Polymer Science Overview - American Chemical Society

1 Herman F. Mark: The Early Years, 1895-1926 G. A L L A N STAHL

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"In my boyhood, life in Vienna was like a wheel with equal parts of discipline, creativity, and sports, Oh yes, sports." H. F. Mark Herman Francis Mark was born in Vienna on May 3, 1895. The oldest of three children and son of a family physician, he was raised in that city's Fourth District, then a semi-commercial area inhabited by lower middle class families. Mark's father was a German Jew who embraced Lutheranism on marriage. Mark's turn of the century Vienna was exciting yet genteel. Its atmosphere was one which fostered new things. An atmosphere which has been described as being at its best because it was a time of change tempered by things old. The model of the exposures which Mark was refering above was not inaccurate, for Mark was born into a special place in a special time. The discipline he mentions was taught by example by i n t e l l i gent, benevolent adults. A young middle-class Viennese was taught to seek knowledge and maintain an open mind in judging facts. He was taught cooperation and how to listen, yet intellectual freedom was also fostered. Freedom to question and analyze, and rethink. A freedom which, Mark cautions, should not be confused with undisciplined, boundless movement. C r e a t i v i t y was a l l about him s i n c e Vienna was l e a d i n g the world i n the development of new music, a r t , and a r c h i t e c t u r e . Viennese Arnold Schonberg, Johann Strauss, and Richard Strause were making t h e i r i n d e l i b l e marks on music of the e r a , and the e x p r e s s i o n i s t p a i n t e r s Oskar Kokorshka and Egon S c h i e l e were s t i r r i n g the a r t world. There was a l s o Sigmund Freud and h i s r e v o l u t i o n a r y ideas about the framework of the human mind, and Theodor H e r z l who, w i t h the s c i e n t i s t - a u t h o r Chaim Weizmann, founded and lead the Z i o n i s t movement. Many o f these i n d i v i d u a l s were v i s i t o r s i n the Mark home, and t h e i r presence, by the sheer

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0097-6156/81 /0175-0005$5.00/0 1981 American Chemical Society

Stahl; Polymer Science Overview ACS Symposium Series; American Chemical Society: Washington, DC, 1981.


POLYMER SCIENCE OVERVIEW

Figure 1.

Herman Mark, age 12, near Vienna.



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Early Years 1895-1926

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d r i v e of t h e i r p e r s o n a l i t i e s , had a tremendous i n f l u e n c e on Herman. Completing the wheel was s p o r t s . "Oh yes, s p o r t s " , rendered with a w i s t f u l n e s s which shows t h e i r importance i n Mark's l i f e . In h i s boyhood, he was an e x c e p t i o n a l performer i n soccer, t e n n i s , and mountain c l i m b i n g . A g i f t e d a t h l e t e , Mark ran t o and from s c h o o l , o f t e n exhausting h i s f r i e n d s with seeming unending energy. He played on a l o c a l f o o t b a l l c l u b , and became an accomplished s k i i e r and mountain climber. Besides the obvious p h y s i c a l maturation sports nourished, there was an a d d i t i o n a l benefit. Through s p o r t s , an a t t i t u d e o f healthy competition was developed. Not as e s t a b l i s h e d as today, sports of that era s t r e s s e d p h y s i c a l e x e r c i s e and competition of s k i l l s . Winning was not as important as i t i s now. "My brother always had high grades except i n behavior, and t h i s was a great p a i n t o our father. One day he came home e a r l y and t o l d our mother that he had heard one gentleman t e l l another: 'The worse boys i n the area are the Mark boys!'" Hans Mark, M.D. The three segments i n p l a c e , the mischievious Mark grew up i n a wholesome world. On a t y p i c a l day he would a r i s e and b r e a k f a s t , run two miles to school a t the T h e r e s i a n i c h e Akademie, attend c l a s s e s lunching a t s c h o o l , and then run home. A f t e r school he would p l a y tennis or soccer u n t i l dark, have dinner, and study u n t i l bedtime. This i s , o f course, unless the f a m i l y attended a concert o r opera, which was two or three times a month. On these o c c a s i o n s , he would study during lunch. Between 8 and 15 years o f age, Mark has described h i m s e l f as "ambitious". From 16 t o 18 years, he says he "worked l e s s " and was " l e s s concerned with e x c e l l e n c e " . His e x t r a o r d i n a r y energy was evident at a l l times. At age twelve, Mark experienced one of those molding events which most s c i e n t i s t s appear to have had, and almost a l l seem t o enjoy r e l a t i n g . Mark and h i s c l o s e f r i e n d , Gerhardt K i r s c h , toured the l a b o r a t o r i e s of the U n i v e r s i t y of Vienna a t the i n v i t a t i o n o f Gerhardt's f a t h e r , a p r o f e s s o r of M a t e r i a l Science. The boys returned home e x c i t e d by "the s i g h t o f f l a s k s and beakers and r e t o r t s , of blue flamed Bunsen burners, of bubbling l i q u i d s and the lengths of rubber tubing that c a r r i e d o f f t h e i r vapors". The c l i c h e ' i s probably accurate i n so f a r as "nothing was ever the same again".


