Organic Compounds Research Articles

High-quality utilization of reclaimed asphalt pavement (RAP) in asphalt mixture with the enhancement of steel slag and epoxy asphalt

Achieving high-quality utilization of reclaimed asphalt pavement (RAP) is challenging due to the subpar technical performance of aggregates and the aging of asphalt within RAP. This study investigates the use of epoxy asphalt (EA) and steel slag to enhance recycled asphalt mixtures (RAM) for superior performance and increased RAP content. The rheological performance of epoxy asphalt (EA) was evaluated using a dynamic shear rheometer (DSR), and its curing process was analyzed. Steel slag-epoxy recycled asphalt mixtures (SRAM) with 40 %, 80 %, and 100 % RAP were prepared, and their road performance was assessed through Marshall, wheel tracking, and semi-circular bending tests. Additionally, the effects of steel slag’s surface morphology and element distribution on moisture and skid resistance were examined. The volatile organic compound (VOC) emission characteristics were also studied. The results show that EA forms a uniformly dispersed structure, providing excellent high-temperature deformation resistance. EA and steel slag significantly enhanced the road performance of SRAM, with SRAM-80 (80 % RAP, 20 % steel slag) achieving a dynamic stability of 15027 times/mm. Steel slag improved SRAM-80’s skid resistance, with a British pendulum number (BPN) of 68 and a texture depth (TD) of 0.5889 mm. Compared to 60/80 asphalt, EA reduced VOC emissions by over 75 %. Incorporating 80 % RAP and 20 % steel slag into RAM effectively utilizes RAP while enhancing performance.

Enhanced waste water purification performance of solar-driven interfacial water evaporation through the integration of electrocatalysis

Solar-driven interfacial water evaporation (SDIWE) has been proven to be an effective method for purifying polluted water. However, the challenging issue of removing volatile organic compounds (VOCs) from wastewater is frequently encountered. In this study, the SDIWE-electrocatalysis coupling system is established by employing defective TiO2 as both photothermal and electrode materials, and significant enhancements are achieved in terms of water evaporation rate and distilled water quality. The application of voltage not only generates joule heat but also reduces water evaporation enthalpy, contributing to the improved water evaporation rate. Under solar irradiation of 1.0 kW·m−2, the water evaporation rate increases from 1.43 kg·m−2·h−1 at 0 V to 1.63 kg·m−2·h−1 at 2.0 V. With the utilization of Ti@R-TiO2 foam as the anode and Ti@TiO2 foam as the cathode, it becomes feasible to directly oxidize VOCs at the anode and electrocatalytically reduce O2 at the cathode. Consequently, the VOCs can be effectively eliminated from distilled water. Applying 2.0 V under 1.0 kW·m−2 with oxygen inlet, approximately 25 % removal efficiency was achieved through electrolysis-SDIWE coupling system. This study's approach combining electrolysis with SDIWE presents a promising avenue for advancing SDIWE technology in order to achieve efficient wastewater treatment.

Distribution and Risk Assessment of VOCs in Road Dust Across Different Urban Areas

ABSTRACT Volatile organic compounds (VOCs) are significant pollutants in urban road dust, but their distribution and associated health risks remain unclear. VOC distribution in road dust from six distinct urban areas in Beijing Daxing District, China was systematically investigated. Eighteen VOCs were detected, with the highest load in commercial areas (7.73 μg/g), followed by industrial parks (6.38 μg/g), residential areas (3.35 μg/g), leisure areas (2.79 μg/g), traffic areas (2.01 μg/g) and urban-rural fringe (1.85 μg/g), much lower than in air and water phases. Typical VOCs in road dust include methyl tertiary butyl ether (MTBE) (0.82–1.24 μg/g), benzene series compounds (0.02–4.19 μg/g) and volatile halogenated alkanes (0.002-0.095 μg/g). Incomplete combustion of road vehicle fuels is the key source of VOCs. Particular attention was given to VOCs in typical sites within the urban-rural fringe, known for their unique pollution characteristics. The VOCs loads were ranked as follows: Gas Stations (2.61–2.62 μg/g) > Intersection (1.41 μg/g) > Main Road (1.34 μg/g) > University Gate (1.27 μg/g). Increased vehicle activity and frequent stalling contribute to higher VOCs accumulation in road dust. Health risk assessment indicates there is no appreciable non-carcinogenic risk associated with exposure to road dust VOCs. Further research should consider VOCs in the broader environmental context, including air and water.

