scholarly journals Hygroscopicity of organic compounds as a function of organic functionality, water solubility, molecular weight and oxidation level

2021 ◽  
Author(s):  
Shuang Han ◽  
Juan Hong ◽  
Qingwei Luo ◽  
Hanbing Xu ◽  
Haobo Tan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Functional Groups ◽  
Organic Compounds ◽  
Water Solubility ◽  
Chemical Properties ◽  
Molecular Formula ◽  
Differential Mobility Analyzer ◽  
Differential Mobility ◽  
Hygroscopic Properties ◽  
Physico Chemical

Abstract. Hygroscopic properties of 23 organics including carboxylic acids, amino acids, sugars and alcohols were characterized using a Hygroscopicity Tandem Differential Mobility Analyzer (HTDMA). We show that hygroscopicity of organics varies widely with different functional groups and organics with additional functional groups are more hygroscopic. However, some compounds sharing the same molecular formula or functionality show quite different hygroscopicity, demonstrating that other physico-chemical properties may contribute to their hygroscopicity as well. If the organics are fully dissolved in water (solubility > 7× 10−1 g/ml), we found that their hygroscopicity is mainly controlled by their molecular weight. For the organics that are not fully dissolved in water (slightly soluble: 5 × 10−4 g/ml < solubility < 7 × 10−1 g/ml), we observed that some of them show no obvious water uptake, which probably due to that they may not deliquesce under our studied conditions up to 90 % RH. The other type of slightly soluble organics is moderate hygroscopic and the larger their solubility the higher their hygroscopicity. Moreover, the hygroscopicity of organics generally increased with O : C ratios, although this relationship is not linear. Hygroscopicity of organic compounds were also predicted by two thermodynamic models using the Extended Aerosol Inorganics Model (E-AIM) and UManSysProp. Both models do not consider phase transition and intermolecular interactions in the simulations and show poor representation of the hygroscopicity for most of the organics.

Hygroscopicity of organic compounds as a function of organic functionality, water solubility, molecular weight and organic oxidation level

2021 ◽  
Author(s):  
shuang han ◽  
Juan Hong ◽  
Qingwei Luo ◽  
Hanbing Xu ◽  
Haobo Tan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Functional Groups ◽  
Organic Compounds ◽  
Water Solubility ◽  
Chemical Properties ◽  
Hygroscopic Properties ◽  
Physico Chemical ◽  
Model Predictions ◽  
Hygroscopic Behavior ◽  
Molecular Compounds

&lt;p&gt;Hygroscopic properties of 23 organic compounds with different physico-chemical properties including carboxylic acids, amino acids, sugars and sugar alcohols were measured using a Hygroscopicity Tandem Differential Mobility Analyzer (HTDMA). We converted our experimental GF data of organics at 90% RH to &amp;#954; to facilitate the comparison and we find that organic compounds with different molecular functionality present quite different hygroscopicity. Compounds with extra functional groups usually show higher hygroscopicity compared to their parental molecular compounds. Moreover, some compounds share the same molecular structure or functionality but vary differently in hygroscopicity. In general, the hygroscopicity of organics increase with functional groups in the following order: (-CH3/-NH2) &lt; (-OH) &lt; (-COOH/C=C/C=O). For highly soluble organics, the hygroscopicity decreases with molecular weight; while for slightly soluble organics which are not fully dissolved in aerosol droplets, their hygroscopicity can be divided into two categories. One is non-hygroscopic compounds, which may not fully deliquesce in the aerosol droplets. The other is moderate hygroscopic compounds, of which the hygroscopicity is mainly limited by their water solubility. Moreover, the hygroscopicity of organic compounds generally increased linearly with O:C ratios, although some of them have the same O:C ratio of but with different hygroscopicity. The experimental determined hygroscopicity are also compared with model predictions using the Extended Aerosol Inorganics Model (E-AIM) and the UManSysProp at 10-90% RH. Both models poorly represent the hygroscopic behavior of some organics, which may due to that the phase transition and intermolecular interactions are not considered in the simulations.&lt;/p&gt;

scholarly journals Nano-hygroscopicity tandem differential mobility analyzer (nano-HTDMA) for investigating hygroscopic properties of sub-10 nm aerosol nanoparticles

2020 ◽  
Author(s):  
Ting Lei ◽  
Nan Ma ◽  
Juan Hong ◽  
Thomas Tuch ◽  
Xin Wang ◽  
...  
Keyword(s):  
Materials Science ◽  
Current Knowledge ◽  
Measurement Techniques ◽  
Chemical Properties ◽  
High Accuracy ◽  
Hygroscopic Growth ◽  
Differential Mobility Analyzer ◽  
Differential Mobility ◽  
Aerosol Nanoparticles ◽  
Hygroscopic Properties

