Influence Of Physicochemical Properties Research Articles

Predicting the acute toxicity of organophosphate esters (OPEs) to aquatic organisms by modelling the structure-toxicity relationships using partial least square regression

Organophosphate esters (OPEs) have been used worldwide as organophosphate flame retardants (OPFRs) since brominated flame retardants (BFRs) were banned. Due to the toxicity of these OPEs, environmental concerns and ecological risks arose. However, there are still large gaps in the understanding of their toxicity to organisms and the mechanisms of toxicity. After collecting the existing toxicity information and obtaining molecular descriptors of OPEs, a partial least square (PLS) regression model was used in this study to quantify the structure-toxicity relationships of OPEs. Based on the regression results, the acute toxicity of the remaining OPEs lacking acute toxicity data was predicted, and the risk level of total common OPEs was classified. The acute toxicity of 15 chemicals was collected, and >1660 molecular structure descriptors were obtained. The cross-validation results of the partial least square regression indicated that two principal components met the regression requirements with the selected features, and the regression equations of these chemicals were generated with selected molecular descriptors. The influence of physicochemical properties, such as hydrophobicity/molecular weight, in traditional perception of OPE toxicity was not that obvious, and acute toxicity was mainly influenced by the autocorrelation coefficients. However, the regression results indicated that the correlation between autocorrelation coefficients calculated based on different physicochemical properties and toxicity was different. According to the prediction result based on PLS regression, CDP may pose a high risk and halogenated alkyl-substituted OPEs such as TCEP may be less toxic. The results of the present study may help inform the environmental management and risk assessment of emerging chemicals such as OPEs.

Influence of physicochemical properties and structure of mixed solvents propylene glycol – macrogol 400 on their in vitro release

Aim. To study the density and dynamic viscosity of the mixed solvents propylene glycol (PG) – macrogol 400 (M400), to calculate their excess values and excess activation parameters of viscous flow, to evaluate the features of the structure of the mixed solvents and its influence on the in vitro release of PG and M400.
 Materials and methods. The mixed solvents PG - M400 were studied over the entire concentration range at temperatures from 293.15 to 313.15 K. The density and dynamic viscosity were determined, and the excess density, excess dynamic viscosity, activation parameters of viscous flow, and excess activation parameters of viscous flow were calculated. The in vitro release of PG and M400 from the mixed solvents was studied using vertical diffusion cells. The content of PG and M400 in the receptor medium was determined by gas chromatography using validated analytical procedures. The release rate, cumulative content, percentage of released PG or M400, coefficients of correlation and coefficients of determination were calculated.
 Results. The isotherms of excess density and excess dynamic viscosity of the mixed solvents PG-M400 pass through a maximum. The enthalpy makes the main contribution to the free activation energy of the viscous flow. The excess free energy is positive and has small values; the values of the excess entropy and excess enthalpy are negative, and the isotherms have the minimum at PG concentrations of 70‑75mol %. The release parameters of M400 are greater in binary mixtures where the M400 structure predominates. At PG content of ~75 mol %, the release parameters for PG and M400 are identical. With the increase in PG content above 75 mol %, when the PG structure predominates in the system, the release parameters of PG increase dramatically, and the release parameters of M400 decrease sharply.
 Conclusions. The structure of the binary system PG – M400 depends on its composition. Based on the isotherms of excess activation of viscous flow, it is possible to differentiate the areas where the structure of PG or the structure of M400 dominates, or the mixed structure of the binary solvent prevails. The in vitro release parameters for PG and M400 depend on the structure of the mixed solvents. The greatest difference in the release parameters of PG and M400 was observed in the area where the structure of PG dominates

Influence of physicochemical properties and shape characteristics of coal gangue coarse aggregate on concrete strength

Influence of physicochemical properties and shape characteristics of coal gangue coarse aggregate on concrete strength

Rapid and low-cost synthesis of ZSM-5 zeolite nanosheet assemblies for conversion of methanol to gasoline

