Search

1,2-Dimethoxyethane (DME) has been widely used as an electrolyte solvent for lithium metal batteries on account of its intrinsic reductive stability; however, its low oxidative stability presents a major challenge for use in high-voltage Li metal batteries (LMBs). In this direction, herein, we introduce a new low-dielectric solvent, 1,2-dimethoxypropane (DMP), as an electrolyte solvent. Compared to DME, DMP has decreased solvation power owing to its increased steric effects, thus promoting anion–Li+interactions. This controlled solvation structure of the 2 M LiFSI-in-DMP electrolyte facilitated the formation of an anion-driven, stable interface at the lithium metal anode and oxidative stability for compatibility with widely adopted cathodes to afford Li|LiFePO4and Li|LiNi0.8Co0.1Mn0.1O2cells with decent cycling stability. These results imply the usefulness of steric control as an alternative strategy to commonly used fluorination to fine-tune the solvation power and, in general, the design of new solvents for practical lithium metal batteries.

The development of porous materials is of great interest for the capture of CO2 from various emission sources, which is essential to mitigate its detrimental environmental impact. In this direction, porous organic polymers (POPs) have emerged as prime candidates owing to their structural tunability, physiochemical stability and high surface areas. In an effort to transfer an intrinsic property of a cyclotetrabenzoin-derived macrocycle—its high CO2 affinity—into porous networks, herein we report the synthesis of three-dimensional (3D) macrocycle-based POPs through the polycondensation of an octaketone macrocycle with phenazine-2,3,7,8-tetraamine hydrochloride. This polycondensation was performed under ionothermal conditions, using an eutectic salt mixture in the temperature range of 200 to 300 oC. The resulting polymers, named 3D-mmPOPs, showed reaction temperature-dependent surface areas and gas uptake properties. 3D-mmPOP-250 synthesized at 250 °C exhibited a surface area of up to 752 m2 g−1 and high microporosity originating from the macrocyclic units, thus resulting in an excellent CO2 binding enthalpy of 40.6 kJ mol−1 and CO2 uptake capacities up to 3.51 mmol g−1 at 273 K, 1.1 bar.

There exists an urgent demand for the advancement of technologies that reduce and capture carbon dioxide (CO

Electrolyte engineering is a highly promising strategy in lithium–sulfur batteries to increase the sulfur utilization and maintain a stable interface at the lithium metal anode for long-term cycling. Whereas high donor electrolytes can increase the solubility of polysulfides to promote the sulfur utilization and therefore operate under lean electrolyte conditions, their poor thermodynamic stability toward lithium metal anode causes uncontrolled decomposition at its interface and impair the cycle life severely. Here, we introduce a dual functional high donor electrolyte, 3-fluoropyridine (3-FPN), to simultaneously achieve high polysulfide solubility up to 1.5 M and compatibility with lithium metal. These features result in a high specific capacity of 1087.9 mAh gsulfur–1and robust cycling under a lean electrolyte condition of 7 μLelectrolytemgsulfur–1in the absence of LiNO3. Remarkably, 3-FPN preserves stable cyclability even at a high areal sulfur loading of 8 mgsulfurcm–2, which opens a new avenue in advancing the electrolytes for lithium–sulfur batteries toward their high volumetric energy density and long cycle life

Porous organic polymers (POPs) have gained tremendous attention owing to their chemical tunability, stability and high surface areas. Whereas there are several examples of fully conjugated two-dimensional (2D) POPs, three-dimensional (3D) ones are rather challenging to realize in the absence of structural templates. Herein, we report the base-catalyzed direct synthesis of a fully conjugated 3D POPs, named benzyne-derived polymers (BDPs), containing biphenylene and tetraphenylene moieties starting from a simple bisbenzyne precursor, which undergoes [2+2] and [2+2+2+2] cycloaddition reactions to form BDPs primarily composed of biphenylene and tetraphenylene moieties. The resulting polymers exhibited ultramicroporous structures with surface areas up to 544 m2 g-1 and very high CO2/N2 selectivities.

This review highlights the recent advances in the development of porous organic polymers (POPs) for CO2 capture, separation and conversion and evaluates their structural and textural features to outline design principles for efficient sorbents.