Abstract. Interactions between water and nanoparticles are relevant for atmospheric multiphase processes, physical chemistry, and materials science. Current knowledge of the hygroscopic and related physico-chemical properties of nanoparticles, however, is restricted by limitations of the available measurement techniques. Here, we present the design and performance of a nano-hygroscopicity tandem differential mobility analyzer (nano-HTDMA) apparatus that enables high accuracy and precision in hygroscopic growth measurements of aerosol nanoparticles with diameters less than 10 nm. Detailed methods of calibration and validation are provided. Beside maintaining accurate and stable sheath/aerosol flow rates (± 1 %), high accuracy of DMA voltage (± 0.1 %) in the range of ~0–50 V is crucial to achieve accurate sizing and small sizing offsets between the two DMAs (

Assessment of efficacy of biocides in different soil types for use in sorption studies of low molecular weight organic compounds

Soil Research ◽  
2018 ◽  
Vol 56 (5) ◽  
pp. 451 ◽  
Author(s):  
Sheridan Martin ◽  
Rai S. Kookana ◽  
Lynne M. Macdonald ◽  
Mark Farrell
Keyword(s):  
Molecular Weight ◽  
Biological Activity ◽  
Microbial Activity ◽  
Organic Compounds ◽  
Chemical Properties ◽  
Low Molecular Weight ◽  
Physico Chemical ◽  
Important Regulator ◽  
Selection For ◽  
Different Soils

The abiotic protection of low molecular weight organic compounds (LMWOC) in soils may be an important regulator of C cycling. The study of the protection of LMWOC through sorption typically employs soils shaken in solution, which may be compromised by biological activity. We used 14C-labelled glucose as a LMWOC in batch assays of four different soils with contrasting physico-chemical properties (Arenosol, Luvisol, Ferralsol and Andisol). The commonly used biocides NaN3 and HgCl2 were employed alone or in concert across a range of concentrations to assess their efficacy in inhibiting microbial degradation. For short (<1 day) sorption experiments, low NaN3 concentrations (50 µM) were sufficient to inhibit microbial activity, whereas for longer (2 week) equilibrium assays, only high HgCl2 concentrations (10 mM) were effective in all soils tested. All combinations of biocide were most effective in inhibiting microbial activity in the Arenosol and least effective in the Andisol. Thus, in some soils, particular care is required with biocide selection for complete inhibition of biological activity. The findings presented here are of relevance for the design of studies investigating sorption of labile organic compounds in soils.

Physico-Chemical Properties of Recombinant Desulphatohirudin

1990 ◽  
Vol 63 (03) ◽  
pp. 499-504 ◽  
Author(s):  
A Electricwala ◽  
L Irons ◽  
R Wait ◽  
R J G Carr ◽  
R J Ling ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gel Filtration ◽  
Chemical Properties ◽  
Alpha Helix ◽  
Apparent Molecular Weight ◽  
Correlation Spectroscopy ◽  
Nmr Studies ◽  
Recombinant Hirudin ◽  
Physico Chemical ◽  
Recombinant Molecule

SummaryPhysico-chemical properties of recombinant desulphatohirudin expressed in yeast (CIBA GEIGY code No. CGP 39393) were reinvestigated. As previously reported for natural hirudin, the recombinant molecule exhibited abnormal behaviour by gel filtration with an apparent molecular weight greater than that based on the primary structure. However, molecular weight estimation by SDS gel electrophoresis, FAB-mass spectrometry and Photon Correlation Spectroscopy were in agreement with the theoretical molecular weight, with little suggestion of dimer or aggregate formation. Circular dichroism studies of the recombinant molecule show similar spectra at different pH values but are markedly different from that reported by Konno et al. (13) for a natural hirudin-variant. Our CD studies indicate the presence of about 60% beta sheet and the absence of alpha helix in the secondary structure of recombinant hirudin, in agreement with the conformation determined by NMR studies (17)

scholarly journals Estimation of the retention behaviour of s-triazine derivatives applying multiple regression analysis of selected molecular descriptors

2013 ◽  
pp. 229-237 ◽  
Author(s):  
Lidija Jevric ◽  
Sanja Podunavac-Kuzmanovic ◽  
Strahinja Kovacevic ◽  
Natasa Kalajdzija ◽  
Bratislav Jovanovic
Keyword(s):  
Dissociation Constant ◽  
Water Solubility ◽  
Molecular Descriptors ◽  
Chemical Properties ◽  
Log P ◽  
Retention Factors ◽  
Solute Retention ◽  
Physico Chemical ◽  
Hydrophilic Lipophilic Balance ◽  
Triazine Derivatives