Highly Efficient Near-Infrared Luminescent Radicals with Emission Peaks over 750 nm.

Purely organic molecules exhibiting near-infrared (NIR) emission possess considerable potential for applications in both biological and optoelectronic technological domains, owing to their inherent advantages such as cost-effectiveness, biocompatibility, and facile chemical modifiability. However, the repertoire of such molecules with emission peaks exceeding 750 nm and concurrently demonstrating high photoluminescence quantum efficiency (PLQE) remains relatively scarce due to the energy gap law. Herein, we report two open-shell NIR radical emitters, denoted as DMNA-Cz-BTM and DMNA-PyID-BTM, achieved through the strategic integration of a donor group (DMNA) onto the Cz-BTM and PyID-BTM frameworks, respectively. We found that the donor-acceptor molecular structure allows the two designed radical emitters to exhibit a charge-transfer excited state and spatially separated electron and hole levels with non-bonding characteristics. Thus, the high-frequency vibrations are effectively suppressed. Besides, the reduction of low-frequency vibrations is observed. Collectively, the non-radiative decay channel is significantly suppressed, leading to exceptional NIR PLQE values. Specifically, DMNA-Cz-BTM manifests an emission peak at 758 nm alongside a PLQE of 55%, whereas DMNA-PyID-BTM exhibits an emission peak at 778 nm with a PLQE of 66%. Notably, these represent the pinnacle of PLQE among metal-free organic NIR emitters with emission peaks surpassing 750 nm.

Molecular geometry specific Monte Carlo simulation of the efficacy of diamond crystal formation from diamondoids.

Diamondoids are a class of organic molecules with the carbon skeletons isostructural to nano-diamond, and have been shown to be promising precursors for diamond formation. In this work, theformation of diamond crystals from various diamondoid molecule building blocks was studied using our developed molecular geometry specific Monte Carlo method. We maintained the internal carbon skeletons of the diamondoid molecules, and investigated how the carbon-carbon bonds form between diamondoid molecules and how efficient the process is to form diamond crystals. The simulations show that higher diamondoid molecules can produce structures closer to a diamond crystal compared with lower diamondoid molecules. Specifically, using higher diamondoid molecules, larger bulk diamond crystals are formed with fewer vacancies. The higher propensity of certain diamondoids to form diamond crystals reveals insights into the microscopic processes of diamond formation under high-pressure high-temperature conditions.

Tetraphenylethylene-based conjugated polymers with valine-containing side chains: Aggregation-induced emission, helical self-assembly, complexation-induced circularly polarized luminescence

Realizing high circularly polarized luminescence (CPL) in polymer system is an important but challenging task. Herein, we provide a strategy for designing conjugated polymers with high CPL performance upon the complexation with mandelic acids. Two tetraphenylethylene (TPE)-based conjugated polymers, l-P1 and d-P1, were synthesized by Sonogashira polycoupling reactions between the TPE-containing diethynyl monomer and dibromo aryl monomers carrying valine methyl ester groups. Both the polymers showed aggregation-induced emission (AIE) properties and the capabilities to self-assemble into regular helical nanostructures on nanoscale and fluorescent microfibers on microscale. They exhibited weak circular dichroism (CD) signals; upon the complexation with R/S-mandelic acids, their CD absorption and fluorescence emission can be efficiently enhanced. The composite films of l/d-P1 and R/S-mandelic acids exhibited excellent complexation-induced CPL properties with the absolute luminescence dissymmetric factor (glum) up to 0.01 and the fluorescence quantum yield up to 26.8%; the glum values showed little dependence on their emission wavelength. Various types of carboxyl acids have been screened and only mandelic acids show significantly chiroptical induction. The specific interaction between mandelic acids and l/d-P1 also makes the latter promising candidates for the enantioselective recognition of chiral organic molecules.