Nanoscale zeolites with short diffusion paths show significantly enhanced mass transportation and easier accessibility for active sites in catalysis compared to microsized zeolites. However, the high cost and complex process involved in existing synthetic methods limit their application, so the development of a rapid and low-cost synthesis technology is of great significance. Herein, ZSM-5 zeolite nanosheet assemblies (Z5-NS-t) are rapidly synthesized by a microwave irradiation (MW) assisted seed-induced method using low-cost polyhexamethylene biguanide hydrochloride (PHMB) as a crystal growth inhibitor of the b-axis. The crystallization kinetics of the resultant materials and the formation mechanism of ZSM-5 zeolite nanosheets, as well as the influence of physico-chemical properties on their catalytic performance for the methanol-to-gasoline (MTG) reaction, are systematically investigated. Compared with the ZSM-5 nanoparticle assemblies (Z5-NP-60), which are synthesized by using the same method except for the addition of PHMB, Z5-NS-180 nanosheets with an approximate density of strong Brønsted acid sites exhibit excellent catalytic performance in the MTG reaction, giving rise to a high gasoline selectivity of 73.2% at a methanol conversion of 99.9% and a large amount of external carbon deposits. This is attributed to the synergy of accessibility of acid sites located in the pore intersections and the shorter diffusion paths for coke precursors out of the zeolite channel. This study provides an effective strategy for the synthesis of ZSM-5 nanosheets as catalysts for the MTG reaction, and it is expected to be applied for the synthesis of other zeolite nanosheets for important catalytic processes.

Influence of physicochemical properties on the production of alternative healthy gummy jelly from tilapia (Oreochromis niloticus) skin with added Thai rice powder.

We developed a new healthy gummy jelly from tilapia skin-derived gelatine and four rice cultivar powders. The gelatine from the tilapia fish skin was obtained using acid and alkaline extraction. The extracted gelatine comprised 96.77±0.96% protein and featured a breaking force of 5.21±0.58g, which indicates high gel strength. The fish gelatine was combined with the rice varieties to produce a gummy jelly with an enhanced nutritional value, and its flavor profile was determined. Gummy jelly products with added black sticky rice powder exhibited the highest protein and carbohydrate contents. The gummy jelly supplemented with rice berry had the highest score, with 90% acceptance, on a nine-point hedonic scale. Microbiological analysis showed that no microorganisms were detected in any of the samples. These results indicate that fish gelatine and rice powder may be used as nutritive ingredients in sports food to improve athletic performances.

ZnIn2S4‐Based Nanostructures in Artificial Photosynthesis: Insights into Photocatalytic Reduction toward Sustainable Energy Production

As one of the most attractive technologies, photocatalysis arouses tremendous interest to directly harvest, convert, and store renewable solar energy for solving the energy crisis. Zinc indium sulfide (ZnIn2S4), a novel ternary metal chalcogenide, is highly desired owing to its non‐toxicity, low cost, and easy fabrication. However, it still suffers from some problems, including low charge‐carrier transfer rate and the ultrafast electron–hole recombination. Hence, various efficient modification methods are developed for enhancing the photocatalytic performance of ZnIn2S4 nanomaterials. Herein, the photocatalytic energy applications of ZnIn2S4‐based nanocomposites are systematically summarized, followed by a thorough discussion on the synthesis methods of ZnIn2S4 micro/nanostructures. Furthermore, special attention is paid to various design strategies, including dimensionality tuning, element doping, vacancy control, cocatalyst loading, and heterojunction construction. Many important energy conversion applications are also addressed, such as photocatalytic water splitting, carbon dioxide reduction, and nitrogen fixation. The influence of physicochemical properties, including structure, optical, electronic, and adsorption, on the charge dynamics for boosted photocatalytic energy applications are concluded to unravel the property–application relationship. Through reviewing the significant state‐of‐the‐art advances on this topic, the current challenges and the crucial issues of ZnIn2S4‐based photocatalysts are prospected.

