Organic Materials Research Articles

Application of Bioelectrochemical System in Nitrogen Removal via Simultaneous Autotrophic Nitrification and Denitrification from Wastewater

AbstractBioelectrochemical systems (BES) is a new and expanding technology that can simultaneously convert chemical energy into electrical energy by removing nutrients. The present study investigated the BES in removing nitrogen compounds and produce electricity. To this end, a BES reactor with two chambers of cathode and anode and nafion 117 membrane was used as a separator between the two chambers. Then, the BES performance at different concentrations of COD and primary ammonium at different retention times was investigated to remove nitrogen compounds and organic matter. Voltage, current and power density were measured. The results showed that the maximum COD removal efficiency was 73.2 % for the substrate concentration of 2000 mg/L, which decreased to 72.6 % when the substrate concentration increased to 10000 mg/L. The maximum removal efficiency of nitrogen compounds was 83.4 % at COD 10000 mg/L and the initial ammonium concentration was 50 mg/L. The maximum voltage, current and power density in this phase were 391 mV, 460 mA/m2, 63/48 mW/m2, respectively. The results of the study showed that BES can be used as a suitable method to remove high amounts of ammonium in wastewater and organic materials and simultaneously produce electricity.

Dipole polarization modulating of vinylene-linked covalent organic frameworks for efficient photocatalytic hydrogen evolution

Photocatalytic hydrogen (H2) evolution using covalent organic frameworks (COFs) is an attractive and promising avenue for exploration, but one of its big challenges is low photo-induced charge separation. In this study, we present a straightforward and facile dipole polarization engineering strategy to enhance charge separation efficiency, achieved through atomic modulation (O, S, and Se) of the COF monomer. Our findings demonstrate that incorporating atoms with varying electronegativities into the COF matrix significantly influences the local dipole moment, thereby affecting charge separation efficiency and photostability, which in turn affects the rates of photocatalytic H2 evolution. As a result, the newly developed TMT-BO-COF, which contains highly electronegative O atoms, exhibits the lowest exciton binding energy, the highest efficiency in charge separation and transportation, and the longest lifetime of the active charges. This leads to an impressive average H2 production rate of 23.7 mmol g−1 h−1, which is 2.5 and 24.5 times higher than that of TMT-BS-COF (containing S atoms) and TMT-BSe-COF (containing Se atoms), respectively. A novel photocatalytic hydrogen evolution mechanism based on proton-coupled electron transfer on N in the structure of triazine rings in vinylene-linked COFs is proposed by theoretical calculations. Our findings provide new insights into the design of highly photoactive organic framework materials for H2 evolution and beyond.

Application of Metal–Organic Framework-Based Composite Materials for Photodegradation of Dye Pollutants in Wastewater

Application of Metal–Organic Framework-Based Composite Materials for Photodegradation of Dye Pollutants in Wastewater

Interacting Emission Species among Donor and Acceptor Moieties in a Donor-Grafted Polymer Host/TADF-Guest System and Their Effects on Photoluminescence and Electroluminescence.

Thermally activated delayed fluorescence (TADF)-based electroluminescence (EL) devices adopting a host/guest strategy in their emitting layer (EML) are capable of realizing high efficiency. However, TADF emitters composed of donor and acceptor moieties as guests dispersed in organic host materials containing a donor and/or an acceptor are subject to donor-acceptor (D-A) interactions. In addition, electron delocalization between neighboring emitter molecules could form different species of aggregates. Here, we investigate the effects of intermolecular interacting emission species on the optoelectronic properties of sky-blue/green/red (sB/G/R) TADF emitters as guests using poly(biphenyl-Si/Ge) grafted with various donor moieties as hosts. We found the presence of guest/guest exciplex (Dg/Ag)*, host/guest exciplexes (Dh/Ag)*, and aggregates through the exploration of interactions between neighboring TADF guest molecules and between host and TADF-guest molecules. The nonradiative 3(Dh/Ag)* (ΔEST ≈ 0.5 eV) could increase the internal conversion rate (kIC) and reduce delayed luminescence, and both of them could cause a decrease in PLQY. The luminescence of 3(Dh/Ag)* may have a positive or negative effect on PLQY depending on its triplet energy. As the singlet and triplet energies of (aggregate)* are lower than those of (ICT)*, energy transfer from (ICT)* to (aggregate)* could occur. The low PLQY nature of (aggregate)* means that it is more likely to cause quenching in device emission. The emissions from (Dh/Ag)* and (aggregate)* are found to have increased full width at half-maximum and lead to lower emission color purity. Such intermolecular interactions should also occur in host/guest (TADF) systems and nondoped TADF emitter systems and thus are important factors for the molecular design of the TADF emitter and/or its accompanying host for high device efficiency and emission color purity.