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Before long both Herman and Gerhardt had made l a b o r a t o r i e s of t h e i r bedrooms. T h e i r access to chemicals, through t h e i r f a t h e r s , was broad. They performed c o l o r changing r e a c t i o n s , burned s u l f u r , and e v e n t u a l l y graduated i n t o more s o p h i s t i c a t e d , q u a l i t a t i v e a n a l y s i s of metal s a l t s and the g e n e r a t i o n of gases. They even once obtained a spectroscope to experiment with, through the avuncular g e n e r o s i t y of a Mr. Waldstein. It should a l s o be noted, that Herman and G e r h a r d t s i n t e r e s t i n s c i e n c e was f u r t h e r e d by one of t h e i r teachers, a p r i e s t named H I a v a t i . F r . H l a v a t i taught mathematics, p h y s i c s , and chemistry. With h i s l e c t u r e s and e s p e c i a l l y h i s demonstrations and experiments, he piqued t h e i r imaginations, and, according to Mark, was the one man who most i n t e r e s t e d them i n the study of nature and, i n p a r t i c u l a r , p h y s i c a l s c i e n c e . Gerhardt K i r s c h , three years o l d e r than Herman, graduated from gymnasium, attended the U n i v e r s i t y o f Vienna, and e v e n t u a l l y became a p r o f e s s o r of p h y s i c s .


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"Oh, they always g i v e b i g medals to the high ranks, and l e s s e r ones to the others. I was j u s t f o r t u n a t e enough to be a L i e u t e n a n t . " H. F. Mark

"I f i r s t met Mark i n 1918 a t the U n i v e r s i t y of Vienna where we both had a summer study leave from the armed f o r c e s . I quickly recognized that he was a g i f t e d student i n a d d i t i o n to having gained e x c e p t i o n a l merit i n the war. That summer he was presented the Leopold Orden which was unusual f o r a junior o f f i c e r . " E. Schmid Herman took h i s f i n a l examination i n J u l y , 1913. At that time m i l i t a r y s e r v i c e was mandatory f o r a l l young men, thus h i s only d e c i s i o n was whether to go d i r e c t l y i n t o the army f o r h i s one year's s e r v i c e , or to take h i s s t u d i e s a t the U n i v e r s i t y and then serve. He, a f t e r c o n s u l t a t i o n with h i s f a t h e r , e n l i s t e d as a p r i v a t e i n the e l i t e A l p i n e i n f a n t r y u n i t , the K a i s e r s c h u t z e n regiment. He was immediately s t a t i o n e d i n the mountains of South T i r o l . Pre-World War I army l i f e was f a r from d i s a g r e e a b l e to Mark. I t s a t i s f i e d both h i s need f o r p h y s i c a l a c t i v i t y and t h i r s t f o r knowledge. A f t e r a few months he was an acknowledged mountaineer, spoke I t a l i a n , and even, he claimed, was growing on the "good" army food.



STAHL

Early

Figure 2.

Figure 3.

Years

1895-1926

The 1913 externe class of the Theresianiche Akademie.

Lt. Herman Mark and comrades in the South Tirol, 1917.



