A simple, scalable synthesis of mechanically robust and self-healable superlattice nanocomposites is achieved through self-assembly of single-component "sticky" polymer-grafted nanoparticles. The multi-valent hydrogen-bonding interactions between the nanoparticles provide strong cohesive energy, binding the nanoparticles into strong and tough materials. Furthermore, the dynamic hydrogen-bonding interactions afford the formation of highly dynamic, self-healing, and mechanochromic nanocomposite materials in the bulk.

The large-scale assembly of asymmetric colloidal particles is used in creating high-performance fibres. A similar concept is extended to the manufacturing of thin films of self-assembled two-dimensional crystal-type materials with enhanced and tunable properties. Here we present a spray-coating method to manufacture thin, flexible and transparent epoxy films containing zirconium phosphate nanoplatelets self-assembled into a lamellar arrangement aligned parallel to the substrate. The self-assembled mesophase of zirconium phosphate nanoplatelets is stabilized by epoxy pre-polymer and exhibits rheology favourable towards large-scale manufacturing. The thermally cured film forms a mechanically robust coating and shows excellent gas barrier properties at both low-and high humidity levels as a result of the highly aligned and overlapping arrangement of nanoplatelets. This work shows that the large-scale ordering of high aspect ratio nanoplatelets is easier to achieve than previously thought and may have implications in the technological applications for similar materials.

We have prepared a polydomain smectic liquid crystalline (LC) elastomer by introducing 2 mol % 1,3,5-benzenetricarboxylic acid as a cross-linker into a main-chain BB-5 polyester. The elastomer designated as BB-5/E2 forms isotropic and smectic CA (SmCA) LC phases in order of decreasing temperature similarly to the un-cross-linked BB-5 polyester. BB-5/E2 in the isotropic liquid phase shows a typical rubberlike elasticity, whereas that in the SmCA phase shows a characteristic elongation behavior accompanying a polydomain−monodomain transition: the initial strain up to 100% orients the smectic layer with its normal parallel to the elongation direction, and the further elongation does not change the layer orientation and results in permanent deformation. The corresponding stress−strain curve shows a quasi-plateau, which is a so-called “soft stress plateau”, over a wide strain region from 100% to 450%. These indicate that the polymer chains folded in the oriented smectic LC elastomer at a strain of 100% are stretched on further elongation and locked by the smectic layer order. At a strain of more than 300%, the SmCA phase begins to transform into a crystal because of the entropy reduction due to direct stress to the fully extended polymer chains.

A direct colloidal self-assembly approach was utilized to prepare photonic crystals based on exfoliated graphene oxide (GO) in aqueous solution. The GO sheets form ordered photonic structure spontaneously without the need for multiple processing steps. The wavelength of light reflected by the GO photonic crystal dispersion can be controlled over the entire visible light spectrum simply by varying the GO concentration. The aspect ratio of the GO sheets and mediation of the intersheet forces are found to be the key factors influencing the stability of photonic crystal formation. The usefulness and limitations of the GO photonic crystals prepared in this study are discussed.