Adsorption of Typical VOCs Onto Ti2CO2 MXene with Implications in Early‐Stage Lung Cancer Diagnosis: A DFT Study

AbstractIn this work, Ti2CO2 MXene is employed as a sensing material to detect volatile organic compounds (VOCs). Using Density Functional Theory (DFT) calculations, the adsorption properties of toluene, isopropanol, formaldehyde, and acetonitrile are calculated and compared. The electronic properties are analyzed to gain insight into the adsorption mechanism. Additionally, the recovery time and sensitivities are studied to evaluate the sensing performance of Ti2CO2 in detecting these VOCs. The results show that the four molecules undergo physisorption. Bader charge analysis shows a small charge transfer from the molecules to the MXene material. The adsorption of these molecules induces changes in the electronic properties of Ti2CO2, particularly in terms of resistance and work function. These changes are used to estimate the sensing response of this material toward these VOCs. Notably, the results highlight that Ti2CO2 exhibits good sensitivity and selectivity, especially in the case of isopropanol. These findings demonstrate the ability of Ti2CO2 as a sensing material for detecting VOCs for the early diagnosis of cancer.

Biogenic and Anthropogenic Secondary Organic Aerosols Become Fluorescent after Highly Acidic Aging.

Primary biological aerosol particles (PBAPs) and secondary organic aerosol (SOA) both contain organic compounds that share similar chemical and optical properties. Fluorescence is often used to characterize PBAPs; however, this may be hindered due to interferences from fluorophores in SOA. Despite extensive efforts to understand the aging of SOA under elevated particle acidity conditions, little is known about how these processes affect the fluorescence of SOA and thereby their interference with the measurements of PBAPs. The objective of this study is to investigate the fluorescence of SOA and understand the influence of acidity on the optical properties of organic aerosols and potential interference for the analysis of bioaerosols. The SOA was generated by O3- or OH-initiated oxidation of d-limonene or α-pinene, as well as by OH-initiated oxidation of toluene or xylene. The SOA compounds were then aged by exposure to varying concentrations of aqueous H2SO4 for 2 days. Absorption and fluorescence spectrophotometry were used to examine the changes in the optical properties before and after aging. The key observation was the appearance of strongly light-absorbing and fluorescent compounds at pH = ∼-1, suggesting that acidity is a major driver of SOA aging. The aged SOA from biogenic precursors (d-limonene and α-pinene) resulted in stronger fluorescence than the aged SOA from toluene and xylene. The absorption spectra of the aged SOA changed drastically in shape upon dilution, whereas the shapes of the fluorescence spectra remained the same, suggesting that the fluorophores and chromophores in SOA are separate sets of species. The fluorescence spectra of aged SOA overlapped with the fluorescence spectra of PBAPs, suggesting that SOA exposed to highly acidic conditions can be confused with PBAPs detected by fluorescence-based methods. These processes are likely to play a role in the atmospheric regions where high concentrations of H2SO4 persist, such as the upper troposphere and lower stratosphere.

