Solvent Effects Research Articles

Effective Lithium Polysulfides Anchoring on Vanadium Disulfide Facets for Lithium-Sulfur Batteries – A Computational Study

The commercialization of Li-S batteries is hindered by the shuttle effects of lithium polysulfides (LiPS) and the sluggish reaction kinetics. Hence, effectively trapping and promoting the conversion rates of LiPSs is of prime importance1. However, the fundamental kinetics of the electrocatalytic charging and discharging of Li-S batteries and the underlying mechanism have not been sufficiently explored yet.2 Therefore, by taking the 2D transition metal sulfide, VS2 as a model, we conducted a systematic investigation using density functional theory to study the ability of dominant exposed crystal planes of VS2 to trap LiPSs from leaching into electrolyte solvents and to act as an electrocatalyst to increase the Sulfur Reduction Reaction (SRR) kinetics3. To reflect a realistic environment of a battery, the effect of electrolyte solvents on the electrocatalytic activity was further investigated. Our calculations show that VS2 has moderate binding energy toward LiPSs which inhibits LiPS from leaching into electrolytes while fulfilling the key prerequisite to act as an electrocatalyst simultaneously.4 At the discharge, the conversion of S8 to the long chain Li2S8 was facile with a lower energy barrier while the rest of the reactions were sluggish explaining the accumulation of LiPSs. Further, the VS2 (001) facet exhibits excellent electrocatalytic activity for the SRR and Li2S decomposition reaction at charging compared to other dominant crystal planes, which significantly lowers the energy barriers of LiPS conversion during the charging and discharging process, ensuring high-rate performance and longer cycle life4. References Manthiram, A., Fu, Y., Chung, S.-H., Zu, C., & Su, Y.-S. (2014). Rechargeable Lithium–Sulfur Batteries. Chemical Reviews, 114(23), 11751–11787.Abraham, A. M., Thiel, K., Shakouri, M., Xiao, Q., Paterson, A., Schwenzel, J., Ponnurangam, S., & Thangadurai, V. (2022). Ultrahigh Sulfur Loading Tolerant Cathode Architecture with Extended Cycle Life for High Energy Density Lithium–Sulfur Batteries. Advanced Energy Materials, 2201494.Abraham, A. M., Boteju, T., Ponnurangam, S., & Thangadurai, V. (2022). A global design principle for polysulfide electrocatalysis in lithium–sulfur batteries—A computational perspective. Battery Energy, 20220003.Boteju, T., Abraham, A. M., Ponnurangam, S., & Thangadurai, V. (2023). Theoretical Study on the Role of Solvents in Lithium Polysulfide Anchoring on Vanadium Disulfide Facets for Lithium–Sulfur Batteries. The Journal of Physical Chemistry C.

Unlocking the potential: strategic synthesis of a previously predicted pyrazolate-based stable MOF with unique clusters and high catalytic activity.

The metal-organic framework (MOF) constructed from [Co4Pz8] clusters (Pz = pyrazolate) and 1,3,5-tris(pyrazolate-4-yl) benzene (BTP3-) ligands was structurally predicted many years ago, and expected to be a promising candidate for various applications owing to its unique clusters and highly open 3D framework structure. However, this MOF has not been experimentally prepared yet, despite extensive efforts were made. In this work, we present the successful construction of this MOF, hereinafter referred to as BUT-124(Co), by adopting a two-step synthesis strategy, involving the initial construction of a template framework (BUT-124(Cd)) followed by a post-synthetic metal metathesis process. The effects of various cobalt sources and solvents were systematically investigated, and an innovative stepwise metathesis strategy was employed to optimize the exchange rates and the porosity of the material. BUT-124(Co) demonstrates high catalytic activity in the oxygen evolution reaction (OER), achieving a competitive performance with an overpotential of 393 mV at a current density of 10 mA cm-2, and also affords remarkable long-term stability during potentiostatic electrolysis in 1 M KOH solution, surpassing the durability of many benchmark catalysts. This work not only introduces a novel MOF material with promising properties but also exemplifies a strategic synthesis approach for pyrazolate-based MOFs, paving the way for advancements in diverse application fields.