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POLYMER SCIENCE

OVERVIEW

On June 23, 1914, as Mark neared the end of h i s s e r v i c e , the events of Serajevo changed everything. The K a i s e r s c h u t z e n regiment was immediately reassigned to combat, not i n the mountains, but on the p l a i n s of G a l i c i a on the Russian f r o n t . I l l t r a i n e d f o r d e f e n s i v e warfare on a massive f r o n t the A u s t r i a n s f e l l back before a coordinated Russian a t t a c k . In the ensuing two months they r e t r e a t e d n e a r l y 300 m i l e s . Corporal Mark, however, f r e q u e n t l y stood out. In the b i t t e r b a t t l e s of Lvov and Przemysl, i n which the regiment r e p o r t e d l y l o s t e i g h t y - f i v e percent of i t s men, Mark was decorated f o r bravery. Once i n a r e a r guard a c t i o n he s i n g l e handedly held ten Russians a t bay u n t i l h i s u n i t was s a f e l y withdrawn. His stamina kept him i n good stead, j u s t out of harm, u n t i l i n September, 1914, he was shot i n the r i g h t a n k l e . Wounded, he was evacuated to Hungary, where i t was a s c e r t a i n e d that the b u l l e t had broken a bone, and he would require additional hospitalization. He was then sent to Vienna. Back i n Vienna, Mark spent the Christmas of 1914 h e a l i n g at home. But r e s t and r e l a x a t i o n f o r t h i s s o l d i e r took an unusual form, f o r d u r i n g t h i s break he began h i s study of chemistry at the U n i v e r s i t y of Vienna. He completed one of the e i g h t r e q u i r e d semesters of study, and then returned with h i s regiment to the f r o n t . T h i s time they were sent to the more f a m i l i a r but no longer h o s p i t a b l e mountains along the A u s t r i a n I t a l i a n border. During the next three years A u s t r i a and I t a l y fought a stalemate, n e i t h e r side a b l e to win a d e c i s i v e v i c t o r y . Slowly, however, the t i d e began to r i s e i n favor of the I t a l i a n s . In those days, the desperate A u s t r i a n s used the K a i s e r s c h u t z e n regiment as an a t t a c k f o r c e to r e g a i n l o s t t e r r a i n . On one such occasion Lieutenant Mark, now decorated f o r v a l o r on numerous occasions, won one of A u s t r i a ' s highest awards for bravery, the Leopolds-Orden, at Zugna T o r t a . In the summer of 1918, the I t a l i a n s captured Zugna T o r t a , a peak, and threatened the c i t y of Trento. Tossed i n t o the c o n f l i c t , Mark's regiment s u f f e r e d g r e a t l y t r y i n g to recapture the h e i g h t s . In a f i n a l and desperate d r i v e , Mark l e d s e v e r a l hundred men over the r i d g e , and, thus, saved the c i t y . During the same summer, he returned to the campus and completed another semester of study. The semester i n which, as Schmid p o i n t s out, his e x c e p t i o n a l l y h i g h academic a b i l i t i e s were recognized. Mark returned to the f r o n t during the f a l l , but h i s s a c r i f i c e s were i n v a i n . The A u s t r i a n f r o n t c o H a s p e d i n November, 1918, and Mark, now the most decorated companygrade o f f i c e r i n the A u s t r i a n Army, was imprisoned by the Italians.