π-Conjugation-Induced In Situ Nanoscale Ordering of Spiro-OMeTAD Boosts the Efficiency and Stability of Perovskite Solar Cells.

Spiro-OMeTAD hole transport materials typically exhibit an amorphous state in perovskite solar cells. However, the lack of structural ordering leads to weak intermolecular interaction, inferior carrier transfer, and poor stability in devices. Herein, we developed a π-conjugation-induced short-range ordering strategy to modulate the stacking order of spiro-OMeTAD during film formation. A clear molecular ordering at the nanoscale is observed, which enhances intermolecular π-π stacking in spiro-OMeTAD and enables effective carrier extraction and favorable energy level alignment. The nanoscale-ordered spiro-OMeTAD allows the achievement of perovskite solar cells with a champion efficiency of 25.37%, surpassing devices utilizing amorphous spiro-OMeTAD (23.52%). The unencapsulated device demonstrates enhanced operational stability by retaining 98% of its initial efficiency under continuous 1 sun equivalent illumination at 60 °C for 840 h. This work establishes a significant and valid modulation concept for the stacking order of organic transport materials, paving the way for the development of efficient and stable perovskite solar cells.

Fluorescent Dye-Based Chiral Crystalline Organic Salt Networks for Circularly Polarized Luminescence.

A facile and general strategy is developed herein for the construction of circularly polarized luminescence (CPL) materials with simultaneously high fluorescence quantum efficiency (Φ) and large luminescence dissymmetry factor (glum). The self-assembly of fluorescent dye, disodium 4,4'-bis(2-sulfonatostyryl)biphenyl (CBS), with chiral diamines such as (R,R)/(S,S)-1,2-diaminocyclohexane (R/S-DACH) and R/S-1,2-diaminopropane (R/S-DAP), produces four chiral crystalline organic salt networks (COSNs). These as-synthesized organic salts emit strong blue-color CPL upon excitation, with both high Φ and glum values of up to 79% and 0.022. The well-defined molecular structures and arrangements of CBS are directly observed through single crystal X-ray analysis, offering crucial information regarding the origins of high-efficiency CPL performance. The chirality of amine is effectively transferred to CBS and further amplified to the supramolecular structure by multiple hydrogen bonding and π-π stacking interactions, giving rise to the large glum factors; meanwhile, the fixation and the ordered arrangement of CBS by these multiple interactions empower efficient suppression of molecular motions, facilitating strong fluorescence. This work can inspire the assembly of CPL organic materials with high Φ and glum via charge-assisted hydrogen bonds between fluorescent dyes and chiral inducers. It also offers important insight into the structural origins of supramolecular chirality and CPL performance.

Shift of bacterial and fungal communities upon soil amelioration is driven by carbon degradability of organic amendments

