DYEING WITH ALIZARIN LAKE* BY J. W. ACKERMAN
Parks' devised a short process for Turkey-Red Dyeing, which consisted of the preparation of a colloidal solutiori of alumina and soap, fixing such a colloid on the fiber, and then dyeing the mordant. The mordant adsorbs the dye, and we have a lake formed on the fiber. Since wool will adsorb alumina, it will probably adsorb alumina with the dyestuff adsorbed on it. If this can be accomplished, it would make the process of dyeing with the mordant dyes easier and faster. It would eliminate the long and costly operations that are used to put the dyes on the fiber, for it would do away with the mordanting of wool, and the other long operations necessary to fix the dye on the fiber. With such a new method, there would be only two operations-first, the formation of the lake, and second, the adsorption of the lake by the fiber. Furthermore, the lake maker who is familiar with the formation of lakes, may prepare the lake, and the dyer would have only to run the operation of putting it in a bath and having the wool or cotton adsorb it. A study of the problem from the standpoint of the above mentioned theory involves the consideration of three different things. ( I ) Formation of the lake (2) Peptization of the lake ( 3 ) Dyeing with the lake Procedure and Experimental Results Preparation of the alumina.-Alumina may be prepared in many ways, but we eliminate the use of alum or aluminum sulphate, for Bancroft* has shown that the sulphate coagulates the hydrolyzed salt so readily that large amounts of alumina or basic salt are precipitated in the bath or in the fiber in such a form that it readily rubs off. The alumina was prepared by using 12.5 grams of aluminum chloride (hydr. cryst.-Kahlbaum) dissolved in 500 cc. of hot water. An electric stirrer was adjusted to stir the solution, and to the aluminum chloride was added 3 5 cc. of concentrated ammonium hydroxide. The alumina was immediately fornied as a white gel, and was stirred for about fifteen minutes to insure complete mixing of the constituents. The alumina settled out with a clear supernatant liquid above. The alumina is positively charged, but due to its great adsorbing power it adsorbs chloride ions from the solution and the latter tend to coagulate the alumina. It was then washed * This work is part of the programme now being carried out a t Cornell University under a grant to Professor Bancroft from the Heckscher Foundation for the Advancement of Research established by August Heckscher a t Cornell University. J. Phys. Chem., 35, 488 (1931). Bancroft: J. Phys. Chem., 26, ,515 (1922).
491
DYEING WITH ALIZARIN LAKE
five times and a t the last washing, it did not settle out. The washing helps remove some of the chloride ions and thus keep the alumina in colloidal solution. It was peptized completely with a small amount of HCl, which gave it a positive charge due to the preferential adsorption of hydrogen ion. It was examined in a slit ultramicroscope (Zeiss), and found to be colloidal with a slight tendency to flocculate. It was necessary to determine the amount of A1203 present, so 50 cc. of alumina were evaporated to dryness and weighed. The weights were as follows on three runs: Run I.-0.1262 gms. Run z . - o . I z ~ ~gms. Run 3 -0.12 59 gms. Average = 0.12 j j gms. The reaction may be expressed as follows:2
+
+
+
A1CL 6 “,OH --f A1203 6 “4‘21 3 HzO. Al1O3 3 HzO --t A1203.x HzO (Alumina).
+
The formula is given as above, for the water content may be variable. “Since a colloidal solution is one in which a finely divided phase is kept from coalescing in some way, it is clear that there may be any number of colloidal aluminas, for instance varying from anhydrous alumina, Al2O3,up t o the most highly hydrous form that can be obtained.”’ Bancroft has shown that this is a hydrous oxide and not a basic salt.2 A sodium alizarate solution was made by dissolving 2.88 gms. of alizarin (Kahlbaum) in the proper amount of sodium hydroxide and boiled to put in solution. It was diluted with water to one liter, and had a purple color. The alizarin was not used as such for it is insoluble in cold and very slightly soluble in boiling water, but dissolves readily in caustic soda. It is in true solution, as the diffusion experiments of Bull and Adam9 have shown. A solution of calcium acetate (0.I N) was prepared. Formation of th,e Zake.-Weiser and Portel.4 have shown that the formation of the alizarin lakes from sodium alizarate baths is due to the adsorption of the dye anion, and the effect of the calcium ion on the formation of the lakes is to increase the charge on the mordant, thereby enabling it to adsorb more of the dye anion. Also they have shown that the effect of the calcium is marked and increases with its concentration. “By the addition of a strongly adsorbed cation one may use a slightly basic bath in which the alizarin is soluble and a t the same time avoid the displacement of the dye anion by the OH. That the effectiveness of the calcium is not due to the direct precipitation of the calcium alizarate is evidenced by the fact that the quantit,y of calcium present may be greater than the equivalent of the alizarin without the dyebath becoming exhausted.” Bancroft: “Applied Colloid Chemistry,” 204 (1926). Bancroft: J. Phys. Chem., 18, 435 (1914). Bull and Adarns: J. Phys. Chem., 25, 660 (1921). Weiser and Porter: J. Phys. Chem., 31, 1824 (1927); Weiser: J. Phys. Chem., 33, 1713 (1929).