Understanding of Anion Effect on Iron Redox Behavior and Oxygen Reduction Activity of Fe-N-C Electrocatalysts

Fe-N-C catalysts are the most promising platinum group metal (PGM) free electrocatalysts for oxygen reduction reaction (ORR). Significant progress has been made in understanding the active site structure and activity and improving the ORR performance. It is generally accepted that the Fe-N-C sites are associated with FeNx centers embedded in a defective nitrogen-doped graphene. As reported in literature, both pyrrolic N and pyridinic N can support Fe single site; however, it is difficult to distinguish between the two. Furthermore, experimental characterization, such as in-situ X-ray absorption spectroscopy (XAS) and Mössbaruer, has elucidated the redox behavior of Fe2+ to Fe3+ during the reaction. Interestingly, in different acidic environments, the ORR activity exhibits differently. For instance, in comparison between H2SO4 and HClO4 solutions at the same pH value, the Fe redox happens at lower potential in H2SO4; however, the right shift of half-wave potential (E1/2) of ORR in H2SO4, compared with HClO4, indicates higher ORR activity. This indicates that the electrolyte systems have a significant impact on ORR activity. To further understand the active site structure and their ORR activity, density functional theory (DFT) calculations utilizing explicit solvation effect are carried out. XANES simulation using FDMNES suggests that as prepared catalysts could consist of Fe single atom sites supported by both pyrrolic and pyridinic N atoms; however, the pyrrolic species are not as stable as pyridinic species in solution. As presented by DFT simulation, the anions in solutions can interact with FeN4 site differently. SO4 2- binds strongly with the FeN4 center, while HSO4- and ClO4- interact rather weakly. Furthermore, the redox potential and limiting potential are evaluated via mechanistic study. By focusing on more stable Fe center supported by pyridinic N, the results suggest that the transformation of Fe2+ to Fe3+ happens at 0.52 V in H2SO4, which is lower than that in HClO4, 0.69V. More interestingly, the limiting potential (activity) of ORR in H2SO4 is higher than that in HClO4 (0.94 vs 0.68 V). DFT simulation indicated that the anions in electrolyte can impact the Fe redox behavior and ORR performance, which agrees well with the experimental investigation. This work also provides significant guidance to further improve ORR activity of Fe-N-C catalysts.

Insight into solvent effects on growth morphology of MgCO3·3H2O in CO2 mineralization: Molecular dynamics simulations and DFT studies

Experimental evidence shows that the solvent effect greatly affects the MgCO3·3H2O morphology, but the atomic-level mechanism still remains elusive. In this study, the influence mechanisms of H2O and EtOH on MgCO3·3H2O morphology were systematically investigated by a combination of crystal growth experiments, molecular dynamics (MD) simulations, and DFT calculations. In contrast to the traditional DFT calculations, the interface microenvironments were introduced to the crystal growth model first. The modified attachment energy (MAE) model proved that (1 0 1), (-1 0 1), and (0 1 1) surfaces dominate MgCO3·3H2O morphology in vacuum, H2O, and EtOH/H2O environments. The solvent molecules created an extensive H-bond network at solid-liquid interfaces, which greatly changed diffusion and combination during the crystal growth process. Compared to the H2O molecule, EtOH only forms H-bonds through the hydroxyl group. The CH3- end created some hydrophobic cavities, which led to weaker H-bond connectivity. The weaker H-bond network facilitated the removal of water from the crystal surface and strengthened the connection between the growth unit and surface, while reducing the solvent effect on the growth unit, thereby accelerating crystal growth and changing morphology. This study reveals the significant role of solvent in the crystallization process of MgCO3·3H2O, providing valuable insights for controlling the MgCO3·3H2O morphology at the atomic level.