Comparison of LDH-Organic/Inorganic Compound Modified Materials as Adsorbents for Heavy Metal Adsorption: Characteristic Structure and Adsorption Mechanism

This study modified layered double hydroxide (LDH) with organic compounds in hydrochar made from rambutan peels (prepared by hydrothermal method) and polyoxometalate compounds (tipe Keggin K4[ -SiW12O40].nH2O compound and prepared by sol-gel method). The synthesis of modified material was conducted through the coprecipitation method. The material was then applied as an adsorbent for Fe²⁺ ions. The material's properties were analyzed using XRD (X-ray diffraction), FT-IR (Fourier-transform infrared spectroscopy), and BET surface area analysis. The physicochemical characteristics of the modified material, a combination of the pure LDH and hydrochar/polyoxometalate compounds, will influence the adsorption results of Fe²⁺ metal ions. Furthermore, its application as an adsorbent was analyzed through kinetic and isotherm parameters, which were found to follow the pseudo-first-order (PFO) and Freundlich models. The adsorption capacities for NiAl-LDH, NiAl-LDH/Hc (modified with Hc), and NiAl-LDH/POM (modified with POM) materials were 32.789 mg/g, 47.393 mg/g, and 90.091 mg/g, respectively. It can be concluded that the adsorption process occurs via physisorption, forming multilayer adsorbates at the adsorbents active sites. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)

DNA-Origami-Based Precise Molecule Assembly and Their Biological Applications.

Inspired by efficient natural biomolecule assembly with precise control on key parameters such as distance, number, orientation, and pattern, the constructions and applications of artificial precise molecule assembly are highly important in many research areas including chemistry, biology, and medicine. DNA origami, a sophisticated DNA nanotechnology with rational design, can offer a predictable, programmable, and addressable nanoscale scaffold for the precise assembly of various kinds of molecules. Herein, we summarize recent progress, particularly in the last three years, in DNA-origami-based precise molecule assembly and their emerging biological applications. We first introduce DNA origami and the progress on DNA-origami-based precise molecule assembly, including assembly of various kinds of molecules (e.g., nucleic acids, proteins, organic molecules, nanoparticles), and precise control of important parameters (e.g., distance, number, orientation, pattern). Their biological applications in sensing, imaging, therapy, bionics, biophysics, and chemical biology are then summarized, and current challenges and opportunities are finally discussed.

A comprehensive assessment of potentially toxic elements, volatile organic compounds and petroleum hydrocarbons in different soil layers and groundwater of an abandoned Al/Cu industrial site

Compound pollution at industrial sites impedes urban development, especially when there is a lack of understanding about the spatial variations of internal pollution in industrial areas producing light-weight materials. In this study, spatial distribution and ecological risks of potentially toxic elements (PTEs), volatile organic compounds (VOCs), and petroleum hydrocarbons (C10-40) in the soil and groundwater of an Al/Cu (aluminum/copper) industrial site have been analyzed comprehensively. Results revealed the progressive clustering of pollutants in different soil layers, which indicated varying levels of penetration and migration of pollutants from the surface downward. Furthermore, severity of pollution varied according to pollutant type, with Cu (5-10,228mgkg-1) often exceeding the background levels significantly (>40). Cd (0.03-2.60mgkg-1) and Hg (0.01-3.73mgkg-1) were found at elevated concentrations in deeper soil layers, suggesting distinct variations of PTEs across different soil depths. Among the more hazardous VOCS, polychlorinated biphenyls (1.80 to 234μgkg-1) were particularly prevalent in the deeper layers of soil. Petroleum hydrocarbons (C10-40) were widely detected (6-582mgkg-1), showing significant migration potential from surface to deep soil. These findings suggest that prolonged industrial activities lead to deep-seated accumulation of pollutants, which also impacts the groundwater, contributing to long-term dispersion of contaminants. Furthermore, multivariate statistical analysis indicated certain positive correlations among the distribution of Cu, Pb and petroleum hydrocarbons, indicating possible coupling of these pollutants. Severe Cu pollution caused an ecological risk in the surface soil layer (covering >20% area of high pollution site, contributing >40% ecological risk). While the Hg and Cd posed significant risks in the deeper soil layers, showing higher risk coefficients and mobility. The study provides crucial insights into the transformation of urban areas with a history of industrial uses into community spaces and highlights the risks posed by the remaining pollutants.

