scholarly journals The effect of hydroxyl functional groups and molar mass on the viscosity of non-crystalline organic and organic–water particles

2017 ◽  
Vol 17 (13) ◽  
pp. 8509-8524 ◽  
Author(s):  
James W. Grayson ◽  
Erin Evoy ◽  
Mijung Song ◽  
Yangxi Chu ◽  
Adrian Maclean ◽  
...  
Keyword(s):  
Functional Groups ◽  
Optical Tweezers ◽  
Molar Mass ◽  
Hydroxyl Groups ◽  
Structure Property ◽  
Strong Function ◽  
Oh Groups ◽  
Carbon Backbone ◽  
Structure Property Relationship ◽  
Dry Conditions

Abstract. The viscosities of three polyols and three saccharides, all in the non-crystalline state, have been studied. Two of the polyols (2-methyl-1,4-butanediol and 1,2,3-butanetriol) were studied under dry conditions, the third (1,2,3,4-butanetetrol) was studied as a function of relative humidity (RH), including under dry conditions, and the saccharides (glucose, raffinose, and maltohexaose) were studied as a function of RH. The mean viscosities of the polyols under dry conditions range from 1.5  ×  10−1 to 3.7  ×  101 Pa s, with the highest viscosity being that of the tetrol. Using a combination of data determined experimentally here and literature data for alkanes, alcohols, and polyols with a C3 to C6 carbon backbone, we show (1) there is a near-linear relationship between log10 (viscosity) and the number of hydroxyl groups in the molecule, (2) that on average the addition of one OH group increases the viscosity by a factor of approximately 22 to 45, (3) the sensitivity of viscosity to the addition of one OH group is not a strong function of the number of OH functional groups already present in the molecule up to three OH groups, and (4) higher sensitivities are observed when the molecule has more than three OH groups. Viscosities reported here for 1,2,3,4-butanetetrol particles are lower than previously reported measurements using aerosol optical tweezers, and additional studies are required to resolve these discrepancies. For saccharide particles at 30 % RH, viscosity increases by approximately 2–5 orders of magnitude as molar mass increases from 180 to 342 g mol−1, and at 80 % RH, viscosity increases by approximately 4–5 orders of magnitude as molar mass increases from 180 to 991 g mol−1. These results suggest oligomerization of highly oxidized compounds in atmospheric secondary organic aerosol (SOA) could lead to large increases in viscosity, and may be at least partially responsible for the high viscosities observed in some SOA. Finally, two quantitative structure–property relationship models (Sastri and Rao, 1992; Marrero-Morejón and Pardillo-Fontdevila, 2000) were used to predict the viscosity of alkanes, alcohols, and polyols with a C3–C6 carbon backbone. Both models show reasonably good agreement with measured viscosities for the alkanes, alcohols, and polyols studied here except for the case of a hexol, the viscosity of which is underpredicted by 1–3 orders of magnitude by each of the models.

scholarly journals The effect of adding hydroxyl functional groups and increasing molar mass on the viscosity of organics relevant to secondary organic aerosols

2016 ◽  
Author(s):  
James W. Grayson ◽  
Mijung Song ◽  
Erin Evoy ◽  
Mary Alice Upshur ◽  
Marzieh Ebrahimi ◽  
...  
Keyword(s):  
Linear Relationship ◽  
Functional Groups ◽  
Organic Molecules ◽  
Molar Mass ◽  
Functional Group ◽  
Structure Property ◽  
Carbon Backbone ◽  
Structure Property Relationship ◽  
Experimental Values ◽  
The Relationship