Solvent effects on the structures of the hydrated copper dication clusters

Understanding the solvation process requires an understanding of how the solvent affects the molecular cluster configurations. The current study examined the impact of solvents on the structures of the hydrated Cu2+ cation, as well as the temperature dependence, and the energetics of the hydrated Cu2+ cation clusters from sizes n=1 from n=10 (Cu2+(H2O)n=1−10). The potential energy surfaces (PESs) in the solvent phase (represented by a dielectric continuum medium) at the MP2/6-31++G(d,p) level of computation have been comprehensively investigated. We employed the integral equation formalism polarized continuum model (IEF-PCM) to describe the dielectric continuum medium. It is pointed out that changes in PESs of hydrated copper dication isomers and structural morphologies occur in the continuum medium. Thus, the relative energies are smallest at T=0 K and for the cluster populations of Cu2+(H2O)n=1−10 are modified. Thus, in the solvent phase, the competition between the conformers is more severe than in the gas phase. Furthermore, highly coordinated conformers are more favorable, and favored conformers in the gas phase are disfavored in the solvent phase. The structural investigations are validated by the analysis of Wiberg Bond Index (WBI) at 300 K. In the solvent phase, the WBIs of the most stable isomers are the smallest and the WBIs of axial bonds are lower than those of equatorial bonds. Concerning the energy analysis, the binding energies were predicted for enormous sizes (at saturation) using a fit function. Thus, the new values of the binding energies obtained are -5467.8 and ▪ in the gas and solvent phases respectively. All these observed differences are due to the effects of the implicit solvent.

Effect of different solvents on ZnO thin films for gas sensing application by nebulizer spray pyrolysis method

Effect of different solvents on ZnO thin films for gas sensing application by nebulizer spray pyrolysis method

A comprehensive study on three typical photoacid generators using photoelectron spectroscopy and abinitio calculations.

Conducting a comprehensive molecular-level evaluation of a photoacid generator (PAG) and its subsequent impact on lithography performance can facilitate the rational design of a promising 193nm photoresist tailored to specific requirements. In this study, we integrated spectroscopy and computational techniques to meticulously investigate the pivotal factors of three prototypical PAG anions, p-toluenesulfonate (pTS-), 2-(trifluoromethyl)benzene-1-sulfonate (TFMBS-), and triflate (TF-), in the lithography process. Our findings reveal a significant redshift in the absorption spectra caused by specific PAG anions, attributed to their involvement in electronic transition processes, thereby enhancing the transparency of the standard PAG cation, triphenylsulfonium (TPS+), particularly at ∼193nm. Furthermore, the electronic stability of PAG anions can be enhanced by solvent effects with varying degrees of strength. We observed the lowest vertical detachment energy of 6.6eV of pTS- in PGMEA solution based on the polarizable continuum model, which prevents anion loss at 193nm lithography. In addition, our findings indicate gas-phase proton affinity values of 316.4 kcal/mol for pTS-, 308.1 kcal/mol for TFMBS-, and 303.2 kcal/mol for TF-, which suggest the increasing acidity strength, yet even the weakest acid pTS- is still stronger than strong acid HBr. The photolysis of TPS+-based PAG, TPS+·pTS-, generated an excited state leading to homolysis bond cleavage with the lowest reaction energy of 83 kcal/mol. Overall, the PAG anion pTS- displayed moderate acidity, possessed the lowest photolysis reaction energy, and demonstrated an appropriate redshift. These properties collectively render it a promising candidate for an effective acid producer.

Investigating solvent effects on synthesizing novel cobalt hydroxide and fluoride complex from Co(BF4)2 as active materials of the battery supercapacitor hybrid

Metal-organic framework (MOF) derivatives with tunable pore structure and improved conductivity are intensively designed as electroactive materials. Incorporating structure directing agents (SDA) is beneficial for designing MOF derivatives with excellent electrochemical performances. Ammonium fluoroborate has been reported as an effective SDA, coupled with cobalt salt and 2-methylimidazole, to synthesize zeolitic imidazolate framework-67 (ZIF-67) derivatives for charge storage. However, the synthetic environment for growing cobalt-based active materials is relatively complex. In this study, cobalt tetrafluoroborate (Co(BF4)2) is proposed as a novel cobalt precursor, supplementing cobalt ions and acting as the SDA in a single chemical, to synthesize the cobalt-based electroactive material of energy storage electrodes. Interactions between solvent molecules and solutes play significant roles on the morphology, composition, and electrochemical performance of active materials. Deionized water, methanol and ethanol are used as precursor solvents to understand their effects on material and electrochemical properties. The optimal electrode presents a specific capacitance of 608.3 F/g at 20 mV/s, attributed to the highest electrochemical surface area and evident compositions of cobalt fluoride and hydroxide. A battery supercapacitor hybrid achieves the maximum energy density of 45 Wh/kg at 429 W/kg. The CF retention of 100% and Coulombic efficiency of 99% are achieved after 10,000 cycles.

