-}% FUNDAMENTALS OF S U BM I C RO S COPI C MORPHOLOGY I 



Nageli's scheme (Fig. 59a), two intermicellar substances are drawn 

 between the micelles; one of these substances may be eliminated. What is 

 new in Fio-. 59b is the determination of the inner structure of the micelles; 

 for the rest, however, there is complete agreement with Fig. 59a. The 

 micelles were considered as disperse phase, surrounded by intermicellar 

 spaces which are accessible to the dispersing medium. To account for the 

 coherence of the crystalline micelles in a solid framework, special micellar 

 forces had to be assumed. Meyer and Mark considered these to be large 

 cohesive forces which, in cellulose for instance, are additively composed 

 of the molar cohesions of the numerous OH-groups. However, since these 

 same forces act intramicellarly as lattice forces, it was difficult to see what 

 the difference might be between the forces responsible for the />//ramicellar 

 coherence of the chain molecules in a crystal lattice and the /«/^rmicellar 

 "micellar forces". 



According to Nageli, when a gel is dissolved, the micelles are dispersed, 

 and the sol contains independent crystals. This point of view has often been 

 adopted by others, in particular for cellulose sols, although such solutions 

 do not give X-ray diagrams (e.g.,HERZOG, 1927). According to Staudinger 

 (1932), the high polymer natural substances are dissolved as separate chain 

 molecules instead of crystalline particles. At present, therefore, only crystal- 

 Une suspensoid colloids such as gold-, vanadium pentoxide-, ferric oxide 

 sols, etc. can be claimed to be micellar solutions in Nageli's sense; they 

 show mostly a strong birefringence of flow and partly also X-ray inter- 

 ferences. 



In the case of gels, our recent knowledge of the structure of high 

 polymers raises further objections to Nageli's concept of micelle, for it is 

 found that the chain molecules are much longer than the crystalline regions 

 (Fig, 54, p. 70). It follows that the micelles, instead of possessing individual 

 character as assumed by Nageli, have grown together and are to a certain 

 extent absorbed in the gel structure. Nowadays they can no longer be 

 considered to be substantial (not even conditionally substantial) particles 

 (Frey-Wyssling, 1936a, c; Kratky and Mark, 1937). They consist of well- 

 ordered chain molecules, which protrude from the crystalline into the amor- 

 phous regions and perhaps take part again in other ordered lattice regions. 



We conclude that i . there are sols containing chain molecules which are 

 more or less independent, rather than micelles in Nageli's sense, and 2. that 

 the micelles in gels do not represent independent crystallites but at best 

 can be described as lattice regions. Taking into account the constant danger 

 of confusion with the colloid chemical concept, which by micelle means an 

 electrically charged instead of a crystalline particle, it would perhaps be 

 better in our considerations to give up the concept micelle. If one wishes 

 to use it nevertheless, one should not assign any special significance to this 

 concept, but simply use it in the sense of supermolecular colloid particle. 

 This would exclude all possibility of confusion. One would then have to 

 distinguish between two different kinds of colloid particles: i. super- 