Harvest Initiated Volatile Organic Compound Emissions from In-Field Tall Wheatgrass

Harvest Initiated Volatile Organic Compound Emissions from In-Field Tall Wheatgrass

Assessment of potential health impact of volatile organic compounds of underground water samples around fuel station in Okinni area Osogbo, Osun State, Nigeria

Assessment of potential health impact of volatile organic compounds of underground water samples around fuel station in Okinni area Osogbo, Osun State, Nigeria

Indoor Emission, Oxidation, and New Particle Formation of Personal Care Product Related Volatile Organic Compounds

Indoor Emission, Oxidation, and New Particle Formation of Personal Care Product Related Volatile Organic Compounds

Thermal Annealing Effects on Long-lived Fluorenol Room Temperature Phosphorescence for Styrene Detection.

Fluorene derivatives have been widely developed in OLEDs because of its efficient fluorescence quantum efficiency, but for which unique rigid biphenyl planar structure and large conjugated system, we hypothesize that they have a great potential for room temperature phosphorescence (RTP) applications, and confirmed this conjecture by subjecting polyvinyl alcohol (PVA) and phosphors to thermal annealing. The cross-linked structure formed during thermal annealing judiciously modulates the phosphorescence emission characteristics of the fluorenol with the synergistic interaction between PVA and fluorenol. Specifically, the lifetime exhibited a substantial increase from 1352.2 ms to 2874.1 ms, accompanied by a quantum yield augmentation from 4.8% to 11.3%, which substantiate that cross-linked induced by thermal annealing effectively amplifies the phosphorescent intensity and stability of the phosphors, facilitating ultralong phosphorescent emission at ambient conditions. Furthermore, an effective probe based on this film is developed for its highly sensitive, quantitative and immediate detection of volatile organic compounds. This investigation not only proffers a novel paradigm for the development of advanced RTP materials but also imparts insightful considerations for optimizing the performance of polymers in conjunction with functional materials, encompassing bioimaging, sensing, and optoelectronic devices.

Association Between Ethylene Oxide Exposure and Cognitive Function in US Older Adults: NHANES 2013-2014.

Ethylene oxide (EO) is a common organic compound associated with many adverse health outcomes. However, studies exploring the association between EO exposure and cognitive function are limited. This study aims to examine this relationship between EO exposure and cognition in older adults. This study enrolled 438 older adults from the National Health and Nutrition Examination Survey (NHANES) 2013-2014 cycle. EO exposure was quantified by the measurements of blood hemoglobin adducts of ethylene oxide (HbEO) concentrations. Cognitive function was measured by the Consortium to Establish a Registry for Alzheimer's Disease battery (CREAD), the Animal Fluency test (AFT), and the Digit Symbol Substitution Test (DSST). Linear regression model, generalized additive model, and smooth curve fitting were applied to examine the linear and nonlinear relationship between EO exposure and cognitive function. We used a two-piecewise linear regression model to detect the threshold effect of EO exposure on cognitive function. Participants with higher HbEO levels had lower AFT and DSST scores than those with lower HbEO levels. After adjusting for all confounding factors, log2-transformed HbEO levels were negatively associated with AFT score. The smooth curve fitting demonstrated the nonlinear relationship between EO exposure and DSST scores. When log-2 transformed HbEO levels >4.34 pmol/g Hb, EO exposure was negatively associated with DSST score. This study indicated that high levels of HbEO were associated with cognitive decline in US older adults. Future cohort studies are needed to verify our findings.

Rational Design and Facile Preparation of Palladium-based Electrocatalysts for Small Molecules Oxidation.

