Simulating the binding of organic functional groups to aqueous calcium carbonate species

2021 ◽  
Author(s):  
Alicia Schuitemaker ◽  
Julie Aufort ◽  
Katarzyna B Koziara ◽  
Raffaella Demichelis ◽  
Paolo Raiteri ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Functional Groups ◽  
Organic Molecules ◽  
Organic Functional Groups ◽  
Minerals Processing ◽  
Carbonate Species

The interaction of organic molecules with mineral systems is relevant to a wide variety of scientific problems both in the environment and minerals processing. In this study, the coordination of...

Effect of Ozonation and Hydrogen Peroxide Oxidation on the Structure of Humic Acids and their Removal

2012 ◽  
Vol 610-613 ◽  
pp. 1256-1259 ◽  
Author(s):  
Peng Kang Jin ◽  
Xin Jin ◽  
Xiao Chang Wang ◽  
Fan Bai
Keyword(s):  
Hydrogen Peroxide ◽  
Molecular Weight ◽  
Organic Matter ◽  
Functional Groups ◽  
Humic Acids ◽  
Great Improvement ◽  
Small Dose ◽  
Organic Molecules ◽  
Peroxide Oxidation ◽  
Organic Functional Groups

Using pyrolysis-GC-MS and HPLC techniques, a series of studies were conducted on the effect of pre-oxidation on the structure of natural humic acids (HA) by ozone and hydrogen peroxide (H2O2). Both ozone and H2O2 could more or less result in direct removal of organic matter, but the removal of UV254 was much higher than that of TOC, implying that an important function of the oxidants is to change the structure of the organic molecules rather than to decompose them into inorganic matters. The result of pyrolysis-GC-MS analysis showed that in the process of oxidation, the organic functional groups on the HA molecules underwent a significant change in their structure, mostly from cyclic to chain hydrocarbons and/or from aromatics to aliphatics. This process was also accompanied by a decrease in the molecular weight of the HA. With an apparent change in the structure and molecular weight of the HA molecules after pre-oxidation, a great improvement was seen on the overall removal of TOC as coagulation or GAC adsorption was subsequently applied. Additionally, in the case of H2O2, a small dose of O3 showed much better catalysing effect than Mn2+, Cu2+ or Fe2+ ions.

Hydration Free Energies of Organic Molecules in the FreeSolv Database Calculated with Polarized Atom In Molecules Atomic Charges and the GAFF Force Field.

2018 ◽  
Author(s):  
Maximiliano Riquelme ◽  
Alejandro Lara ◽  
David L. Mobley ◽  
Toon Vestraelen ◽  
Adelio R Matamala ◽  
...  
Keyword(s):  
Force Field ◽  
Functional Groups ◽  
Electrostatic Interactions ◽  
Organic Molecules ◽  
Force Fields ◽  
Chemical Elements ◽  
Atomic Charges ◽  
Free Energies ◽  
Molecular Systems ◽  
Solvent Model

<div>Computer simulations of bio-molecular systems often use force fields, which are combinations of simple empirical atom-based functions to describe the molecular interactions. Even though polarizable force fields give a more detailed description of intermolecular interactions, nonpolarizable force fields, developed several decades ago, are often still preferred because of their reduced computation cost. Electrostatic interactions play a major role in bio-molecular systems and are therein described by atomic point charges.</div><div>In this work, we address the performance of different atomic charges to reproduce experimental hydration free energies in the FreeSolv database in combination with the GAFF force field. Atomic charges were calculated by two atoms-in-molecules approaches, Hirshfeld-I and Minimal Basis Iterative Stockholder (MBIS). To account for polarization effects, the charges were derived from the solute's electron density computed with an implicit solvent model and the energy required to polarize the solute was added to the free energy cycle. The calculated hydration free energies were analyzed with an error model, revealing systematic errors associated with specific functional groups or chemical elements. The best agreement with the experimental data is observed for the MBIS atomic charge method, including the solvent polarization, with a root mean square error of 2.0 kcal mol<sup>-1</sup> for the 613 organic molecules studied. The largest deviation was observed for phosphor-containing molecules and the molecules with amide, ester and amine functional groups.</div>

The Swiss army knife of biological catalysis: A compact toolkit of organic functional groups

Complexity ◽  
2006 ◽  
Vol 11 (3) ◽  
pp. 9-10 ◽  
Author(s):  
Harold J. Morowitz ◽  
Vijayasarathy Srinivasan ◽  
Eric Smith
Keyword(s):  
Functional Groups ◽  
Organic Functional Groups ◽  
Biological Catalysis

Colorimetric methods for determining organic functional groups. II

1969 ◽  
Vol 57 (4) ◽  
pp. 821-825 ◽  
Author(s):  
Walter L. Nazimowitz ◽  
T. S. Ma
Keyword(s):  
Functional Groups ◽  
Organic Functional Groups ◽  
Colorimetric Methods

Styrylsilane coupling reagents for immobilization of organic functional groups on silica and glass surfaces

2018 ◽  
Vol 54 (71) ◽  
pp. 9961-9964 ◽  
Author(s):  
Soo-Bin Kim ◽  
Chang-Hee Lee ◽  
Chul-Ho Jun
Keyword(s):  
Functional Groups ◽  
Coupling Reagents ◽  
Organic Functional Groups ◽  
Glass Surfaces

Styrylsilanes serve as new coupling reagents for introducing organic functional groups on silica and glass surfaces.

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