Solvent and media effects on the photophysics of cranad-2 and cranad-58

Alzheimer’s disease (AD) represents the most widespread form of age-related cognitive degeneration, characterized by long-term degenerative damage, cognitive dysfunction, and profound deficits in logical thinking, knowledge acquisition, and interpersonal communication. A principal biomarker of AD involves the emergence and aggregation of β-amyloid (Aβ). Cranad derivatives are fluorescent probes capable of detecting, quantifying, and imaging Aβ aggregates. In this work, the effect of solvent and microheterogeneous environments on the photophysical behavior of CRANAD-2 and CRANAD-58 was investigated employing a large solvent set and several microorganized systems. Both the absorption and fluorescence spectra exhibit a substantial solvatochromic effect, resulting in significant Stokes shifts. Application of linear solvation energy relationships to correlate the fluorescence spectra maxima and the Stokes shift with microscopic solvent parameters suggests significant intramolecular charge transfer during the excitation, as corroborated by the increased dipole moment in the excited state. Generally, fluorescence quantum yields determined for CRANAD-2 exceed those of CRANAD-58 in most solvents, with low values in polar solvents and bigger values in non-polar solvents. Introduction of CRANAD-2 and CRANAD-58 into micellar and vesicular solutions notably augments the fluorescence emission intensity, accompanied by a blue shift in the fluorescence maxima. The fluorescence maxima values observed within microheterogeneous systems closely parallel those reported for interactions between CRANAD derivatives and soluble or aggregated Aβ amyloids which potentially constrains the efficacy of “in vivo” Aβ detection trials, because localization of CRANAD derivatives in non-polar microenvironments present in biological media could interfere with the detection of amyloid fibers.

Determination and analysis of 4-hydroxyphenylacetamide solubility in different solvents by Hansen solubility parameters, solvent effect and thermodynamic properties

4-Hydroxyphenylacetamide (HPAD) is commonly used in the synthesis of high value-added chemicals in the fields of medicine, food and agriculture, such as atenolol, p-hydroxyphenylacetic acid, L-phenylalanine and D-phenylalanine. HPAD relies on chemical synthesis, involving multi-step reactions and multiple chemical catalysts. It is crucial to select appropriate organic solvent to improve yield and purity. In this work, the solubility of HPAD in 12 pure solvents (water, acetonitrile, methanol, ethanol, n-propanol, isopropanol, n-butanol, n-hexane, n-heptane, methyl acetate, ethyl acetate, n-butyl acetate) and 3 binary solvents (n-hexane + methanol, acetonitrile + methanol, n-heptane + methanol) was investigated in the range of 278.15–323.15 K. The solubility of HPAD in the selected solvents was positively correlated with the temperature. Hansen solubility parameters were used to study the dissolution behavior of HPAD. Then, the solvent effect was analyzed by KAT-LSER model, and it was found that the hydrogen bond acidity and nonspecific dipolarity/polarizability of solvents favored the dissolution of HPAD. Moreover, the modified Apelblat model (MA model), λh model, CNIBS/R-K model (CNK model), Jouyban-Acree model (JA model), and SUN model were used to fit and analyze experimental data. The results showed that the MA model and the CNK model were the best models for single and binary solvents, respectively. Finally, van’t Hoff analysis showed that the dissolution of HPAD in the selected solvents was an endothermic and entropic driven process. This work provided reference data for the separation, purification and crystallization of HPAD, and had certain guiding significance for its industrial production and application.

Synthesis of Carboxyl-Functionalized COFs with Alternate Stable β-Ketoenamine and Benzimidazole Linkages: Unraveling Exceptional Solvent Effects for Efficient Uranium Separation.

