Soft 2D nanoarchitectonics
Ariga et al. NPG Asia Materials
Soft 2D nanoarchitectonics
Katsuhiko Ariga 0 1
Shun Watanabe 1 2
Taizo Mori 0
Jun Takeya 0 1
0 World Premier International (WPI) Research Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS) , 1-1 Namiki, Tsukuba 305-0044 , Japan
1 Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo , 5-1-5 Kahiwanoha, Kashiwa, Chiba 277-8561 , Japan
2 JST, PRESTO , 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 , Japan
Nanoarchitectonics is a new paradigm to combine and unify nanotechnology with other sciences and technologies, such as supramolecular chemistry, self-assembly, self-organization, materials technology for manipulation of the size of material objects, and even biotechnology for hybridization with bio-components. The nanoarchitectonic concept leads to the synergistic combination of various methodologies in materials production, including atomic/molecularlevel control, self-organization, and field-controlled organization. The focus of this review is on soft 2D nanoarchitectonics. Scientific views on soft 2D nanomaterials are not fully established compared with those on rigid 2D materials. Here, we collect recent examples of 2D nanoarchitectonic constructions of functional materials and systems with soft components. These examples are selected according to the following three categories on the basis of 2D spatial density and motional freedom: (i) well-packed and oriented organic 2D materials with rational design of component molecules and device applications, (ii) well-defined assemblies with 2D porous structures as 2D network materials, and (iii) 2D control of molecular machines and receptors on the basis of certain motional freedom confined in two dimensions.
Introduction
Although various scientific disciplines have contributed
to developments in functional materials, there is a
common consensus concerning methodologies to create
functional materials, such as (i) the design, synthesis, and
functionalization of unit molecules and materials1?7 and
(ii) the rational organization of synthesized units into
functional architectures8?15. Regulation of nanoscale
structures and their organization is crucial to synthesize
functional materials. As a powerful concept for the
science and technology of nanoscale objects,
nanotechnology has been accepted as a novel methodology to regulate
nanoscale objects. In fact, the observation and
characterization of atoms, molecules, and the other nanoscale
objects is realized with various techniques in
nanotechnology. For example, the manipulation of nanoscale
objects, including molecular machines16 and nanocars17,
can be performed using ultra-sharp tip motions. Great
successes and developments in fundamental and applied
sciences on the nanoscale have been realized with
nanotechnology18?20.
However, nanotechnology is not always practical in the
construction of useful-sized functional materials from
nanoscale units. In this instance, other research
disciplines are applied, such as supramolecular chemistry for
self-assembly and self-organization, materials science for
manipulation of the size of materials, and even
biotechnology for hybridization with bio-components.
Therefore, it is a useful to create a new paradigm to
combine and unify nanotechnology with these other
sciences and technologies. This new concept is referred as to
nanoarchitectonics (Fig. 1). The nanoarchitectonics
concept was initially proposed as a technical term in a
conference title: ?1st International Symposium on
Nanoarchitectonics Using Suprainteractions? in Tsukuba,
Japan, in 2000 by Masakazu Aono21,22 and is now
accepted by various studies from basic sciences to applied
environmental and biomedical fields23?29. The
nanoarchitectonics concept leads to the synergistic
combination of various methodologies in materials
production, including atomic/molecular-level control,
selforganization, and field-controlled organization30,31.
However, nanoscale material production and
structure fabrication are fundamentally different from those
on the microscale and macroscale. On the latter scales,
the strength of interactions (size of interaction
envelope) between construction components is large enough
to avoid influence from the surrounding environment32.
Therefore, structures can be precisely obtained
according to the intended design in microscopic and
macroscopic architectonics. In contrast, this precise
design-construction strategy is not always applicable to
objects on the nanoscale, because the strength of their
interactions is not usually large enough to effectively
avoid external disturbances. Various uncontrollable
factors, such as thermal fluctuations, static
distributions, and certain quantum effects, may have
nonnegligible influences on the architecting processes of
nanoscale components under ambient conditions. In
the latter cases, the harmonization of various factors
may be a more approp (...truncated)