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Two-dimensional (2D) materials, like 2D covalent organic frameworks (COFs), have been attracting increasing research interest. They are usually obtained as polycrystalline powders. Solid-state NMR spectroscopy is capable of delivering structural information about such materials. Previous studies have applied, for example, 13 C cross-polarization magic angle spinning (CP MAS) NMR experiments to characterize 2D COFs. Herein, we demonstrate the usefulness of high-field and fast-spinning 1 H MAS NMR spectroscopy to resolve and quantify the signals of different 1 H species within 2D COFs, including the edge sites and/or defects. Moreover, 1 H- 13 C heteronuclear correlation (HETCOR) spectroscopy has also been applied and can provide improved resolution to obtain further information about stacking effects as well as edge sites/defects.

Electrochemical proton storage plays an essential role in designing next-generation high-rate energy storage devices, e.g., aqueous batteries. Two-dimensional conjugated covalent organic frameworks (2D c-COFs) are promising electrode materials, but their competitive proton and metal-ion insertion mechanisms remain elusive, and proton storage in COFs is rarely explored. Here, we report a perinone-based poly(benzimidazobenzophenanthroline) (BBL)-ladder-type 2D c-COF for fast proton storage in both a mild aqueous Zn-ion electrolyte and strong acid. We unveil that the discharged C-O - groups exhibit largely reduced basicity due to the considerable π-delocalization in perinone, thus affording the 2D c-COF a unique affinity for protons with fast kinetics. As a consequence, the 2D c-COF electrode presents an outstanding rate capability of up to 200 A g -1 (over 2500 C), surpassing the state-of-the-art conjugated polymers, COFs, and metal-organic frameworks. Our work reports the first example of pure proton storage among COFs and highlights the great potential of BBL-ladder-type 2D conjugated polymers in future energy devices., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Linear conjugated polymers have attracted significant attention in organic electronics in recent decades. However, despite intrachain π-delocalization, interchain hopping is their transport bottleneck. In contrast, two-dimensional (2D) conjugated polymers, as represented by 2D π-conjugated covalent organic frameworks (2D c-COFs), can provide multiple conjugated strands to enhance the delocalization of charge carriers in space. Herein, we demonstrate the first example of thiophene-based 2D poly(arylene vinylene)s (PAVs, 2DPAV-BDT-BT and 2DPAV-BDT-BP, BDT=benzodithiophene, BT=bithiophene, BP=biphenyl) via Knoevenagel polycondensation. Compared with 2DPAV-BDT-BP, the fully thiophene-based 2DPAV-BDT-BT exhibits enhanced planarity and π-delocalization with a small band gap (1.62 eV) and large electronic band dispersion, as revealed by the optical absorption and density functional calculations. Remarkably, temperature-dependent terahertz spectroscopy discloses a unique band-like transport and outstanding room-temperature charge mobility for 2DPAV-BDT-BT (65 cm 2  V -1  s -1 ), which far exceeds that of the linear PAVs, 2DPAV-BDT-BP, and the reported 2D c-COFs in the powder form. This work highlights the great potential of thiophene-based 2D PAVs as candidates for high-performance opto-electronics., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Two-dimensional conjugated polymers (2DCPs), composed of multiple strands of linear conjugated polymers with extended in-plane π-conjugation, are emerging crystalline semiconducting polymers for organic (opto)electronics. They are represented by two-dimensional π-conjugated covalent organic frameworks, which typically suffer from poor π-conjugation and thus low charge carrier mobilities. Here we overcome this limitation by demonstrating two semiconducting phthalocyanine-based poly(benzimidazobenzophenanthroline)-ladder-type 2DCPs (2DCP-MPc, with M = Cu or Ni), which are constructed from octaaminophthalocyaninato metal(II) and naphthalenetetracarboxylic dianhydride by polycondensation under solvothermal conditions. The 2DCP-MPcs exhibit optical bandgaps of ~1.3 eV with highly delocalized π-electrons. Density functional theory calculations unveil strongly dispersive energy bands with small electron-hole reduced effective masses of ~0.15m 0 for the layer-stacked 2DCP-MPcs. Terahertz spectroscopy reveals the band transport of Drude-type free carriers in 2DCP-MPcs with exceptionally high sum mobility of electrons and holes of ~970 cm 2  V -1  s -1 at room temperature, surpassing that of the reported linear conjugated polymers and 2DCPs. This work highlights the critical role of effective conjugation in enhancing the charge transport properties of 2DCPs and the great potential of high-mobility 2DCPs for future (opto)electronics., (© 2023. The Author(s).)

