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Immobilization of enzyme could offer the biocatalyst with increased stability and important recoverability, which plays a vital role in the enzyme’s industrial applications. In this study, we present a new strategy to build an intelligent enzyme carrier by coating titania nanoparticles with thermoresponsive epoxy-functionalized polymers. Zero-valent copper-mediated living radical polymerization (Cu(0)-LRP) was utilized herein to copolymerize N-isopropylacrylamide (NIPAM) and glycidyl acrylate (GA) directly from an unprotected dopamine-functionalized initiator to obtain an epoxy-containing polymer with terminal anchor for the “grafting to” or “one-pot” modification of titania nanoparticles. A rhodamine B-labeled laccase has been subsequently used as a model enzyme for successful immobilization to yield an intelligent titania/laccase hybrid bifunctional catalyst. The immobilized laccase has shown excellent thermal stability under ambient or even relatively high temperature above the lower critical solution temperature (LCST) at which temperature the hybrid particles could be facilely recovered for reuse. The enzyme activity could be maintained during the repeated use after recovery and enzymatic degradation of bisphenol A was proven to be efficient. The photocatalytic ability of titania was also investigated by fast degradation of rhodamine B under the excitation of simulated sunlight. Therefore, this study has provided a facile strategy for the immobilization of metal oxide catalysts with enzymes, which constructs a novel bifunctional catalyst that will be promising for the “one-pot” degradation of different organic pollutants.\ud \ud

We numerically study the entanglement dynamics of free fermions on a cubic lattice with potential disorder following a quantum quench. We focus, in particular, on the metal-insulator transition at a critical disorder strength and compare the results to the putative many-body localization (MBL) transition in interacting one-dimensional systems. We find that at the transition point the entanglement entropy grows logarithmically with time $t$ while the number entropy grows $\sim\ln\ln t$. This is exactly the same scaling recently found in the MBL phase of the Heisenberg chain with random magnetic fields suggesting that the MBL phase might be more akin to an extended critical regime with both localized and delocalized states rather than a fully localized phase. We also show that the experimentally easily accessible number entropy can be used to bound the full entanglement entropy of the Anderson model and that the critical properties at the metal-insulator transition obtained from entanglement measures are consistent with those obtained by other probes.

In this study, titanium dioxide (TiO2) nanoparticles coated with non-leachable biocides were prepared by chemically attaching tertiary-amine-containing polymers to the surface of TiO2. Copper(0)-mediated living radical polymerization (Cu(0)-LRP) was utilized to fabricate the effective antibacterial surfaces via both “grafting to” and “grafting from” strategies. The Cu(0)-LRP of 2-(dimethylamino)ethyl methacrylate (DMAEMA) and 2-(diethylamino)ethyl methacrylate (DEAEMA) was first performed directly from an unprotected dopamine-functionalized initiator using either a commercial copper wire or in situ generated copper powders from the disproportionation of CuBr/Me6TREN as the activators. The synthesized dopamine-terminal polymers were grafted on the surface of TiO2via strong catechol bonding to yield an environmental-responsive surface. Subsequently, the tertiary amine polymers were directly grafted from the TiO2 nanoparticles via surface initiated Cu(0)-LRP in DMSO or aqueous solutions, which showed a higher grafting density. The obtained TiO2@polymer hybrid nanocomposites showed good dispersion stability in water and efficient recovery could be achieved due to the self-flocculation effect. The degradation of rhodamine B under the irradiation of simulated sunlight proved the maintenance of photocatalytic ability after the surface modification of TiO2. The antibacterial activity of the tertiary amine polymer-coated nanocomposites before and after quaternization was tested against Escherichia coli (E. coli), during which the unmodified tertiary amine polymer surprisingly inhibited the growth of E. coli and the quaternized polymer showed almost 100% killing efficiency.

In this study, we report on the synthesis of thermoresponsive polymers with different microstructures, a precisely tunable lower critical solution temperature (LCST) and terminal catechol anchors by copper(0) mediated living radical polymerization (Cu(0)-LRP). All the Cu(0)-LRP polymerizations were performed directly from the unprotected dopamine-functionalized initiators at ambient temperature or below in aqueous solution with full or close to full conversion obtained in minutes. The resulting polymers exhibited a designed molecular weight (MW), narrow MW distribution and high end-group fidelity capable of in situ block copolymerization. We demonstrate their application toward the surface modification of titanium dioxide nanoparticles by the successful preparation of smart nanocomposites with a self-flocculation effect. A “one-pot” strategy was then developed for the simultaneous polymerization and surface modification to simplify the multi-step purification and immobilization processes. The subsequent degradation of Rhodamine B under the irradiation of simulated solar light proved the potential application of hybrid nanocomposites in water treatment and a switching effect of photocatalytic ability below or above the LCST was also observed.

The superior photocatalysis of titanium dioxide (TiO2) had received much attention, but the effect of its separation and agglomeration on the water disinfection performance should not be ignored. Herein, lactose-containing glycopolymers grafted onto magnetic TiO2 nanomaterials were prepared through copper (0) mediated controlled radical polymerization and “grafting to” strategy to improve their separation and dispersibility properties. The physicochemical properties of the Fe3O4@TiO2/glycopolymers were systematically characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, dynamic light scattering, transition electron microscopy, and vibrating sample magnetometer. The result of the survival bacterial ratio under ultraviolet exhibited the well photocatalytic antibacterial activity of Fe3O4@TiO2/glycopolymers towards E. coli, which retained the photocatalytic sterilization performance of TiO2. Among them, Fe3O4@TiO2@poly(LacA) showed an excellent ability to identify and trap E. coli because of the carbohydrate-protein recognition effect. The endocytosis of E. coli on Fe3O4@TiO2@poly(LacA) was further confirmed by the image of transition electron microscopy. Considering the magnetic characteristics of Fe3O4@TiO2/glycopolymers, it is speculated that these antibacterial agents can be easily recovered by the external magnetic field, and thus be a promising candidate for photocatalysis water disinfection.