Publisher’s version / Version de l'éditeur:
Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la
première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca.
Questions? Contact the NRC Publications Archive team at
PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information.
https://publications-cnrc.canada.ca/fra/droits
L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB.
Technical Translation (National Research Council of Canada), 1948-10-02
READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE.
https://nrc-publications.canada.ca/eng/copyright
NRC Publications Archive Record / Notice des Archives des publications du CNRC : https://nrc-publications.canada.ca/eng/view/object/?id=ee5d22c8-32e2-4ddf-b31c-896b986a83ab https://publications-cnrc.canada.ca/fra/voir/objet/?id=ee5d22c8-32e2-4ddf-b31c-896b986a83ab
NRC Publications Archive
Archives des publications du CNRC
For the publisher’s version, please access the DOI link below./ Pour consulter la version de l’éditeur, utilisez le lien DOI ci-dessous.
https://doi.org/10.4224/20331642
Access and use of this website and the material on it are subject to the Terms and Conditions set forth at
Knowledge of crystallization from freezing, part III
Ser Q21 ~ 2 t 4 no. TT-80 IRC PUB COPY NO.
NATIONAL
RESEARCH
COUNCIL
OFCANADA
DIVISION OF MECHANICAL ENGINEERINGTECHNICAL 'TRANSLATION NO. TT
-
80THE
KNOWLEDGE OF CRYSTALLIZATION
FROM
FREEZING, PART 111
(ZUR KENNTNIS DER KRISTALLISATION VON SCHMELZEN, Ill) BY JULIUS MEYER AND WILLY PFAFF
OTTAWA 2 OCTOBER, 1948
Tkf I? REPOET hlAy K07. HE PI ! s [ . ( C i " D i : ?.." :. I' f
OR IF) r.qr.: ;~,l-:!q:j~ T; - r g , ; :r.:t:r ,;i- T H E fid?':?NP\h RE.. i:Ccr-i:C:i 2:,i-13.i C t L
N A T I O N A L RESEAHCH LABORATORIES
O t t a w a , Canada
TEC I-TJJICAL TRANSLATION
D i v i s i o n of Mechanical E n g i n e e r i n g Pages
-
P r e f a c e-
1-
Text-
1 0 Ff g u r e s-
3 Tech, Trans, TT-80 Date-
2 October, 1948, F i l e-
12-R4-22Lab, Order No, 5424A
T i t l e : Zur K e n n t n i s d e r K r i s t a l l i s a t f o n von Schmelzen, 111,
By: J u l i u s Meyer and W i l l y P f a f f ,
Reference : Ze i t s c h r f f t f a r a n o r g a n i s c h e und a l l g e m e i n e Chemie, Vol, 224 ( 1 9 3 5 ) , pp, 305-313,
S u b j e c t : THE KNOWLEDGZ OF CRYSTALLIZATION FROM FREEZING, PART 111, S u b m i t t e d by:: J o Lo O r r , T r a n s l a t e d by: Head, D o A , S i n c l a i r , Low Temperature L a b o r a t o r y , Approved by: J o Ho P a r k i n , D i r e c t o r ,
Tech, T r a n s , TT-80
.
THE KNO7i?LZDGE OF CRYSTALLIZATION PXOJA FREEZING
P Y _ _ _ Y _ _ _ - - ---
PART I11
The c r y s t a l l i z s t i o n o f s u p e r c o o l e d , f u s o d sub- s t a n c e s and s u p e r s a t u r a t e d s o l x t i o n s depends p r i m a r i l y on two f a c t o r s , t h e p r e s e n c e and nurnber o f c r y s t a l l i z a t i o n n u c l e i , c r , n o , and t h e c r g s t n l l i z a t i o r l v e l o c i t y , c r , v , , a t which t h e s e n u c l e i grow w i t h i n t h s o l u t i o n s and f'used s u b s t a n c e s , I n p r e v i o u s i n v e a t i g t ; t i o n s l T t h e a u t h o r s were a b l e t o r e d u c e t h e num5er o f c r , n , , , o r t o e l i m i n a t e them e n t i r e l y , by
s u i t a b l e f i l t r a t i o n , \ T i t h a c o n s i d e r a b l e number o f o r g a n i c s a b s t a n c e s t h e y were s u c c e s s f u l i n o b t a i n i n g masses which, d e s p i t e extreme s u p e r c o o l i n g , have now remained f l u i d f o r two g e a r s , The o r g a n i c s u b s t a n c e s which t h e y i n v e s t i g a t e d a t t h a t time f o r t u n a t e l y had v e r y low c r , v , , s o t h a t i t w a s s t i l l p o s s i b l e t o remove c r , n o by f i l t r a t i o n even from