High-efficient and fast adsorption of uranium is important to reduce the hazards caused by the uranium contamination of water environment due to the increased human activities. Herein, brewer's spent grain (BSG)-supported superabsorbent polymers (SAP) with different cross-linking densities are prepared as cheap and eco-friendly adsorbents for the first time via one-pot swelling and graft polymerization. A 7 wt% NaOH solution is used to swell BSG before grafting and subsequently neutralize the acrylic acid to control the reaction rate without producing alkaline wastewater. Compared with the traditional methods, swelling improves the grafting density and the utilization of raw materials due to the increased disorder degree of the BSG fibers. This results in the grafting of abundant carboxyl and amide groups onto the BSG backbone, forming a strongly hydrophilic polymer network of the BSG-SAP. Compared with the reference polymers without BSG, BSG-SAP presents higher adsorption capacity and enhanced reusability. The highly cross-linked BSG-SAP (BSG-SAP-H) shows an outstanding adsorption capacity of U(VI) (1465 mg/g at pH 0  = 4.6), a fast adsorption rate (81% of equilibrium adsorption capacity in 15 min), and a high selectivity in the presence of competing ions. Adsorption mechanism studies reveal the involvement of amide groups, a bidentate binding structure between UO 2 2+ and the carboxyl groups, and a cation exchange between Na + and UO 2 2+ . More importantly, the adsorption capacity of BSG-SAP-H reaches 254.4 mg/g in the fixed-bed column experiment at a low initial concentration (c 0 (U) = 30 mg/L) and keeps 80% of the adsorption capacity after four cycles, indicating a great potential for uranium removal from wastewater. This work shows a suitable approach to explore the untreated biomass to prepare SAP with enhanced adsorption performance via a general and low-cost strategy., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Choanal Atresia is a congenital condition that presents as a blockage from the nasal cavity to the nasopharynx. According to the German statistical Institute (Statistisches Bundesamt), the incidence in Germany in 2018 reached 2.74 in 10,000 live births. It can present unilaterally or bilaterally. As newborns are obligate nasal breathers, management of bilateral atresia has to be performed early after birth. As for unilateral atresia, the optimal age for treatment was determined to be between 6 and 12 months in a recently published consensus., Objective: The main purpose of this study is to characterize the patients treated for choanal atresia in the Department of Otorhinolaryngology and Head and Neck Surgery at a tertiary hospital in the south of Germany and, based in the demographic characteristics as well as intra- and post-operative treatment, to identify factors for success or failure of the surgery. A secondary goal was to describe the complications in the use of stents and analyse its influence in the results., Material and Methods: The cohort-based observational study included 29 patients, with a minimum follow up of one year, who underwent surgical endoscopic correction of both unilateral and bilateral choanal atresia from 2003 to 2020. Analysis of the demographics, intraoperative, and postoperative treatment, and their results, was performed. Multinomial logistic regression was applied for categorical values. Comparisons were performed using Fischer/chi-square test where applicable. A significance level of 0.05 was reached., Results: The population was comprised of 34.5% male and 65.5% female patients. The age varied from 2 days to 20 years old, with a mean of 4.98 years and Standard Deviation (SD) 6.88. The weight of the patients varied between 1.4 kg and 85.0 kg, with a mean of 19.36 and SD 22.58. Unilateral choanal atresia was present in 58.6%, and bilateral in 41.4%. Out of this population, 48.3% presented with associated malformations. The number of procedures per patient performed in general anesthesia varied from 1 to 9, with a mean of 2.52 and SD of 2.23: statistically higher for patients presenting with bilateral atresia with a p value of 0.001*. 