Molecular Dynamics and the Water Molecule: An Introduction to Molecular Dynamics for Physical Chemistry Students

1997 ◽  
Vol 74 (11) ◽  
pp. 1350 ◽  
Author(s):  
Enrique Saiz ◽  
Maria Pilar Tarazona
Keyword(s):  
Physical Chemistry ◽  
Molecular Dynamics ◽  
Water Molecule ◽  
Chemistry Students

On the interface of organic aerosols: molecular level understanding of surface melting, mixing and water adsorption/desorption dynamics

2021 ◽  
Author(s):  
Josip Lovrić ◽  
Xiangrui Kong ◽  
Sofia M. Johansson ◽  
Erik S. Thomson ◽  
Jan B. C. Pettersson
Keyword(s):  
Physical Chemistry ◽  
Molecular Dynamics ◽  
Melting Point ◽  
Molecular Beam ◽  
Molecular Level ◽  
Organic Aerosols ◽  
Md Simulations ◽  
Valeric Acid ◽  
Good Representative ◽  
Hydrophilic Character

<p>The detailed description of organic aerosols surfaces in the atmosphere remains an open issue, which limits our ability to understand and predict environmental change. Important research questions concern the hydrophobic/hydrophilic character of fresh and aged aerosols and the related influence on water uptake in solid, liquid as well in intermediate state.  Also, surface characterization remains big challenge but we find it reachable by conjunction of Molecular Dynamics (MD) simulations and the environmental molecular beam (EMB) experimental method.  A  picture of the detailed molecular-level behavior of water molecules on organic surfaces is beginning to rise based on detailed experimental and theoretical studies; one example is a recent study that investigates water interactions with solid and liquid n-butanol near the melting point [1], another example focus on interaction of water with solid nopinone [2]. From the other side, in order to characterize surface properties during and before melting we employ MD simulations of n-butanol, nopinone and valeric acid. Nopinone (C<sub>9</sub>H<sub>14</sub>O) is a reaction product formed during oxidation of β-pinene and has been found in both the gas and particle phases of atmospheric aerosol. n-butanol (C<sub>4</sub>H<sub>9</sub>OH) is primary alcohol, naturally occurs scarcely and here serves as good representative for alcohols. In the same way valeric acid (CH<sub>3</sub>(CH<sub>2</sub>)<sub>3</sub>COOH) serves as a good representative for a family of carboxylic acids. Valeric acid is, as n-butanol, straight-chain molecule. We show that a classical force field for organic material is able to model crystal and liquid structures. The surface properties near the melting point of the condensed phase are reported, and the hydrophobic and hydrophilic character of the surface layer is discussed.  Overall surface melting dynamic is presented and quantified in the terms of structural and geometrical properties. Mixing of a methanol with the solid nopinone surface is examined and hereby presented.</p><p><strong>References</strong></p><p>[1] Johansson, S. M., Lovrić, J., Kong, X., Thomson, E. S., Papagiannakopoulos, P., Briquez, S., Toubin, C, Pettersson, J. B. C. (2019). Understanding water interactions with organic surfaces: environmental molecular beam and molecular dynamics studies of the water–butanol system. Physical Chemistry Chemical Physics. https://doi.org/10.1039/C8CP04151B   </p><p>[2] Johansson, S. M., Lovrić, J., Kong, X., Thomson, E. S., Hallquist, M., & Pettersson, J. B. C. (2020). Experimental and Computational Study of Molecular Water Interactions with Condensed Nopinone Surfaces Under Atmospherically Relevant Conditions. The Journal of Physical Chemistry A, acs.jpca.9b10970. https://doi.org/10.1021/acs.jpca.9b10970</p><p>Keywords: Molecular Dynamics, organic crystal, organic aerosols, water uptake, surface procesess, molecular level</p>

Physical chemistry students discover the computer

1971 ◽  
Vol 48 (5) ◽  
pp. 314 ◽  
Author(s):  
Donald L. Peterson ◽  
Maton E. Fuller
Keyword(s):  
Physical Chemistry ◽  
Chemistry Students

Learning quantum chemistry via a visual-conceptual approach: students' bidirectional textual and visual understanding

2014 ◽  
Vol 15 (3) ◽  
pp. 297-310 ◽  
Author(s):  
Vered Dangur ◽  
Shirly Avargil ◽  
Uri Peskin ◽  
Yehudit Judy Dori
Keyword(s):  
Physical Chemistry ◽  
High School ◽  
High School Students ◽  
Quantum Chemistry ◽  
Undergraduate Students ◽  
Real Life ◽  
Quantum Mechanical ◽  
Chemistry Students ◽  
Undergraduate Chemistry ◽  
Visual Understanding

Most undergraduate chemistry courses and a few high school honors courses, which focus on physical chemistry and quantum mechanics, are highly mathematically-oriented. At the Technion, Israel Institute of Technology, we developed a new module for high school students, titledChemistry – From “the Hole” to “the Whole”: From the Nanoscale to Microelectronics. The module is based on a qualitative approach to teaching quantum chemistry, emphasizing interdisciplinary real-life applications and integration of visualization. While aimed at honors high school chemistry students, the module was also partially implemented and assessed in an undergraduate chemistry course. The research objective was to investigate the effect of the module on the visual and textual understanding of quantum mechanical concepts among 122 honors and 65 volunteer undergraduate chemistry students. The research tools included students' pre- and post-questionnaires. High school honors and undergraduate students, who were exposed to the module, significantly improved their textual and visual understanding of quantum mechanical concepts and their ability to move across illustrations and explanations. Honors and undergraduate students minimized the gap that had existed between them in terms of integrating micro and quantum levels into their post-questionnaire answers. Our findings augment the current set of the four chemistry understanding levels – macro, micro, symbol and process – by adding the quantum mechanical level as a fifth level of chemistry understanding. The study contributes to teaching physical chemistry by providing a tool for learning, assessment, and research of chemistry understandingviaboth visual and textual modes.

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