Conventional synthetic materials, like metals, ceramics or glass, are
usually isotropic substances, and their suitability for structural
applications is achieved by morphological design and combination in the
macroscopic scale. However, in modem engineering this is often not
acceptable. As an alternative, the use of non-homogeneous, anisotropic
materials, with significant stiffness and strength only in the
directions these mechanical properties are really needed, can lead to
enormous material (and weight) savings. This is the case of multiphase
systems called composite materials. In these composites, different
material parts are added and arranged geometrically, under clearly
designed and controlled conditions. Usually, a structure of fibers
provides strength and stiffness and a matrix helds them together, whilst
providing the geometric form. Carbon fibers are among the
high-performance fibers employed in these advanced structural
composites, which are profoundly changing many of today's high
technology industries. New research and development challenges in this
area include upgrading the manufacturing process of fibers and
composites, in order to improve characteristics and reduce costs, and
modifying the interfacial properties between fibers and matrix, to
guarantee better mechanical properties. The interdisciplinary nature of
this "new frontier" is obvious, involving chemistry, materials science,
chemical and mechanical engineering. Other topics, which more often are
treated separately, are also important for the understanding of the
processes of fiber production. Carbon filaments is one such topic, as
the study of their mechanisms of nucleation and growth is clearly quite
relevant to the production of vapour-grown carbon fibers.