The estimation of retention factors by correlation equations with physico-chemical properties can be of great helpl in chromatographic studies. The retention factors were experimentally measured by RP-HPTLC on impregnated silica gel with paraffin oil using two-component solvent systems. The relationships between solute retention and modifier concentration were described by Snyder?s linear equation. A quantitative structure-retention relationship was developed for a series of s-triazine compounds by the multiple linear regression (MLR) analysis. The MLR procedure was used to model the relationships between the molecular descriptors and retention of s-triazine derivatives. The physicochemical molecular descriptors were calculated from the optimized structures. The physico-chemical properties were the lipophilicity (log P), connectivity indices (?), total energy (Et), water solubility (log W), dissociation constant (pKa), molar refractivity (MR), and Gibbs energy (GibbsE) of s-triazines. A high agreement between the experimental and predicted retention parameters was obtained when the dissociation constant and the hydrophilic-lipophilic balance were used as the molecular descriptors. The empirical equations may be successfully used for the prediction of the various chromatographic characteristics of substances, with a similar chemical structure.

Correlations between Molecular Descriptors from Various Volatile Organic Compounds and Photocatalytic Oxidation Kinetic Constants

2013 ◽  
Vol 11 (2) ◽  
pp. 799-813 ◽  
Author(s):  
Cécile Raillard ◽  
Valérie Héquet ◽  
Bifen Gao ◽  
Heyok Choi ◽  
Dionysios D. Dionysiou ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Photocatalytic Oxidation ◽  
Molecular Descriptors ◽  
Equilibrium Constants ◽  
Oxidation Kinetic ◽  
Chemical Properties ◽  
Physico Chemical ◽  
Degradation Rates ◽  
Volatile Organic

Abstract The photocatalytic oxidation of seven typical indoor volatile organic compounds (VOCs) is experimentally investigated using novel nanocrystalline TiO2 dip-coated catalysts. Not only the role of hydrophilicity of the reactants but also other physico-chemical properties and molecular descriptors are studied and related to kinetic and equilibrium constants. The main objective of this work consists in establishing simple relationships that will be useful to deepen the understanding of gas-phase heterogeneous photocatalytic mechanisms and for the prediction of degradation rates of these VOCs using an indoor air treatment process.

scholarly journals Application of a hygroscopicity tandem differential mobility analyzer for characterizing PM emissions in exhaust plumes from an aircraft engine burning conventional and alternative fuels

2018 ◽  
Vol 18 (23) ◽  
pp. 17029-17045 ◽  
Author(s):  
Max B. Trueblood ◽  
Prem Lobo ◽  
Donald E. Hagen ◽  
Steven C. Achterberg ◽  
Wenyan Liu ◽  
...  
Keyword(s):  
Alternative Fuels ◽  
Particle Diameter ◽  
Aircraft Engine ◽  
Aviation Fuel ◽  
Limited Information ◽  
Differential Mobility Analyzer ◽  
Differential Mobility ◽  
Fischer Tropsch ◽  
Hygroscopic Properties ◽  
Exhaust Plumes

Abstract. In the last several decades, significant efforts have been directed toward better understanding the gaseous and particulate matter (PM) emissions from aircraft gas turbine engines. However, limited information is available on the hygroscopic properties of aircraft engine PM emissions which play an important role in the water absorption, airborne lifetime, obscuring effect, and detrimental health effects of these particles. This paper reports the description and detailed lab-based performance evaluation of a robust hygroscopicity tandem differential mobility analyzer (HTDMA) in terms of hygroscopic properties such as growth factor (GF) and the hygroscopicity parameter (κ). The HTDMA system was subsequently deployed during the Alternative Aviation Fuel EXperiment (AAFEX) II field campaign to measure the hygroscopic properties of aircraft engine PM emissions in the exhaust plumes from a CFM56-2C1 engine burning several types of fuels. The fuels used were conventional JP-8, tallow-based hydroprocessed esters and fatty acids (HEFA), Fischer–Tropsch, a blend of HEFA and JP-8, and Fischer–Tropsch doped with tetrahydrothiophene (an organosulfur compound). It was observed that GF and κ increased with fuel sulfur content and engine thrust condition, and decreased with increasing dry particle diameter. The highest GF and κ values were found in the smallest particles, typically those with diameters of 10 nm.

Sign in / Sign up

Export Citation Format

Share Document