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Investigation of monomolecular organic layers and their interaction with atmospheric oxidants and pollutants
Habartová, Alena ; Jungwirth, Pavel (advisor) ; Jedlovszky, Pal (referee) ; Klán, Petr (referee)
Title: Investigation of monomolecular organic layers and their interaction with atmospheric oxidants and polutants Author: Mgr. Alena Habartová Institute: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic Advisor: prof. Mgr. Pavel Jungwirth, DSc. Abstract: Using classical molecular dynamics simulations, we studied interac- tions between Langmuir monolayers of palmitic acid (PA) and haloalkanes as serious atmospheric pollutants, to model naturally occurring and atmospherical- ly relevant complex surfaces of extended water bodies and aqueous aerosols. We investigated partitioning, orientation, solvation, as well as structure and morphol- ogy of the individual components and their mixture at water/vapor interfaces at different temperatures in order to validate our computational model and com- plement experimental data with molecular-level details. First, we have shown that halocarbon molecules adsorbed on amorphous ice nanoparticles at 100 K remain mostly isolated and do not form aggregates, in contrast to their cluste- ring on cryogenic argon nanoparticles. Next, we report that chloro-, bromo-, and iodoalkanes with short alkyl chains (up to C5) exhibit high preference for the outermost region of the water/vapor interface. Their average residence times of several...
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Investigation of monomolecular organic layers and their interaction with atmospheric oxidants and pollutants
Habartová, Alena ; Jungwirth, Pavel (advisor) ; Jedlovszky, Pal (referee) ; Klán, Petr (referee)
Title: Investigation of monomolecular organic layers and their interaction with atmospheric oxidants and polutants Author: Mgr. Alena Habartová Institute: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic Advisor: prof. Mgr. Pavel Jungwirth, DSc. Abstract: Using classical molecular dynamics simulations, we studied interac- tions between Langmuir monolayers of palmitic acid (PA) and haloalkanes as serious atmospheric pollutants, to model naturally occurring and atmospherical- ly relevant complex surfaces of extended water bodies and aqueous aerosols. We investigated partitioning, orientation, solvation, as well as structure and morphol- ogy of the individual components and their mixture at water/vapor interfaces at different temperatures in order to validate our computational model and com- plement experimental data with molecular-level details. First, we have shown that halocarbon molecules adsorbed on amorphous ice nanoparticles at 100 K remain mostly isolated and do not form aggregates, in contrast to their cluste- ring on cryogenic argon nanoparticles. Next, we report that chloro-, bromo-, and iodoalkanes with short alkyl chains (up to C5) exhibit high preference for the outermost region of the water/vapor interface. Their average residence times of several...
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Molecular simulations unravel preference of haloalkanes for the air/water interface
Habartová, Alena ; Minofar, Babak ; Obisesan, A. ; Roeselová, Martina
Halogenated organics are emitted into the atmosphere from a variety of sources of both natural and anthropogenic origin (Finlayson-Pitts et al., 2000). Their uptake at the surface of aerosols can affect their reactivity, for example in processes which take part in ozone destruction due to production of reactive chlorine, bromine and iodine radicals. This study presents results of molecular dynamic (MD) simulations carried out to investigate the interaction of short-chain haloalkanes with aqueous surfaces. We report on a free energy minimum that the haloalkanes exhibit at the air/water interface.
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