objection to macromolecules; now, after settling their role, they were compatible
with both small components and long chains.” [16]
Amazingly enough, Staudinger was anything but enthusiastic about receiving
“support from representatives of physical chemistry and X-ray structural analysis”
[19, p. 253]. He did in fact maintain a long-running feud with Meyer and Mark. We
will be looking into his reasons for this later on.
In 1927, Staudinger succeeded in providing proof that “individual ( ) molecules
can encompass a large number of elementary cells” [18, p. 232]. His X-rays of
polyoxymethylene showed “an elementary cell with only four methylene oxide
groups [. . .], whereas it was, on the other hand, an undisputed fact that this
substance definitely had to consist of far more such basic units” [18]. In spite of
this, the evidence in favour of the macromolecule concept was still too tenuous to
change the minds of opponents and notorious sceptics. Staudinger had to come up
with proof that focussed on the core of his theory and made it watertight, i.e. that
there were primary valence bonds between all the links in the postulated chain
molecule with respect to electromagnetic attraction. Because only they were able to
weld atoms and molecules together to form a stable unit irrespective of size
(cf. [10], p. 6 and [1], p. 317) and substantiate the difference between an individual
molecule and a molecular complex, i.e. between a genuine macromolecule in the
form of an integrated whole and a pseudo-macromolecule (in the sense of a
combination of several molecules forming a compound that is only held together
by weaker secondary valence bonds). But how was the difference between macromolecules and clusters of low molecular particles, also known as micelles (see
Appendix 3), to be demonstrated specifically in a thoroughly convincing way?
2.12 Micelle or Molecular Colloid?
Staudinger [1], p. 108) said: “The procedure adopted in explaining composition
issues in macromolecular chemistry is exactly the same as in low-molecular
chemistry, i.e. the substance is dissolved and the size and composition of its
dissolved particles are investigated” (cf. [10], p. 15). The premise was: “In view
of the size of the molecules, macromolecular substances can [. . .] only dissolve
colloidally” [1, p. 119]. If dissolved substances do in fact take on this glue-like
consistency, less is, however, achieved than hoped, because it cannot be concluded
that the dissolved substance is macromolecular in structure on the basis of the
formation of a colloid alone; this can be a characteristic of micelles too (cf. [16],
p. 10). In other words, it would only be definite that the substance consisted of
macromolecules if it could be proved that “the colloidal nature [. . .] was due to the
special composition of the substance” [1, p. 111]. Staudinger coined the term
“molecular colloid” to describe this finding: “In micelle colloids, the colloid
particles are loose collections of small molecules, whereas the colloid particles in
molecular colloids are the macromolecules themselves” [1, p. 320].
100
M. Weber and G. Deussing
with both small components and long chains.” [16]
Amazingly enough, Staudinger was anything but enthusiastic about receiving
“support from representatives of physical chemistry and X-ray structural analysis”
[19, p. 253]. He did in fact maintain a long-running feud with Meyer and Mark. We
will be looking into his reasons for this later on.
In 1927, Staudinger succeeded in providing proof that “individual ( ) molecules
can encompass a large number of elementary cells” [18, p. 232]. His X-rays of
polyoxymethylene showed “an elementary cell with only four methylene oxide
groups [. . .], whereas it was, on the other hand, an undisputed fact that this
substance definitely had to consist of far more such basic units” [18]. In spite of
this, the evidence in favour of the macromolecule concept was still too tenuous to
change the minds of opponents and notorious sceptics. Staudinger had to come up
with proof that focussed on the core of his theory and made it watertight, i.e. that
there were primary valence bonds between all the links in the postulated chain
molecule with respect to electromagnetic attraction. Because only they were able to
weld atoms and molecules together to form a stable unit irrespective of size
(cf. [10], p. 6 and [1], p. 317) and substantiate the difference between an individual
molecule and a molecular complex, i.e. between a genuine macromolecule in the
form of an integrated whole and a pseudo-macromolecule (in the sense of a
combination of several molecules forming a compound that is only held together
by weaker secondary valence bonds). But how was the difference between macromolecules and clusters of low molecular particles, also known as micelles (see
Appendix 3), to be demonstrated specifically in a thoroughly convincing way?
2.12 Micelle or Molecular Colloid?
Staudinger [1], p. 108) said: “The procedure adopted in explaining composition
issues in macromolecular chemistry is exactly the same as in low-molecular
chemistry, i.e. the substance is dissolved and the size and composition of its
dissolved particles are investigated” (cf. [10], p. 15). The premise was: “In view
of the size of the molecules, macromolecular substances can [. . .] only dissolve
colloidally” [1, p. 119]. If dissolved substances do in fact take on this glue-like
consistency, less is, however, achieved than hoped, because it cannot be concluded
that the dissolved substance is macromolecular in structure on the basis of the
formation of a colloid alone; this can be a characteristic of micelles too (cf. [16],
p. 10). In other words, it would only be definite that the substance consisted of
macromolecules if it could be proved that “the colloidal nature [. . .] was due to the
special composition of the substance” [1, p. 111]. Staudinger coined the term
“molecular colloid” to describe this finding: “In micelle colloids, the colloid
particles are loose collections of small molecules, whereas the colloid particles in
molecular colloids are the macromolecules themselves” [1, p. 320].
100
M. Weber and G. Deussing