Search

This study is aimed at booming intelligent polymers and their applications in catalysis, presenting an intelligent polymer catalyst with photo-mediated catalytic ability. This catalyst was fabricated with polymeric 2-acrylamide-2-methylpropylsulfonic acid (acidic moieties capable of catalytic hydrolysis) and photo-sensitive acrylamide-azobenzene prepared from the synthesis of 4-aminoazobenzene with acryloyl chloride. Under the radiation of ultraviolet light, this catalyst would undergo a change of cis/trans-conformation of azobenzene, causing alterable accessibility to the internal catalytic sites and as a result mediated catalytic ability. This catalyst presented significant catalytic ability at ambient conditions due to the trans-conformation of azobenzene which endorsed accessibility to the internal catalytic sites. Conversely, this catalyst showed limited catalytic ability under ultraviolet light, in response to the isomerization of the cis-conformation of azobenzene which inhibited the accessibility. In this way, this catalyst showed the photo-mediated catalytic ability. The suggestion of this polymer catalyst provides a prospect to optically modulate the catalytic proceedings, particularly for complicated processes. [ABSTRACT FROM AUTHOR]

The study is aimed at the present challenge in tandem catalysis, addressing how to achieve tandem catalytic ability and meantime to avoid a mutual engagement between the tandem processes. This objective was met by constituting a nanoreactor with bio-inspired compartments made of core-and-shell architectures. The core-and-shell architectures allowed the nanoreactor to spatiotemporally separate the tandem catalytic processes from each other, in virtue of the restriction from mass transfer and the radial distribution of reaction loci. The shell in this nanoreactor admitted a precursor reaction while the core was responsible the following reaction. There was no mutual engagement in the tandem processes, due to the spatiotemporally-driven sequential catalysis in the nanoreactor. In this way, this nanoreactor demonstrated the "undisturbed" tandem catalytic ability. Differing from reported nanoreactors and bi-functional catalysts which often involve a mutual competition and even cross-reactions between the tandem processes, this nanoreactor may partition the tandem catalytic processes and avoid the mutual engagement. The constitution of this nanoreactor suggests a prospect to develop "undisturbed" tandem catalysts for complicated catalytic processes. [ABSTRACT FROM AUTHOR]

Molecular imprinting is a promising technique for the preparation of polymers with predetermined selectivity and high affinity. Normally, based on the self-assembly of functional monomers and templates (i.e., imprint molecules), the imprinted polymers are produced by crosslinking polymerizations. The templates are subsequently removed from the polymer, leaving behind binding sites complementary to the imprint species in terms of the shape and the position of functional groups. Recognition of the polymer constitutes an induced molecular memory, which makes the binding sites capable of selectively recognizing the imprint species. This article presents a limited review on molecular self-assembly and the uses of these imprinted polymers in separation, sensors, and catalysis. Other aspects including related backgrounds are also discussed. [ABSTRACT FROM AUTHOR]