masses t h a t were a l r e a d y s l i g h t l y s u p e r c o o l e d , A f l u i d which showed d e c i d e d r e s i s t a n c e t o a l l s u p e r c o o l i n g t e s t s o f a more d r a s t i c n a t u r e was w a t e r , Y i t h t h i s s u b s t a n c e , t o o , t h e a u t h o r s t r i e d t o p r e v e n t c r y - s t a l l i z a t i o n b y removing t h e c r , n o However, t h e g r e a t c r , v , o f w a t e r h a s s o f a r p r e v e n t e d t h i s , R e c e n t l y G o Tammann and A o ~ u e c h n e r ~ ) h a v e s t u d i e d t h e s u p e r c o o l i n g c a p a c i t y o f w a t e r , p a y i n g p a r t i c u l a r a t t e n t i o n t o t h e e x t e n t t o which i t s c r , v , m i g h t b e a l t e r e d t h r o u g h t h e p r e s e n c e o f o t h e r s u b s t a n c e s , Because of t h e v e r y g r e a t c r , v , o f w a t e r , which can be a s h i g h a s 1 0 m, p e r rniaute, i t h a s s o f a r h a r d l y proved p o s s i b l e t o c o u n t t h e c r , n , o f w a t e r a s G , Tammann and h i s c o l l a b o r a t o r s had suc- ceeded i n d o i n g i n t h e i r p r e v i o u s i n v e s t i g a t i o n s , c h i e f l y w i t h o r g a n i c s u b s t a n c e s o
The p r e s e n t a u t h o r s now a t t e m p t e d t o r e d u c e t h e number o f c r , n o a17d t o e l i m i n a t e them s o t h a t t h e c r y s t a l l i z a t i o n o f w a t e r u n d e r c o n d i t i o n s o f s u p e r c o o l i n g mfght p e r h a p s be a v o i d e d and t h u s a n amorphous g l a s s o f p u r e w a t e r would be a t t a i n e d , Depending on i t s d e g r e e o f p u r i t y , w a t e r i s e a s i l y s u p e r c o o l e d t o between - 5 t o
- l o o ,
b u t g e n e r a l l y s p e a k i n g , a f t e r a few s e c o n d s , even w i t h s m a l l q u a n t i t i e s o f water, c r y s t a l l f z s t i o n s e t s i n b e f o r e t h e w a t e r h a s r e a c h e d t h e t e m p e r a t u r e o f t h e c o l d b a t h , The spontarleouss o l i d i f i c a t i o n o f w a t e r was r e g u l a r l y o b s e r v e d b y Tarmnann and Buechner a t a p p r o x i m a t e l y 1 3 O s u p e r c o o l i n g , I t i s known t h a t
w a t e r c o n t a i n i n g a i r g e n e r a l l y c r y s t a l l 1 z e s a t a p p r o x i m a t e l y Z 0 h i g h e r t h a n w a t e r p u r i f i e d by b o i l i n g , By blowing a i r
Page . - 2
Tech, Trans, TT-811..
throdgh w a t e r which has been s u p e r c o o l e d t o approximately
-6 t o - 7 O t h e e n t i r e q u a n t f t g o r w a t e r may b e blaought f n - s t a n t a n e o u s l y t o s o l f d i f i c a t i o n w i t $ t h e spontaneous f o r - mation o f c o u n t l e s s t i n y i c e f l a k e s . ' ) , Tamrilanngs observa-
kfons, whfcn showed t h a t w i t h o r d i n a r y water the whole v e s s e l v e r y quizkky becomes i n t e r s p e r s e d wl t h d e n d r i t i c i c e c r y s t a l s , even a t s l i g h t s u p e r c o o l f n g , were confirmed b y t h e p r e s e n t a u t h o r s , F o r t h e i n i t i a t i o n s f c r y s t a l l % z a t i o n i n s u p e r c o o l e d s u b s t a n c e s a c r , n , i s always n e c e s s a r y , i , e , ; a s o l i d phase, which may be o f t h e same s u b s t a n c e , b u t may a l s o c o n s i s t of
an a1 togethela f o r e i g n one, b ' l u i d s which a r e e n t i r e l y f r e e from c r , n o a r e n o t bound by t h e o r d 5 r a ~ y % i m f t % n g s o l i d f f i - c a t i o n tem r a t u r e s , I n s u p p o r t of t h i s vfew Dufour Is ob- s c r v a t i o n s ~ ~ may b e c i t e d , Among o t h e r t h i n g s h f o u r e s t a b - l i s h e d t h e f a c t t h a t f l u i d s remain f l u i d f a r below t h e i r normal s o l i d i f f c a t i o n t e m p e r a t u r e s provided t h e y a r e n o t i n c o n t a c t w i t h s o l i d b o d i e s , b u t f l o a t , , f o r example, i n o t h e r f l u i d s , A drop o f l i q u i d s u l p h u r of 6 mm, d i a m e t e r w a s s t i l l f l o a t i n g i n l i q u i d form f n l i q u f d z i n c c h l o r i d e a t 50°C, a l t h o u g h t h e s o l f d i f i c a t f o n p o i n t of s u l p h u r f s approximately 11200 S f m f l a r l ~ , drops of w a t e r were c o o l e d w i t h o u t s o l i d i f y - i n g t o -20° i n a m i x t u r e of almond o i l and chloroform, Accord- i n g t o A, tlregener % o b s e r v a t i o n s s m a l l e r d r o p l e t s i n t h e Green- l ~ n d f o g appear t o w i t h s t a n d s u p e r c o o l i n g down t o -30°, I n a l l t h e s e phenomena ' i t would appear t h a t t h e s m a l l d i a m e t e r
