 8.0

- 0.6 0.4 + 1*1 + 4*0 +15.6

0.0 + 0.6 + 2.3 + 6.1 +21.0

+ 0.6 + 1,2 ■+ 2,7 + 7.4 +24.1

0.0 + 0.4 + 3.0 + 8.2 +26,3

- 1.4 0.0 ~ 0.5 + 3.5 + 8.6

+ 0.2 + 2*5 + 4*3 + 8.1 +17.3

+ 1,3 + 4*4 + 6.8 +11.2

+ 3.7 + 5.0 + 8.6 +12.6

+24.0

+27,0

+ 2.4 + 5.6 +10.6 +14.5 +31.9

1.5 2.0 1.7 1.0 1.2

+ + +

0.2 1.3 1.5 1.8 3.3

+ + + +

0.8 0.2 0.4 0.6 1.2

| j | -

VjJ

*

TABLE

VII

SOIL REMOVAL EFFICIENCIES FOR STANDARD SOILED FABRICS TREATED PITH NO ENZYME, YET BDFFERED AT DIFFERENT pH VALUES, at 54-60°C. UNSTARCHED STANDARD SOILED FABRICS STARCHED STANDARD SOILED FABRICS Length pH of Per ceni: soil i■emoval efficiencsies at the Per cent . soil removal efficiencies at the of Reaction Buffer end of i,he fol_cnving nuriter of 1treatments end of the foliowing numher of treatments 50 20 10 40 30 50 20 30 40 10 Time 4*1 10 5.5 7.0 minutes 8.4 11.0

- 8.6 - 9.0 -8.5 -11.7 - 8.1

- 8.4 -10.6 - 8.7 -12.1 - 9.1

-12.2 -11.7 -10.4 -13.3 - 8.9

-11.4 -11.4 - 8.7 -11.9 - 6.4

-11.8 - 9.6 - 8.3 - 8.1 - 4.7

+

0.4 1.9 2.0 1.6 3.5

+ + +

0.8 1.0 1.0 0.4 8.8

0.0 - 0.2 00 + 2.0 +13.8

+ 1.0 + 0.4 + 0.2 + 2.6 +17.7

+ 1.8 0.0 - 0.4 + 2.4 +20.7

4.1 5.5 25 7.0 minutes 8*4 11.0

- 8.5 - 6.1 -10,2 - 5.1 - 8.3

- 9.5 - 5.9 -10.g - 5.5 - 8.5

-12.3 - 7.0 -11.8 - 2.2 - 8.9

-11.5 - 5.9 -11.2 - 3.8 - 6.0

-11.7 - 6.1 -10.0 - 2.4 - 4.7

+ + +

2.0 0.6 1.6 1.6 8.1

- 1.2 + 2.5 + 0.2 + 6.1 +17.5

- 0.2 + 3.8 + 1.2 + 8.1 +25.4

+ 0.8 + 5«1 + 1.8 + 9.2 +30.5

0.0 + 4.0 + 1.4 + 9.7 +35.3

4.1 5.5 7.0 8.4

-10.3 - 4.9 - 4.5 - 7.6 - 1.9

-10.1 - 5.6 - 6.0 - 7.0 + 2.9

-13.6 - 7.7 - 5.3 - 4.8 + 3.7

-11.9 - 5.5 - 4*7 - 4.0 + 7.1

-11.5 - 4.7 - 3.2 - 1.3 + 8.7

- 1.0 - 1.6 - l.C + 3.1 +11.5

+ 1.4 + 1.8 + 1.0 + 8.4 +24.1

+ 2.4 + 2.8 + 2.9 +12.5 +35.5

+ 3*6 + 3.6 + 3.7 +13.4 +42.3

+ 3.4 + 4.2 + 3.5 +14.2 +51.3

60 minutes

u-'°—

£

A

R E M O V A L O F SOIL. F R O M SOILED FAB RIC S DURING*

IO M IN UTE5j USING DIFFERENT pH VALUES

3% E N ZY M E

5Q,

40

0 ? o

e n z y m e

40.

30

30

a—

-a

»ln

:LtA

>

r.

Nu

A B *

m

&

e r

pH 4.1 ± .10 pH 5.5 ± .10 p H 1.0 * .10

k T**

o f

P ^

L

N

PER

.

CENT

SOIL.

REM OVAL.