The structural response of bacterial and fungal soil communities to four carbon-rich organic amendments of increasing recalcitrance was investigated. Wheat straw, green compost, a mixed product based on biogas residues, and a fermented biochar were applied to a sandy agricultural soil of low organic carbon content. After laboratory incubation for 6 months, the community structure was investigated via DNA sequencing. All amendments caused changes in the communities of bacteria and fungi, but to different extents, with the communities exposed to more recalcitrant amendments showing the least variation compared to the non-amended soil. Changes in species composition as well as their relative abundances were observed. While the straw had a pronounced effect on bacteria (e.g., the highest number of indicator species), effects of the composted, fermented, or pyrolyzed materials were minor. Hierarchical clustering showed that the fungal communities were more different from each other than the bacterial ones with the straw-soil being most different and the biochar-soil least different from the non-amended soil. While the abundant fungal species in biochar-soil and non-amended soil were very alike, especially rare fungal species shifted upon addition of biochar. An indicator species analysis identified specific taxonomic groups which were triggered by the different organic materials. We conclude that bacterial and fungal communities strongly change upon input of degradable carbon (straw), while fungi in particular respond to the application of processed organic materials. With this study, we report the consequences of applying organic materials for the microbial community in one soil. We provide these data for meta-analyses that are required to unravel all relevant interactions across different soils, organic materials, and time. This will allow to better understand and predict the effects of organic soil amelioration measures on soil microorganisms.

James Hutton and the measurement of atmospheric moisture

Measuring the amount of water in the air has been one of the most challenging of routine tasks in meteorology. From the 1650s onwards the methods involved either the uptake of moisture by organic materials such as human hair and whalebone (hygrometry) or the measurement of cooling due to loss of latent heat during evaporation (psychrometry). In 1792 James Hutton reported that a thermometer previously moistened by water records a lower temperature when exposed to cooling in the wind. This led to the development of the first condensation hygrometer by John Leslie in 1801 based on wet- and dry-bulb thermometers, whose design was refined and improved throughout the nineteenth century. Determining relative and absolute humidity values from a hygrometer required the use of a psychrometric equation, first developed by James Ivory in 1822 and later refined by Ernst Ferdinand August, James Apjohn and many others. Modern-day determinations of humidity often involve an aspirated psychrometer located in a Stevenson screen, whose origin can be traced directly back to Hutton’s observation of cooling due to evaporation. An extensive review of the literature on psychrometry records only cursory and ill informed acknowledgement of Hutton’s contribution. This article reasserts Hutton’s seminal role in the history of psychrometry.

Deciphering the Coarse-Grained Model of Ionic Liquid by Tunning the Interaction Level and Bead Types of Martini 3 Force Field

In recent years, ionic liquids (ILs) have served as potential solvents to dissolve organic, inorganic, and polymer materials. A copolymer (for example, Pluronic) can undergo self-organization by forming a micelle-like structure in pure IL medium, and its assembly depends upon the composition of IL. To evaluate the role of ILs, accurate coarse-grained (CG) modeling of IL is needed. Here, we modeled 1-ethyl-3-methylimidazolium dicyanamide ([EMIM][DCA]) ionic liquid (IL) using a CG framework. We optimized CG parameters for the [DCA]− anion by tuning the non-bonded parameters and selecting different kinds of beads. The molecular density (ρ) and radial distribution function (RDF) of our CG model reveal a good agreement with the all-atom (AA) simulation data. We further validated our model by choosing another imidazolium-based cation. Our modified CG model for the anion shows compatibility with the cation and the obtained density matches well with the experimental data. The strategies for developing the CG model will provide a guideline for accurate modeling of new types of ILs. Our CG model will be useful in studying the micellization of non-ionic Pluronic in the [EMIM][DCA] IL medium.

Azopyridine Aqueous Electrochemistry Enables Superior Organic AZIBs.

Azo compounds (AZO), such as azobenzene, are classic organic electrode materials featuring a redox potential close to Zn/Zn2+. Recent studies show that azobenzene could work as a cathode in aqueous zinc-ion batteries (AZIBs), providing a voltage output of around 0.7 V. However, the energy storage mechanism of AZO cathodes in AZIBs remains unclear, and their practical usage in AZIBs is hindered by the low voltage. In this study, azopyridine isomers, the hydrophilic analogues of azobenzene, were adopted as cathodes for AZIBs, and the energy storage mechanism was unveiled through aqueous electrochemical studies. Through in situ electrochemical characterizations and theoretical computations, we reveal that both the electron-withdrawing effect of the pyridyl group and the H+-involved -N = N-/-NH-NH- redox reaction uplift the redox potential of the azopyridine cathodes. These findings led to the first AZO-based AZIB, providing a voltage output of 1.4 V. The proposed air-stable AZIBs deliver a high energy/power density and a capacity of around 200 mAh g-1. This work discovers different azopyridine electrochemistry in aqueous and organic electrolytes and enabling AZIBs to outperform its competitors from the AZO family.