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P r i s o n as i t turned out was i n an o l d convent near Monopoli i n Southern I t a l y . Mark and h i s comrades had a r e l a t i v e l y good l i f e . C e r t a i n l y they would have p r e f e r e d to have been home, but most of them, p r o f i t a b l y , used the time to study. I t a l i a n was the most popular s u b j e c t , but a few, l i k e Mark, i n c l u d e d French and E n g l i s h . Very few, however, j o i n e d Mark i n extending t h e i r s t u d i e s to i n c l u d e chemistry. Good hosts, the I t a l i a n s purchased books f o r t h e i r p r i s o n e r s . These were d i f f e r e n t times i n t h i s f i r s t of the modern wars. Many of the o l d ways s t i l l p r e v a i l e d . The p r i s o n e r s , j u s t as an example, r e c e i v e d t h e i r pay and m a i l . Mark would have passed these times p a t i e n t l y had he not r e c e i v e d a l e t t e r from Vienna i n May, 1919, informing him that h i s f a t h e r was s e r i o u s l y i l l . I n a made f o r Hollywood s c r i p t , Mark prearranged a f i s t f i g h t w i t h another p r i s o n e r i n order to be sent t o a d i s c i p l i n a r y camp. I n r o u t e , he bribed an I t a l i a n sergeant to look the other way as he escaped i n the washroom of a r a i l w a y s t a t i o n . Next, he sewed on a few brass buttons t o make h i s green A u s t r i a n uniform look more l i k e that o f a B r i t i s h p r i v a t e , and boarded a t r a i n headed n o r t h . Enroute, a B r i t i s h C o l o n e l sat near him. For m i l e s he avoided the C o l o n e l ' s s t a r e u n t i l , f i n a l l y , Mark decided that candor was h i s best course. " I f e e l o b l i g e d to e x p l a i n the s i t u a t i o n , " he s a i d i n h i s r e c e n t l y p o l i s h e d E n g l i s h . He d i d , and continued home without f u r t h e r i n c i d e n t . On a r r i v a l i n Vienna i n August, 1919, he found h i s f a t h e r much improved and himself a n a t i o n a l hero. Unimpressed, Mark e n r o l l e d i n the U n i v e r s i t y i n September, 1919, to continue his s t u d i e s . "I have e s p e c i a l l y high expectations of young Mark." E. Schroedinger

"The concept of 'Free R a d i c a l s ' was not known i n 1920, w e l l perhaps i n p o l i t i c s but not i n chemistry." H. F. Mark Mark took advantage of every opportunity t o recover the time l o s t during the war; completing three academic semesters a year he graduated suma cum laude w i t h a Ph.D. i n chemistry i n J u l y , 1921. His major p r o f e s s o r was Wilhelm Schlenk, a h i g h l y respected organic chemist. His work, i n which h i s experimental d e x t e r i t y was e s p e c i a l l y notable, was both timely and w e l l r e c e i v e d . Mark, i n h i s d i s s e r t a t i o n t i t l e d "The Synthesis of Pentaphenylethyl", discussed the presence of the r e c e n t l y proposed f r e e r a d i c a l . The f i n d i n g s were published i n two papers with Schlenk (1, 2 ) .



