@article{PoghosyanArsenyanShahinyanetal.2016, author = {Poghosyan, Armen H. and Arsenyan, Levon H. and Shahinyan, Aram A. and Koetz, Joachim}, title = {Polyethyleneimine loaded inverse SDS micelle in pentanol/toluene media}, series = {Colloids and surfaces : an international journal devoted to the principles and applications of colloid and interface science ; A, Physicochemical and engineering aspects}, volume = {506}, journal = {Colloids and surfaces : an international journal devoted to the principles and applications of colloid and interface science ; A, Physicochemical and engineering aspects}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0927-7757}, doi = {10.1016/j.colsurfa.2016.07.018}, pages = {402 -- 408}, year = {2016}, abstract = {An atomic scale molecular dynamics simulation (100 ns) was carried out to reveal the conformational features of a cationic polyelectrolyte, i.e., hyperbranched polyethyleneimine (PEI), inside of water-in-oil microemulsion droplets stabilized by the anionic sodium dodecyl sulfate surfactant (SDS) layer. Simulations show that the polymer reorients very quickly and is localized at the headgroup region, i.e., the polymer nitrogens are close to SDS sulfur atoms. In spite of the availability of surface roughness caused by the polymer, we track a stable inverse micelle during the production run. In overall, the obtained parameters are well compared with experimental findings. (C) 2016 Elsevier B.V. All rights reserved.}, language = {en} } @article{PoghosyanArsenyanAntonyanetal.2015, author = {Poghosyan, Armen H. and Arsenyan, Levon H. and Antonyan, Lilit A. and Shahinyan, Aram A. and Koetz, Joachim}, title = {Molecular dynamics simulations of branched polyethyleneimine in water-in-heptanol micelles stabilized by zwitterionic surfactants}, series = {Colloids and surfaces : an international journal devoted to the principles and applications of colloid and interface science ; A, Physicochemical and engineering aspects}, volume = {479}, journal = {Colloids and surfaces : an international journal devoted to the principles and applications of colloid and interface science ; A, Physicochemical and engineering aspects}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0927-7757}, doi = {10.1016/j.colsurfa.2015.03.053}, pages = {18 -- 24}, year = {2015}, abstract = {We have performed a 50 ns molecular dynamics simulation of a hyperbranched polymer, i.e. polyethyleneimine (PEI), inside inverse micelles formed with zwitterionic surfactants 3-(N, N-dimethyldodecylammoniio)-propansulfonate (SB) in heptanol. The runs were performed using the GROMACS simulation package. During simulation time the PEI molecule undergoes a conformational deformation and compaction. The radius of gyration of the PEI molecule finally located in the center of the water droplet is decreased from 3 nm to 1.7 nm. The unusual shrinking of the PEI molecule inside the micelle explains the extraordinary template effect of these microemulsions by making cadmium sulfide or gold clusters. (C) 2015 Elsevier B.V. All rights reserved.}, language = {en} }