scholarly journals Predicting the glass transition temperature and viscosity of secondary organic material using molecular composition

2018 ◽  
Vol 18 (9) ◽  
pp. 6331-6351 ◽  
Author(s):  
Wing-Sy Wong DeRieux ◽  
Ying Li ◽  
Peng Lin ◽  
Julia Laskin ◽  
Alexander Laskin ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Chemical Composition ◽  
Organic Compounds ◽  
Molar Mass ◽  
Solid Phase ◽  
Amorphous Solid ◽  
Semi Solid ◽  
Oxygen Atoms

Abstract. Secondary organic aerosol (SOA) accounts for a large fraction of submicron particles in the atmosphere. SOA can occur in amorphous solid or semi-solid phase states depending on chemical composition, relative humidity (RH), and temperature. The phase transition between amorphous solid and semi-solid states occurs at the glass transition temperature (Tg). We have recently developed a method to estimate Tg of pure compounds containing carbon, hydrogen, and oxygen atoms (CHO compounds) with molar mass less than 450 g mol−1 based on their molar mass and atomic O : C ratio. In this study, we refine and extend this method for CH and CHO compounds with molar mass up to ∼ 1100 g mol−1 using the number of carbon, hydrogen, and oxygen atoms. We predict viscosity from the Tg-scaled Arrhenius plot of fragility (viscosity vs. Tg∕T) as a function of the fragility parameter D. We compiled D values of organic compounds from the literature and found that D approaches a lower limit of ∼ 10 (±1.7) as the molar mass increases. We estimated the viscosity of α-pinene and isoprene SOA as a function of RH by accounting for the hygroscopic growth of SOA and applying the Gordon–Taylor mixing rule, reproducing previously published experimental measurements very well. Sensitivity studies were conducted to evaluate impacts of Tg, D, the hygroscopicity parameter (κ), and the Gordon–Taylor constant on viscosity predictions. The viscosity of toluene SOA was predicted using the elemental composition obtained by high-resolution mass spectrometry (HRMS), resulting in a good agreement with the measured viscosity. We also estimated the viscosity of biomass burning particles using the chemical composition measured by HRMS with two different ionization techniques: electrospray ionization (ESI) and atmospheric pressure photoionization (APPI). Due to differences in detected organic compounds and signal intensity, predicted viscosities at low RH based on ESI and APPI measurements differ by 2–5 orders of magnitude. Complementary measurements of viscosity and chemical composition are desired to further constrain RH-dependent viscosity in future studies.

scholarly journals Predicting the glass transition temperature and viscosity of secondary organic material using molecular composition

2017 ◽  
Author(s):  
Wing-Sy Wong DeRieux ◽  
Ying Li ◽  
Peng Lin ◽  
Julia Laskin ◽  
Alexander Laskin ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Chemical Composition ◽  
Organic Compounds ◽  
Molar Mass ◽  
Solid Phase ◽  
Amorphous Solid ◽  
Semi Solid ◽  
Oxygen Atoms

Abstract. Secondary organic aerosols (SOA) account for a large fraction of submicron particles in the atmosphere. SOA can occur in amorphous solid or semi-solid phase states depending on chemical composition, relative humidity (RH), and temperature. The phase transition between amorphous solid and semi-solid states occurs at the glass transition temperature (Tg). We have recently developed a method to estimate Tg of pure compounds containing carbon, hydrogen, and oxygen atoms (CHO compounds) with molar mass less than 450 g mol−1 based on their molar mass and atomic O : C ratio. In this study, we refine and extend this method for CH and CHO compounds with molar mass up to ~ 1100 g mol−1 using the number of carbon, hydrogen, and oxygen atoms. We predict viscosity from the Tg-scaled Arrhenius plot of fragility (viscosity vs. Tg / T) as a function of the fragility parameter D. We compiled D values of organic compounds from literature, and found that D approaches a lower limit of ~ 10 (±1.7) as the molar mass increases. We estimated viscosity of α-pinene and isoprene SOA as a function of RH by accounting for hygroscopic growth of SOA and applying the Gordon-Taylor mixing rule, reproducing previously published experimental measurements very well. Sensitivity studies were conducted to evaluate impacts of Tg, D, hygroscopicity parameter (κ), and the Gordon-Taylor constant on viscosity predictions. Viscosity of toluene SOA was predicted using the elemental composition obtained by high-resolution mass spectrometry (HRMS), resulting in a good agreement with the measured viscosity. We also estimated viscosity of biomass burning particles using the chemical composition measured by HRMS with two different ionization techniques: electrospray ionization (ESI) and atmospheric pressure photoionization (APPI). Due to differences in detected organic compounds and signal intensity, predicted viscosities at low RH based on ESI and APPI measurements differ by 2–5 orders of magnitude. Complementary measurements of viscosity and chemical composition are desired to further constrain RH-dependent viscosity in future studies.