Influence of Physicochemical Properties and Parent Material on Chromium Fractionation in Soils

Chromium is an element that possess several oxidation states and can easily pass from one to another, so its behavior in soils is very complex. For this reason, determining its fate in the environment can be difficult. In this research work we tried to determine which factors affect the chromium fractionation in natural soils, conditioning chromium mobility. We paid special attention to the parent material. For this purpose, extraction experiments were carried out on spiked soils incubated for 50–60 days, using H2O, CaCl2 and diethylenetriaminepentaacetic acid (DTPA). The most efficient extraction rate in all soils was achieved using water, followed by CaCl2 and DTPA. We obtained models with an adjusted R2 of 0.8097, 0.8471 and 0.7509 for the H2O Cr, CaCl2 Cr and DTPA Cr respectively. All models were influenced by the amount of chromium added and the parent material: amphibolite and granite influenced the amount of H2O Cr extracted, and schist affected the other two fractions (CaCl2 and DTPA). Soil texture also played an important role in the chromium extraction, as well as the amounts of exchangeable aluminum and magnesium, and the bioavailable phosphorus. We concluded that it is possible to make relatively accurate predictions of the behavior of the different Cr fractions studied, so that optimized remediation strategies for chromium-contaminated soils can be designed on the basis of a physicochemical soil characterization.

Tailoring physicochemical and electrical properties of Ni/CeZrOx doped catalysts for high efficiency of plasma catalytic CO2 methanation

Promoters covering alkaline earth metals, lanthanides, transition and some of the typical rare earth metals, were added to Ni/CeZrOx based catalysts and examined in non-thermal plasma (NTP)-assisted CO2 methanation. The influence of physicochemical properties was examined by X-Ray Diffraction, N2 adsorption/desorption, H2-TPR, CO2-TPD, TPD-MS and FTIR spectroscopy. Moreover, the measurement of the dielectric constant of each catalyst was also performed. The promotion of Ni/CeZrOx with 4 wt% Gd significantly increases the energy efficiency. Furthermore, NiCZ-Gd resulted in the highest activity with 85 % conversion of CO2 fully converted to methane at 7 W. The enhancement of energy efficiency was attributed to electrical and physicochemical properties in particular: a low dielectric constant, a high metal dispersion, a high percentage of medium basic sites and finally an adequate promoter’s cation radii. This study allowed to set up a new methodology to select the most appropriate catalysts in terms of energy efficiency for plasma catalytic CO2 methanation.

Influence of physicochemical properties and starch fine structure on the eating quality of hybrid rice with similar apparent amylose content

In this study, we compared the physicochemical properties and starch structures of hybrid rice varieties with similar apparent amylose content but different taste values. In addition to the apparent amylose content, gel permeation chromatography analysis showed that the higher proportions of amylopectin short chains and relatively lower proportions of amylopectin long chains, which could lead to higher peak viscosity and breakdown value, as well as a softer and stickier texture of cooked rice, were the key factors in determining the eating quality of hybrid rice. High-performance anion-exchange chromatography analyses showed that the proportion of amylopectin short chains (degree of polymerization 6–10) and intermediate chains (degree of polymerization 13–24), which might affect the gelatinisation enthalpy and crystallinity, also contributed greatly to the eating quality of hybrid rice. Moreover, this study indicated that a greater diversity of forms and sizes of starch granules might influence the eating quality of hybrid rice.

Inhalable Nanoparticles/Microparticles of an AMPK and Nrf2 Activator for Targeted Pulmonary Drug Delivery as Dry Powder Inhalers

Metformin is an activator of the AMPK and Nrf2 pathways which are important in the pathology of several complex pulmonary diseases with unmet medical needs. Organic solution advanced spray drying in the absence of water in closed-mode was used to design and develop respirable dry powders. Following comprehensive characterization, the influence of physicochemical properties was correlated with performance as aerosols using inertial impaction and three different human dry powder inhaler (DPI) devices varying in device properties. In vitro cell assays were conducted to test safety in 2D human pulmonary cell lines and in 3D small airway epithelia comprising primary cells at the air-liquid interface (ALI). In addition, in vitro transepithelial electrical resistance (TEER) was carried out. Metformin remained crystalline following advanced spray drying under these conditions. All SD powders consisted of nanoparticles/microparticles in the solid state. In vitro aerosol dispersion performance showed high aerosolization for all SD metformin powders with all DPI devices tested. High emitted dose for all powders with all three DPI devices was measured. Differences in other aerosol performance parameters and the interplay between the properties of different formulations produced at specific pump rates and the three different DPI devices were correlated with spray drying pump rate and device properties. Safety over a wide metformin dose range was also demonstrated in vitro. Aerosol delivery of metformin nanoparticles/microparticles has the potential to be a new “first-in-class” therapeutic for the treatment of a number of pulmonary diseases including pulmonary vascular diseases such as pulmonary hypertension.