Abstract. In the following we determine the viscosity of four polyols (2-methyl-1,4-butanediol, 1,2,3-butanetriol, 2-methyl-1,2,3,4-butanetetrol, and 1,2,3,4-butanetetrol) and three saccharides (glucose, raffinose and maltohexaose) mixed with water. The polyol studies were carried out to quantify the relationship between viscosity and the number of hydroxyl (OH) functional groups in organic molecules, whilst the saccharide studies were carried out to quantify the relationship between viscosity and molar mass for highly oxidised organic molecules. Each of the polyols was of viscosity less than or equal to ≤ 6.5e2 Pa s, and a linear relationship was observed between log10 (viscosity) and the number of OH functional groups (R2 ≥ 0.99) for several carbon backbones. The linear relationship suggests that viscosity increases by 1–2 orders of magnitude with the addition of an OH functional group to a carbon backbone. For saccharide-water particles, studies at 28 % RH show an increase in viscosity of 3.6–6.0 orders of magnitude as the molar mass of the saccharide is increased from 180 to 342 g mol−1, and studies at 77–80 % RH, show an increase in viscosity 4.6–6.2 orders of magnitude as molar mass increases from 180 to 991 g mol−1. These results suggest oligomerisation of highly oxidised compounds in atmospheric SOM could lead to large increases in viscosity, and may be at least partially responsible for the high viscosities that are observed in some SOM. Finally, two quantitative structure-property relationship models were used to predict the viscosity of the four polyols studied. The model of Sastri and Rao (1992) was determined to over-predict the viscosity of each of the polyols, with the over-prediction being up to 19 orders of magnitude. The viscosities predicted by the model of Marrero-Morejón and Pardillo-Fontdevila (2000) were much closer to the experimental values, with no values differing by more than 1.3 orders of magnitude.

scholarly journals Examining the effect of hydroxyl groups on the thermal properties of polybenzoxazines: using molecular design and Monte Carlo simulation

RSC Advances ◽  
2018 ◽  
Vol 8 (32) ◽  
pp. 18038-18050 ◽  
Author(s):  
Kan Zhang ◽  
Lu Han ◽  
Yijing Nie ◽  
Matthew Louis Szigeti ◽  
Hatsuo Ishida
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Thermal Properties ◽  
Monte Carlo Simulations ◽  
Molecular Interactions ◽  
Molecular Design ◽  
Hydroxyl Groups ◽  
Structure Property ◽  
First Report ◽  
Structure Property Relationship

This article is the first report on understanding the structure-property relationship between molecular interactions and thermal properties of polybenzoxazines by Monte Carlo simulations.

Soil Chemistry

2003 ◽  
Author(s):  
Anthony S. R. Juo ◽  
Kathrin Franzluebbers
Keyword(s):  
Surface Charge ◽  
Functional Groups ◽  
Soil Chemistry ◽  
Chemical Properties ◽  
Hydroxyl Groups ◽  
Oh Groups ◽  
Surface Hydroxyl ◽  
Mineral Structure ◽  
Ph Dependent ◽  
Soil Colloids

Soil chemistry deals with the chemical properties and reactions of soils. It is essentially the application of electrochemistry and colloid chemistry to soil systems. Major topics include surface charge properties of soil colloids, cation and anion sorption and exchange, soil acidity, soil alkalinity, soil salinity, and the effects of these chemical properties and processes on soil biological activity, plant growth, and environmental quality. The ability of the electrically charged surface of soil colloids to retain nutrient cations and anions is an important chemical property affecting the fertility status of the soil. There are two major sources of electrical charges on soil organic and inorganic colloids, namely, permanent or constant charges and variable or pH-dependent charges. Permanent or constant charges are the result of the charge imbalance brought about by isomorphous substitution in a mineral structure of one cation by another of similar size but differing valence (see also section 2.3.2). For example, the substitution of Mg2+ for Al3+ that occurs in Al-dominated octahedral sheets of 2:1 clay minerals results in a negative surface charge in smectite, vermiculite, and chlorite. The excess negative charges are then balanced by adsorbed cations to maintain electrical neutrality. Permanent negative charges of all 2:1 silicate minerals arise from isomorphous substitutions. The l:l-type clay mineral, kaolinite, has only a minor amount of permanent charge due to isomorphic substitution. The negative charges on kaolinite originate from surface hydroxyl groups on the edge of the mineral structure and are pH-dependent. Variable or pH-dependent charges occur on the surfaces of Fe and Al oxides, allophanes, and organic soil colloids. This type of surface charge originates from hydroxyl groups and other functional groups by releasing or accepting H+ ions, resulting in either negative or positive charges. Other functional groups are hydroxyl (OH) groups of Fe and/or Al oxides and allophanes and the COOH and OH groups of soil organic matter. Variable-charge soil colloids bear either a positive or a negative net surface charge depending on the pH of the soil. The magnitude of the charge varies with the electrolyte concentration of the soil solution.

scholarly journals Investigating structure–property relationships of biomineralized calcium phosphate compounds as fluorescent quenching–recovery platform