UV‐Triggered In Situ Formation of a Robust SEI on Black Phosphorus for Advanced Energy Storage: Boosting Efficiency and Safety via Rapid Charge Integration Plasticity

AbstractBlack phosphorus (BP) emerges as a highly promising electrode material for next generation of energy‐storage systems. Yet, its full potential is hindered by the instability of the solid‐electrolyte interphase (SEI) and the inflammability of its liquid systems. Here a pioneering UV‐induced in situ strategy is introduced for SEI construction, which leverages rapid electron supply to fracture sulfur‐dihalide bonds. This technique yields internal dihalide inorganic components and an external polymer segment, with any excess organic material being purged through pores. The (E)‐2‐chloro‐4‐((3′‐chloro‐4′‐hydroxyphenyl)diazinyl)phenyl acrylate (CA), with chlorine‐terminated groups, is initially in situ transformed into a flame‐retardant phenyl carboxylic acid (PCA), and then encapsulated within an ultrathin BP nanostructure, further nested in nitrogen (N), boron (B) co‐doped carbon (C) sheets that accommodate cobalt (Co) single atoms/nanoclusters (Co‐NBC). The Co‐NBC@BP@PCA construct demonstrates an impressive initial Coulombic efficiency (ICE) of 99.1% and maintains exceptional stabilities in terms of mechanical, chemical, and electrochemical performancecritical for prolonged cycle and calendar life. This research sheds light on the interplay between the rapid charge supply integrated in situ plasticity (RSIP) approach and the proactive establishment of an artificial SEI layer, offering profound insights into enhancing the durability and providing a solid foundation for advancements in energy storage technology.

Environmental triggers of pemphigus vulgaris and bullous pemphigoid: a case control study

BackgroundPrevious case–control studies have suggested that environmental factors including exposure to pesticides and organic materials, diet and medications have an important role in the pathogenesis of pemphigus vulgaris. These studies lacked geographical population controls and had less than three controls per case.ObjectiveTo identify environmental and occupational risk factors associated with the development of pemphigus vulgaris (PV) and bullous pemphigoid (BP).MethodCases were patients with PV (n = 25) and BP (n = 29) recruited from 2009 to 2017. Controls for PV (n = 72) and BP (n = 84) were recruited from the general population via electoral commission matching, matched for age, sex, residential location, and ethnicity. Data about demographics, environmental exposures and occupational exposures, was collected using a structured questionnaire. Conditional logistic regression analysis was undertaken using SPSS software to identify significant variables.ResultsSignificant factors associated with PV included the daily consumption of leeks (odds ratio (OR) 3.6; p = 0.025), mustard oil (OR = 4.4; p = 0.049), tomatoes (OR = 4.735; p = 0.032), multivitamins (OR 3.6; p = 0.009), alcohol (0.039), and calcium supplements (OR = 44, p < 0.001). Other associated factors included the number of lifetime sunburns (p = 0.019), high levels of mental stress (p < 0.001), and the use of lime household cleaning products (p < 0.001), Significant factors associated with BP included the daily consumption of green or herbal tea (OR = 3.7; p = 0.004), fish oil (OR = 5.7; p < 0.001), calcium supplements (OR = 6.1; p < 0.001), multivitamins (OR = 2.6; p = 0.043), and glucosamine (OR = 3.0; p = 0.046). The use of lime household cleaning products (p < 0.001) and high levels of mental stress (p = 0.007) were also associated with BP.ConclusionDietary factors containing thiol groups such as leeks, tomatoes, and mustard oil may be potential triggers for PV. High levels of mental stress, the use of supplementary medications such as calcium and multivitamins, and chemical cleaning products containing lime may be associated with an increased risk of developing both PV and BP. Lifestyle changes should be part of routine management for these patients.

Polyurethanes and Their Biomedical Applications.