Influence of physicochemical properties of the soil solution on the 226Ra distribution coefficient in soils

Defined as the ratio between the isotope’s activity concentrations in the solid fraction of the soil and in the soil solution, the distribution coefficient (Kd) of 226Ra is an equilibrium constant that encompasses all the interface processes that comprise its sorption as a whole. However, there is a great variability in the reported measured values of radium Kd. A first classification of soils in terms of their texture reduces this variability somewhat, but the chemical environment of the soil solution is also expected to exert a significant influence on the sorption process and therefore on the Kd. In the present work, linear regressions are applied to look for relationships between the radium Kd and the physicochemical properties of the soil solution. The soil solutions were studied of three soils with different textural characteristics but taken from the same natural soil. For the soil classified as loamy coarse sand, the significant independent variables affecting Kd were the pH, conductivity, and dissolved organic matter; for the soil classified as loamy fine sand, they were the bivalent cation concentration and pH; and for the soil classified as loam, they were the conductivity and nitrate concentration.

The Level of Luvisols Biochemical Activity in Midfield Shelterbelt and Winter Triticale (xTriticosecale Wittm. ex A. Camus) Cultivation

This study aimed to evaluate the usage of Luvisols under the midfield shelterbelt and in the cultivation of winter triticale, together with the influence of physicochemical properties on enzymatic activity. Soil samples were collected in spring, summer, and autumn from the depth of 0–15 cm along the following measurement transect: midfield shelterbelt (S), the border between the shelterbelt and the triticale field (B), cultivated field at a distance of 50 m from point B (F50), and cultivated field at a distance of 100 m from point B (F100). The activities of dehydrogenase (DHA), acid phosphatase (PAC), and alkaline phosphatase (PAL) were determined, and a water retention curve (pF) was established. The pH, soil organic carbon (SOC) content, and total nitrogen (Ntotal) were also measured. The analysis of the activity results for DHA, PAC, and PAL showed that the triticale soil had a higher level of enzyme activity than the midfield shelterbelt soil during the entire growing season. The soil under the triticale cultivation was slightly acidic, and the shelterbelt soil was very acidic. It was observed that the timing of soil sampling had an impact on the activity of the studied enzymes. The highest levels of DHA, PAC, and PAL activity were found in summer. The midfield shelterbelt demonstrated greater water retention than the winter triticale. The SOC content and Ntotal were higher in the shelterbelt than in the winter triticale field.

Removal of heavy metal ions from water using adsorbents from agro waste materials

When discharged without adequate treatment into water resources, hazardous metal ions found in industrial wastewater influence the risk to human and environmental health. Low-cost adsorbents with a high metal-binding potential are widely used for heavy metal removal. Intrinsic physico-chemical structural features of adsorbents significantly affect their potential for adsorption. The influence of physico-chemical properties on the adsorption capacity is comparable for all three metal cations namely Cu2+, Co2+, and Zn2+. Acidic surface functionalities were bound with Cu2+ and Co2+. Carboxylic groups were involved in adsorption of Cu2+ and Zn2+ whereas lactonic groups were interact with Zn2+ and convert into complexation. The pH effect demonstrated a dramatic increase in adsorption efficiency by rising the solution pH from 3 to 6. It was proven that adsorbent could be used as an effective adsorbent for removal of Ni(II) ions from water solutions as an alternative to commercial activated carbons.

Influence of Physicochemical Properties on Gas Transport Properties of Silver-Containing Ionic Liquid Mixtures for Olefin/Paraffin Membrane Separation

