The Microscopic Structure-Property Relationship of Metal-Organic Polyhedron Nanocomposites.

Monodispersed hairy nanocomposites with typical 2 nm (isophthalic acid)24 Cu24 metal-organic polyhedra (MOP) as a core protected by 24 polymer chains with controlled narrow molecular weight distribution has been probed by imaging and scattering studies for the heterogeneity of polymers in the nanocomposites and the confinement effect the MOPs imposing on anchored polymers. Typical confined-extending surrounded by one entanglement area is proposed to describe the physical states of the polymer chains. This model dictates the counterintuitive thermal and rheological properties and prohibited solvent exchange properties of the nanocomposites, whilst those polymer chain states are tunable and deterministic based on their component inputs. From the relationship between the structure and behavior of the MOP nanocomposites, a MOP-composited thermoplastic elastomer was obtained, providing practical solutions to improve mechanical/rheological performances and processabilities of inorganic MOPs.

Transparent 1T-MoS2 nanofilm robustly anchored on substrate by layer-by-layer self-assembly and its ultra-high cycling stability as supercapacitors.

Two-dimensional MoS2 materials have attracted more and more interest and been applied to the field of energy storage because of its unique physical, optical, electronic and electrochemical properties. However, there are no reports on high-stable transparent MoS2 nanofilms as supercapacitors electrode. Here, we describe a transparent 1T-MoS2 nanofilm electrode with super-long stability anchored on the indium tin oxide (ITO) glass by a simple alternate layer-by-layer (LBL) self-assembly of a highly charged cationic poly(diallyldimethylammonium chloride) (PDDA) and negative single-/few-layer 1T MoS2 nanosheets. The ITO/(PDDA/MoS2)20 electrode shows a transmittance of 51.6% at 550 nm and obviously exhibits excellent transparency by naked eye observation. Ultrasonic damage test validates that the (PDDA/MoS2)20 film with the average thickness about 50 nm is robustly anchored on ITO substrate. Additionally, the electrochemical results indicate that the ITO/(PDDA/MoS2)20 film shows areal capacitance of 1.1 mF cm-2 and volumetric capacitance of 220 F cm-3 at 0.04 mA cm-2, 130.6% retention of the original capacitance value after 5000 cycles. Further experiments indicate that the formation of transparent (PDDA/MoS2) x nanofilm by LBL self-assembly can be extended to other substrates, e.g., slide glass and flexible polyethylene terephthalate (PET). Thus, the easily available (PDDA/MoS2) x nanofilm electrode has great potential for application in transparent and/or flexible optoelectronic and electronics devices.

Polymer-templated supramolecular co-assemblies of proteins and metal oxide clusters as versatile platform for chemo-enzymatic catalysis.

The hybridization of enzymes and inorganics in controlled manner is challenging, however, critical for the development of chemo-enzymatic cascade catalyst with high efficiency and selectivity. Here, proteins and metal oxide clusters can be facilely co-assembled on the surface of colloid of poly(4-vinylpyridine) (P4VP) via hydrogen bonding, due to their enriched surface hydrogen bonding donors. The co-assembly method can be generally applied for preparing chemo-enzymatic catalyst within the selected database of various proteins and metal oxide clusters while the assembly units retain their structures and activities. Typically, a 2.5 nm metal oxide cluster {Mo72Fe30}, with peroxidase-like activity, are complexed with glucose oxidase (GOX) on P4VP for the catalysis against the oxidization of o-dianisidine (ODA) with the existence of glucose. Due to the synergistic effects of chemical and enzymatic catalysis, the co-assemblies show even higher ODA oxidation activity compared to GOX/catalase bi-enzymatic system, confirming the effectiveness of the co-assembly protocol for cascade catalysis and enabling its applications in rapid glucose detection and biomass conversion.

Poly(ethylene glycol) nanocomposites of sub-nanometer metal oxide clusters for dynamic semi-solid proton conductive electrolytes.

Sub-nm-scale metal oxide clusters (PW12O40 3-) show high solubility in the melt of poly(ethylene glycol) (PEG) and the obtained semi-solid nanocomposites show promising proton conductivities under ambient conditions. Suggested from scattering studies, the clusters are homogeneously dispersed in the PEG melt at the molecular scale with high loading amounts (70 wt%) and the formed real solutions can be stable for months with no aggregation or phase separation. The conductivities of the nanocomposites which are governed by the concentrations of H3PW12O40 can reach as high as 1.01 × 10-2 S cm-1 at the highest concentration. Due to the dynamic cross-linking hydrogen bonding between clusters and PEG, the nanocomposites behave like solids with negligible flow at high concentrations of clusters. Upon the application of high-speed shear forces (>32 s-1), the composites can flow with continuously decreasing viscosities. The shear thinning properties of the nanocomposites enable their convenient processing into required morphologies and the wettability of electrolytes to electrodes under typical high shear rate processing conditions and the safety of the produced devices can be ensured by their solid-like properties in the static state.