Thermodynamics of hydrogen bonding from molecular orbital theory: 1. Water

Wolbach, Jeffrey P.; Sandler, Stanley I.

doi:10.1002/aic.690430622

Cited by 29 publications

(18 citation statements)

References 41 publications

(41 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In their work, the effect of dimerization and trimerization of carboxylic acids in the vapor phase was considered and the solvation between water and carboxylic acid was asserted to be very weak. This assertion was validated by Wolbach and Sandler,27–29 with quantum mechanical ab initio calculations based on the Gibbs energy of formation of acid + acid and acid + water dimerization. It was observed that the acid + acid dimerization is about 100 times stronger than acid + water solvation.…”

Section: Background On Hydrogen Bonding In Carboxylic Acidsmentioning

confidence: 79%

Effect of different isocyanates on the properties of soy‐based polyurethanes

Javni¹,

Zhang²,

Petrovìć³

2003

J of Applied Polymer Sci

151

127

View full text Add to dashboard Cite

New types of polyurethanes were prepared by reacting soybean oil-based polyol and different isocyanates. The polyurethanes can be used as foams, elastomers, coatings, adhesives, etc. Their properties strongly depend on crosslinking density and the structure of isocyanates. Aromatic triisocyanates impart the highest density, glass transition, modulus, and tensile strength, but have the lowest elongation at break, swelling in toluene, and impact resistance. Aliphatic triisocyanates and diisocyanates give rubbery materials with the highest elongation at break, highest swelling, and the lowest tensile strength. Polyurethanes with aromatic and cycloaliphatic diisocyanates were similar in properties, with values between those of the two groups.

show abstract

Section: Background On Hydrogen Bonding In Carboxylic Acidsmentioning

confidence: 79%

Effect of different isocyanates on the properties of soy‐based polyurethanes

Javni¹,

Zhang²,

Petrovìć³

2003

J of Applied Polymer Sci

151

127

View full text Add to dashboard Cite

show abstract

“…Estimation of SAFT parameters from "first principles" (ab-initio calculations, spectroscopy)-establishment of the physical meaning of the equation of state parameters (both those related to the "physical" and the "association" terms). Several attempts in this direction have been reported by Sandler and co-workers [46][47][48][49][50]. 2.…”

Section: Further Future Challengesmentioning

confidence: 99%

Capabilities, limitations and challenges of a simplified PC-SAFT equation of state

Solms

Kouskoumvekaki

Michelsen

et al. 2006

Fluid Phase Equilibria

View full text Add to dashboard Cite

“…Based on these rules, Wolbach and Sandler 56,57 proposed the combining rule given by Equation (8.50) (Chapter 8), which is essentially Elliott's rule for the association strength. It is possible to eliminate one of the two association parameters of SAFT, but typically not both.…”

Section: Estimation Of Association Model Parameters Using Qcmentioning

confidence: 99%

“…Examples of combining rules evaluated are the CR-1 and Elliott's rules, discussed in Chapters 7 and 8 (Equations (7.12) and (8.50)).Details of the two molecular orbital methods (HF and DFT) can be found in Wolbach and Sandler56,57 .Water and alcohols were assumed to form linear dimers, while acids form cyclic dimers.Table 16.3 summarizes the enthalpy and entropy change values for some of the compounds considered. Phase equilibrium calculations with SAFT-type models using association parameters from QC calculations.…”

mentioning

confidence: 99%

Quantum Chemistry in Engineering Thermodynamics

Kontogeorgis

Folas

2009

Thermodynamic Models for Industrial Applications

View full text Add to dashboard Cite

Quantum mechanics (QM) or quantum chemistry (QC) calculations have been extensively used in the past for the calculation of heats of formation and reaction, heat capacities, reaction pathways and transition states. 1 They are currently becoming increasingly popular for estimating phase equilibria and other properties. The starting point in QM, the Schr€ odinger equation, cannot be solved exactly for multielectron systems, and thus approximations are necessary. Deciding upon the method and level that the computations should be made is not a trivial task. Therefore, there are today a number of software packages available for QM calculations, e.g. Gaussian (www.gaussian.com), Schr€ odinger (www.schrodinger.com, distributing the software Jaguar), Turbomole (www.turbomole.com) and Gamess 2 . The packages include various calculation procedures, such as ab initio and density functional methods.The purpose of this chapter is not to review these computational methods, but rather to provide a short presentation and evaluation of certain QM methods which have already found use in engineering applications. For further information on the computational methods, the reader is referred to the references of this chapter, especially the reviews by Sandler and co-workers. 1,3,4 Before presenting the methods that we will highlight in this chapter, it is important to emphasize that QM calculations can be used in different semi-direct or indirect approaches in engineering thermodynamics:1. Calculation of the intermolecular potential from QM and then phase equilibrium calculations using molecular simulation. 2. QM calculations to determine parameters in existing thermodynamic models. 3. The continuum solvation (polarizable) models such as COSMO-RS.The first method will not be discussed in detail in this chapter. It is currently computationally very intensive and limited to rather simple molecules. It has been used to calculate the second virial coefficients and VLE of a few molecules and systems such as methyl fluoride, methanol, acetonitrile and methanol-hydrogen fluoride. The agreement is best for the simpler molecules but for hydrogen bonding compounds such as methanol and hydrogen fluoride, corrections are required. This may be due to the fact that for hydrogen bonding molecules,

show abstract

Thermodynamics of hydrogen bonding from molecular orbital theory: 1. Water

Cited by 29 publications

References 41 publications

Effect of different isocyanates on the properties of soy‐based polyurethanes

Effect of different isocyanates on the properties of soy‐based polyurethanes

Capabilities, limitations and challenges of a simplified PC-SAFT equation of state

Quantum Chemistry in Engineering Thermodynamics

Contact Info

Product

Resources

About