Olefin/paraffin separation by cryogenic distillation is one of the most energy-consuming processes not only among the entire chemical processes but also among all the energy-consuming activities by human beings. The purification of propylene and ethylene accounts for 0.3% of global energy use (1). Membrane separation is an attractive alternative, owing to its high energy-efficiency compared to conventional distillation processes. Liquid membranes that utilize gas transport through the liquid phase confined in the pore structures have shown promising performance due to the faster transport compared to solid membrane materials (2).Since the liquid phase is where the transport of olefin/paraffin molecules occurs, the liquid membrane performance in terms of permeability, selectivity, and stability mainly relies on the properties of the liquid component. Ionic liquids are a suitable material since the liquid component in the membranes provide stable separation performance owing to their extremely low vapor pressure and good thermal/chemical stability. Moreover, the limitless turnability of ionic liquids can be manipulated to enhance the molecular interaction with certain gas molecules to result in better gas solubility. For olefin/paraffin separation, in addition to physical solubility of the olefin in the ionic liquid, silver ions are commonly added to further improve olefin solubility. The silver ions can complex with olefin molecules via interaction between the double bonds of olefins and the orbitals of silver ions.Here we have investigated the effect of the anion, concentrations of the silver salt, and temperatures on the physicochemical properties of the silver-containing ionic liquid mixtures. The macroscopic physicochemical properties, such as viscosity and density, affect the filling of the membrane pores and stability to transmembrane pressure. However, we show that they are also indicators of ion aggregation in the mixtures, which can be correlated with relevant membrane properties, including solubility, diffusivity and silver ion reactivity with contaminant gases. The physiochemical viewpoint on the silver-containing ionic liquid mixture will provide appropriate insight for understanding the olefin/paraffin gas transport in the ionic liquid mixture, which leads to a design idea for better separation performance.(1) D. S. Sholl, R. P. Lively, Seven chemical separations: to change the world: purifying mixtures without using heat would lower global energy use, emissions and pollution--and open up new routes to resources. Nature 532, 435 (2016).(2) C. M. Sanchez, T. Song, J. F. Brennecke, B. D. Freeman, Hydrogen Stable Supported Ionic Liquid Membranes with Silver Carriers: Propylene and Propane Permeability and Solubility. Industrial & Engineering Chemistry Research 59, 5362-5370 (2020).

Influence of Physicochemical Properties on Gas Transport Properties of Silver-Containing Ionic Liquid Mixtures for Olefin/Paraffin Membrane Separation

Physicochemical properties, including viscosity and density, of silver salt-containing ionic liquids were measured and used to rationalize the permeability of ethane, ethylene, and helium through supported ionic liquid membranes (SILMs). Mixtures investigated included 1-hexyl-3-methylimidazolium bis(trifluoromethyl-sulfonyl)imide ([hmim][Tf2N]) and 1-hexyl-3-methylimidazolium nitrate ([hmim][NO3]) and their corresponding silver salts. The gas transport properties were very different for the two different ionic liquid/silver salt mixtures, consistent with very different behavior of viscosity and density upon silver salt dissolution. The distinctive dependence of both viscosity and density on temperature and silver salt concentration suggests different interion interactions and molecular arrangements in the two ionic liquids. Free volume and physical/chemical interactions between the anion and the gas solutes are critical in determining gas permeabilities.

Correlations between physico-chemical properties and nickel adsorption parameters in soils used in sanitary landfill liners

The adsorption of heavy metals by sanitary landfill liners represents a measure of protection of surface and groundwaters against contamination by metals, mitigating risks to public health. Hence, this research aimed to identify, from correlations, the influence of physico-chemical properties of soils applied in landfill liners using nickel adsorption parameters. Batch equilibrium tests with initial nickel concentrations of 45 to 1440 mg.L-1 were performed in clayey sand and bentonite clay soil, as well as in mixtures. Nickel adsorption parameters from Freundlich and Langmuir isotherm models were obtained, exhibiting a better adjustment in the Freundlich model based on R² and RMSE criteria. Thus, the addition of bentonite clay improved the adsorption to nickel, and the cationic exchange capacity (CEC) was the property that considerably influenced the metal retention in the studied soils.

Identification of the sources and influencing factors of potentially toxic elements accumulation in the soil from a typical karst region in Guangxi, Southwest China

