assembly of macromolecules to form a (either intramolecular or intermolecular)
multi-level hierarchical structure via strong sub-valence interactions is often called
themolecular self-assemblyprocess (Lehn 1995 ).
1.3 Role of Polymer Physics
Polymer physics is a multi-disciplinary subject derived mainly from polymer
chemistry and condensed matter physics, and pushed forward by the high demands
of materials, engineering and life sciences. It studies physical states and processes,
as well as their intrinsic correlations to the microscopic structures and molecular
motions of the macromolecules. A comprehensive understanding of the basic
principles governing the polymeric behaviors constitutes the main objective of
polymer physics. As a subject of macromolecular substances, polymer chemistry
evolved in the last century directly from organic chemistry that was the subject of
organic substances, while inorganic chemistry was the earliest subject of inorganic
substances evolved since the epoch of alchemy. Such an evolution sequence of
chemical subjects coincides with the creation of corresponding substances in
nature, following the common trend of evolutions from simple to complex.
Macromolecules, such as nucleic acids, carbohydrates and proteins acting sepa-
rately as the basic substances in genetic inheritance, energy storage and hierarchical
functioning in the living body, have exhibited admirable complexity and accuracy
by the use of their strong yet flexible chain-like backbones. Inspired by nature, our
knowledge of polymer chemistry has expanded extremely fast on making, measur-
ing and modeling of polymeric materials. The field of traditional condensed matter
physics also faces the new challenge of soft matter (sometimes called complex
fluids). Polymers are a typical kind of soft matter, featured with metastable states
and nonlinear viscoelasticity. Many basic theoretical tools of condensed matter
physics, such as the mean-field theory, the scaling analysis, the self-consistent-field
theory, the density functional theory, molecular dynamics simulations and Monte
Carlo simulations, have been commonly applied to investigate the behaviors of
polymers. In our daily life, polymer materials have become basic materials as
common as metals and ceramics. The early strategy to investigate polymer
materials was mainly based on the trial-and-error experiments, i.e. synthesizing a
series of polymer compounds with varing chemical structures and compositions, to
identify a proper range of useful properties. Nowadays, the molecular design of the
properties has given impetus to the development of new polymer materials. Such an
approach demands for our deep understanding of the relationships between the
molecular-level structures and polymer properties. Many engineering processes
involve macromolecules, such as the chemical engineering of polymer materials,
food processing, oil recovery and long-distance piping. The rapid progress of life
sciences also demands our approaches of physics and chemistry to elucidate the
microscopic mechanisms of living processes. As the vitally important substances,
macromolecules are often involved into the microscopic living processes.
1.3 Role of Polymer Physics 5