492
J. W. ACKERMAN
It was thought best to check this work, since it was suggested by Bull and Adams,l and Williamson* that the formation of the alizarin lakes is due to the direct adsorption of the neutral sodium alizarate. Alizarin forms a purple solution when dissolved in alkali, and a thin film of sodium alizarate is purple both in transmitted and reflected light. Alizarin acid is insoluble in water, and the alcoholic solution has a reddish-yellow color similar to that of the solid crystals. If neutral, undissociated sodium alizarate was taken up by the alumina, we should expect the lake to be colored purple. Experiments were run with alumina and sodium alizarate in varying proportions, and in no case was there a purple lake formed. The alumina was made from aluminum chloride and ammonium hydroxide, and since there are probably chlorine ions present, the next experiments were run with a pure alumina, made according to a method given by M e l l ~ r . ~ “If a clean strip of aluminum be placed in a bottle containing a few cc. of mercury and all shaken, the aluminum when exposed to air, rapidly oxidizes, and white tufts of alumina grow up to about a cni. above the surface of the metal. If the aluminum be placed in water instead of in air, the water is decomposed, and the aluminum oxidized. If a little mercury be poured into a beaker of water and a clean sbrip of aluminum be dipped in the vessel, no action occurs until the aluminum touches the mercury. The water then decomposes and the action continues until all the aluminum has been transformed into alumina, and this even after the mercury has been removed.” An alumina was made according to this method, and then treated with sodium alizarate. In no case was a purple lake formed, and a red lake resulted due to the adsorption of the alizarin anion. In order to show that the solid sodium alizarate is purple, drops of the sodium alizarate solution were placed on a porous white plate, and the concentrations were varied from very weak to very concentrated. For each drop the color was purple. Also a solution of sodium alizarate was evaporated to dryness on a water bath, and the color was purple. However, it must be kept in mind that in dilute solutions the color is red. The color then is not due to sodium alizarate, but probably due to the alizarate anion. This was shown by preparing the pure alumina and treating it with alizarin in solution, which is prepared by dissolving the crystals of alizarin in alcohol and heating to get in solution. The alizarin was used in varying concentrations, and it was found that a series of lakes were formed varying from a pink color to a red. Following a suggestion of Weiser the newly formed oxide was suspended in alcohol and treated with an alcoholic solution of alizarin. In this way the precipitation of the alizarin is prevented. A red lake was formed similar to that obtained with sodium alizarate. Since the color of the lake with sodium alizarate is red and not purple, as it should be if neutral sodium alizarate was taken up, nor the orange of the Bull and Adams: J. Phys. Chem., 25, 660
(1921).
* F. S. Williamson: J. Phys. Chem., 28, 891 (1924). ,J. W. Melior: “Modern Inorganic Chemistry,” 774, (1925).