o$ t h e d r o p l e t may be o f some s i g n f f i c a n c e ,
From a l l t h e s e o b s e r v a t i o n s f t can be con- cluded t h a t t h e c r y s t a l l i z a t i o n o f w a t e r , t o o , i s i n f t i a t e d by s o l i d f o r e i g n b o d i e s a c t i n g a s c , n o According t o t h e i n v e s t i g a t i o n s o f A , T o L i l i e i l t h a l ~ f t h e lorvest o b s a ~ v e d s u p e r c o o l i n g o f water t o d a t e i s 2105a0 T h e r e f o r e , i n s p i t e o f i t s v e ~ y h i g h c r , v,, i t should be p o s s i b l e t o reduce t h e s u p e r c o o l i n g t e m p e r a t u r e el' w a t e r s t i l l f u r t h e r by c a r e f u l remcval of t h e s o l i d
f o r e i g n b o d i e s and c r , n , a s was done i n t h e c a s e o f pre- v i o u s l y i n v e s t f g a t e d o ~ g a n i c s u b s t a n c e s ; and if a s u f f i c i e n t r e d u c t i o n i n t h e nunbela o f c r , n o can be o b t a i n e d , i t s h o u l d a l s o b e p o s s i b l e t o c u l t i v a t e m o n o c r y s t a l s of' i c e , a l t h o u g h p r e v i o u s l y t h e f l u i d water h a s u s u a l l y s o l i d i f i e d i n t o an i r r e g u l a r l y m a t t e d mass, Owing t o t h e g r e a t d i s s o l v i n g c a p a c i t y o f w a t e r e l l m f n a t f o n o f t h e c r , n o p r e s e n t s s p e c i a l d i f f i c u l t i e s , Furthermore an u n u s u a l l y l a r g e v a r i e t y o f s o l i d s u b s t a n c e s seem a b l e t o a c t a s c r y s t a l n u c l e i , s o t h a t n o t o n l y t h e matelaial o f t h e a p p a r a t u s , b u t a l s o t h e d u s t of t h e a i r , e t c , , may cause t h e break-up o f t h e super- cooled f l u i d , Even i f i t can be assumed t h a t d i s s o l v e d
Page
-
3 Tech, T r a n s , TT- 8 0 s u b s t a n c e s , e s p e c i a l l y i n t h e form of i o n s , do n o t i n i t i a t e c r y s t a l l i z a t i o n , n e v e r t h e l e s s i t must s t i l l be c o n s i d e r e d t h a t p r e c i p i t a t i o n of t h e m a t e r i a l i n q u e s t i o n by water causes t h e f o r m a t i o n o f porous and r o u g h * p l a c e s on t h e m a t e r i a l w a l l s , and t h e s e may t h e n a c t a s n u c l e i , I t i s t h e r e f o r e p r o b a b l e t h a t t h e q u a l f t y of t h e g l a s s used i n t h e s u p e r c o o l i n g t e s t s o f water i s i m p o r t a n t , Highly a l k a l o i d g l a s s w i l l f a v o u r t h e f o r m a t i o n o f n u c l e i more t h a n g l a s s of low a l k a l i c o n t e n t , t h e s u r f a c e of which s u f f e r s l i t t l e o r no damage, The ques- t i o n of t h e i n f l u e n c e o f t h e glass m a t e r i a l was c l a r i f i e d by s e v e r a l experiments u s i n g f r e s h l y d i s t i l l e d w a t e r i n t e s tt u b e s o f 5 t o 6 cm, l e n g t h and 0,4 t o 0,6 cm, d i a m e t e r , These t u b e s were made o f d i f f e r e n t k i n d s of g l a s s , The w a t e r was d i s t i l l e d d i r e c t l y i n t o t h e t u b e s , which had p r e v i o u s l y been cleaned w i t h a b s o l u t e a l c o h o l and e t h e r , and t h e tubes were immediately s e a l e d , They were p l a c e d g e n t l y and c a r e f u l l y i n a t r a n s p a r e n t Dewar f l a s k c o n t a i n i n g a c o l d mixture a t a temperature o f -15O, The r e s u l t s a r e c o n t a i n e d i n Table I , TABLE I Ordinary g l a s s J e n e n s e r g l a s s I
The r e s u l t s showed good r e p r o d u c i b i l i t y i n r e - p e a t e d t e s t s and i t i s t h u s proved t h a t t h e b e t t e r t h e g l a s s m a t e r i a l , t h e l e s s i t i s a f f e c t e d by t h e w a t e r and t h e fewer
c r , n o i t w i l l p r o v i d e ,