The tunable mechanical properties of polyurethanes (PUs), due to their extensive structural diversity and biocompatibility, have made them promising materials for biomedical applications. Scientists can address PUs' issues with platelet absorption and thrombus formation owing to their modifiable surface. In recent years, PUs have been extensively utilized in biomedical applications because of their chemical stability, biocompatibility, and minimal cytotoxicity. Moreover, addressing challenges related to degradation and recycling has led to a growing focus on the development of biobased polyurethanes as a current focal point. PUs are widely implemented in cardiovascular fields and as implantable materials for internal organs due to their favorable biocompatibility and physicochemical properties. Additionally, they show great potential in bone tissue engineering as injectable grafts or implantable scaffolds. This paper reviews the synthesis methods, physicochemical properties, and degradation pathways of PUs and summarizes recent progress in applying different types of polyurethanes in various biomedical applications, from wound repair to hip replacement. Finally, we discuss the challenges and future directions for the translation of novel polyurethane materials into biomedical applications.

Unusual Cross-Conjugation in Cyclic Dipeptide-Based Building Blocks for Donor-Acceptor Semiconducting Conjugated Polymers.

Cross conjugation, though prevalent in many organic compounds, is typically considered less effective for electron delocalization compared to linear conjugation. Consequently, it is rarely used as the backbone structure for semiconducting conjugated polymers. In this study, we designed and synthesized a novel building block, TIDP, which features a central cyclic dipeptide with cross conjugation characteristics. Strong intramolecular hydrogen bonding interactions confer TIDP with a highly rigid and coplanar conformation. Importantly, theoretical calculations reveal that π electrons are well delocalized across the entire structure, despite its low aromaticity. Conjugated polymers incorporating TIDP exhibit high charge carrier mobilities, demonstrating the effective π electrons delocalization of this innovative building block. Our findings show that with rational design, cross conjugation can achieve effective π electrons delocalization, providing a valuable approach for developing high-performance conjugated polymers for organic electronic materials.

Porous Organic Frame Materials for Adsorption and Removal of Pesticide Contaminants: A Review

Porous Organic Frame Materials for Adsorption and Removal of Pesticide Contaminants: A Review

Unusual Cross‐Conjugation in Cyclic Dipeptide‐Based Building Blocks for Donor–Acceptor Semiconducting Conjugated Polymers

AbstractCross conjugation, though prevalent in many organic compounds, is typically considered less effective for electron delocalization compared to linear conjugation. Consequently, it is rarely used as the backbone structure for semiconducting conjugated polymers. In this study, we designed and synthesized a novel building block, TIDP, which features a central cyclic dipeptide with cross conjugation characteristics. Strong intramolecular hydrogen bonding interactions confer TIDP with a highly rigid and coplanar conformation. Importantly, theoretical calculations reveal that π electrons are well delocalized across the entire structure, despite its low aromaticity. Conjugated polymers incorporating TIDP exhibit high charge carrier mobilities, demonstrating the effective π electrons delocalization of this innovative building block. Our findings show that with rational design, cross conjugation can achieve effective π electrons delocalization, providing a valuable approach for developing high‐performance conjugated polymers for organic electronic materials.

The Enderby Bark Shield: A New Model for the Ancient World

A 2300 year old bark shield found in Enderby, Leicestershire, in 2015 is the only known example of its type. Made from the bark of a willow tree, it has a woven basket boss, a roundwood handle, and a rim of split roundwood edging and lime bast bindings. Pre-Roman shields made from organic materials rarely survive in Britain and Ireland and those without metal components are exceptionally rare. Contemporaneous wooden shields are known from anaerobic environments in Scandinavia but, unlike Enderby, none of these has a body of tree bark. The complexity of the design of the Enderby shield, the skill with which it was made, and the similarities between this and metal examples suggests it was a tried and tested design, rather than a one-off. With no other example against which to compare it, experiments in reproducing the shield have been used as a tool for interpretation and have proved vital to understanding the original design. As a result of this research, it is proposed that this single artefact represents a more commonly available form of shield in the 1st millennium bc than does any metal enhanced version.