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POLYMER SCIENCE

OVERVIEW

At the time of Mark's graduation, Schlenk accepted a p o s i t i o n as successor to E m i l F i s c h e r at the U n i v e r s i t y of Berlin. Mark and three other graduates w i t h great p o t e n t i a l went w i t h Schlenk. In B e r l i n , he was exposed to s c i e n t i s t s who were world renown experts i n t h e i r r e s p e c t i v e r e s e a r c h fields. Among the chemists he met K a r l Fruedenberg ( p o l y s a c c h a r i d e s ) , Herman Leuchs ( a l k a l o i d s ) , Max Bergmaun ( p o l y p e p t i d e s ) , and C a r l H a r r i e s (rubber), and the great Walther Nernst. He a l s o met some c e l e b r a t e d p h y s i c i s t s i n c l u d i n g A l b e r t E i n s t e i n , Erwin Schrodinger, Max Planck, and Max von Laue. Mark's r e s e a r c h was an extension of h i s s t u d i e s with Schlenk i n Vienna. A second and g r e a t e r o p p o r t u n i t y came h i s way i n the s p r i n g of 1922. P r o f e s s o r F r i t z Haber, d i s c o v e r e r of the Haber ammonia s y n t h e s i s process and head of the K a i s e r Wilhelm I n s t i t u t e f o r P h y s i c a l Chemistry (now known as the Max Planck I n s t i t u t e ) , contacted P r o f e s s o r Schlenk. Haber's I n s t i t u t e , although e s t a b l i s h e d to study pure r e s e a r c h i n 1911, was completely i n v o l v e d w i t h the development of gas warfare i n the F i r s t World War. A f t e r the war, as Germany's l e a d i n g s c i e n t i f i c o r g a n i z a t i o n , i t was again d i v e r t e d . T h i s time to study the e x t r a c t i o n of gold from sea water i n an e f f o r t to pay Germany's war r e p a r a t i o n . T h i s e f f o r t would be u n s u c c e s s f u l and would torment Haber f o r the remainder of h i s l i f e . However, while d i v e r t e d , Haber recognized the need to s t i m u l a t e the l a r g e German chemical i n d u s t r y , and thus he helped e s t a b l i s h s i m i l a r i n s t i t u t e s f o r a p p l i e d r e s e a r c h . The I n s t i t u t e f o r F i b e r Research, e s t a b l i s h e d i n 1920 and d i r e c t e d by R. 0. Herzog, was one such o r g a n i z a t i o n . In 1922, Herzog had gathered a team of e x c e l l e n t p h y s i c a l chemists and p h y s i c i s t s . Among them, Michael P o l a n y i , K a r l Weissenberg, E r i c h Schmid, and Rudolf B r i l l . Since he i n tended to study organic f i b e r s s t a r t i n g with c e l l u l o s e , he f e l t i t a d v i s a b l e to broaden t h i s team with an organic chemist. Haber asked h i s o l d f r i e n d Schlenk to recommend a young organic chemist w i t h a wide range of i n t e r e s t s . As a r e s u l t of Schlenk's recommendation, Mark was c a l l e d to meet with Haber. Mark r e c a l l s that Haber and Schlenk s a t on e i t h e r s i d e of him, enveloped h i s head i n a cloud of c i g a r smoke, and then, a p p r o p r i a t e l y , recommended that a change i n atmosphere would be to h i s advantage. That summer, Mark moved to the B e r l i n suburb of Dahlem, and j o i n e d P o l a n y i ' s r e s e a r c h s e c t i o n .


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" A f t e r I f i n i s h e d my high s c h o o l s t u d i e s i n Vienna, I j o i n e d the s t a f f i n Dahlem, and was t o l d I would work i n X-ray c r y s t a l structure. I t o l d Mark I couldn't imagine the vaguest t h i n g about i t . He s a i d , "Don't worry." You shouldn't l e t people i n t i m i d a t e you with t h e i r Hokus-Pokus."


0. Kratky

Mark's f i r s t assignment was, with B r i l l , to set up two X-ray tubes i n order to study the s t r u c t u r e of simple compounds. Mark c r e d i t s t h i s approach t o Herzog and P o l a n y i , and has s a i d that i t was a key to h i s l a t e r successes i n the polymer areas. " I f we had s t a r t e d " , Mark summarized over a h a l f century l a t e r , "with c e l l u l o s e and rubber, and not z i n c and t i n , we would have f a i l e d . " However, i n 1922 t h e i r problems were even more b a s i c . Neither Mark nor B r i l l had any experience i n the f l e d g i n g study of X-rays. Although Herzog would e v e n t u a l l y devote o n e - t h i r d o f the I n s t i t u t e to X-ray s t r u c t u r e determination, t h i s p a r t i c u l a r e a r l y e f f o r t could not even be placed i n the I n s t i t u t e ' s b u i l d ing. Thus Mark and B r i l l began hand c o n s t r u c t i o n of t h e i r equipment i n the basement of Haber's v i l l a . Haber d i d not mind the i n t r u s i o n , and although she d i d not approve, Mrs. Haber accepted the workers. The Haber's dog had d i f f e r e n t views. Had the r e s o u r c e f u l novice c r y s t a l l o g r a p h e r s not learned t o b r i b e the pug w i t h sausage, the course of X-ray s t r u c t u r e determination might have been d i f f e r e n t . When Mark and B r i l l began using t h e i r X-ray equipment to i n v e s t i g a t e the l a t t i c e s t r u c t u r e o f metals, and simple organic and i n o r g a n i c compounds, equipment Mark has s i n c e d e s c r i b e d as an a i r f i l l e d X-ray tube, a r u l e r , and a l o g t a b l e , they were e a r l y students o f an i n f a n t a n a l y t i c a l technique. Only a few l a b o r a t o r i e s were, at that time, working e x t e n s i v e l y i n the f i e l d . They i n c l u d e d the l a b o r a t o r i e s of Debye and Scherrer (Gottingen), the Braggs (London), Nishikawa and Ono (Tokyo), and Herzog (Dahlem). X-ray d i f f r a c t i o n was i n 1922 only r e c e n t l y born of the b r i l l i a n t hypothesis and experimental v e r i f i c a t i o n by Max von Laue, and e q u a l l y b r i l l i a n t c o n f i r m a t i o n of von Laue's work by the B r i t i s h p h y s i c i s t s , W. H. Bragg and h i s son W. L. Bragg.