In o r d e r t o prove t h a t t h e manner o f p r e p a r a - t i o n of t h e w a t e r and i t s degree o f p u r i t y a l s o have a de- c i s i v e e f f e c t on t h e s u p e r c o o l i n g c a p a c i t y , s e v e r a l t e s t t u b e s of t h e same kind of g l a s s were f i l l e d w i t h w a t e r which had been p r e p a r e d i n v a r i o u s ways, These t e s t tubes were supercooled i n t h e Dewar f l a s k t o a g i v e n t e m p e r a t u r e , A f t e r a f i x e d number of minutes t h e number of c r y s t a l l i z e d t u b e s was counted, Ordinary d i s t i l l e d w a t e r from t h e u s u a l s t o c k c o n t a i n e r was used, a s w e l l a s d i s t i l l e d water which had been r e - d i s t i l l e d i n t o t h e t e s t t u b e s w i t h t h e o u t s i d e a i r excluded i n s o f a r a s p o s s i b l e , and f i n a l l y w a t e r was f i l t e r e d through a J e n e n s e r f r i t f i l t e r , no, F4, The r e s u l t s a r e g i v e n i n Table 11,
Page = 4 Tech, Trans, T T - 8 $ o f c r y s t a l l i z e d
--
I t I s a p p a r e n t f r o n t h e t e s t ~ t h a t t h e number of c r y s t a l l i z a t i o n s d e c r e a s e s wf th i n c r e a s i n g p u r i t y of t h e w a t e r , I n a l l t h e g l a s s v e s s e l s employed c a r e must of course be taken t h a t no e x t r a n e o u s n u c l e i a r e p r e s e n t i n t h e a p p a r a t u si n tho f o m of rough p l a c e s due t o i n j u r i e s o r o t h e r c a u s e s , The i n t e ~ i o r s u r f a c e s should be srnocth and undamaged, F ~ o m t h e s e t e s t s i t a p p e a r s t h a t t h e removal of t h e l a r g e r f o r e i g n b o d i e s a t l e a s t i s p o s s i b l e and t h a t t h e s u p e ~ c o o l i n g c a p a c i t y of water can t h u s be f u ~ t h e r i n c ~ e a s e d ,
The pore d i a m e t e r of the J e n e n s e r s i n t e r e d g l a s s f f l t e r s , which had a l r e a d y been u s e d p r e v i o u s l y by t h e
Page
-
5Teeh, Trans, TT- 88 a u t h o r s , seemed t o be too l a r g e f o r t h e c r , n o u f t h e w a t e r , s o t h a t a complete removal of t h e s e n u c l e i bg f i l t r a t i o n through t h e s e proved i m p o s s i b l e , Attemr t3s ware t h e r e f o r e
made t o reduce t h e s i z e of the p o r e s by f n t ~ o d u c i n g c o l l o d i o n , b u t the d e s i r e d r e s u l t was n o t a t t a i n e d by t h i s means e f t h e r ,
The removal of t h e c r , n o was t h e n a t t a n ~ p t ~ c d by means of
fT l t r a t f o n through s m a l l c o l l s u i a ~ l sacks of a kind s i m f l a r t o t h a s e o f t e n used p r e v i o ~ ~ s l y , The p r e p a r a t i o n and t h e c h a r a c t e r f s t i c s of t h e s e smal.1 olhodictt s a c k s were i n v e s t i
-
67
g a t e d i n d e t a i l by W, Linnhoff The p r e s e n t autho s made
x
7
t h e i r s a c k s by d i l u t i n g commercial c c l l o d i o n D o A o B o,
t o t h e r e q u i r e d s t r e n g t h s w i t h a l c o h o l and e t h e r s o a s t o g e t v a r i o u s w a l l t h i c k n e s s e s , Small Erlenmeyer f l a s k s o r g l a s s b e a k e r s of 25 e e , c a p a c i t y were t h e n c e n t ~ . i f u g a l l y s p ~ a y e d with t h i s s o l u t i o n , A f t e r t h e s o l v e n t had e v a p o r a t e d t h e s a c k s formed i n t h i s way were f o r c e d o u t w i t h d i s t i l l e d w a t e r , During t h i s p r o c e s s c a r e had t o be taken t o p r e v e n t t h e c o l l o d i o n f i l t e E ' s from d r y i n g too thoroughly i n - t h e v e s s e l s g o t h e r w i s e t h e y might become t o o impervious and f i n a l l y would n o t p e r -m i t passage of the w a t e r , F i l t e r s which s t i l l c o n t a i n t o o much alcohol. and e t h e r become cloudy when t h e w a t e r i s added'),
I n t h e a u t h o r s 9 x p e r i m e n t s i t was e s t a b l i s h e d t h a t t h e
f i l t r a t e s from t h e s a c k s whfch were washed o u t w i t h d i s t f l l e d water o n l y , of t e n showed d i f f e r e n t behuviour from t h e f i l t r a t e s of sacks which had been r i n s e s e v e r a l times w i t h d i l u t e d
88
h y d ~ o c h l o r f c a c i d , Biermann o b t a i n e d s i m i l a r r e s u l t s i n t e s t s of t h e c o n d u c t i v i t y of w a t e r , and he a t t ~ i b u t e s t h e g r e a t e r c o n d u c t i v i t y of t h e f i r s t f i l t r a t e s t o t h e p r e s e n c e of s a l t s of low s o l u b i l i t y o r i g i n a t i n g from t h e wash w a t e r used i n p r e p a r i n g t h e c o l l o d i o n , Longer washfng with d i s -