Metallic lithium (Li) is regarded as the ideal anode material in lithium‐ion batteries due to its low electrochemical potential, highest theoretical energy density and low density. There are, however, still significant challenges to be addressed such as Li‐dendrite growth and low interfacial stability, which impede the practical application of Li metal anodes. In order to circumvent these shortcomings, herein, we present a gel polymer electrolyte containing imidazolium ionic liquid end groups with a perfluorinated alkyl chain (F‐IL) to achieve both high ionic conductivity and Li ion transference number by fundamentally altering the solubility of salt within the gel electrolyte through Lewis‐acidic segments in the polymer backbone. Moreover, the presence of F‐IL moieties decreased the binding affinity of Li cation towards the glycol chains, enabling a rapid transfer of Li cation within the gel network. These structural features enabled the immobilization of anions on the ionic liquid segments to alleviate the space‐charge effect while promoting stronger anion coordination and weaker cation coordination in the Lewis‐acidic polymers. Accordingly, we realized a high Li ion conductivity (9.16×10−3 S cm−1) and high Li ion transference number of 0.69 simultaneously, along with a good electrochemical stability up to 4.55 V, while effectively suppressing Li dendrite growth. Moreover, the gel polymer electrolyte exhibited stable cycling performance of the Li|Li symmetric cell of 9 mAh cm−2 for more than 1800 hours and retained 86.7 % of the original capacity after 250 cycles for lithium‐sulfur (Li‐S) full cell., A gel polymer electrolyte containing imidazolium ionic liquid end groups with a fluorinated alkyl chain (F‐IL) was developed to suppress Li dendrite growth by realizing both high ionic conductivity and Li ion transference number. Lewis‐acidic segments in the polymer backbone reduce the mobility of Li salt anion and decrease the binding affinity of Li cation towards the glycol chains.

The COVID-19 pandemic started to affect Turkey in March 2020. In this study, we retrospectively investigated spontaneous rectus sheath hematoma (S-RSH) in patients with COVID-19 presenting with acute abdominal pain during the ongoing pandemic.The demographic characteristics, laboratory findings, length of hospital stay, and treatment processes of COVID-19 cases with S-RSH detected between March and December 2020 were recorded. The rectus sheath hematoma diagnosis of the patients was made using abdominal computed tomography, and the patients were followed up. Low-molecular-weight heparin treatment, which was initiated upon admission, was continued during the follow-up.S-RSH was detected in 13 out of 220 patients with COVID-19 who were referred to general surgery for consultation due to acute abdominal pain. The mean age of these patients was 78±13 years, and the female-to-male ratio was 1.6. Mechanical ven-tilation support was applied to three patients, all of whom were followed up in the intensive care unit. Two patients died for reasons independent of rectus sheath hematoma during their treatment. Among the laboratory findings, the activated partial thromboplastin time (aPTT) values did not deviate from the normal range. While there was no correlation between the international normalized ratio (INR) and aPTT (p0.01), a significant correlation was found between INR and interleukin-6 (IL-6) (p0.002). None of the patients required surgical or endovascular interventional radiology procedures.In the literature, the incidence of S-RSH in patients presenting with acute abdominal pain is 1.8%. However, in our series, this rate was approximately 3 times higher. Our patients' normal INR and aPTT values suggest that coagulopathy was mostly secondary to endothelial damage. In addition, the significantly higher IL-6 values (p0.002) indicate the development of vasculitis along with the acute inflammatory process. S-RSH can be more commonly explained the high severity of vasculitis and endothelial damage due to viral infection.

The advancement of liquid electrolytes in Li-metal batteries is an important strategy to realize a robust and uniform solid electrolyte interphase (SEI) on the Li metal anode while simultaneously achieving high oxidative stability and addressing the shortcomings of traditional carbonate and ether-based electrolytes suffering from side reactions and high-voltage decomposition, respectively. To circumvent these challenges, here, a fluorinated dioxolane-based cyclic co-solvent, that is 2-(2,2,2-trifluoroethoxy)-4-(trifluoromethyl)-1,3-dioxolane (TTD), is developed. After pairing 1.5 M lithium bis(fluorosulfonyl)imide (LiFSI) with TTD and 1,2-dimethoxyethane (DME), the 1.5 M LiFSI-8TTD-2DME electrolyte exhibits remarkable oxidation stability up to 6 V and a Coulombic efficiency of 99.4% over 210 cycles at 3 mA cm–2with a cut-off capacity of 3 mA h cm–2in the Li|Cu half-cell originating from efficient regulation of the electrolyte solvation structure and consequent anion-derived inorganic SEI layer formation. Full cells with advanced electrolytes, using 20 μm of Li foil paired with the NCM811 cathode by a negative and positive capacity ratio (N/P) of 2.5, achieve 75% capacity retention after 160 cycles at 0.5 C. Furthermore, even at an ultra-high charge cut-off voltage of 4.7 V, the Li|NCM811 full cell still realizes 80% retention at 0.5 C after 100 cycles.