20 patients had a tube (Vygon, France) placed at first surgery. In 5 patients, a drug-eluting stent (Propel mini (R) ; Intersect ENT, USA) was applied intraoperatively, without complications. In unilateral choanal atresia, surgical and functional success was attained in 88.2% of the cases. In bilateral cases, it reached 75%. We observed a strong linear relationship between the weight of the patient and the size of the choana perioperatively: R quadrat 0.596, which may be a determinant factor in the wound healing. Weight, age, and concomitant pathology achieved statistical significance in the logistic regression model (p respectively 0.001*, 0.001* and 0.010*), which shows its influence in the result of the surgery. In particular, weight inferior to 3 kg (p 0.001*, chi-square test) at the time of the first surgery is a determinant demographic factor for need of revision in order to achieve patency. There were no major complications associated with the use of a stent, besides its dislodgement. We could not infer an implication of its use on the success of the surgery in the present cohort., Limitations: for this study were the small size of the cohort and non-standardized records for some variables., Conclusions: Younger patients presenting with low weight and concomitant pathology have worse results after surgical endoscopic treatment of choanal atresia, revealing these characteristics to be determinant for success. The size of the neochoana is related to the weight of the patient, which is a limiting factor. In particular, patients under 3 kg had to undergo more procedures in order to achieve patency. The implication of the use of locally applied medication needs to be further studied., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The interest in two-dimensional conjugated polymers (2D CPs) has increased significantly in recent years. In particular, vinylene-linked 2D CPs with fully in-plane sp 2 -carbon-conjugated structures, high thermal and chemical stability, have become the focus of attention. Although the Horner-Wadsworth-Emmons (HWE) reaction has been recently demonstrated in synthesizing vinylene-linked 2D CPs, it remains largely unexplored due to the challenge in synthesis. In this work, we reveal the control of crystallinity of 2D CPs during the solvothermal synthesis of 2D-poly(phenylene-quinoxaline-vinylene)s (2D-PPQVs) and 2D-poly(phenylene-vinylene)s through the HWE polycondensation. The employment of fluorinated phosphonates and rigid aldehyde building blocks is demonstrated as crucial factors in enhancing the crystallinity of the obtained 2D CPs. Density functional theory (DFT) calculations reveal the critical role of the fluorinated phosphonate in enhancing the reversibility of the (semi)reversible C-C single bond formation., (© 2022 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

Developing biosorbents derived from agro-industrial biomass is considered as an economic and sustainable method for dealing with uranium-contaminated wastewater. The present study explores the feasibility of oxidizing a representative protein-rich biomass, brewer's spent grain (BSG), to an effective and reusable uranyl ion adsorbent to reduce the cost and waste generation during water treatment. The unique composition of BSG favors the oxidation process and yields in a high carboxyl group content (1.3 mmol/g) of the biosorbent. This makes BSG a cheap, sustainable, and suitable raw material independent from pre-treatment. The oxidized brewer's spent grain (OBSG) presents a high adsorption capacity of U(VI) of 297.3 mg/g ( c 0 (U) = 900 mg/L, pH = 4.7) and fast adsorption kinetics (1 h) compared with other biosorbents reported in the literature. Infrared spectra (Fourier transform infrared), 13 C solid-state nuclear magnetic resonance spectra, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and thermogravimetric analysis were employed to characterize the biosorbents and reveal the adsorption mechanisms. The desorption and reusability of OBSG were tested for five cycles, resulting in a remaining adsorption of U(VI) of 100.3 mg/g and a desorption ratio of 89%. This study offers a viable and sustainable approach to convert agro-industrial waste into effective and reusable biosorbents for uranium removal from wastewater., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)