DYEIKG WITH ALIZARIN LAKE
493
alizarin acid, and since the color of the lake is red when pure alumina is treated with alizarin acid we conclude that the color of the lake is due to the adsorption of the alizarate anion by the alumina. This confirms the results of Weiser.’ “The color of the alumina-alizarin lake is neither the dark purple to purplish black of thin films of alkali and alkaline earth alizarates nor the yellow orange of the alizarin acid, but is a bright red suggestive of the color of alizarate ion in aqueous solution. “A newly formed oxide free from adsorbed ions will form a red lake either from an aqueous solution of sodium alizarate or from an alcoholic solution of alizarin. Depending on the conditions of formation and the age of the oxide, the adsorption of alizarate may be exchange adsorption, direct adsorption, or both. The effect of calcium was tested by adding a solution of calcium chloride to a solution of sodium alizarate in varying concentrations, and in every case a purple precipitate was formed. When insufficient calcium is added a purple precipitate is obtained and a red filtrate, which is probably sodium alizarate. Some of this filtrate was added to alumina and a red lake was produced which did not change its appearance when treated with more calcium. Also to the alcoholic solution of alizarin calcium chloride was added and a brown precipitate and some purple precipitate were formed. The former is due to the alizarin precipitating and the latter is due to the formation of calcium alizarate. Since the color of calcium alizarate is purple, and since calcium added to an alumina lake does not produce a color lake but intensifies the red color, the conclusion of Weiser that the effect of the calcium ion is to increase the charge on the mordant, thereby enabling it to adsorb more of the dye anion, is the correct one. The lake is then formed by the addition of sodium alizarate to alumina, and then the addition of calcium acetate. The lake was made as follows:z o o cc. of alumina 7 5 cc. of sodium alizarate was added 2 5 cc. of calcium acetate (0.01N) was then added Temperatures: Room Temp. (25O), 30°, 3 5 O , 4 5 O , 5 s 0 , 6 j 0 , 75’ and 8j”. A red lake was formed in all cases, which settled out on standing. The lake a t 2 5 ’ was chosen for peptization experiments, for Bancroft2 has shown that the amount of adsorption must decrease with rising temperature, and this lake would contain the greatest quantity of the dye adsorbed. Peptzzatzon of the lake.-Since the lake settled out on standing it would be better to peptize it, for then it would be in colloidal solution and taken up more readily by the fiber. With ammonium hydroxide :-Weber3 said that the solubility in dilute ammonia is a property common to all the alumina lakes of the ortho-dihy-
8
Weiser: J. Phys. Chem., 33, 1713 (1929). Bancroft: “Applied Colloid Chemistry,” 131 (1926). Weber: J. SOC.Chem. Ind., 12, 650 (1893).
494
J. W. ACKERMAN
droxyl dyes. Alizarin is the classical ortho-dihydroxyl dye, so Weber's statement suggested that the lake might be peptized by using ammonium hydroxide. Peptization with ammonium hydroxide.-A dilute solution of ammonium hydroxide was made by adding 500 cc. of water to IOO cc. of concentrated ammonium hydroxide. The lake was made as before, but no calcium was added. Using a constant amount of lake, the following amounts of ammonium hydroxide were added, after the lake had settled out. Amount of Lake Ij 11 11
11 11 11
11 11
1) 11
11 11 11
cc.
Amount of
",OH
cc. 2 cc. 3 cc. 4 cc. 5 cc. 1 0 cc. I 5 cc. 2 0 cc. 2 5 cc. 30 cc. 35 cc. 40 cc. 45 cc. I
Temp.
Room
Result
Lake precipitated out 11
7,
1
11
11
1s
11
11
11
11
11
1,
11
1f
,,
11
11
1
11
1,
11
11
11
1,
The same runs were made a t the following temperatures: 30' C, 35', 40°, Result: These lakes were all precipitated out. The lake is precipitated before the addition of the ammonium hydroxide by the sodium alizarate and the addition of the hydroxide only increases the negative charge on the particles and thus keeps them precipitated instead of peptizing them. The lake was made according to the formula previously given with the calcium acetate present. The same amount of lake and the same amounts of dilute ammonium hydroxide were used with the temperature varied as in the previous attempt for peptization. The results were the same as before-the lake precipitated out. The conclusion is then drawn that ammonium hydroxide will not peptize the lake under the conditions given. A better method to peptize the lake would be to add the ammonium hydroxide and then the sodium alizarate. I n this way, the alumina would probably be peptized and also the lake. This experiment was not carried out, for a subsequent experiment showed that the addition of a peptizing agent is unnecessary. Peptization of alumina with acetic acid.-The peptization of alumina by acetic acid was done by Rentley and Rose,' although they claimed that a 45', so', 55', 60°, and 65'.
1
Bentley and Rose: J. Am. Chem. SOC., 35, 1490 (1913).
495
DYEING WITH ALIZARIN LAKE
colloidal basic acetate was formed and not colloidal alumina. K. C. Sen1 was able to peptize alumina with acetic acid. Following the outline of Sen's work it was found that alumina could be peptized by acetic acid, but that the amount of acid reaches a maximum. With increase in concentration the stability decreases which is probably due to the fact that since the suspension is positively charged, the increasing concentration of the negative ion of the acid will have a coagulating effect on it. The alumina was made as before from aluminum chloride and ammonium hydroxide. The acetic acid used was 8% and a t a temperature of 60" C. Run
Amount of alumina
I
25
2
25
3
25
4
25
5
25
6
2j
7 8
25
9
25
25
cc. Acetic acid added
cc. cc. cc. cc. cc. cc. cc. cc. cc.
cc. cc. 3 cc. 4 cc. 5 cc. 6 cc. 7 cc. 8 cc. 9 cc. I
Result
Peptized
2
Small amount settled out More than Run j settled out )I
tf
11
6
If
I>
Almost completely ppt. Precipitated out
This checks the results of Sen.