t i l l e d water d i d i n d e e d reduce t h e c o n d u c t i v i t y o f t h e f i l t r a t e , b u t a l s o l e s s e n e d t h e d u r a b i l i t y of t h e s a c k s , which soon became u n s e r v i c e a b l e due t o t h e f o r m a t i o n of fun- gus c u l t u r e s ,
A f t e ~ about 25 c c , of d i s t i l l e d water had passed through t h e sack t h e f i l t r a t i o n was conducted i n such a way t h a t t h e f i l t r a t e i n a covered g l a s s b e a k e r dropped d i r e c t l y i n t o c a r e f u l l y c l e a n e d t e s t t u b e s of supremax g l a s s , The t u b e s were t h e n immediately s e a l e d ,
I t was e s t a b l i s h e d t h a t the m a j o r i t y of water samples t r e a t e d i n t h i s manner show g r e a t e r s u p e r c o o l i n g
c a p a c i t y t h a n o r d i n a r y w a t e r , o r water d i s t i l l e d i n t h e u s u a l manner, I t was p o s s i b l e t o keep some of t h e t u b e s l i q u i a
o l d m i x t u r e of -20". i n some c a s e a , ---.%2-- -,
s Note: Deutsches Apo thekerbuch
-
Geman Pharma-Page
-
6Tech, Trans, TT-- 80
when t h e r e was a ~ i ' f i c i e n t q c f e t , t h e s u p e ~ c o o l f n g c o u l d be broughb t o -24", V i b r a t i o n s and shocks u s u a l l y l e d r a p i d l y t o
c r y s t a l l i z a t i o n g % ,
The addqtfon of o f 1 r e t a r d s t h e s o l i d i f i c a t i o n of s u p e r c o o l e d w a t e r l 0 f . P r e p a r a t i o n s t r e a t e d i n t h i s manner were a l s o l e s s s e n s i t i v e t o v f b r u t i o n s , D i s t i l l e d w a t e r which had been p a s s e d through c o l l o d i o n f i l t e r s and then o v e r c l e a n p a r ~ f f i n o i l was p l a c e d i n q u a r t z t u b e s , These t u b e s were
t h e n p u t i n t o a c o l d m i x t u r e of 100 p a r t s i c e , 2 p a r t s
p o t a s s i a n n i t r a t e and 112 p a r t s p o t a s s i u m t h i s c y a n f t e , In two o u t of f i v e t e s t t u b e s i t proved p o s s f b l e on s e v e r a l o c c a s i o n s t o keep s m a l l q u a n t i t i e s o f w a t e r p e r f e c t l y f l u f d a t -32O and even a t -330 o v e r a l o n g p e r i o d , A f t e r s e v e r a l days t h i s extreme s u p e r c o o l i n g c o u l d be reproduced i n o n l y one o f t h e same t u b e s , The o t h e ~ t u b e s s o l i d i f f e d f i r s t a t -28O and -26" l a t e r a t - 2 4 O , I n any c a s e i t was shown t o be e n t i r e l y p o s - s i b l e , by c a r e f u l p r e p a r a t i o n , t o s u p e r c o o l v e r y pure w a t e r bebow t h e p r e v i o u s l y o b s e r v e d tempekature of -21°, But even
a t t h e s e low t e m p e r a t u r e s t h e w a t e r remains t h i n l y l i q u i d ,
I t s h o u l d a l s o be mentioned t h a t when o r d i n a r y t a p w a t e r , and even w a t e r t h a t h a s been d i s t i l l e d o n l y once,
solidifies i n t h e s e a l e d t e s t tube, i t f s n e a r l y always cloudy and mflky, whereas p u r e r w a t e r g e n e r a l l y c r y s t a l l i z e s w i t h complete t r a n s p a r e n c y . This i s no doubt due t o t h e f a c t t h a t i n l e s s pure w a t e r , because of t h e large..number o f c r y s t a l n u c l e i , a g r e a t many s m a l l , i r r e g u l a r l y a r r a n g e d i c e c r y s t a l s
form, whereas i n pure w a t e r o n l y a few voluminous ones o c c u r , S f n c e complete e l e m i n a t i o n of the c r o n o from t h e w a t e r by means o f f i l t e r i n g w i t h J e n e n s e r s i n t e r e d f i l t e r s and c o l l a d i o n s a c k s was n o t a t t a i n e d a s d e s i r e d , an a t t e m p t was made t o remove t h e nuclei. by r e p e a t e d d i s t i l l a t i o n w i t h t h e a i r and i t s f n l p u r f t i e s e x c l u d e d , The a p p a r a t u s w a s made of J e n e n s e r a p p a r a t u s g l a s s g which had been steamed and c a r e - f u l l y c l e a n e d , Five g l a s s t u b e s , each e i g h t c e n t i m e t r e s Bong and 0,6 c e n t i m e t r e s i n d i a m e t e r , were f'used o n t o a s p h e r i c a l f l a s k two c e n t i m e t r e s i n d i a m e t e r , and t h e l a t t e r was h a l f f i l l e d w i t h w a t e r ,