Direct liquid fuel cells (DLFCs) can convert the chemical energy of small organic molecules directly into electrical energy, which is a promising technique and always calls for electrocatalysts with high activity, stability and selectivity. Palladium (Pd)-based catalysts for DLFCs have been widely studied with the pursuit of ultra-high performance, however, most of the preparation routes require complex agents, multi-operation steps, even extreme experimental conditions, which are high-cost, energy-consuming, and not conducive to the scalable and sustainable production of catalysts. In this review, the recent progresses on not only the rational design strategies, but also the facile preparation methods of Pd-based electrocatalysts for small molecules oxidation reaction (SMOR) are comprehensively summarized. Based on the principles of green chemistry in material synthesis, the basic rules of "facile method" have been restricted, and the fabrication processes, perks and drawbacks, as well as practical applications of the "real" facile methods have been highlighted. The landscape of this review is to facilitate the mild preparation of efficient Pd-based electrocatalysts for SMOR, that is, to achieve a balance between "facile preparation" and "outstanding performance", thereby to stimulate the huge potential of sustainable nano-electrocatalysts in various research and industrial fields.

Generative Deep Learning-Based Efficient Design of Organic Molecules with Tailored Properties

Generative Deep Learning-Based Efficient Design of Organic Molecules with Tailored Properties

Tailored small molecule for inflammation treatment: Dual scavenger targeting nitric oxide and reactive oxygen species

Inflammation-related diseases are often marked by elevated levels of nitric oxide (NO) and reactive oxygen species (ROS), which play important roles in the modulation of inflammation. However, the development of organic materials effective in managing NO/ROS levels has remained a challenge. This study introduces a novel organic compound, NmeGA, engineered to scavenge both NO and ROS. NmeGA ingeniously integrates N-methyl-1,2,-phenylenediamine (Nme), a NO scavenger, with gallic acid (GA), a ROS scavenger, through an amide bond, endowing it with enhanced scavenging capabilities over its individual component. This compound exhibits reduced toxicity and increased lipophilicity value, underlining its increased biological applicability and highlighting its potential as an inflammation management tool. Through in vitro studies on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells, NmeGA displayed remarkable scavenging efficiency for NO and ROS, coupled with significant anti-inflammatory effects. In an LPS-induced peritonitis model, administration of NmeGA substantially decreased mortality rates, NO and ROS levels, and inflammatory cytokine concentrations. These findings highlight NmeGA's versatility as a therapeutic agent against various inflammatory diseases.

Transforming Drinking Water Treatment Residuals into Efficient Adsorbents: A Review of Activation and Modification Methods.

The management of drinking water treatment residuals (DWTRs) poses significant environmental and economic challenges for water treatment facilities; however, these residues have considerable potential as effective adsorbents for pollutant removal. The objectives of this review are to evaluate research conducted from 2015 to 2024 on treatment and modification techniques aimed at enhancing DWTRs' efficacy as adsorbents, analyze the influence of preparation methods on DWTRs performance, evaluate DWTRs adsorbents for different pollutants, and discuss the limitations and challenges in DWTRs applications. The review addresses the knowledge gap by detailed analysis of these advanced modification methods, which have not been extensively reviewed before, and their direct impact on the physicochemical properties and adsorption performance of DWTRs. The review explores various methods including thermal treatment, chemical activation, granulation, pelletization, and the development of composite materials. Key findings indicate that thermal treatment significantly increases surface area and porosity, while chemical activation introduces functional groups that enhance adsorption capacity. Composite DWTRs, incorporating metals, organic compounds, or magnetic properties, demonstrate superior performance in adsorbing diverse contaminants such as dyes and heavy metals. Despite these advancements, challenges remain, particularly in reporting the life cycles and costs of the treated and modified DWTRs and the regeneration of spent adsorbents. The review highlights the importance of optimizing preparation techniques to enhance the physicochemical properties and adsorption performance of DWTRs. By synthesizing existing knowledge and identifying key areas for future research, this review aims to advance sustainable practices in water treatment and resource recovery, aligning with global sustainability goals.