P e p a m t i o n of the lake with acetic acid.-Since it is possible to peptize alumina, the next experiment is to try to peptize the alumina when the alizarate anion is adsorbed. The general scheme was to take a constant amount of lake and add to it varying amounts of acetic acid, keeping the temperature constant, and the strength of the acetic acid constant. The amount of lake was 1 5 cc., the temperature was 25' C. and the cc. of acid used were I , 2 , 3 , 4, 5 , I O and 2 5 cc. The concentration was 17~. The result was that the lake precipitated out. Then keeping the amount of lake constant as before, the same acid was varied from 1% to 157~. The lake precipitated as before. Finally, the same runs were made as the following temperatures: 45', js', 65' and 75' C. The results were the same-the lake precipitated out. The conclusion is that dilute acetic acid will not peptize the lake through the range of temperatures given. Weiser2 has shown by cataphoresis experiments that the lake is negatively charged. The addition of hydrogen ions from the acetic acid will tend to neutralize the charge on the lake, and it would be precipitated and not peptized. Peptization OJ' the lake without the addition of outside peptizing agent8.Weiser and Porter2 found that the proper amount of sodium alizarate would peptize the lake. This is the best way to peptize the lake for it eliminates the addition of a peptizing agent. 'K. C. Sen: J. Phys. Chem., 28, 1029 (1924). Weiser and Porter: J. Phys. Chem., 31, 1824 (1927).
496
J. W. ACKERMAN
The general scheme was as follows:The runs were carried out a t room temperature. 5 cc. of sodium alizarate was placed in a I O O cc. glass stoppered bottle. 2 j cc. of alumina was added and the bottle shaken immediately. Results: Temp. = Room temperature Run
Alumina
cc. Na Alizarate
I
25
5
2
25
IO
cc.
,I
,,
I,
25
I1
25
I2
,,
5 6
25
I3
Red
7 8 9
25
I5
25
16
25
I7
3 4
I1
25
I4
IO
25
18
I1
25
I9
25
20
I3
25
21
I4
25
22
I5
25
23
16
25
24
17
25
25
18
25
30
I a
Result
Color
Orange Deep red
,, ,, ,,
Lake precipitated out "
,,
,I
9,
,,
If
Lake settled out slightly ,I
,,
,?
,,
Lake stayed in suspension 1J
f
1,
,,
JI
1'
JJ
JI
,,
JI
1,
,,
,, ,,
t,
1,
,,
,,
)I
,I
tl
7,
JI
)7
>,
17
1,
Red-violet After standing a small quantity settled t o the bottom ,, I , Same as previous run but a little more settled out tt ,l Same as previous run but more settled out Violet-red Settled out I, I, Violet
,,
If
I,
Color-There is a gradual increase in the red color until run No. 13 where it goes toward the violet and then keeps increasing in violet color through run
No. 18. In the runs 1-3, the adsorption of the dye anions which are negatively charged neutralize the positive charges on the alumina, so that the lake settles out. The precipitation is less marked in runs 4 and 5, and between runs j and 6, which is a difference of I cc. of sodium alizarate the lake or the alumina reaches the iso-electric point, and with 14 cc. of sodium alizarate the alumina becomes negatively charged and stays in suspension. The addition of more of the sodium aliaarate did not have any apparent effect until the total quantity present was 2 1 cc. More than this started precipitation and when 2 j cc. had been added the precipitation was complete. The lake in suspension was examined with a slit ultramicroscope (Zeiss) and exhibited colloidal particles, uniformly dispersed, in lively Brownian movement. Peptization of the lake (calcium added).-We have said that the effect of the calcium ion on the formation of alizarin lakes is to increase the charge on
DYEING WITH ALIZARIN LAKE
49 7
the mordant, thereby enabling it to adsorb more of the dye anion. It was thought advisable to work on the lake with calcium acetate added, because more of the dye anion is adsorbed. The lake as made in the previous run KO.7 was used, because it was of good color and stayed up in suspension. A solution of 0.01 N calcium acetate was used. The general run was as follows: I j cc. of sodium alizarate was placed in a glass stoppered bottle ( IOO cc.) ; added I cc. of calcium acetate and then 2 j cc. of alumina. The bottle was shaken, and a red lake was formed. The runs were made at room temperature. The amount of sodium alizarate used in each run was 15 cc., the amount of alumina used was 2 5 cc., and the calcium acetate was varied. Run I
2
3 4
5 6 7 8 9
Calcium Acetate
cc. 2 cc. 3 cc. 4 cc. 5 cc. 6 cc. 7 cc. 8 cc. 9 cc. I
Result
Color
Deep red
Lake stayed in suspension