2018 ◽  
Vol 5 (2) ◽  
pp. 170877 ◽  
Author(s):  
Liuzheng Wang ◽  
Xiang He ◽  
Wei Zhang ◽  
Yong Liu ◽  
Craig E. Banks ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Functional Groups ◽  
Crystalline Structure ◽  
Structure Property ◽  
Property Relationship ◽  
Structure Property Relationships ◽  
Fluorescent Quenching ◽  
Sensing Platform ◽  
Structure Property Relationship ◽  
Phosphate Compounds

The structure–property relationship between biomineralized calcium phosphate compounds upon a fluorescent quenching–recovery platform and their distinct crystalline structure and surficial functional groups are investigated. A fluorescence-based sensing platform is shown to be viable for the sensing of 8-hydroxy-2-deoxy-guanosine in simulated systems.

scholarly journals Viscosity of erythritol and erythritol–water particles as a function of water activity: new results and an intercomparison of techniques for measuring the viscosity of particles

2018 ◽  
Vol 11 (8) ◽  
pp. 4809-4822 ◽  
Author(s):  
Yangxi Chu ◽  
Erin Evoy ◽  
Saeid Kamal ◽  
Young Chul Song ◽  
Jonathan P. Reid ◽  
...  
Keyword(s):  
Functional Groups ◽  
Water Activity ◽  
Optical Tweezers ◽  
Functional Group ◽  
Average Molecular Weight ◽  
Carbon Backbone ◽  
Water Matrix ◽  
Rectangular Area ◽  
Standard Deviations ◽  
Rhodamine B Isothiocyanate

Abstract. A previous study reported an uncertainty of up to 3 orders of magnitude for the viscosity of erythritol (1,2,3,4-butanetetrol)–water particles. To help reduce the uncertainty in the viscosity of these particles, we measured the diffusion coefficient of a large organic dye (rhodamine B isothiocyanate–dextran, average molecular weight ∼70000gmol-1) in an erythritol–water matrix as a function of water activity using rectangular-area fluorescence recovery after photobleaching (rFRAP). The diffusion coefficients were then converted to viscosities of erythritol–water particles using the Stokes–Einstein equation. In addition, we carried out new viscosity measurements of erythritol–water particles using aerosol optical tweezers. Based on the new experimental results and viscosities reported in the literature, we conclude the following: (1) the viscosity of pure erythritol is 184-73+122 Pa s (2 standard deviations); (2) the addition of a hydroxyl (OH) functional group to a linear C4 carbon backbone increases the viscosity on average by a factor of 27-5+6 (2 standard deviations); and (3) the increase in viscosity from the addition of one OH functional group to a linear C4 carbon backbone is not a strong function of the number of OH functional groups already present in the molecule up to the addition of three OH functional groups, but the increase in viscosity may be larger when the linear C4 carbon backbone already contains three OH functional groups. These results should help improve the understanding of the viscosity of secondary organic aerosol particles in the atmosphere. In addition, these results show that at water activity>0.4 the rFRAP technique, aerosol optical tweezers technique, and bead-mobility technique give results in reasonable agreement if the uncertainties in the measurements are considered. At water activity<0.4, the mean viscosity values determined by the optical tweezers technique were higher than those determined by the bead-mobility and rFRAP techniques by 1–2 orders of magnitude. Nevertheless, the disagreement in viscosity measured using multiple techniques reported in this paper is smaller than reported previously.

scholarly journals Viscosity of erythritol and erythritol-water particles as a function of water activity: new results and an intercomparison of techniques for measuring the viscosity of particles

2018 ◽  
Author(s):  
Yangxi Chu ◽  
Erin Evoy ◽  
Saeid Kamal ◽  
Young Chul Song ◽  
Jonathan P. Reid ◽  
...  
Keyword(s):  
Functional Groups ◽  
Water Activity ◽  
Optical Tweezers ◽  
Functional Group ◽  
Average Molecular Weight ◽  
Optical Tweezer ◽  
Carbon Backbone ◽  
Water Matrix ◽  
Standard Deviations ◽  
Rhodamine B Isothiocyanate

