Water Reuse Fit for Purpose by a Sustainable Industrial Wastewater Management Concept

Water shortage is often a challenge for industrial park developments. To ensure a more sustainable water supply, the Industrial Wastewater Management Concept with a focus on Reuse (IW²MC→R) provides a strategy to meet the challenges. Main requirements to achieve water reuse fit for purpose are optimized wastewater treatment, an optimized sewer and pipe system, and an innovative water quality monitoring concept. To evaluate water‐reuse concepts, a reuse factor is calculated, which relates to all wastewater inflows to the central wastewater treatment plant and all reuse‐water flows.     

Experimental Investigation of the Froth Height in Columns with Sandwich Packings

Sandwich packings, consisting of alternatingly stacked conventional structured packings with different geometric surface areas, are promising for increasing capacity and efficiency of separation columns. Film flow and froth flow evolve along a stack, which requires comprehensive fluid dynamic analysis. In particular, the froth height is an essential parameter to determine the spatial extent of the flow regimes. Ultrafast X‐ray tomography and a 3D‐printed pressure drop profile measurement module were applied to independently estimate this parameter. The results are compared with existing correlations.     

Phosphorylated sodium alginate/APP/DPER intumescent flame retardant used for polypropylene

Flame-retardant polypropylene (FR-PP) materials are realized by use of natural-sourced flame-retardant materials. Phosphorylated sodium alginate, ammonium polyphosphate, and dipentaerythritol are used to create an intumescent flame retardant (IFR). This realized flame retardant is embedded into polypropylene (PP) through melt blending method. The components, chemical structures, thermal properties, and degradation mechanisms of the samples are characterized by infrared spectrometry, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy, and cone calorimeter test. The results indicate that an effective IFR is obtained due to gas phase and condensed phase synergistic flame-retardant ability during combustion and degradation of FR-PP. This work presents a facile method for preparing FR-PP with efficient flame retardancy. This study is a first proof of concept for an innovative flame retardant, which could find application in future in the fields of automotive industry and the construction of electronic devices. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47794.     

Interfacial Strain Gradients Control Nanoscale Domain Morphology in Epitaxial BiFeO3 Multiferroic Films

Domain switching pathways fundamentally control performance in ferroelectric thin film devices. In epitaxial bismuth ferrite (BiFeO₃) films, the domain morphology is known to influence the multiferroic orders. While both striped and mosaic domains have been observed, the origins of the latter have remained unclear. Here, it is shown that domain morphology is defined by the strain profile across the film–substrate interface. In samples with mosaic domains, X‐ray diffraction analysis reveals strong strain gradients, while geometric phase analysis using scanning transmission electron microscopy finds that within 5 nm of the film–substrate interface, the out‐of‐plane strain shows an anomalous dip while the in‐plane strain is constant. Conversely, if uniform strain is maintained across the interface with zero strain gradient, striped domains are formed. Critically, an ex situ thermal treatment, which eliminates the interfacial strain gradient, converts the domains from mosaic to striped. The antiferromagnetic state of the BiFeO₃ is also influenced by the domain structure, whereby the mosaic domains disrupt the long‐range spin cycloid. This work demonstrates that atomic scale tuning of interfacial strain gradients is a powerful route to manipulate the global multiferroic orders in epitaxial films.     

Light‐Driven Proton Transfer for Cyclic and Temporal Switching of Enzymatic Nanoreactors

Temporal activation of biological processes by visible light and subsequent return to an inactive state in the absence of light is an essential characteristic of photoreceptor cells. Inspired by these phenomena, light‐responsive materials are very attractive due to the high spatiotemporal control of light irradiation, with light being able to precisely orchestrate processes repeatedly over many cycles. Herein, it is reported that light‐driven proton transfer triggered by a merocyanine‐based photoacid can be used to modulate the permeability of pH‐responsive polymersomes through cyclic, temporally controlled protonation and deprotonation of the polymersome membrane. The membranes can undergo repeated light‐driven swelling–contraction cycles without losing functional effectiveness. When applied to enzyme loaded‐nanoreactors, this membrane responsiveness is used for the reversible control of enzymatic reactions. This combination of the merocyanine‐based photoacid and pH‐switchable nanoreactors results in rapidly responding and versatile supramolecular systems successfully used to switch enzymatic reactions ON and OFF on demand.     

Highly Tunable Thiol-Ene Photoresins for Volumetric Additive Manufacturing

Volumetric additive manufacturing (VAM) forms complete 3D objects in a single photocuring operation without layering defects, enabling 3D printed polymer parts with mechanical properties similar to their bulk material counterparts. This study presents the first report of VAM-printed thiol-ene resins. With well-ordered molecular networks, thiol-ene chemistry accesses polymer materials with a wide range of mechanical properties, moving VAM beyond the limitations of commonly used acrylate formulations. Since free-radical thiol-ene polymerization is not inhibited by oxygen, the nonlinear threshold response required in VAM is introduced by incorporating 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) as a radical scavenger. Tuning of the reaction kinetics is accomplished by balancing inhibitor and initiator content. Coupling this with quantitative measurements of the absorbed volumetric optical dose allows control of polymer conversion and gelation during printing. Importantly, this work thereby establishes the first comprehensive framework for spatial–temporal control over volumetric energy distribution, demonstrating structures 3D printed in thiol-ene resin by means of tomographic volumetric VAM. Mechanical characterization of this thiol-ene system, with varied ratios of isocyanurate and triethylene glycol monomers, reveals highly tunable mechanical response far more versatile than identical acrylate-based resins. This broadens the range of materials and properties available for VAM, taking another step toward high-performance printed polymers.