Experimento Pelotas Saltarinas
B.J. Basu, V. Hariprakash, S.T. Aruna, R. V Lakshmi, J. Manasa, B.S. Shruthi, Effect of microstructure and surface roughness on the wettability of superhydrophobic sol-gel nanocomposite coatings, J. Sol-Gel Sci. Technol. 56 (2010) 278-286.
C.. van Oss, R.. Good, M.. Chaudhury, The role of van der Waals forces and hydrogen bonds in “hydrophobic interactions” between biopolymers and low energy surfaces, J. Colloid Interface Sci. 111 (1986) 378-390.
C.J. van Oss, Long-range and short-range mechanisms of hydrophobic attraction and hydrophilic repulsion in specific and aspecific interactions, J. Mol. Recognit. 16 (2003) 177-90. doi:10.1002/jmr.618.
Q.-W. Lu, T.R. Hoye, C.W. Macosko, Reactivity of Common Functional Groups with Urethanes: Models for Reactive Compatibilization of Thermoplastic Polyurethane Blends, J. Polym. Sci. Part A Polym. Chem. 40 (2002) 2310-2328.
N. Stobie, B. Duffy, J. Colreavy, P. McHale, S.J. Hinder, D.E. McCormack, Dual-action hygienic coatings: Beneficios de la hidrofobicidad y la liberación de iones de plata para la protección de superficies ambientales y clínicas, J. Colloid Interface Sci. 345 (2010) 286-292.
Química computacional
Tipo de puesto: NOTICIAS EN BREVE. Un equipo de empresas del sector energético liderado por SGP BioEnergy junto con el Gobierno de Panamá han anunciado el desarrollo del mayor centro de producción y distribución de biocombustibles del mundo. Una vez completada en cinco años, la Biorrefinería Ciudad Dorada, ubicada en Colón y Balboa (Panamá), será la mayor plataforma de producción de SAF del mundo, produciendo 180.000 barriles diarios (2.600 millones de galones al año) de biocombustibles avanzados. Comunicado de prensa: “SGP BioEnergy anuncia la mayor instalación de producción de biocombustibles avanzados del mundo”, 18/05/2022. Este proyecto, desarrollado en colaboración con propietarios privados, con la empresa Panama Oil Terminals (POTSA) y con el gobierno de Panamá, reconvertirá las instalaciones existentes que actualmente procesan y almacenan el 70% del fuel-oil del país, en instalaciones de refinado y almacenamiento de biocombustibles derivados de aceites vegetales cultivados con fines específicos, y de grasas y desechos. Reducirá inmediatamente la producción de carbono de
Enlaces de van der waals en polimeros online
In this work we review the most common and powerful molecular simulation techniques for the description of polymers at the atomic and molecular scale, which have been classified as quantum or classical depending on how the interactions between particles are described. Several applications of these methodologies, carried out in our laboratory, are also presented in the context of the study of the structure and properties of polymers. In particular, applications of classical techniques to the determination of crystal structures, to the study of lamellar folding of nylons, to the stability of supramolecular structures observed in some surfactant-polyelectrolyte complexes and to the diffusion of gases in polymeric matrices are shown, while the use of quantum techniques has been illustrated by presenting studies dedicated to the prediction of cooperative effects, specific interactions and spectroscopic parameters.
The most important computational techniques employed to simulate the structure and properties of polymers at the miscroscopic level have been reviewed. They have been classified in quantum or classical methods depending on the expressions used to describe the interactions between the particles. Furthermore, the applicability of such modeling tools is shown with some results recently obtained by our group. More specifically, we show the applicability of classical methods to determine the crystal structure of polymers, to model the lamellar folding of nylons, to predict the stability of the supramolecular structures adopted by some surfactant-polyelectrolite self-assembled complexes and to investigate the diffusion of simple gases through polymeric matrices. The reliability of quantum methods has been illustrated displaying some studies devoted to study cooperative effects, specific interactions and spectroscopic parameters.
Enlaces de van der waals en polimeros en línea
The basic form of the potential energy function in molecular mechanics includes terms (called bonding terms for atomic interactions that are bound by covalent bonds and terms for those non-covalent interactions (called non-bonding terms) that describe the electrostatic interaction of charged groups and the van der Waals force. The specific decomposition of the terms depends on the force field, but a general way to describe the total energy of a force field can be written as the sum of the components:
The term describing the bond and the angle are usually modeled by quadratic energy functions that do not allow for bond breaking. A more realistic description of a covalent bond with high stretching is given by the Morse potential, although it requires more computational resources for its calculation. The form of the function for the dihedral energy is variable from one force field to another. Additionally, “improper torsion” terms can be added to ensure the planarity of aromatic rings and other conjugated systems, as well as “cross” terms describing the coupling of different internal variables such as bond angles and bond lengths. Some force fields even include explicit terms for hydrogen bridges.