The prevalent π-π interactions in 2D covalent organic frameworks (COFs) impart a certain flexibility to the structures, making the stacking of COF layers susceptible to external stimuli and introducing some structural disorder. Recent research indicates that the flexibility between COF layers and the associated disorder significantly influence their selective adsorption performance toward gas molecules. However, the adsorption process in a solution environment is more complex compared to gas-phase adsorption, involving interactions between adsorbents and adsorbates, as well as the solvation effects of flexible 2D COFs. Therefore, the inherent flexibility and disorder in 2D COFs under solution conditions and their impact on the adsorption performance of metal ions have not been observed yet. Herein, the synthesis of a novel carboxyl-functionalized COF featuring stable β-ketoenamine and benzimidazole linkages, named DMTP-COOH, is presented. DMTP-COOH exhibits excellent selective adsorption capability for uranium, with significantly different adsorption capacities observed after treatment with different solvents. This notable difference in adsorption capacity is observed under varying pH, concentration, time, and even in the presence of multiple competing ions. This work represents the first observation of the significant impact of solvent soaking treatment on the selective adsorption performance of COFs for uranium under liquid conditions.

Green plastics: Direct production from grocery wastes to bioplastics and structural characterization by using synchrotron FTIR

Lignocellulosic bioplastics were produced using four different green wastes: hemp, parsley stem, pineapple leaves and walnut shell. Two different solutions were used to dissolve the green wastes: trifluoroacetic acid (TFA) and pure water. The changes in their natural structures and the solvent effect during the regeneration in biofilm formation were investigated by using Synchrotron FTIR Microspectroscopy (SR-µFTIR). The presence of cellulose, hemicellulose and lignin components in the water-based biofilms was confirmed. After dissolving in TFA, the spectra demonstrated some additional bands especially in the hemicellulose region. This is due to the hydrolysis of ester bonds and conversion to carboxylic acids. Principal component analysis showed grouping due to different solvents and polymer addition. Hemp-PVA (Polyvinyl Alcohol) composite biofilms were obtained by adding polyvinyl alcohol to the hemp solution to give extra strength to the hemp biofilms. It has been shown that water-based hemp-PVA biofilms do not cause any significant spectral changes, comparing with pure hemp and PVA spectra. However, after dissolving in TFA, unlike water-based biofilms, it appears that TFA molecules are retained by PVA through hydrogen bonds of TFA’s carboxylic acid and hydroxyl groups and distinct spectral regions belong to TFA bands are clearly identified.

Solvent Effects on Particle Size of Alumina Produced by Corrosion and Sol-Gel Method

Solvent Effects on Particle Size of Alumina Produced by Corrosion and Sol-Gel Method

Characterization of a mixed mode fluorocarbon/weak anion exchange sorbent for the separation of perfluoroalkyl substances.

The ubiquitous presence and persistence of per- and polyfluoroalkyl substances (PFAS) in the environment have raised concerns in the scientific community. Current research efforts are prioritizing effective PFAS remediation through novel sorbents with orthogonal interaction mechanisms. Recognized sorption mechanisms between PFAS and sorbents include hydrophobic, electrostatic, and fluorine-fluorine interaction. The interplay of these mechanisms contributes significantly to improved sorption capacity and selectivity in PFAS separations. In this study, a primary/secondary amine-functionalized polystyrene-divinylbenzene (Sepra-WAX) polymer was modified to create a fluorinated WAX resin (Sepra-WAX-KelF-PEI). The synthesis intermediate (Sepra-WAX-KelF) was also tested to assess the improvement of the final product (Sepra-WAX-KelF-PEI). The adsorption capacity of Sepra-WAX, Sepra-WAX-KelF, and Sepra-WAX-KelF-PEI, and their interactions with PFAS were evaluated. The effect of pH, ionic strength, and organic solvents on PFAS sorption in aqueous solution was also investigated. The sorbents showed varied adsorption capacities for perfluorooctanoic acid, perfluoropentanoic acid, perfluoro-n-decanoic acid, and hexafluoropropylene oxide dimer acid, with the average extraction capacity of the four analytes being Sepra-WAX-KelF-PEI (523mg/g)>Sepra-WAX (353mg/g)>Sepra-WAX-KelF (220mg/g). Sepra-WAX-KelF-PEI provided the highest adsorption capacity for all analytes tested, proving that the combination of electrostatic and hydrophobic/fluorophilic interactions is crucial for the effective preconcentration of PFAS and its future applications for PFAS remediation from aqueous solutions.