f )
11
1,
,,
,I
1,
11
t,
,, ,, ,l
91
,l
,l
11
11
lf
17
,, ,,
,,
,, ,,
f,
Settled out slightly Settled more Settled more than run No. 5 11
2,
1,
11
”
6
Almost completely ppt. Precipitated out
The lakes in suspension were examined with an ultramicroscope and exhibited colloidal particles clustered together in loose aggregates ( I O to 30 particles in an aggregate), but with only slight Brownian movement within the clusters, which indicated a tendency to flocculate. The calcium added in runs 1-3 is adsorbed by the alumina and increases the positive charge on the mordant, thereby enabling it to adsorb more of the dye anion. There is not enough adsorbed to precipitate the lake, so it stays in suspension. As the concentration of the calcium is increased, its effectiveness increases and more dye anions are taken up by the alumina. However, a point is reached a t which the adsorption of more dye anions is the same as adding more sodium alizarate. As in the case of the lake made with the alumina and sodium alizarate, a point is reached a t which the addition of more dye anions starts the precipitation of the lake. This starts at run No. 4 and the lake precipitates more and more until a t run No. 9 it is precipitated completely. The lake will then remain peptized as long as the calcium acetate is not added to the point a t which it starts the precipitation of the lake. This lake can then be used for dyeing, since it is peptized. Dyeing wool with alizarin lake:-A ball of wool (Fleisher’s Knitting Worsted) was cut up into strips about two feet long. The yarn was first (washing the wool) treated with a warm, dilute solution of Ivory soap and was then rinsed in tap water followed by many changes of hot distilled water.
498
J. W. ACKERMAN
The yarn was dried under a bell jar which contained some calcium chloride to take up the moisture. The lake for use in the dyeing was made as follows: 7 5 cc. of sodium alizarate Add 15 cc. of calcium acetate Then add I 7 5 cc. of alumina
-0.01
K
This was carried out at room temperature and the lake was stirred with an electric stirrer for a half hour, to insure complete mixing. Run No. I-The lake was put in a 500 cc. R.B. flask with a condenser attached to prevent evaporation. A sample of the fiber weight 1 . 2 7 gms. was put into the bath after it had been brought to a boil. Then slow but steady boiling was continued for forty-five minutes. The fiber was removed and allowed to stand under the bell jar with calcium chloride in it. The following day it was dry and found to weigh 1 . 2 9 gms. The wool was colored a deep red color. The sample of the fiber was tested by boiling in distilled water for a half hour. The water was colored and the lake was taken off the fiber to a large extent. Run No. 2-The same procedure was followed as in Run KO.I , but the bath was boiled for two hours with the fiber in it, and the rate of boiling was kept the same as No. I by estimation of the size of the flame and the rate of condensing. In this run the weight was found to be increased by 0.04 gms. The wool was dyed a deep red. The fiber was boiled in distilled water for one half hour, and part of the color came out of the fiber, but not as much as in run No. I . Run No. 5.-The same procedure was followed as in Run NO. I , but the bath was boiled for three hours with the fiber in it. In this run the weight of the fiber was found to be increased by 0.06 gms. After drying the wool was dyed a deep red. The fiber was placed in boiling distilled water for one half hour and the water was slightly colored, but very little color came off the fiber. Run No. 4.-The same procedure was followed as in Run No. I , but the bath was boiled for four hours with the fiber in it. I n this run the fiber was found t o have increased 0.068 gms. in weight. The wool was dyed a deep red. The fiber was placed in boiling distilled water for one half hour and the water was colorless. Tests on the Dyed Fibers Fading.-The tests for fading were carried out by means of the Fadeometer. The particular “Color Fade-ometer” used was run so that twenty hours of exposure to the Fade-ometer was equivalent to fifty hours of direct June sunlight. The fibers were exposed for a total of eighty hours, equivalent to two hundred hours of sunlight. Results.-Sample I.-This was faded very little, but it was noticed that it had an appearance of being a little more yellow than the original sample. The fading is so slight that it can be ignored.