Abstract. A previous study reported an uncertainty of up to three orders of magnitude for the viscosity of erythritol (1,2,3,4-butanetetrol) – water particles. To help reduce the uncertainty in the viscosity of these particles, we measured the diffusion coefficient of a large organic dye (rhodamine B isothiocyanate-dextran, average molecular weight ~ 70,000 g mol−1) in erythritol-water matrix as a function of water activity using rectangular area fluorescence recovery after photobleaching (rFRAP). The diffusion coefficients were then converted to viscosities of erythritol-water particles using the Stokes-Einstein equation. In addition, we carried out new viscosity measurements for erythritol-water particles using aerosol optical tweezers. Based on the new experimental results and viscosities reported in the literature, we conclude the following: 1) the viscosity of pure erythritol is 247−107+188 Pa s (two standard deviations), 2) the addition of a hydroxyl (OH) functional group to a linear C4 carbon backbone increases the viscosity on average by a factor of 27−5+6 (two standard deviations), and 3) the increase in viscosity from the addition of one OH functional group to a linear C4 carbon backbone is not a strong function of the number of OH functional groups already present in the molecule up to the addition of three OH functional groups, but the increase in viscosity may be larger when the linear C4 carbon backbone already contains three OH functional groups. These results should help improve the understanding of the viscosity of secondary organic aerosol particles in the atmosphere. In addition, these results show that the rFRAP technique, aerosol optical tweezer technique, and bead-mobility technique give results in reasonable agreement if the uncertainties in the measurements are considered.

Exploration of Bis(Arylimidazole) Iridium Picolinate Complexes

2017 ◽  
Author(s):  
Aron Huckaba ◽  
sadig aghazada ◽  
iwan zimmermann ◽  
giulia grancini ◽  
natalia gasilova ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Photophysical Properties ◽  
Structure Property ◽  
Aryl Group ◽  
Ligand Modification ◽  
Property Relationship ◽  
Structure Property Relationship

The straightforward synthesis and photophysical properties of a new series of heteroleptic Iridium (III) bis(2-arylimidazole) picolinate complexes is reported. Each complex has been characterized by NMR, UV-Vis, cyclic voltammetry, and the emissive properties of each is described. By systematically modifying first the cyclometallating aryl group on the arylimidazole ligand and then the picolinate ligand, the ramifications of ligand modification in these complexes was better understood through the construction of a structure-property relationship.

Exploration of Bis(Arylimidazole) Iridium Picolinate Complexes

2017 ◽  
Author(s):  
Aron Huckaba ◽  
sadig aghazada ◽  
iwan zimmermann ◽  
giulia grancini ◽  
natalia gasilova ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Photophysical Properties ◽  
Structure Property ◽  
Aryl Group ◽  
Ligand Modification ◽  
Property Relationship ◽  
Structure Property Relationship

The straightforward synthesis and photophysical properties of a new series of heteroleptic Iridium (III) bis(2-arylimidazole) picolinate complexes is reported. Each complex has been characterized by NMR, UV-Vis, cyclic voltammetry, and the emissive properties of each is described. By systematically modifying first the cyclometallating aryl group on the arylimidazole ligand and then the picolinate ligand, the ramifications of ligand modification in these complexes was better understood through the construction of a structure-property relationship.

Quantitative Structure-Property Relationship (QSPR) Study of the Hydrophobicity of Phenols and 2-(Aryloxy-a-acetyl)-phenoxathiin Derivatives

2008 ◽  
Vol 59 (11) ◽  
Author(s):  
Adrian Beteringhe ◽  
Ana Cristina Radutiu ◽  
Titus Constantinescu ◽  
Luminita Patron ◽  
Alexandru T. Balaban
Keyword(s):  
Water Solubility ◽  
Molecular Descriptors ◽  
Log P ◽  
Structure Property ◽  
Substituted Phenols ◽  
Reverse Phase ◽  
Aromaticity Index ◽  
Structure Property Relationship ◽  
Layer Chromatography ◽  
Energy Of Formation

In a preceding study, the molecular hydrophobicity (RM0) was determined experimentally from reverse-phase thin-layer chromatography data for several substituted phenols and 2-(aryloxy-a-acetyl)-phenoxathiin derivatives, obtained from the corresponding phenoxides and 2-(a-bromoacetyl)-phenoxathiin. QSPR correlations for RM0 were explored using four calculated molecular descriptors: the water solubility parameter (log Sw), log P, the Gibbs energy of formation (DGf), and the aromaticity index (HOMA). Triparametric correlations do not improve substantially the biparametric correlation of RM0 in terms of log Sw and HOMA.

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