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POLYMER SCIENCE

OVERVIEW

P r i o r to von Laue, p h y s i c i s t s had obtained i n f o r m a t i o n about c r y s t a l s t r u c t u r e through chemical a n a l y s i s , i n t e r f a c i a l angle measurements, and the determination of p h y s i c a l properties. There was l i t t l e knowledge of the i n t e r n a l s t r u c t u r e , although i t was b e l i e v e d that c r y s t a l s were b u i l t up by p e r i o d i c r e p e t i t i o n of some u n i t , probably an atom or molecule, and that these u n i t s were about 1 or 2 Â a p a r t . I t was a l s o suspected, but not confirmed, that X-rays were electromagnetic waves of about 1 or 2 Â i n wavelength. Von Laue, w i t h these p o i n t s i n mind, hypothesized i n 1912 that i f c r y s t a l s were composed of r e g u l a r l y spaced atoms of i n t e r a t o m i c d i s t a n c e about equal to the wavelength of X-rays they might a c t as s c a t t e r i n g centers f o r X-rays. As a model, he knew of the phenomenon of d i f f r a c t i o n , and as an example he knew that v i s i b l e l i g h t was s c a t t e r e d by a set of r e g u l a r l y spaced o b j e c t s , such as a r u l e d g r a t i n g . Under von L a u e s d i r e c t i o n , two young p h y s i c i s t s F r i e d r i c h and Knipping t e s t e d t h i s hypothesis by a simple experiment. They set a c r y s t a l of copper s u l f a t e i n the path of a narrow beam of X-rays and i n f r o n t of a photographic p l a t e to r e c o r d the presence of d i f f r a c t e d beams. On development of the p l a t e , they found that the f i r s t experiment was s u c c e s s f u l . I t demonstrated without a doubt that X-rays were d i f f r a c t e d by the c r y s t a l out of the primary beam forming a p a t t e r n of spots on the photographic plate. By the f o l l o w i n g year, the Braggs had confirmed von Laue's d i f f r a c t i o n experiment, given d i r e c t proof of the e x i s t a n c e of the space l a t t i c e , and provided a simple expression (the Bragg Law) f o r the r e l a t i o n s h i p between the wave length of X-rays used and the l a t t i c e spacings i n the c r y s t a l . The r o u t i n e c o l l e c t i o n of d i f f r a c t i o n p a t t e r n s was l a t e r promoted by the i n v e n t i o n of the X-ray goniometer by K. Weissenberg i n Dahlem i n 1924. The technique r e c e i v e d immediate acceptance by those studying c r y s t a l s t r u c t u r e , and was q u i c k l y a p p l i e d to the i n v e s t i g a t i o n of n a t u r a l f i b e r s by R. 0. Herzog at the I n s t i t u t e f o r F i b e r Research. By the summer of 1920, Herzog and h i s a s s i s t a n t W i l l i e Jancke were o b t a i n i n g powder p a t t e r n s from crushed c e l l u l o s i c f i b e r s and had began to i r r a d i a t e e n t i r e f i b e r s i n the hope that evidence of a r e g u l a r s t r u c t u r e along the l e n g t h of the f i b e r might be found. 1

"He (Mark) once showed me an X-ray burn on h i s f i n g e r that he got w h i l e a d j u s t i n g a camera. Herzog c h a r a c t e r i z e d h i s manner of working as, 'Mark does not experiment w i t h X-rays; he f i g h t s w i t h them.'" 0. Kratky



Figure 4.

