Page 112 - Visions of the Future Chemistry and Life Science

The secret of Nature’s microscopic patterns 101

science’ operating in natural environments. This is surprising since many
of the same types of materials are present in the natural environment, e.g.
spherical particles comprising silica or a monomer, free polymer, salt and
other additives such as fatty acids. Furthermore, the synthetic colloid sci-
entist can manipulate the components within a system in ways that are
not accessible to nature, i.e. there is unlikely to be a genetic mechanism
that can suddenly add 0.2g of polymer or increase the ionic strength to
0.1m! Genetic input is simply not responsive enough in relation to the
speed of reactions. However, Nature is a far better chemist than man –
although she has had many more millennia to get it right – and discover-
ing the finesse and natural controlling factors would certainly enhance the
ability of the relatively crude synthetic chemist. By analogy to the chaotic
systems proposed previously, Nature may prepare systems at the boundary
of stability and through subtle changes in one parameter, tip the system
over the edge resulting in significant architectural changes. The approach
taken in our work has been to try to manipulate the behaviour of synthetic
organic colloids with a view to reproducing patterns and architecture
present in the natural materials; this will inter alia uncover the control-
ling factors used by nature. Utilisation of organic components in synthetic
biological self-assembly is new and presents complexity of interpretation.
However, it is essential if we are to progress beyond qualitative description
to quantitative and defined understanding.
First though, we must outline albeit very briefly, the basic factors
important to colloidal stability and self-assembly. It is these areas that
clearly hold the insights we require. Throughout the section, we highlight
possible control mechanisms available to the natural system.
The Greeks also believed that only two forces – love and hate – could
account for all fundamental phenomena. There are in reality four distinct
forces; the strong nuclear interactions that bind nuclei together, weak
interactions associated with electron clouds and the two forces the Greeks
‘missed’, electrostatic and gravitational forces. In actual fact, the Greeks
did observe these latter two interactions but could not explain them. In the
seventeenth century, Newton showed that the interaction between mole-
cules within an ensemble affected their bulk physical properties.
Phenomena such as capillary rise – the way water creeps up the sides of a
very thin glass tube – led to the suggestion that different glass/liquid and
liquid/liquid interactions must exist. It was the Dutch scientist van der
Waals who made the breakthrough; in order to explain why gases do not