The a p p a r a t u s was e v a c u a t e d w i t h t h e w a t e r j e t pump and t h e n s e a l e d , The t u b e s were p l a c e d i n a b a t h con- t a i n i n g a m i x t u r e o f i c e and t a b l e s a l t and t h e w a t e r was d i s t i l l e d from t h e s u p p l y f l a s k i n t o t h e t u b e s , By c o o l i n g each i n d i v i d u a l tube i n t u r n and warning t h e p r e v f o u s one i t
was p o s s i b l e t o d i s t i l l t h e pure w a t e r i n t o t h e f i f t h t u b e , When a l l f f v e t u b e s had t h u s been s u p p l i e d w i t h w a t e r o f i n -
Page
-
7 Tach, T~aans , TT- 8Q c r o a s i n g p u r i t y t h e y were s u p e r c o o l e d f n t h e b a t h , I t was c l e a r l y e s t a b l i s h e d i n t h i s e x p e r i m e n t t h a t t h e a u p e r c s o l i n g c a p a c i t y o f t h e w a t e r i n c r e a s e d w i t h t h e nmnber o f d i s t i l l a - t i o n s , i , e , , w i t h t h e d e g r e e o f p u r i t y , Whereas i n t h e f i r s t t u b e s a c r y s t a l l i z a t i o n s t a r t i n g from s e v e r a l p o i n t s c o u l d be o b s e r v e d , t h e s o l i d i f i c a t i o n o f t h e P a s t t u b e s was e n t i r e l y g l a s s y , c l e a r , and t r a n s p a r e n t , The c o n t e n t s o f t h e s p h e r i c a l f l a s k , on t h e o t h e r hand, were always m i l k y and c l o u d y , I n t h e c l e a r , t r a n s p a r e n t c r y s t ~ l masses monocrys t a l s a r ea p p a r e n t l y p r e s e n t , which, on Lrurther s u p e r c o o l i n g , b r e a k away from %he g l a s s w a l l and show c r a c k s and c r e v f c e s ,
I t was f u ~ t h e r n o t e w o r t h y t h a t i n t h e f f r s t and second t ~ i b e s o f t h e a p p a r a t u s v e r y c l e a r , t r a r ~ s p a r e n t s p e a r s d e v e l o p e d o u t o f t h e l i q u i d , some o f which grew up- wards t o t h e g l a s s w a l l , C r y s t a l s u r f a c e s were c l e a r l y r e c o g - n i z a b l e on a number o f t h e s e f o r m a t i o n s , O f t e n s e v e r a l s u c h
c r y s t a l f o r m a t i o n s c o u l d b e o b s e r v e d i n t h e same t u b e , I n one e a s e t h e r e were f o u r o f them growing i n t o t h e g a s e o u s
?base, These c r y s t a l s p e a r s o c c u r r e d quf t e f r e q u e n t l y i n
t h e f i r s t and second t u b e s b u t n o t s o f r e q u e n t l y i n t h e l a s t two, They were a b o u t 1 cm, i n l e n g t h , and one w a s a c t u a l l y 3 cm,
From t h e s e t e s t s i t i s c o n c l u d e d t h a t by ex- c l u s i o n of t h e i m p u r i f y i n g a i r , and by r e p e a t e d distillation
i n a vacuum, w a t e r may be f r e e d p r o g r e s s i v e l y o f c r , n , However i t was n o t p o s s i b l e t o a t t a i n complete e l i m i n a t i o n by t h i s method, I t i s assumed t h a t t h e c r , n o i n t h e l a s t
t ~ i b e s a r e t o be a t t r i b u t e d t o rough c r y s t a l l i n e p l a c e s on
t h e g l a s s s u r f a c e o f t h e a p p a r a t u s , To t h e a u t h o r s i t a p p e a r s v e r y d i f f i c u l t t o f i n d a m a t e r i a l whose s u r f a c e c a n be made s o smooth a n d . amorphous t h a t no r o u g h p l a c e s which may a c t
as c r y s t a l n u c l e f even i n t h e p u r e s t , n u c l e u s - f r e e w a t e r w i l l o c c u r , I n any c a s e , t h e a u t h o r s were s u c c e s s f u l i n s u p e r - c o o l i n g w a t e r down t o -3aQ by r e d u c i n g t h e number o f c r , n o and b y u s i n g s u i t a b l e m a t e r i a l f o r t h e c o n t a i n e r , The Formation o f I c e M o n o c r y s t a l s
---
2 A r e p o r t w r i t t e n b Oscar B a l l y " 8 b e r e i n e e f g e n a r t i re E i s k r i s t n l l b i l d u n g " l g ) (An Unusual I c e C r y s t a l Formation?