DYEING WITH ALIZARIN LAKE
499
Sample 2.-This was the same as Sample I . Samples 3 and 4.-The samples were changed a little by fading, since they had a yellow tinge, The fading is so slight that they can be considered fast to light. Bleeding.-This has been explained under the various runs. It was noted that in run No. 4 the bleeding was negligible, so that the conclusion is that the fibers must be boiled in the bath between three and four hours. This is probably due to the fact that the longer boiling coagulates the lake on the fibers. Action of soap-A fairly concentrated solution of soap was made by cutting the Ivory soap and boiling in distilled water. The dyed fibers were then allowed to boil in the solution for one half hour and when removed, rinsed and dried, no change could be detected. Action of acid.-A strip of the dyed fiber was steeped for one hour in a 5% acetic acid solution. It was removed, rinsed and dried. No change could be detected. The wool was dyed a deep red color, and is very fast under the conditions given. There is little fading, only a slight bleeding, and the color resists the action of soap and also of acid. The color is satisfactory, but since a little color was washed off the fiber, the use of Turkey-red oil to fix the alumina more strongly on the fiber was tried, Weiser and Porter’ say: “If the fiber is treated with so-called sulphonated oils before mordanting with alumina, there results the brilliant Turkey-red, a color remarkable for its fastness to light and the action of soap and water.” Treatment of the jtber uith Turkey-red oil.-Parks2 has shown that sulphonated oils are adsolbed by cotton. Similar experiments with wool show that it adsorbs the sulphonated oil. The purpose of this set of experiments was to determine which was more desirable : Fibers treated with Turkey-red oil and then dyed. (I) Fibers dyed and then treated wit,h Turkey-red oil, (2) Run X o . I.-Wool, which had been kept under the bell jar containing calcium chloride, was dried in an oven at 5o°C. for twenty-four hours. Pieces of wool were then placed in solut,ions of Turkey-red oil and shaken in an electric shaker for eighteen hours a t room temperature. The wool was then removed from the solution and hung up to dry without previously pressing out the oil. However, the surplus could drain from the sample. After airdrying, the samples were then used for the dye bath. A lake was made by adding 7 5 cc. of sodium alizarate to zoo cc. of alumina, and then adding 15 cc. of 0.01N calcium acetate. 190 cc. of the above lake was used for the dyebath, which was brought to a boil. The wool was added and the bath WRS allowed to boil for four hours. Slow but steady boiling was WeiRer and Porter: J. Phya. Chem., 31, 1824 (1927). *Parks: J. Phys. Chem., 35, 4% (1931).
5 00
J. W. ACKERMAN
maintained. The wool was dried at room temperature. I t was dyed a deep red color, which was uniformly fixed on the fiber, and did not rub off. Run No. $.-The same bath was used as in the previous run, and the wool was dyed a red color. I t was then placed in a bottle containing the same concentration of Turkey-red oil and shaken for eighteen hours. It was dried at room temperature. I t was noted that the excess Turkey-red oil solution was a pink color a t the end of the shaking, which indicated that part of the lake came off the wool. The result was a red of much brighter color than in the previous run. I t was a brighter color for the wool had a shiny appearance, but the loss of color would not compensate for the additional brilliance of the finished product. Run No. 3.-This experiment was made to show the relative colors of the wool impregnated with Turkey-red oil and then dyed, of wool dyed and then treated with the oil, and finally of wool dyed with no treatment of oil. The same bath was used as in the previous runs, and the wool was used in the same amount and dyed in the same manner, without the use of Turkeyred oil. The red color obtained was lighter than Run No. I (wool impregnated and then dyed), but darker than Run No. z (wool dyed and then impregnated). The conclusion is that for the deeper color it is better to treat the fiber with oil and then dye; and for a brighter color it is better to dye the wool and then treat with oil, although the color is less intense. hlr. Parks’ has found that Turkey-red oil has a great affinity for alumina and is adsorbed by the cotton. He also says: “Experiments with Turkey-red oil and soap solutions show that whenever they come in contact with aluminum salts a colloid is formed. Therefore, if sulphonated oil be adsorbed by the fiber and this brought in contact with a bath of aluminum acetate, a colloid is formed which is fixed on the fiber. And since experiment shows that alumina removes soap from solution, the above-mentioned colloid must be due to the adsorption of alumina from solution by the sulphonated oil or soap. In fact the fiber is mordanted with alumina fixed by the oil or soap. Heat coagulates this colloid which then has the property of adsorbing more sulphonated oil or soap; and thus can adsorb more alumina. This is a property made use of by the dyers who repeat the oiling and metallic mordanting process several times in order to obtain a suitable amount of oxide on the fiber. ” This explanation is applicable for our results. The wool adsorbs the Turkey-red oil, and when it comes into contact with the lake, the oil adsorbs the alumina or lake, and heat coagulates the colloid which then adsorbs more alumina and fixes it on the fiber.
Cotton Dyeing with Alizarin Lakes Ordinary cotton cloth was used for this work, and the finish was destroyed by boiling the cloth in dilute alkali for one hour. I t was then dried at room temperature. Parks: J. Phys. Chem., 35, 488 (1931).