ZO

■s

iTT^

£Un

t r e a t m e n t s

FIGURE 3 Z I r

^ pH ° PH

8 .4 .15 ,, n + ,c b

R E M O V A L . O F S O IL F R O M S O IL E D FA B R IC S DURING 10 M IN U T E S -, U S IN G D IF F E R E N T p H VALUES a t 3 6 - 4 . 0 ° C . STARCHED

S O IL E D

FA B R IC S

3 To E N 1 V M E

07o E N Z .Y M E

HUMBER OF T R E A T M E N T S UNSTARCHED

S O IL E D

F A B R IC S

3% ENZYM E

40 Y3r 030

zo

— J 20 3*0

NUMBER A

pH

. 10

□

pH

5 .5 ±. .10

X

pH

1,0 ±. .10

sW

OF

c

Vo

^o

TREATMENTS

u" p H f

,g u r ™

0

«

p h

8 .4 - ±

.15

R E M O V A L O F S O IL FR O M S O IL E D F A B R IC S D U R IN G 2 5 M IN U T E S , U S IN G D IF F E R E N T p H VALUES a t 3 f e - 4 0 ° C -

STARCHED

S O IL E D

F A B R IC S

E F F IC IE N C Y

+

30

3 % ENZYM E

30

REMOVAL

20

30

so

NUM BER O F

SOIL

UNSTARCHED

50

30 TREATM ENTS

S O IL E D

F A B R IC 5

50

CENT.

40

PER

30

20

20 OF

A

pH 4.1 A. .10

X

pH

1.0±.AO

Vo 'T R E A T M E N T S n / pH

F IG U R E

2 H

6 .4

±-,1 5

REMOVAL OF GO M IN U T E S

d

S O IL F R O M U 5 IN G

D IF F E R E N T

STARCHED 3 %

S O IL E D

S O IL E D

F A B R IC S

D U R IN G

p H VALUES a t 3 G -4 0 ° C .

F A B R IC S

E N Z Y M E

0 7 ® EN LYM E

0 5« cn X

>*

0

—o

GT^lr uJ 0 a, a z°i

Yi

uJ

f

50

o

5*0

NUMBER

5

To

So

OF T R E A T M E N T S

UNSTARCHED

UJ

O

S O IL E D

F A B R IC S

CL 3 %

0?o

E N Z Y M E

ENZYM E

0

1 5.5 7.0 8.4 11.0

22.0 23.1 22.6 20.5 10.3 23.7 23.4 22.7 21.1 1.7

1056 1229 1171 1197 1250 .... 1016 1336 1458 1118 1135

_

Instantaneous Dispersion Values in mgs. Carbon/lOO cc.

r

One Hour Deflocculation Values in mgs. Carbon/lOO cc.

6.0 10*4 12.4 11.0 6.0 3.4 4.2 3.4 5.2 6.0

45.4 33.0 26.0 25.6 45.2 20.6 10.0 11.6 11.6 40.0

20.3 12.4 13.2 10.8 24.8 19.0 16*4 13.4 13.0 23.6

24.8 a.o 20.0 21.4 31.0 26.4 28.2 23.2 25.0 44*4 __________

: ---

TABLE X DATA ON PHYSICAL TESTS OF ENZYME SOLUTIONS BUFFERED AT DIFFERENT q R VALUES, at 56.5° C.

Type Solution

Per Cent, Enzyme

3% 0.04$ Starch Solution

0%

3% Distilled Water a%

pH of Solution

Interfacial Tension Against Wetting Time of Hydrogenated Cotton Seed Oil Carbon in in Dynes/cm. Seconds

4.1 5-5, 7.0 8.4 11.0 4.1 5.5 7.0 3.4 11.0

22.9 22.9 23.1 19.6 7.4 23.0 23.8 23.6 21.3 11.6

1193 1064 1422 1405 992 1012 1135 941 1304 1212

4.1 5.5 7.0 3.4 11.0 4.1 5.5 7.0 8.4 11.0

24.2 23.1 23.4 21.3 6.1 23.1 23.3 23.2 20.5 5.3

970 1139 923 1034 1203 1230 753 912 934 1006

Instantaneous Dispersion Values in mgs. Carbon.100 cc.

^

One Hour Deflocculation Values in mgs. Carbon/lOO cc.

7.2 8.0 8.6 13.4 5.4 ____ 6.0 5.2 4.0 4.3 15.4

62.0 27.6 23.6 17.8 17.3 20.1 12.4 8.4 10.0 50.0

12.4 13.2 8.0 9.2

32.0 31.2 27.4 28.2 3.8.2 50.0 38.6 30.2 29.2 38.8

... -12-4-.... 24.