Fiber Research Institute in Dahlem in 1923.


1

Os

I

Oo

δ

H


16


Mark, i n the f i v e years he worked a t the I n s t i t u t e , e s t a b l i s h e d himself as an expert c r y s t a l l o g r a p h e r . Between 1923 and 1927 more than f i f t y papers were (co)authored on the l a t t i c e s t r u c t u r e of metals, simple organic and i n o r g a n i c compounds, and polymers. The l a b o r a t o r y became known as an e f f i c i e n t , smoothly f u n c t i o n i n g r e s e a r c h o r g a n i z a t i o n which a t t r a c t e d a l l kinds of v i s i t o r s . Max von Laue was a frequent v i s i t o r as was P. P. Ewald, the author of the f i r s t book on X-ray d i f f r a c t i o n . Others who v i s i t e d Dahlem were J . R. Katz from H o l l a n d , 0. H a s s e l from Norway, C.T. Greenwood from S c o t l a n d , J . J . T r i l l a t from France, S. N. Bose from I n d i a , and A l b e r t E i n s t e i n from B e r l i n . Working f i r s t with P o l a n y i , Weissenberg, and B r i l l , and l a t e r as the leader of the T e x t i l e Chemistry S e c t i o n , Mark s u c c e s s i v e l y published papers on the c r y s t a l s t r u c t u r e s of hexamethylenetetramine, p e n t a e r y t h r i t o l , z i n c s a l t s , t i n , urea, t i n s a l t s , triphenylmethane, bismuth, g r a p h i t e , s u l f u r , o x a l i c a c i d , acetaldehyde, ammonia, ethane, diborane, carbon d i o x i d e , and some aluminum s i l i c a t e s . Each paper showed h i s and the l a b o r a t o r y ' s i n c r e a s i n g s o p h i s t i c a t i o n i n the technique of X-ray d i f f r a c t i o n . T h e i r work over the p e r i o d broadened t o i n c l u d e c o n t r i b u t i o n s to the t h e o r i e s of atomic and molecular s t r u c t u r e and X-ray s c a t t e r i n g theory. A number of h i s papers were p a r t i c u l a r l y notable i n c l u d i n g h i s work w i t h P o l a n y i on the s t r u c t u r e of white t i n (_3, 4-), E. Wigner on the s t r u c t u r e of rhombic s u l f u r (5), and E. Pohland on the low temperature c r y s t a l s t r u c t u r e of ammonia and carbon d i o x i d e (6^ 7). The M a r k - S z i l a r d e f f e c t , a c l a s s i c a l component of X-ray p h y s i c s , was a r e s u l t of h i s c o l l a b o r a t i o n w i t h Leo S z i l a r d ( 8 ) . And h i s work w i t h E. A. Hauser (9, 10, 11) on rubber and J . R. Katz (12, 13, 14) on c e l l u l o s e introduced him to the r e s e a r c h f i e l d i n which he gained h i s g r e a t e s t fame. Mark's success at t h i s time can be a t t r i b u t e d to h i s aggressive and t i r e l e s s l a b o r a t o r y work complimented by acute powers of observation, a w i l l i n g n e s s to u n s e l f i s h l y p u b l i s h , and, by no means l a s t , to h i s remarkable a b i l i t y to l e a d . The e x c e l l e n c e of Mark and h i s a s s o c i a t e s was q u i c k l y recognized throughout the s c i e n t i f i c c i r c l e s of Europe. T h i s r e c o g n i t i o n was demonstrated i n many ways, but, as Mark adds, "one of the most p l e a s i n g acceptances" came i n 1923 when A l b e r t E i n s t e i n asked him to conduct some experiments of " s p e c i a l i n t e r e s t " . The r e s u l t of t h i s c o l l a b o r a t i o n was the r e p e t i t i o n by Mark and h i s a s s o c i a t e , Hartmut Kallmann, of A. H. Compton's famous c o n f i r m a t i o n of E i n s t e i n ' s light-quantum hypothesis (15,16).


Early

Years

1895-1926


STAHL

Figure 5.

X-Ray diffraction apparatus in the Fiber Research Institute.