DYEING WITH ALIZARIN LAKE
501
A bath of the lake was prepared as follows:-To zoo cc. of alumina was added 7 5 cc. of sodium alizarate and then I j cc. of 0.01N calcium acetate. A red lake was formed. The cloth strips were put in the boiling bath, and boiling was continued for four hours. The cloth was removed, washed and dried a t room temperature. The color on the cloth was a good red, but a little lighter than that obtained wit'h the wool. The same theory applies for the dyeing the cotton as was used for the wool. Briefly, the alumina adsorbs the aliaarate anion of the sodium alizarate and a red color is produced. Then the cotton cloth adsorbs the alumina and is thus dyed red. The tests, which were used for the dyed wool were applied to the dyed cotton, except the fading test, which was omitted for lack of time. However, we may assume that approximately the same amount of fading would take place on the cotton as on the wool. Bleeding.-The cloth was boiled in water for one half hour and very little color came off the fiber. Acid.-A piece of the dyed fiber was steeped for one hour in a 5% acetic acid solution. I t was removed, rinsed and dried. No change was observed in the color. Soap-A fairly concentrated solution of soap was made by cutting up Ivory soap and boiling in distilled water. The dyed fibers were then allowed to boil in the solution for one half hour, and when removed, rinsed and dried, no change could be detected. Form to send out the lakes.-The lake may be sent out in the form of a paste. When the lake has been nearly filtered dry, it may be taken from the filter, mixed thoroughly with the small amount of water left, placed in bottles and shipped from the lake maker to the dyer. The paste then is redissolved in the required amount of hot water and is ready for use. The disadvantage of this method is that the lake must be shipped in bottles or some other container, which will prevent the evaporation of the water. Another method was tried in which a dilute solution of sodium oleate was added to the lake. Sodium oleate is a water-soluble colloid and is peptized by water. Therefore, if the lake takes up the sodium oleate and is then dried, the sodium oleate will carry the particles of the lake into suspension, when it is redissolved in water. After the addition of the sodium oleate, the lake was dried, then dissolved in water again, and then the dyeing operation was carried out. However, the wool when dyed and dried pulled apart due to the alkali in the lake from the sodium. This was remedied by treating the lake with dilute acetic acid before dyeing, which will neutralize the alkali formed. The wool was then dyed again and this method was found to be satisfactory. The lake might be treated with a dilute solution of ammonium oleate, which would not form an alkali strong enough t o attack the wool, and which consequently would make the addition of acetic acid unnecessary. Formation of a red lake from calcium phosphate and alizarin.-Another method for the preparation of a red lake was suggested by an observation of
J. W. ACKERMAN
502
Edward Bancroft:’ “The remarkable effect of madder in giving its red colour to the bones, but not to the soft parts of animals, with whose food it had been mixed appeared to indicate a considerable attraction between the calcareous earth and the coloring matter of this root, and I was induced by it to employ the former as a basis for the latter, in dyeing on both wool and cotton; but the effect did not answer my expectations, as neither lime recently burnt, nor the carbonate of it, when mixed with madder in water, produced colours more lively and permanent than madder alone. But broadcloth, boiled in water with lime and sulphuric acid, in such proportions as to neutralize the latter; and afterwards dyed with madder took a lasting red colour, though not so bright as when dyed upon the aluminous basis. Cotton, however, being treated in the same manner, was but slightly discolored. “hlr. John Belcher by adding some powder of madder roots to the food of dunghill fowls, found that a similar redness was thereby contributed to their bones; and he gave accounts of his observations and experiments to the Royal Societ,y, which were printed in the Phil. Trans. No. 442, and KO. 433, (1
7361.’’
Since the principal constituent of bones is tricalcium phosphate, and that of madder is alizarin, it was thought that a lake might be made with the phosphate as mordant and alizarin as dyestuff. Procedure and Experimental Results Mordant.-Solutions for the mordant were made up of calcium chloride (Kahlbaum) of a strength--2 grams in 50 cc. of water, and normal sodium phosphate (Na3P04)of a strength--I gram in 350 cc. of water. The mordant was made up in the following manner, using 50 cc. of calcium chloride throughout the run. cc.
Run
Na3POI
I
30
2
-25
3 4
20
5
IO
15
6
5
7 8
4
9
2
IO
Result
Flocculent white precipitate
3 I
,,
,)
,I
,l
,,
,I
,,
,!
If
,, ,) I,
Flocculent white precipitate 1)
,I
3,
White precipitate:-Settled
,,
,,
,,
,,
11
,9
more than 50.7 3 ,
)!