Palladium (Pd) is an indispensable metal due to its wide range of industrial applications. Pd refining, however, is an extremely energy intensive process with a serious environmental impact. Thus, the selective recovery of Pd from secondary sources is rather important. Heterogeneous sorbents are promising candidates owing to their reusability. Here, we report the synthesis of porous polyisothiocyanurates through the trimerization of 1,4-phenyldiisothiocyanate under ionothermal conditions, named Covalent Isothiocyanurate Frameworks (CITCFs), bearing in-situ generated thiourea moieties as binding sites for Pd. High surface area of CICTFs, 1589 m2 g-1, along with the presence of abundant sulfur atoms within a hierarchically porous network enabled an exceptional Pd(II) uptake capacity of 909.1 mg g-1, fast adsorption kinetics, stable uptake over a wide pH range and selective Pd(II) recovery from waste water conditions. Moreover, the reduction of recovered Pd(II) within the polymer networks led to highly efficient heterogeneous catalysts for the Suzuki-Miyaura cross-coupling reaction.

The use of reactive molten salts, i.e., ZnCl2, as a soft template and a catalyst has been actively investigated in the preparation of covalent triazine frameworks (CTFs). Although the soft templating effect of the salt melt is more prominent at low temperatures, close to the melting point of ZnCl2, leading to the formation of abundant micropores, a significant mesopore formation is observed that is due to the partial carbonization and other side reactions at higher temperatures (>400 °C). Evidently, high-temperature synthesis of CTFs in various eutectic salt mixtures of ZnCl2 with alkali metal chloride salts also leads to mesopore formation. We reasoned that using the isocyanate moieties instead of cyano groups in the monomer, 1,4-phenylene isocyanate, could enable efficient interactions between carbonyl moieties and alkali metal ions to realize efficient salt templating to form covalent isocyanurate frameworks (CICFs). In this direction, the trimerization of 1,4-phenylene diisocyanate was carried out under ionothermal conditions at different reaction temperatures using ZnCl2 (CICF) and the eutectic salt mixture of KCl/NaCl/ZnCl2 (CICF-KCl/NaCl) as the reactive solvents. We observed notable differences in the morphologies of the two polymers, whereas CICF showed irregular-shaped micrometer-sized particles, the CICF-KCl/NaCl exhibited a filmlike morphology. Moreover, favorable ion-dipole interactions between alkali metal cations and oxygen atoms of the monomer facilitated two-dimensional growth and the formation of a purely microporous framework in the case of CICF-KCl/NaCl along with a near theoretical retention of the nitrogen content at 500 °C. The CICF-KCl/NaCl showed a BET surface area of 590 m2 g-1 along with a CO2 uptake capacity of 5.9 mmol g-1 at 273 K and 1.1 bar because of its high microporosity and nitrogen content. On the contrary, in the absence of alkali metal ions, CICF showed high mesopore content and a moderate CO2 uptake capacity. This study underscores the importance of the strength of the interactions between the salts and the monomer in the ionothermal synthesis to control the morphology, porosity, and gas uptake properties of the porous organic polymers.

This study investigates the firm- and country-specific factors that affect SMEs’ access to finance and the relationship between financial constraint and firm growth in emerging economies of Central Asia. To address the research questions, a two-stage empirical analysis including ordered probit, probit, and feasible generalized least squares (FGLS) specifications were conducted. Firm-level data used in the analysis is obtained from the fifth round of the Business Environment and Enterprise Survey (BEEPS V) and country-level data acquired from national and international datasets. The study's findings implied that in the Central Asian economies, country-specific factors are more likely to affect access to external finance of SMEs than firm-specific determinants. Among firm-specific factors, only foreign ownership is significantly related to financing constraint perception of SMEs; where, the interest rate is positively, and domestic credit market, inflation, and log of GDP per capita are negatively related to financing constraint level. In Central Asia, an insignificant relationship between growth and financing constraints was found. The determinants of financing constraints and access to finance–growth relations, which address the issue of great significance for SME growth in the selected countries, were interpreted with region-specific factors.

With the advent of silicon-based semiconductors, a plethora of previously unknown technologies became possible. The development of lightweight low-dimensional organic semiconductors followed soon after. However, the efficient charge/electron transfers enabled by the non-porous 3D structure of silicon is rather challenging to be realized by their (metal-)organic counterparts. Nevertheless, the demand for lighter, more efficient semiconductors is steadily increasing resulting in a growing interest in (metal-)organic semiconductors. These novel materials are faced with a variety of challenges originating from their chemical design, their packing and crystallinity. Although the effect of molecular design is quite well understood, the influence of dimensionality and the associated change in properties (porosity, packing, conjugation) is still an uncharted area in (metal-)organic semiconductors, yet highly important for their practical utilization. In this Minireview, an overview on the design and synthesis of porous semiconductors, with a particular emphasis on organic semiconductors, is presented and the influence of dimensionality is discussed.

This study aims to shed light on the capital buffer and risk adjustments in the banking sector of South-Eastern European countries following the financial crisis of 2008 that triggered a series of ...