18

POLYMER SCIENCE

OVERVIEW

Throughout h i s time at Dahlem, Mark worked c l o s e l y on the development of more powerful X-ray tubes which made p o s s i b l e new experiments on the fundamental p r o p e r t i e s of X-rays such as p o l a r i z a t i o n , coherence l e n g t h , anomalous d i s p e r s i o n , and i n e l a s t i c s c a t t e r i n g . B a s i c i n v e s t i g a t i o n s of these p r o p e r t i e s were c a r r i e d out by Mark together with Weissenberg, Ewald, Ehrenberg, Kallman, Wigner, Bose, and S z i l a r d . As the amount of r e s u l t s and the degree of experience progressed, Mark was encouraged to compile h i s f i n d i n g s . In 1927 he p u b l i s h e d an over 500 page t r e a t i s e on the a p p l i c a t i o n of X-rays i n chemistry and technology, "Die Verwendung der Roentgenstrahlen i n Chemie und Technik" (17). The book was a t r u l y imposing achievement f o r a s c i e n t i s t of j u s t over t h i r t y years of age. Otto Kratky, himself a h i g h l y respected s c i e n t i s t , r e c e n t l y s a i d that the book, Mark's f i r s t , " i s a f t e r f i f t y years most i n s t r u c t i v e and very readable".

Acknowledgements

In reviewing Herman Mark's e a r l y years and r i s e to prominence as a p h y s i c a l s c i e n t i s t the author wishes to make s p e c i a l note of the use of an e a r l i e r p r o f i l e of P r o f . Mark by Morton M. Hunt (18) , a s p e c i a l i s s u e of Chemie K u n s t s t o f f e A k t u e l l (19), and two taped i n t e r v i e w sessions with P r o f . Mark (20, 21, 22). A s p e c i a l thanks i s given to Ms. Jeanne S t r a u s s , P h i l l i p s Petroleum Co., f o r her p a t i e n c e i n c l a r i f y i n g a great d e a l of German f o r the author.

Literature Cited 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.

Schlenk, W. and Mark, H. Ber., 1922, 55B, 2285. Schlenk, W. and Mark, H. Ber., 1922, 55B, 2299. Mark, H. and Polanyi, M. Z. Physik, 1923, 18, 75. Mark, H. and Polanyi, M. Z. Physik, 1924, 22, 200. Mark, H. and Wigner, Ε. Z. Physik Chem., 1924, 111, 398. Mark, H. and Pohland, Ε. Z. Kristi, 1925, 61, 532. Mark, H. and Pohland, Ε. Z. Kristi, 1926, 64, 113. Mark, H. and Szilard, L. Z. Physik, 1925, 33, 688. Hauser, E. A. and Mark, H. Kautschuk, 1925, 12, 10. Hauser, Ε. A. and Mark, H. Kolloidchem. Beihefte, 1926, 22, 63. Hauser, E. A. and Mark, H. Kolloidchem. Beihefte, 1926, 23, 64. Katz, J. R. and Mark, H. Verslag. Akod. Wetenschappen Ansterdam, 1924, 33, 294.


1. STAHL Early Years 1895-1926 19


13. 14. 15.

Katz, J. R. and Mark, H. Z. Elektrochem., 1925, 31, 105. Katz, J. R. and Mark, H. Z. Physik Chem., 1925, 115, 385. Kallmann, H. and Mark, H. Naturwissenschaften, 1925, 13, 1012. 16. Kallmann, H. and Mark, H. Z. Physik, 1926, 36, 120. 17. Mark, H. "Die Verwendung der Roentgenstrahien in Chemie und Technik"; Johann Anbrosius Barth: Leipsig, 1926; 528 pp.. 18. Hunt, M. M. New Yorker, 1958. 19. Chemie Kunststoffe Aktwell, 1980, 34(2), 1-18. 20. Stahl, G. A. "Taped Interview with H. Mark", October 11, 1976. 21. Stahl, G. A. J . Chem. Educ, 1979, 56, 83. 22. Stahl, G. A. "Taped Interview with H. Mark", June 2, 1979. RECEIVED

August 10, 1981.


Polymer Science Overview - American Chemical Society

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