Janus‐Membranen sind eine neue Materialklasse mit “gegensätzlichen” Seiten, die selektive und oftmals neuartige Transportcharakteristiken zeigen. In diesem Kurzaufsatz schlagen wird eine Definition der Janus‐...
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Janus‐Membranen sind eine neue Materialklasse mit “gegensätzlichen” Seiten, die selektive und oftmals neuartige Transportcharakteristiken zeigen. In diesem Kurzaufsatz schlagen wird eine Definition der Janus‐Membran vor, die über die Definition der Asymmetrie hinausgeht, und diskutieren gängige Herstellungsmethoden. Wir beschreiben aktuelle und potenzielle Anwendungen im gerichteten Stofftransport und in der schaltbaren Permeation und geben Hinweise zur Membranoptimierung mit detaillierten Mechanismen.
The aim of this work was to remove oxytetracycline and atrazine using novel catalytic composites consisting of a visible light-active photocatalyst (Fe-N doped TiO2) supported on visible excited long afterglow alumina...
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Photodynamic therapy (PDT) is an alternative to traditional cancer treatments. This approach involves the use of photosensitizer (PS) agents and their interaction with light. As a consequence, cytotoxic reactive oxyge...
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ISBN:
(纸本)9781510826380
Photodynamic therapy (PDT) is an alternative to traditional cancer treatments. This approach involves the use of photosensitizer (PS) agents and their interaction with light. As a consequence, cytotoxic reactive oxygen species (ROS) are generated that, in turn will destroy tumors. On the other hand, ZnO is a biocompatible, nontoxic, and biodegradable material with the capability to generate ROS, specifically singlet oxygen (SO), which makes this material a promising candidate for 2-photon PDT. Doping ZnO with Li species is expected to induce defects in the host oxide structure mat favors the formation of trap states that should affect the electronic transitions related to the generation of SO. The present work reports the effect of the level of Lidoping on the ZnO structure and its capability to generate SO. Li-doped ZnO nanoparticles were synthesized under size-controlled conditions using a modified version of the polyol method. XRD measurements confirmed the development of well-crystallized ZnO Wurtzite;the average crystallite sizes ranged between 13.3nm and 14.2 nm, with an increase in Li content. The corresponding band gap energy values, estimated from UV-vis measurements, decreased from 3.33 to 3.25 eV. Photoluminescence (PL) measurements of Li-ZnO revealed the presence of emission peaks centered on 363nm, 390nm, and 556 nm;these emission peaks correspond to the exciton emission, transition of shallow donor levels near of the conduction band to valence band such as interstitial Zn, and oxygen vacancies, respectively. The observed increase of the emission intensity of the 390 nm emission peak, relative to the intensity of the main emission peak at 363 nm, was attributed to the promote of trap states due to interstitial Zn or Li-incorporation into the host oxide lattice. SO measurements evidenced the enhancing effect of the Li concentration on the capability of the doped ZnO to generate this species. This Li-dependence of SO generation can be attributed to the en
Until recently, computational complexities and lack of detailed, nonlinear dynamic models have stood as main obstacles to widespread industrial adoption of model-based on-line optimization for operation of batch and s...
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Until recently, computational complexities and lack of detailed, nonlinear dynamic models have stood as main obstacles to widespread industrial adoption of model-based on-line optimization for operation of batch and semi-batch reactors. With recent advances in both dynamic modeling techniques and nonlinear programming (NLP) solvers, it is conceivable now to use significantly-sized, nonlinear models directly for on-line state/parameter estimation and optimal control calculations. In this study, we propose a framework for doing this. In the proposed framework, nonlinear first principles dynamic model-based optimizations are performed at several time points throughout a batch run over a fixed horizon, in order to estimate the current state of the model and to refine the target batch time and input variables. Here we combine shrinking horizon nonlinear model predictive control (sh-NMPC) with expanding horizon least squares estimation (eh-LSE). This framework is tested on a large-scale anionic propylene oxide (PO) polymerization process, whose operation considers not only certain end-product specifications but also safety constraints. It is shown that the proposed method is not only computationally feasible (averaging less than 10 CPU seconds at each sampling time) but leads to excellent performance, satisfying the product specification target despite initialization errors and measurement noise.
In this work, a fluorescent monomer 2-（9-carbazolyl） ethyl vinyl ether（CEVE） was synthesized in our lab, and its photo-induced living cationic copolymerization behavior with isobutyl vinyl ether（IBVE） was invest...
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In this work, a fluorescent monomer 2-（9-carbazolyl） ethyl vinyl ether（CEVE） was synthesized in our lab, and its photo-induced living cationic copolymerization behavior with isobutyl vinyl ether（IBVE） was investigated in detail using diphenyliodonium chloride（DPICl）/2,2-dimethoxy-2-phenylacetophenone（DMPA） and zinc bromide（Zn Br2） initiating system in dichloromethane solution at 5 °C, -5 °C, and -15 °C, respectively. The living nature of this copolymerization system was confirmed by adding fresh comonomer method after the copolymerization almost finished. In addition, the obtained fluorescent copolymer poly（IBVE-co-CEVE） has a low glass transition temperature（Tg）, below -10 °C.
The entropic effects in the comicellization behavior of amphiphilic AB copolymers differing in the chain size of solvophilic A parts were studied by means of molecular dynamics simulations. In particular, mixtures of ...
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The entropic effects in the comicellization behavior of amphiphilic AB copolymers differing in the chain size of solvophilic A parts were studied by means of molecular dynamics simulations. In particular, mixtures of miktoarm star copolymers differing in the molecular weight of solvophilic arms were investigated. We found that the critical micelle concentration values show a positive deviation from the analytical predictions of the molecular theory of comicellization for chemically identical copolymers. This can be attributed to the effective interactions between copolymers originated from the arm size asymmetry. The effective interactions induce a very small decrease in the aggregation number of preferential micelles triggering the nonrandom mixing between the solvophilic moieties in the corona. Additionally, in order to specify how the chain architecture affects the size distribution and the shape of mixed micelles we studied star-shaped, H-shaped, and homo-linked-rings–linear mixtures. In the first case the individual constituents form micelles with preferential and wide aggregation numbers and in the latter case the individual constituents form wormlike and spherical micelles.
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