Southwestern China contains the largest and most well-developed karst region in the world, and the potentially toxic elements (PTEs) content in the soils of the region is remarkably high. To explore the internal and external control factors and sources of soil PTEs enrichment in this area and to provide a basis for the treatment of PTE pollution, 113 soil samples were collected from Hengxian County, a karst region in Guangxi Province, southwestern China. The importance of eighteen influencing factors including parent material, weathering, physicochemical properties, topography and human activities were quantitatively analyzed by (partial) redundancy analysis. The sources of PTEs were identified using the Pb isotope ratio and absolute principal component score/multiple linear regression (APCS-MLR) model. The contents of all soil PTEs were higher than the corresponding background values of Guangxi soils. The contents in Cu, Zn, Cd, Hg and Pb were the highest in the soil from carbonate rock. The factor group of geological background and weathering explained 26.5% for the accumulation and distribution of soil PTEs and the influence of physicochemical properties was less than 2% but increased to 25.6% through interaction with weathering. Fe (47.1%), Al (42.1%), Mn (22%), chemical index of alteration (12.8%) and clay (11.9%) were the key factors affecting the soil PTEs, while the influence of human activities was weak. Pb isotope ratio and APCS-MLR classified 62.8–74% of soil PTEs as derived from natural sources, whereas 18.23% and 18.95% were derived from industrial activities and agricultural practice/traffic emissions, respectively. The Pb isotope ratio showed that the natural sources account for up to 90% of the Pb in the soil from carbonate rock, the highest contribution among the studied soils. The results of the study can provide background information on the soil PTEs contamination in the karst areas of China and other areas worldwide.

Toxicological Behavior of Gold Nanoparticles on Various Models: Influence of Physicochemical Properties and Other Factors.

Potential applications of gold nanoparticles in biomedicine have increasingly been reported on account of the ease of synthesis, bioinert characteristics, optical properties, chemical stability, high biocompatibility, and specificity. The safety of these particles remains a great concern, as there are differences among toxicity study protocols used. This article focuses on integrating results of research on the toxicological behavior of gold nanoparticles. This can be influenced by the physicochemical properties, including size, shape, surface charge, and other factors, such as methods used in the synthesis of gold nanoparticles, models used, dose, in vivo route of administration, and interference of gold nanoparticles with in vitro toxicity assay systems. Several researchers have reported toxicological studies with regard to gold nanoparticles, using various in vitro, in vivo, and in ovo models. The conflicting results concerning the toxicity of gold nanoparticles should thus be addressed to justify the safe use of gold nanoparticles in biomedicine.

Quantifying the influence of surface physico-chemical properties of biosorbents on heavy metal adsorption

Heavy metals present in industrial wastewater contribute to human and ecosystem health risk when discharged without proper treatment. Low-cost biosorbents with high metal-binding capacity are increasingly being utilized for the removal of heavy metals. Inherent physico-chemical properties of biosorbents significantly influence their adsorption capacity. Studies quantifying the influence exerted by these properties on adsorption capacity are scarce. This study quantifies the influence and relative importance of selected physico-chemical properties on the adsorption capacity of three divalent heavy metals; Cu2+, Cd2+ and Pb2+ using multivariate analysis. Twenty one biosorbent mixtures were created, systematically varying their physico-chemical properties using tea factory waste and coconut shell biochar. Their adsorption capacities were measured using batch sorption studies. The influence of physico-chemical properties on the adsorption capacity is comparable for all three metal cations. Regression models were developed to quantify the influence of physico-chemical parameters on the adsorption capacity based on regression coefficients. All models were found to have high reliability with R2 values above 0.98. Acidic surface functional groups were found to act as the key property that governs the adsorption capacity of Pb2+, Cu2+ and Cd2+. Carboxylic groups played a major role in the adsorption of Cu2+ and Pb2+, while lactonic groups were more important in providing binding sites to Cd2+. SSA failed to demonstrate a significant impact on the adsorption capacity of these three metals on its own when the biosorbent had a low surface functional group density.

The Influence of Physico-Chemical Properties on Heavy Metals Content on the Illegal Land Fill Kadisoka, Sleman, Special Region of Yogyakarta

The Influence of Physico-chemical properties on heavy metals contenton the Illegal Land Fill at Kadisoka, Sleman, Yogyakarta has been carried out. The aims of this research are to evaluatethe metal concentrationin the soil, analyze the physicochemical properties including water and ash contents, pH, electrical conductivity, total organic carbon, cation exchange capacity; and to find out the maximum heavy metals contentthe soil samples.Soil samples were divided into three samples based on places where they were taken in the landfill area, namely sample I, II and III. Heavy Metals content in the solution were measured by Atomic Absorption Spectrophotometer (AAS).The results showed the highest heavy metal content in soil was Zn. Sample II had the highest Zn value at 1,199 mg kg-1, whereas sample I had the lowest total Zn content of 708.54 mg kg-1.