s u g g e s t e d a more d e t a i l e d i n v e s t i g a t i o n i n t o t h e o c c u r r e n c e o f t h e s e i c e c r y s t a l s i n t h e g a s s p a c e , According t o t h e authors" v i o u s o b s e r v a t i o n s t h e e x p l a n a t i o n gibTen b y H, ErlenmeyerP2T
f o r t h e a p p e a r a n c e of B a l i y Q s Lce c r y s t a l s d f d n o t a p p e a r t o be c o r r e c t , According t o t h f s e x p l a n a t i o n t h e i c e c r y s t a l w a s presumed t o grow o u t o f t h e s u p e r c o o l e d s o l u t i on, I t i s much more p r o b a b l e , however,Page
-
8Tech, T ~ a n s , TT-80
t h a t t h e c s g s t a l i s f o m e d by t h e c o n d e n s a t i o n of s u p e r c o o l e a w a t e r vapour from t h e a i or). a ~ cr, n o a t t h e s u r f a c e of t h e w a t e r o r i c e ,
F o r t h e c u l t f v a t f o n o f t h i s type o f i ce c r y s t a l t h e a p p w a t u s shrwrl I n F i c u r e 2 was employed, I t was made of J e n e n s e r g l a s s , supremax g l a s s , and q u a r t z g l a s s , The
l a r g e s p h e r i c a l f l a s k s had a d i a m e t e r of t h r e e t o s i x c e n t i - m e t r e s . The s m a l l e r s p h e r e was two c e n t i m e t r e s i n d i a m e t e r ,
i t s purpose b e i n g t o p r e v e n t a t o o r a p i d d i s t i l h a t i o n and 2 o L l i s i o n of t h e f l u i d ,
The s p h e r i c a l f l a s k , A , was a b o u t h a l f f i l l e d w i t h p u r e w a t e r , t h e i n t a k e tube was connected t o t h e w a t e r
j e t pump and s e a l e d i n t h e vacuum, The d i s t i l l a t i o n was c a r r i e d o u t by warming s p h e r e A t o a p p r o x f n a t e l y 60" and c o o l i n g s p h e r e B i n a m i x t u r e o f i c e and common s a l t , I t
was d i s c o n t i n u e 3 when t h e two s p h e r e s c o n t a i n e d a p p r o x i m a t e l y e q u a l amounts o f w a t e r , The s p h e r e s were now supereoohed, i n p a r t s i m u l t a n e o u s l y , and i n p a r t a l t e r n a t e l y f o r f u r t h e r c u l t i v a t f o n o f a c r y s t a l growing from t h e s u r f a c e and a l r e a d y v i s i b l e i n s p h e r e B, By t h i s means i t was p o s s i b l e t o form c o m p l e t e l y t r a n s p a F e n t c r y s t a l s w i t h s h a r p c o n t o u r s , t h e i r s i z e depending o n l y on t h e a p p a r a t u s , F r e q u e n t l y c r y s t a l s would gkow u n t f
P
t h e y touched t h e g l a s s w a l l and t h e n change d i r e c t i o n , I t was o f t e n p o s s i b l e t o reproduce c r y s t a l s a tt h e same p l a c e i n one o f t h e f l a s k s , a s i g n t h a t s s t a b l e c r , n o was p r e s e n t a c t i n g a s a n i n i t i a t i o n p o i n t , A c r y s t a l of 4 t o 4,s cm, l e n g t h produced I n t h i s manner i s shown i n
F i g u r e 3 , I t h a s grown f a i s l y u n i f o m l y and h a s a l r e a d y r e a c h e d t h e g l a s s w a l l above,
I t now remained t o c l a r i f y t h e q u e ' s t i o n whether t h e growtli o f t h e i c e c r y s t a l s r e s u l t , as m a i n t a i n e d b y
Erlenmeyer, from t h e l i q u E d below, o r whether t h e y a r e de- r i v e d from t h e gaseous phase above, S i n c e i n t h e p r e s e n t experiments c ~ y s t a l s o f t h i s t y p e a l s o f o m e d on t h e w a l l o f t h e o r i g f n a l l y empty s p h e r e &when i t was s u f f i c i e n t l y s u p e r c o o l e d , i t i s t h u s proven t h a t t h e s e ice c r y s t a l s a r e formed by t h e c o n d e n s a t i o n of s u p e ~ c o o l e d w a t e r vapour on a c r y s t a l n u c l e u s , I n t h e l a t t e r case t h e c r , n o i s s i t u a t e d on t h e g l a s s s u r f a c e of t h e s p h e r e and would t h e r e f o r e a p p e a r t o be a rough, c r y s t a l l i n e s p o t on t h i s g l a s s s u r f a c e , i n agreement w i t h t h e view p r e v i o u s l y advanced by t h e a u t h o r s ,