,,
,,
)I
2,
A solution of alizarin was prepared by dissolving alizarin in a solution of water and alcohol. An orange-yellow solution was obtained. 1
Edward Bancroft: “Philosophy of Permanent Colours,” 2 (1813).
503
DYEING WITH ALIZARIN LAKE
In order to determine the best lake it was necessary to add a constant amount of alizarin to the various mordants. The experiments were done at room temperature. Mordant
cc.
or Run
Alizarin
Result
I
5 5
Deep red flocculent ppt.
2
3
I1
11
,,
1)
Red flocculent ppt.
,,
1,
,l
4
5 6
Wine red flocculent ppt.
7
Red flocculent ppt. Light red flocculent ppt.
8
1,
9 IO
91
,,
,,
11
9t
,l
,, ,,
I1
,, 19
The results show that we can obtain a range in color from deep-red to light-red, and what Edward Bancroft observed was the formation of a lake between tricalcium phosphate and alizarin, and it was this lake which gave the red color to the bones. Dyeing.-For the dyeing, a lake was made as follows:-jo cc. calcium chloride, 30 cc. of normal sodium phosphate and 15 cc. of alizarin. A red lake was obtained. It was boiled and then the wool was added. The bath was boiled for three hours, and a bright red color was produced on the wool. I t was brighter and lighter than the lakes made with alumina as mordant.
Tests on the Dyed Fibers Fading.-There was practically no fading with the use of the Fade-ometer, after an exposure of forty hours, equivalent to one hundred hours of direct sunlight. Bleeding.-Boiling in water does not affect the color. Acid-Dilute sulphuric acid takes a small quantity of color off the fiber. Hydrochloric acid-destroys the color on the fiber. Base.-Ammonium hydroxide turns the color purple.
Conclusions The process of dyeing Turkey-red as practised may be summarized as follows : ( I ) The fiber is bleached. Some soapforming oil is adsorbed on the fiber. (2) (3) The oil is saponified on the fiber. (4) The excess soap and oil is removed from the fiber. ( 5 ) The soap containing fiber adsorbs alumina. ( 6 ) The alumina adsorbs alizarin ions and calcium ions. ( 7 ) The clearing operations remove the dirt, increase the size of the particles, and varnish the dyed fiber with a very thin film of tin soap.
504
J. W. ACKERMAN
In the proLess for dyeing Turkey-red as proposed in this paper, a lake is made by the addition of sodium alizarate and calcium acetate to alumina. This lake can be used directly for dyeing, because the wool adsorbs the alumina, which has already taken up the dye. The lake maker can prepare varying ranges of color by different proportions of the materials, and the dyer may obtain different results by the use of Turkey-red oil before or after dyeing. Since alizarin is the chief example of the Mordant dyes, this method of dyeing is applicable to this class. However, the possibilities have been barely touched. With additional work, we might include part of the substantive dyes-those that du not dye wool directly, and the developed dyes which are so insoluble that they do not dye in the bath. Also the methods ought to be worked out for another mordant, such as the hydrous oxide of chromium. With this mordant, chrome colors should be tried, such as Solochrome B, etc. The limitations are few for the method and any color that requires a mordant could probably be used. Many differences in shades, brilliancy and strength of color could be worked out by slight changes in the method to fit the particular dyestuff.
Summary I. Alumina treated with a solution of sodium alizarate or with an alcoholic solution of alizarin yields a red lake. The alumina adsorbs the alizarate anion, producing the red color. Sodium alizarate in the solid state is purple, but in dilute solutions it is red. 4. The purpose of the calcium is to increase the amount of the alizarate anion taken up. 5 . The results 1-4 confirm the work of Weiser and Porter on the aluminaalizarin lakes. 6. The lake cannot be peptized with ammonium hydroxide, under the conditions given. 7. The lake cannot be peptized with acetic acid, under the conditions given. 8. The lake is peptized by adding the proper amount of sodium alizarate t o alumina. 9. A method of dyeing with alizarin lakes is described. IO. The use of Turkey-red oil with lakes is discussed. I I. A red lake is formed by the use of tricalcium phosphate and alizarin. 2.
3.
Acknowledgment I t is with great pleasure that I take this opportunity to express my sincere appreciation to Professor Wilder D. Bancroft, a t whose suggestion this investigation was undertaken. I am greatly indebted to him for his interest, helpful criticism, and valuable suggestions throughout the progress of the work. I also wish to express my appreciation to Professor Clyde W. Mason for his aid and suggestions in connection with the ultramicroscopic work. CorneZZ University.
