Advances in Switchable Supramolecular Nanoassemblies

Abstract

Supramolecular nanoassemblies are gaining increasing importance as promising new materials with considerable potential for novel and promising applications. Within supramolecular nanoassemblies the connectivity of the monomeric units is based on reversible noncovalent interactions, like van der Waals interactions, hydrogen bonding, or ionic interactions. As the strength of these interactions depends on the molecular surrounding, the formation of nanoassemblies in principle can be controlled externally by changing the environment and/or the molecular shape of the underlying monomer. This way it is not only possible to switch the self-assembly on or off, but also to change between different aggregation states. In this minireview we present some recent selected approaches to supramolecular stimuli-responsive nanoassemblies.

Photo‐responsive Bioactive Surfaces Based on Cucurbit[8]uril‐Mediated Host–Guest Interactions of Arylazopyrazoles

“…Cucurbit[8]uril‐mediated host–guest heteroternary complexes including photoactive azobenzenes have been used in photomodulation of the assembly of (bio)molecules on surfaces . For example, Scherman et al.…”

Advances in cryogenic transmission electron microscopy for the characterization of dynamic self-assembling nanostructures

“…A common approach to produce hybrid nanomaterials for chemical sensing or catalysis involves incorporation of metals or semiconducting components with an organic, supramolecular matrix designed to organize the inorganic phase or respond to external stimuli [11]. Cryo-TEM is a reliable technique to visualize the nucleation dynamics of inorganic phases and determine the morphology of organic-inorganic materials due to the increased atomic number and diffraction contrast mechanisms of the inorganic material.…”

“…Cryo-TEM has also proven invaluable for characterization of intermediate protein assemblies or dynamic processes that would be difficult to study using diffraction of protein crystals [10]. In addition, the development of supramolecular “smart” materials that respond to external stimuli often result in morphology changes or dynamic events that occur within a solvent, necessitating cryo-TEM [11–13]. Here we review a subset of organic self-assembling systems and the application of cryo-TEM to study morphology, kinetics, and dynamics of these structures in situ .…”

Mesoscale Characterization of Supramolecular Transient Networks Using SAXS and Rheology

“…Switching of the aggregation state allows for mixing and blending approaches under mild conditions, for example to tune gel properties and incorporate bioactive signals and drugs [2,16]. For compatibility with bioactive signals and drugs, diverse switching approaches and thus multi-responsive systems are desirable [17,18]. …”