Hot-Melt Adhesives: Fundamentals, Formulations, and Applications: A Critical Review

2020 ◽  
Vol 8 (1) ◽  
pp. 1-28
Author(s):  
Swaroop Gharde ◽  
Gaurav Sharma ◽  
Balasubramanian Kandasubramanian
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Organic Compounds ◽  
Processing Speed ◽  
Critical Review ◽  
Volatile Organic ◽  
Industrial Use ◽  
Melt Adhesives ◽  
Hot Melt

Hot-Melt Adhesives (HMAs) are typically used in applications where instant sealing is critically required. HMAs are generally preferred for those applications where processing speed is critical. These materials are widely used in various engineering applications, mainly as sealants in leakages and crack filling of walls and roofs. The industrial use of HMAs is most common in glassware and automobiles for gluing glasses in buildings and bonding heavy motor parts. The formulation of HMAs contains a polymer of suitable nature that makes the base for a strong adhesive, and waxes are added to increase the settling time of adhesive. The tackifiers are used to dilute the polymer to adjust the Glass Transition Temperature (Tg) and to reduce the viscosity for proper flow of hot-melt. This review intends to comprehensively discuss the preparation and formulations of HMAs using various polymer matrices, along with their applications and mechanics. The designing of green HMAs has been discussed in the literature and have been promoted over conventional solvent-based HMAs due to their functionality without Volatile Organic Compounds (VOCs). Various measures, challenges, and resolutions for making hazard-free HMAs have been discussed in the present review.

scholarly journals Predictions of the glass transition temperature and viscosity of organic aerosols from volatility distributions

2020 ◽  
Vol 20 (13) ◽  
pp. 8103-8122 ◽  
Author(s):  
Ying Li ◽  
Douglas A. Day ◽  
Harald Stark ◽  
Jose L. Jimenez ◽  
Manabu Shiraiwa
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Organic Compounds ◽  
Transport Model ◽  
Organic Aerosols ◽  
Chemical Transport ◽  
Basis Set ◽  
Southeastern Us ◽  
Sulfur Containing

Abstract. Volatility and viscosity are important properties of organic aerosols (OA), affecting aerosol processes such as formation, evolution, and partitioning of OA. Volatility distributions of ambient OA particles have often been measured, while viscosity measurements are scarce. We have previously developed a method to estimate the glass transition temperature (Tg) of an organic compound containing carbon, hydrogen, and oxygen. Based on analysis of over 2400 organic compounds including oxygenated organic compounds, as well as nitrogen- and sulfur-containing organic compounds, we extend this method to include nitrogen- and sulfur-containing compounds based on elemental composition. In addition, parameterizations are developed to predict Tg as a function of volatility and the atomic oxygen-to-carbon ratio based on a negative correlation between Tg and volatility. This prediction method of Tg is applied to ambient observations of volatility distributions at 11 field sites. The predicted Tg values of OA under dry conditions vary mainly from 290 to 339 K and the predicted viscosities are consistent with the results of ambient particle-phase-state measurements in the southeastern US and the Amazonian rain forest. Reducing the uncertainties in measured volatility distributions would improve predictions of viscosity, especially at low relative humidity. We also predict the Tg of OA components identified via positive matrix factorization of aerosol mass spectrometer (AMS) data. The predicted viscosity of oxidized OA is consistent with previously reported viscosity of secondary organic aerosols (SOA) derived from α-pinene, toluene, isoprene epoxydiol (IEPOX), and diesel fuel. Comparison of the predicted viscosity based on the observed volatility distributions with the viscosity simulated by a chemical transport model implies that missing low volatility compounds in a global model can lead to underestimation of OA viscosity at some sites. The relation between volatility and viscosity can be applied in the molecular corridor or volatility basis set approaches to improve OA simulations in chemical transport models by consideration of effects of particle viscosity in OA formation and evolution.

Design of Lubricants Using Waste Slag in Large Strain Addition Strip Processing for Ultrafine-Grained Steels

2006 ◽  
Vol 512 ◽  
pp. 319-324 ◽  
Author(s):  
Masashi Nakamoto ◽  
Joon Ho Lee ◽  
Toshihiro Tanaka
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Solid Phase ◽  
Large Strain ◽  
High Hardness ◽  
Municipal Waste ◽  
Hydrothermal Conditions ◽  
Ultrafine Grained

Aiming to design new lubricants in the large strain addition strip process for ultrafine-grained steels, we tested the possibility of using waste slag, which is generated largely from iron and steelmaking processes, municipal waste treatments and so on. We then focused our attention on the slag containing water as the new lubricant. Slag satisfies the requirement of biting the workpiece stably, which cannot be achieved with conventional lubricants, because slag is stable as a solid phase of high hardness at the biting temperature in the strip process (100~200oC). In addition, slag contains water under hydrothermal conditions to provide lubricating effects by lowering glass transition temperature. In the present study, the effect of additive components (Al2O3, B2O3, CaO, MgO, K2O, Li2O and V2O5) on the glass transition temperature of a SiO2-Na2O-based slag containing water was examined. The glass transition temperature of the slag containing water is 150~300 oC, which is lower than that of original slag. It was also found that the glass transition temperature depends on the additive components to the slag.

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