S i n c e t h e s e c r y s t a l s a r e e n t i r e l y c l e a r and t r a n s p a r e n t t h e y a r e a p p a k e n t l y m o n o c ~ ~ y s t a l s of i c e , To d a t e i t h a s n o t been p o s s i b l e t o c a p r y o u t a n i n v e s t i g a t i o n
Page
-
9Tech, T r a n s , TT-80
o f t h e i r " e l a s t i c i t y , e t c , , s i n c e t h e y inlmedfately m e l t a s soon a s t h e g l a s s s p h e r e s a r e opened, C o n s i d e r e d i n con- n e c t i o n w i t h t h e e f n - ~ d s t i g a t f o n s on t h e f a m a t i o n of t u n g s t e n monscrys t a l s faaorn a 1 a t m o s p h e r e o f t u n e s t e n h e x a c h l o r i d e
v s p o u r and oxygen135, however, n o d o u b t s s h o u l d r e m a i n con- cerlzing t h e c h a r a c t e p of t h e s e s p e a r s a s i c e monocr"ystals, E x p e r i m e n t s w i t h Henzol _-"- To d e t e ~ m i n e w h e t h e r t h e c o n d i t i o n s i n o t h e r s u b s t a n c e s w i t h l a r g e C P , v , a r e s i m i l a r t o t h o s e p r e v a i l i n g i n w a t e r , some e x p e r i m e n t s w i t h b e n z o l were c a r r i e d o u t , P u r e commercial b e n z o l was s e a l e d i n t o c a r e f u l l y c l e a n e d t e s t t u b c s and s u p e r c o o l e d t o v a r i o u s t e m p e r a t u r e s , FOP
comparison b e n z o l s a n p l e s , some o f whlch had b e e n f r a c t i o n a t e d once and o t h e r s t h r e e t i m e s , were t r e a t e d i n t h e same manner,
I t was shown h e r e , t o o , a s i n t h o c a s e o f w a t e r , t h a t t h e s u p e r c o o l i n g c a p a c i t y i n c r e a s e s w i t h t h e number o f d i s t i l - l a t i o n s , i , e , , w i t h i n c r e a s i n g p u r i t y , Whereas t h e u n d i s t i l l e d b e n z o l always s o l i d i f i e d i m m e d i a t e l y a t - 8 O , a sample of t h e b e n z o l which had b e e n d i s t i l l e d t h r e e t i m e s r e m a i n e d f l u i d a f t e r f o u r m i n u t e s , w h i l e a n o t h e r was s t i l l f l u i d a f t e r f i v e m i n u t e s , Thus b e n z o l b e h a v e s i n t h e same manner as w a t e r ,
The a t t e m p t s t o o b t a i n m o n o c r y s t a l s o f b e n z o l have n o t had any s a t i s f a c t o r y r e s u l t , I n two c a s e s t r a n s - p a r e n t , n e e d l e - l i k e f o r m a t i o n s o f a p p r o x i m a t e l y 0,5 cm, l e n g t h were s e e n a t t h e s u r f a c e o f t h e s o l i d i f i e d b e n z o l ,
From t h e I n s t i t u t e o f G e n e r a l Chemfs t r y o f t h e U n i v e r s i t y and S c h o o l o f E n g i n e e r i n g , B r e s l a u ,
Page - 10
Tech, Trans, TT-80
BIBLIOGRAPHY
J ~ l Meyer and o W, P f a f f , Z, a n o ~ g , u , a l l g , Chem, 217
Q 1 9 3 4 ) , 257; 222 (19351, 382,
G o Tammamuo A , Bfichno~, Z , a n s r g , u , a l l g , Chem, 222
(h9351, 12, 371,
M f i l l e r - P o u i l i e t , Lehrbuch d e r Physik I11 (190T7), 453, Dufour, f b i d ,
A,T, Libf e n t h a l , Wisdomosci I n s t y t u t u M e t a l u r g j f i o Metaloznawstwa, 1934, 2 e 0
W, L i n n h o f f , K o l l 0 Z t s c h r , 62 ( 1 9 3 2 ) , PO,
R , Zsfgmondy, Lehrb, d o KolSoidchemie, p , 24,
H , Biermann, I n a u g u r a l d i s s e r t a t i o n ( inaugural D i s s e r - t a t i o n ] Cologne, 1934,
Cf,
K O
Schaum and F, Schoenbeck, Ann, Phys, [4] 8 ( 1 9 0 2 ) ~ 652,Cf, m l l e r - P o u f l l e t , Lehrb, d o Physfk I11 ( 1 9 0 7 ) , 453,
0, B a l l y , Helv, 18 (19351, 475,
H o Erlenmeyer, Helv, 13 (19301, 1006,
FIG. 1 - 3 T T - 8 0 V FIG. I FIG. 2 FIG. 3
