Twenty-first century polymer science after staudinger: The emergence of dendrimers/dendritic polymers as a fourth major architecture and window to a new nano-periodic system

Abstract

Staudinger's (1922) "macromolecular hypothesis" stating that most synthetic and natural polymers could be rationalized as extensive covalently linked linear macromolecules, followed by Crick and Watson's (1953) revelation that life was actually based on poly(nucleotide), helical double-stranded variations of Staudinger's linear architectures, launched two of the most significant technological revolutions of the twentieth century. After Staudinger, a total of four major polymer architectures were recognized and each architecture, namely, (I) linear, (II) crosslinked (bridged), (III) branched, and (IV) dendritic (hyperbranched), is highly valued for its intrinsic and unique macromolecular properties. Upon entering the twenty-first century, members of architectural class IV, dendritic polymers (i.e., dendrimers), have now been accepted by both chemists and physics as quantized nanoscale building blocks due to their atom mimicry features and are referred to as "soft superatoms." Atom mimicry, manifested by both soft and hard superatoms (i.e., organic and inorganic nanoscale clusters), has provided the first steps towards a proposed new nano-periodic paradigm, based on first principles from traditional chemistry and physics, for unifying nanoscience. © Springer-Verlag Berlin Heidelberg 2013.