Insight into adsorption-desorption of methylene blue in water using zeolite NaY: Kinetic, isotherm and thermodynamic approaches

It is critical to find an efficient method to separate methylene blue (MB) in wastewater before discharging them into environment. Adsorption using zeolites is the most commonly used one. To determine adsorption mechanism providing useful data to enhance adsorption capacity and practicability of scale-up, kinetic, isotherm and thermodynamic adsorption were evaluated and discussed intensely. Zeolite NaY was synthesized from rice husk ash with a one-stage process. Effects of pH, contact time, initial concentration, adsorbent dose, temperature, solvents and recyclic stability on MB adsorption and desorption were investigated in detail via alternating variable method. Optimal conditions for adsorption were at pH 8, 1 h, 50 mgMB/L, 303K. Adsorption kinetics and isotherms showed that the process fitted to pseudo-second-order, Freundlich and Temkin isotherm, indicating a spontaneous, exothermic and physical adsorption process with multilayer adsorption. Desorption process showed that EtOH:H2O (1:1) solvent at 323K was optimal for releasing MB and its thermodynamic studies revealed that this process was favorable with rising temperature. The maximum adsorption capacity was calculated as 49 mg/g and the adsorbent could maintain its adsorption performance after six cycles. Generally, this study provided a comprehensive approach of an efficient, cost-effective, and recyclable NaY for MB removal from water.

Micro Solvation Effect of Methanol on Excited-State Dynamics of Protonated Tryptophan and Dopamine.

The electronic and vibrational cryogenic ion spectroscopy of protonated tryptophan (TrpH+) and dopamine (DAH+) complexed with methanol has been recorded. These two biological chromophores exhibit ultrafast photochemistry due to excited-state proton transfer (ESPT). We have established the relationship between the structure of the complexes and their photodynamics and compared them with recent results obtained in hydrated complexes. For TrpH+, there is no substantial change between methanol and water complexes; ESPT is hindered by a single solvent molecule. In the DAH+(MeOH)1 complex, the most stable conformer adopts a structure that prevents the direct interaction of the ammonium group of the side chain with the catechol ring, thus blocking the ESPT reaction. Such a ring structure is indeed a very minor populated conformer in the single-hydrated complex. The change in conformal stability between water and methanol clusters is due to a weak CH-π attractive interaction of the methyl group of methanol with the catechol.

Preferential Solvation of Cyclosporin in Aqueous Mixtures of Some Polymeric Cosolvents

Background: Cyclosporin is a cyclic peptide-drug used as immunosuppressant for the prophylaxisof transplant rejection whose physicochemical properties in mixed aqueous solvent systems isstill not well understood. The preferential solvation parameters of cyclosporin in aqueous binarymixtures of diethylene glycol monoethyl ether (DEGME), polyethylene glycol 200 (PEG 200) andpolyethylene glycol 400 (PEG 400) were computed. Methods: Reported mole fraction solubilities of cyclosporin in DEGME-aqueous mixtures,PEG 200-aqueous mixtures, and PEG 400-aqueous mixtures were processed by following theinverse Kirkwood-Buff integrals (IKBI) method as suggested by Marcus and Ben-Naim using somethermodynamic parameters reported in the literature for these aqueous-polymeric mixtures at298.15 K. Results: It is observed that cyclosporin is sensitive to preferential solvation effects in theseaqueous-polymeric binary solvent systems. The preferential solvation parameter by DEGME (δx1,3)is negative in water-rich mixtures but positive in mixtures of 0.12<x1<1.00. It is conjecturablethat hydrophobic hydration around the non-polar methyl and methylene groups of this drug thatcould be present in water-rich mixtures can significantly impact the drug solvation. Otherwise,in mixtures of 0.12<x1<1.00 in DEGME-aqueous mixtures, as well as in almost all the mixtureswith PEGs, the preferential solvation by polymeric cosolvents could be due to the acidic behaviorof cyclosporin in front of ether and hydroxyl oxygen atoms of these polymeric cosolvents. Conclusion: Cyclosporin is preferentially solvated by the polymeric solvents in almost all thestudied mixtures of these aqueous-polymeric binary solvent systems.