Ultrathin Self-Assembled Monolayer for Effective Silicon Solar Cell Passivation.

Passivation technology is crucial for reducing interface defects and impacting the performance of crystalline silicon (c-Si) solar cells. Concurrently, maintaining a thin passivation layer is essential for ensuring efficient carrier transport. With an ultrathin passivated contact structure, both Silicon Heterojunction (SHJ) cells and Tunnel Oxide Passivated Contact (TOPCon) solar cells achieve an efficiency surpassing 26%. To reduce production costs and simplify solar cell manufacturing processes, the rapid development of organic material passivation technology has emerged. However, its widespread industrial production is hindered by environmental safety concerns, such as strong acid corrosion and biological and ecological safety issues. Here, we discovered a low-cost self-assembled monolayer (SAM) hole-selective transport material known as 2PACz ([2-(9H-carbazol-9-yl) ethyl] phosphonic acid) with phosphate groups to form c-Si solar cells for the first time. The ultrathin film of 2PACz with phosphate groups can establish strong and stable P-O-Si bonds on the silicon surface. Meanwhile, like 2PACz, a uniform ultrathin film with a carbazole function group can offer electron-localizing and thus hole-selective properties, which provides ideas for studying dopant-free silicon solar cells. As a result of such interfacial passivation engineering, it plays an important role in repairing porous structures, such as pyramid-textured silicon surfaces, and cutting losses during the commercialization of c-Si solar cells. Crucially, this advancement offers insights for the development of new high-efficiency ultrathin film passivation methods in the postsilicon era.

Organic Circularly Polarized Room‐Temperature Phosphorescence: Strategies, Applications and Challenges

Organic circularly polarized luminescence (CPL) plays crucial roles in chemistry and biology for the potential in chiral recognition, asymmetric catalysis, 3D displays, and biological probes. The long‐lived luminescence, large Stokes shift, and unique chiroptical properties make organic circularly polarized room‐temperature phosphorescence (CPP) a new research hotspot in recent years. Nevertheless, achieving high‐performance organic CPP is still challenging due to the sensitivity and complexity of integrating triplet excitons and polarization within organic materials. This review summarizes the latest advances in organic CPP, ranging from design strategies and photophysical properties to underlying luminescence mechanisms and potential applications. Specifically, the design strategies for generating CPP are systemically categorized and discussed according to the interactions between chiral units and chromophores. The applications of organic CPP in organic light‐emitting diodes, sensing, chiral recognition, afterglow displays, and information encryption are also illustrated. In addition, we present the current challenges and perspectives on developing organic CPP. We expect this review to provide some instructive design principles to fabricate high‐performance organic CPP materials, offering an in‐depth understanding of the luminescence mechanism and paving the way toward diverse practical applications.

Using an electrically charged mist to visualize the potential wells in “sonomaglev,” a combined diamagnetic-acoustic levitator

We use a water mist to experimentally visualize the wells in the potential energy of material levitated by a combined diamagnetic-acoustic levitator. The levitator consists of an 18.5 T superconducting magnet, which can levitate diamagnetic material, such as water, plastics, and organic materials, by applying a magnetic body force counteracting the force of gravity. Low-power ultrasound transducers operated at 37.5 kHz generate an acoustic field that spatially modulates the net force acting on the diamagnetically levitated material, making “sonomaglev” capable of levitating multiple objects in stable equilibrium. In these experiments, we levitate a mist of water droplets that are electrically charged so that they repel each other, preventing them from coalescing as a single drop in each of the local potential minima. The shapes of the potential wells are revealed by the shapes of clusters of droplets, which conform to the isosurfaces of the sum of the magnetic, gravitational, and acoustic potentials. The spacing of the droplets in a cluster is shown to depend on their charge, volume, and the force constant of the well in a simple model. Compared to acoustic levitation alone, the combination of diamagnetic and acoustic levitation allows more scope for the manipulation of levitated objects, since the acoustic field is not constrained by the requirement to balance the force of gravity. The method demonstrated here allows the influence on the potential energy of switching on the acoustic field to be observed directly.