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Polyethylene oxide based solid polymer electrolytes (SPEs) are safer alternatives to the current flammable liquid electrolytes used in lithium‐ion batteries. Lithium ions are typically thought to conduct through the amorphous regions of SPEs with the aid of polymer segmental motion, which is correlated with the glass transition temperature (Tg). The ionic conductivity is generally increased by making the polymer more flexible (decreasing Tg) and/or by increasing the amorphous regions of the SPE, at the cost of compromising its stiffness. This trade‐off makes it impossible to optimize both ionic conductivity and stiffness of SPEs. By incorporating a metal–organic framework (MOF) nanowhisker with the composition EO:Li = 6:1 [EO = ether oxygen, Li = lithium], we synthesized a unique composite electrolyte. We observed an atypical conductivity mechanism in this composite electrolyte, where lithium ions conduct through the crystalline regions without decreasing Tg or increasing amorphous fraction. The room‐temperature ionic conductivity of the 6:1 polymer electrolyte increased by almost 400% when 2 wt% MOF nanowhisker was added. Our results supported the potential of a composite electrolyte, which enables simultaneous improvement in both conductivity and stiffness. [ABSTRACT FROM AUTHOR]

Measurements of the gas sensing performance of nanomaterials typically involve the use of interdigitated electrodes (IDEs). A separate heater is often integrated to provide elevated temperature for improved sensing performance. However, the use of IDEs and separate heaters increases fabrication complexity. Here, a novel gas sensing platform based on a highly porous laser-induced graphene (LIG) pattern is reported. The LIG gas sensing platform consists of a sensing region and a serpentine interconnect region. A thin film of metal (e.g., Ag) coated in the serpentine interconnect region significantly reduces its resistance, thereby providing a localized Joule healing in the sensing region (i.e., self-heating) during typical measurements of chemoresistive gas sensors. Dispersing nanomaterials with different selectivity in the sensing region results in an array to potentially deconvolute various gaseous components in the mixture. The self-heating of the LIG gas sensing platform is first studied as a function of the applied voltage during resistance measurement and LIG geometric parameters (e.g., linewidth from 120 to 240 μm) to achieve an operating temperature from 20 to 80 °C. Systematic investigations of various nanomaterials demonstrate the feasibility of the LIG gas sensing performance. Taken together with the stretchable design layout in the serpentine interconnect region to provide mechanical robustness over a tensile strain of 20%, the gas sensor with a significant response (6.6‰ ppm−1), fast response/recovery processes, excellent selectivity, and an ultralow limit of detection (1.5 parts per billion) at a modest temperature from self-heating opens new opportunities in epidermal electronic devices. [ABSTRACT FROM AUTHOR]

The oligomerization of short alkenes (ethylene and propylene) can be used for producing commodity chemicals. Various catalysts have been used for alkene oligomerization, among which ordered microporous catalysts are thermally and mechanically stable and are already established for large‐scale industrial applications. In this work, we demonstrate ethylene oligomerization reaction on a microporous titanosilicate ETS‐10 (Engelhard Titanosiliate‐10) exchanged with Ni2+ (Ni‐ETS‐10). We demonstrate a template‐free and fluoride‐free ETS‐10 synthesis method that does not produce impurities commonly seen in hydrothermal ETS‐10 synthesis. Ni‐ETS‐10 showed high C2 conversion rate, high selectivity to C4 and high stability comparing to other microporous catalysts investigated in this work for ethylene oligomerization reaction. More deETS, please! ETS‐10 loaded with Ni2+ is shown to be active and stable for ethylene oligomerization. Ni‐ETS‐10 showed high C4 selectivity among microporous catalysts for ethylene oligomerization. [ABSTRACT FROM AUTHOR]

Metal-Organic Framework (MOF) is a type of coordination networks with high surface area and tunable chemistry. MOFs are utilized for molecular recognition-related applications. The interaction of MOFs with molecules of interest occurs at the internal and external surfaces of MOFs, where internal surfaces are mostly inside the MOF pores. It is important to tune this interaction by pore engineering. We reviewed pore engineering at 4 different length scales: unit cell, multi-unit cells, mesoscale and macroscale. Additionally, we also discussed practical consequences of pore engineering on mass transfer, heat transfer and mechanical stability of MOF materials. [Display omitted] • Common chemical methods for engineering MOF pores at various length scales are reviewed. • Consequences of pore engineering are reviewed with applications of such MOFs. • Practical applications of MOF pore engineering on their mass transfer, heat transfer and mechanical properties are reviewed. • Recommendations for future research on hierarchical MOFs are provided. [ABSTRACT FROM AUTHOR]

The Cover Feature shows the conversion of ethylene to 1‐butene on Ni‐ETS‐10 (Ni‐exchanged Engelhard Titanosilicate‐10) catalyst. The oligomerization of ethylene and propylene can be used for producing commodity chemicals, such as additives and comonomers in plastics. In their Communication, J. Thakkar demonstrate that Ni‐ETS‐10 can selectively convert ethylene to C4 alkenes with selectivity to C4 above 80%. Ni‐ETS‐10 showed high C2 conversion rate, high selectivity to C4 and high stability relative to other microporous catalysts investigated in this work. The Communication also introduces a method for synthesizing impurity free ETS‐10. More information can be found in the Communication by J. Thakkar et al. on page 4234 in Issue 19, 2018 (DOI: 10.1002/cctc.201800650). [ABSTRACT FROM AUTHOR]

Finned hierarchical MOF particles (Cu(BDC) nanosheets as fins grown perpendicularly on Ni 2 (BDC) 2 (DABCO) hexagonal prisms) were synthesized on modified cellulose support. The hierarchical MOF particles exposed the open Cu(II) sites on Cu(BDC) to enable selective 1-hexene/ n -hexane separation.

Metal-organic frameworks (MOFs) are a class of customizable porous material, which have shown good performance in separation processes, because of their large surface area and molecular recognition property. Although the effects of chemical structure of MOFs on their separation performance were extensively studied, the exploration of their surface properties was still limited. This work demonstrated a MOF nanosheet with large amount of coordinatively unsaturated metal sites, Cu(BDC) (copper(II) benzenedicarboxylate), where the unsaturated Cu sites were utilized to selectively adsorb organic molecules with Lewis basicity. This work also investigated the direct growth of Cu(BDC) on the cellulose substrate, where the MOF nanosheets were immobilized on the cellulose substrate, enabling the composite material for practical applications. The heterogeneous nucleation and growth of MOF nanosheets on the cellulose were achieved by tuning the basicity of solution and reaction temperature. We believe this direct growth approach can be applied to other MOF composite materials for separation and purification purposes, as well as other applications involving molecular recognition properties of MOFs, such as sensing, catalysis, and enzyme immobilization.