Optical characteristics of brown carbon in the atmospheric particulate matter of Dhaka, Bangladesh: Analysis of solvent effects and chromophore identification

The prevalence of brown carbon (BrC) in the atmosphere has experienced a notable upsurge owing to human activities of anthropogenic origin. This study aims to examine the optical characteristics of BrC in both deionized (DI) water and organic solvents (OS), alongside the identification of BrC chromophores within the ambient atmosphere of Dhaka, Bangladesh. Particulate matter (PM) samples were collected on quartz filters using a low-volume sampler from December 2021 to May 2022 at Mukarram Hussain Khundker Bhaban, University of Dhaka. The concentration of BrC was measured using soot analyzer, optical properties of BrC were determined using UV–Vis spectrometer, and BrC chromophores were identified with GC-MS. Average concentration of BrC was 19.13 ± 5.71 μgm−3. The average of absorption coefficient (babs_365), mass absorption efficiency (MAE), absorption angstrom exponent (AAE), and refractive index (kabs_365) of BrC_DI have been observed to be 38.75 ± 21.90 Mm−1, 2.16 ± 1.42 m2 g-1, 1.51 ± 0.08, 0.06 ± 0.04, respectively. The absorption coefficient and MAE of BrC_OS are 1.3 and 1.36 times, respectively higher than that of BrC_DI. Thirty chromophores of BrC have been identified, predominantly consisting of oxygenated compounds. Derivatives of Bisphenol A (C27H44O2Si2) were detected in all samples of oxygenated compounds, primarily originating from the combustion of plastic and the incineration of e-waste. Additionally, compounds containing nitrogen and sulfur, such as C14H26N2O, C31H55N, and C31H49NO3S, were identified, largely attributed to biomass combustion and traffic emissions. These chromophores play a significant role in the absorption of solar radiation, thus influencing atmospheric photochemistry.

New approach: Solvent effects of benzaldehyde in aliphatic alcohol solvents with FT-IR spectroscopy and augmented vertex-adjacency matrices

In this study of benzaldehyde (BNZ) in 7 aliphatic alcohol solvents, were undertaken to investigate the solvent/solute interaction with Fouirer Transform Infrared Spectroscopy (FT-IR), BNZ produced carbonyl group stretching vibration frequencies (ν(C=O)1 and ν(C=O)2). In the present paper, ν(C=O)1 and ν(C=O)2 of BNZ are observed and correlated with the solvent acceptor number (AN), dipolarity/polarizability (π*), hydrogen-bond donor acidity (α), hydrogen-bond acceptor basicity (β), solvent polarity parameter [ET(30)], KBM parameter ƒ(ε), boiling point (bp) and the linear solvation energy relationship (LSER) using single and multiple regression analysis. All calculations were performed for ν(C=O)1 and ν(C=O)2 and compared. ν(C=O)1 was believed to correspond to a single hydrogen bonded BNZ-alcohol complex, while ν(C=O)2 was believed to correspond to a multiple hydrogen bonded BNZ-alcohol complex and multiple hydrogen-bonded alcohol molecules. It was seen that LSER equation as multiple regression analysis was better than single regression analysis in explaining solute-solvent interactions due to the higher correlation coefficients obtained. The correlations of a set of the mathematical characteristics of the augmented vertex-adjacency matrices (AV-AM) obtained by the chemical structure of BNZ with solvent parameters and ν(C=O) were investigated. It was determined that the correlation factors (R2 > 0.999) of the multiparameter regression models obtained using the matrix results were higher than the correlation factors (R2 > 0.99) of the LSER equations including solvent parameters.

Visualization of Solvent Effect and Oxygen Content via a Red Room-Temperature Phosphorescent Material.

The development of pure organic room-temperature phosphorescent (RTP) materials greatly facilitates the integrated application of luminescent materials. Herein, a type of photoactivated red RTP material was constructed by simply doping 4-(benzo[c][1,2,5]thiadiazol-5-ylthio)benzonitrile (p-NNS) into a poly(methyl methacrylate) (PMMA) matrix. The obtained film realized a controllable photoactivation process by regulation of diverse solvent levels, demonstrating potential advantages in optical anti-counterfeiting applications. Furthermore, luminescent properties of the doped film were utilized to detect oxygen content from 2.00% to 4.90%, which revealed the exact consumption of ambient oxygen under UV light. Every CIE point of the luminescence corresponds to a certain oxygen content, illustrating the visualization of oxygen content. The remarkable regulation of solvent effect and oxygen content in this work will provide competitive material for further optical applications.