We report the construction of dumbbell-shaped hybrid molecules for programming their hierarchical supramolecular nanostructures through a synergetic self-assembly. Our first dumbbell-shaped hybrid molecule is a POM-organic-POSS cocluster produced by covalently coupling a POM cluster and a POSS cluster together through an organic tether. Structural analyses demonstrated a highly ordered lamellar morphology with a 4.9 nm periodicity, indicating a strong thermodynamic force driving a nanoscale phase separation of the POM and POSS blocks. The POM clusters were arranged in an orderly fashion within the POM-containing layer with a 1.38 nm periodicity because of fixed shape and size of the cluster. This investigation provides in-depth understanding of how to construct hierarchical supramolecular nanostructures at a nanoscale less than 5 nm by manipulating and controlling the topological shape of hybrid molecules.

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The heterogenization of a polyoxometalate (POM) catalyst by direct covalent immobilization in polymer matrices with uniform macropores and high specific surface areas was reported. Via click chemistry, organically modified POM clusters were mainly "clicked" on the functionalized channel surface of a macroporous resin. The appraisement of the catalytic performance via catalysis on tetrahydrothiophene (THT) oxidation, demonstrates that the solid catalyst is efficient and has a high selectivity. More attractively, it could be reused several times without detectable catalytic activity loss. And no POM species were detected in the filtrate, stemming from the strong covalent bonding between the POM clusters and the macroporous resin surface. Evidently, such a catalyst heterogenization strategy helps to overcome the fatal leaching problem. Therefore the POM heterogeneous material can become an ideal candidate for industrial processes and will also have great potential in practical application not only for oxidative catalysis.

Temperature responsive liquid chromatography (TRLC) allows for separation of organic solutes in purely aqueous mobile phases whereby retention is controlled through temperature. The vast majority of the work has thus far been performed on poly­[N-isopropylacrylamide] (PNIPAAm)-based columns, while the performance of other temperature responsive polymers has rarely been compared under identical conditions. Therefore, in this work, two novel TRLC phases based on poly­[N-n-propylacrylamide] (PNNPAAm) and poly­[N,N-diethylacrylamide] (PDEAAm) are reported and compared to the state of the art PNIPAAm based column. Optimal comparison is thereby obtained by the use of controlled radical polymerizations, identical molecular weights, and by maximizing carbon loads on the silica supporting material. Analysis of identical test mixtures of homologue series and pharmaceutical samples revealed that PNNPAAm performs in a similar way as PNIPAAm while offering enhanced retention and a shift of the useable temperature range toward lower temperatures. PDEAAm offers a range of novel possibilities as it depicts a different selectivity, allowing for enhanced resolution in TRLC in, for example, coupled column systems. Reduced plate heights of 3 could be obtained on the homemade columns, offering the promise for reasonable column efficiencies in TRLC despite the use of bulky polymers as stationary phases in HPLC.

Biodegradable polymeric materials are intensively used in biomedical applications. Of particular interest for drug-delivery applications are polymers that are stable at pH 7.4, that is, in the blood stream, but rapidly hydrolyze under acidic conditions, such as those encountered in the endo/lysosome or the tumor microenvironment. However, an increase in the acidic-degradation rate of acid-labile groups goes hand in hand with higher instability of the polymer at pH 7.4 or during storage, thus posing an intrinsic limitation on fast degradation under acidic conditions. Herein, we report that a combination of acid-labile dimethyldioxolane side chains and hydroxyethyl side chains leads to acid-degradable thermoresponsive polymers that are quickly hydrolyzed under slightly acidic conditions but stable at pH 7.4 or during storage. We ascribe these properties to high hydration of the hydroxy-containing collapsed polymer globules in conjunction with autocatalytic acceleration of the hydrolysis reactions by the hydroxy groups.