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This study was aimed at addressing the present challenge in self-controlled catalysts, about how to furnish the catalysts with self-governed catalytic ability in water. This objective was met by constructing a polymer composite reactor inspired from marine mussels, made of an aquatically autonomous polymer and encapsulated metal nanoparticles. The aquatically autonomous properties at the polymer support, in combination with the catalytic ability of metal nanoparticles, allowed the reactor to run catalysis with aquatically ‘autonomous’ access, which led to the occurrence of aquatically self-governed catalytic ability. This reactor showed poor catalytic reactivity in water at relatively low temperatures due to the ‘closed’ polymeric networks, which blocked access to the encapsulated metal nanoparticles. This reactor showed, however, significant reactivity in water at relatively high temperatures in response to the ‘openness’ of the access. Unlike the switchable catalysis at reported catalytic reactors which usually involved conventional hydrophilic/hydrophobic transition and the leaching of metal nanoparticles, the switchable catalysis at this reactor ran naturally with the aquatically autonomous access that did not involve any hydrophilic/hydrophobic transition and the leaching of metal nanoparticles. This protocol suggested opportunities for developing robust smart catalysts for aquatic chemical processes. [ABSTRACT FROM AUTHOR]

This study was aimed at addressing the present challenge of cascade reactions, namely, how to furnish the catalysts with desired and hierarchical catalytic ability. This issue was addressed by constructing a cascade-reaction nanoreactor made of a bifunctional molecularly imprinted polymer containing acidic catalytic sites and Pt nanoparticles. The acidic catalytic sites within the imprinted polymer allowed one specified reaction, whereas the encapsulated Pt nanoparticles were responsible for another coupled reaction. To that end, the unique imprinted polymer was fabricated by using two well-coupled templates, that is, 4-nitrophenyl acetate and 4-nitrophenol. The catalytic hydrolysis of the former compound at the acidic catalytic sites led to the formation of the latter compound, which was further reduced by the encapsulated Pt nanoparticles to 4-aminophenol. Therefore, this nanoreactor demonstrated a catalytic-cascade ability. This protocol opens up the opportunity to develop functional catalysts for complicated chemical processes. [ABSTRACT FROM AUTHOR]

This study aimed at the present dilemma in selective catalysis, about how to furnish metal-nanoparticle catalysts with predictable selectivity. This issue was addressed by developing a 'key-vs.-lock'-like polymer reactor made of an elaborate molecularly imprinted polymer containing metal nanoparticles, which was capable of predictably and selectively catalyzing its specified substrate. Unlike reported polymer reactors and enzyme-like imprinted polymer catalysts, which lack either predictable selectivity or reactive metal nanoparticles, this polymer reactor has incorporated both of the molecular recognition ability of the polymer carrier and the catalytic sites of metal nanoparticles into one entire entity and thereby dictated selective catalysis. This study highlighted how this polymer reactor works in a selective way in contrast to reported catalytic polymers or polymer reactors, which thus opens opportunities of tailoring selective catalysts for controlled chemical processes. [ABSTRACT FROM AUTHOR]

Abstract: The siloxane microspheres with core-shell structure (PMMA/PMPS) (MMA, methyl methacrylate; MPS, 3-methacryloxypropyl-trimethoxysilane) have been prepared by dispersion polymerization as described in our previous work. In this paper, the developed poly(MMA-MPS) microspheres, as a carrier, are used to investigate the adsorption behavior of bovine serum albumin (BSA) on them. The Langmuir and Freundlich models have been applied to describe the adsorption behavior. The experimental results indicated that the presence of PMPS evidently increases the adsorption rate and the amount of protein, and it also influences the interaction of BSA molecules. The adsorption of BSA on the poly(MMA-MPS) microspheres seems to be sensitive to pH and ionic strength. The fittings curves from Langmuir and Freundlich models showed that the adsorption was actually more complicated than ideal situation because one or more interactions were involved in the process. For understanding the electronic contribution, the Zeta potential was used to measure the reactive system before and after protein adsorption. [Copyright &y& Elsevier]

Abstract: The core/shell particles consisting of polystyrene core and 3-(methacryloxypropyl)-trimethoxysilane (MPS) shell were prepared in the present study by successive seeding polymerization under kinetically controlled conditions and were characterized by particle size analyser, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The TEM image indicated that the particles containing organic siloxane presented an evident core/shell structure. Additionally, the study of XPS also revealed that MPS could be grafted onto the surface of polystyrene microspheres and the atomic ratio of C/Si on the surface of the core/shell particles (MPS-40) was very close to the ratio of C/Si in the molecule of MPS. The surface properties of the films produced from the core/shell particles were also investigated by the static contact angle method. Compared with the homopolymer of PS, the core/shell particles were more effective to create hydrophobic surface, so, the introduction of MPS was capable of obvious increase in water repellency. [Copyright &y& Elsevier]