Molecular dynamics simulations of branched polyethyleneimine in water-in-heptanol micelles stabilized by zwitterionic surfactants

Poghosyan, Armen H.; Arsenyan, Levon H.; Antonyan, Lilit; Shahinyan, Aram A.; Koetz, Joachim

doi:10.1016/j.colsurfa.2015.03.053

Cited by 15 publications

(11 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The use of coarse-grained MD (CGMD) simulations has in recent times considerably increased thanks to the improvement of the computational power and the accurate understanding of surfactant systems at the molecular scale. Since we now have a better description of the molecular scale, CG models allow to better describe the mesoscale organization of such phases, the molecular properties being taken into account implicitly in effective parameters, for very long times, typically 50 to hundreds of nanoseconds. , Such approaches allow then for accessing dynamical properties of microemulsion phases, in addition to the structure that was already possible with all-atom MD simulations. − Indeed, Gupta et al performed a 100 ns CGMD simulation for studying the transport of solutes across the interface for a series of hexadecane-water interfaces covered by monolayers of nonionic surfactants . In the five last years, a remarkable increase of the simulation times has been achieved, which should become translated into more ambitious calculations.…”

Section: Microemulsions: Entropy Versus Film Packingmentioning

confidence: 99%

Using Microemulsions: Formulation Based on Knowledge of Their Mesostructure

et al. 2021

View full text Add to dashboard Cite

Microemulsions, as thermodynamically stable mixtures of oil, water, and surfactant, are known and have been studied for more than 70 years. However, even today there are still quite a number of unclear aspects, and more recent research work has modified and extended our picture. This review gives a short overview of how the understanding of microemulsions has developed, the current view on their properties and structural features, and in particular, how they are related to applications. We also discuss more recent developments regarding nonclassical microemulsions such as surfactant-free (ultraflexible) microemulsions or ones containing uncommon solvents or amphiphiles (like antagonistic salts). These new findings challenge to some extent our previous understanding of microemulsions, which therefore has to be extended to look at the different types of microemulsions in a unified way. In particular, the flexibility of the amphiphilic film is the key property to classify different microemulsion types and their properties in this review. Such a classification of microemulsions requires a thorough determination of their structural properties, and therefore, the experimental methods to determine microemulsion structure and dynamics are reviewed briefly, with a particular emphasis on recent developments in the field of direct imaging by means of electron microscopy. Based on this classification of microemulsions, we then discuss their applications, where the application demands have to be met by the properties of the microemulsion, which in turn are controlled by the flexibility of their amphiphilic interface. Another frequently important aspect for applications is the control of the rheological properties. Normally, microemulsions are low viscous and therefore enhancing viscosity has to be achieved by either having high concentrations (often not wished for) or additives, which do not significantly interfere with the microemulsion. Accordingly, this review gives a comprehensive account of the properties of microemulsions, including most recent developments and bringing them together from a united viewpoint, with an emphasis on how this affects the way of formulating microemulsions for a given application with desired properties.

show abstract

Section: Microemulsions: Entropy Versus Film Packingmentioning

confidence: 99%

Using Microemulsions: Formulation Based on Knowledge of Their Mesostructure

et al. 2021

View full text Add to dashboard Cite

show abstract

“…However, only a few cases with branching and with only a low-molecular weight (LMW)-PEI were studied. Poghoshan et al carried out MD simulations of hyperbranched PEI inside inverse micelles formed in heptanol . They reported a change in the size of the polymer within the surfactant micelles though it is unclear how they built and connected the starting 3-D atomistic model of their hyperbranched PEI macromolecule.…”

Section: Introductionmentioning

confidence: 99%

pH-Dependent Conformations for Hyperbranched Poly(ethylenimine) from All-Atom Molecular Dynamics

et al. 2018

View full text Add to dashboard Cite

Hyperbranched poly(ethylene imine) (PEI) with its high amino content is a versatile functional polymer that is widely used as a gene delivery vector in biological applications and as a ligand and precursor for ion exchange resins and membranes in water purification and metal recovery. We report here the first fully atomistic model of a 25 kDa hyperbranched PEI macromolecule. We utilized this model to carry out molecular dynamics (MD) simulations with explicit water molecules and chloride ions to study pH-dependent conformational changes. We find that growing the PEI macromolecule sequentially from the monomers yields atomistic structures whose sizes (radius of gyration) are in good agreement with the small angle neutron scattering experiments. Our analysis of the structural properties from MD simulations shows that conformations of the hyperbranched PEI exhibit oblate ellipsoidal elongation at low pH compared to high or neutral pH but with no significant changes in the corresponding sizes. This fully atomistic model of a 25 kDa hyperbranched PEI macromolecule in water provides much needed detailed atomistic information for advancing our fundamental understanding of the structures and host−guest properties of PEI-based functional reagents and materials for biomedical and sustainability related applications.

show abstract

“…The number of molecules for the four components matched the microemulsion composition of 1.44% w/w SDS, 6.49% w/w n -butanol, 0.82% w/w n -heptane, and 91.25% w/w water, as reported by Ishihama et al Using the PACKMOL-generated configuration, MD simulations were performed using GROMACS 5.1.1 (). GROMACS is widely used for molecular simulations and trajectory analysis of biological systems such as proteins, − surfactants, , and lipid systems. − The CHARMM36 force field was used for SDS, n -butanol, and n -heptane molecules, and the TIP3P force field was used for water molecules. The CGenFF software was used for including the atomic structure and atom connections in the CHARMM36 force field library for butanol compound.…”

Section: Methodsmentioning

confidence: 99%

In Silico Prediction of the Thermodynamic Equilibrium of Solute Partition in Multiphase Complex Fluids: A Case Study of Oil–Water Microemulsion

2019

View full text Add to dashboard Cite

Multiphase complex fluids such as micelles, microemulsions, and dispersions are ubiquitous in product formulations of foods, pharmaceuticals, cosmetics, and fine chemicals. Quantifying how active solutes partition in the microstructure of such multiphase fluids is necessary for designing formulations that can optimally deliver the benefits of functional actives. In this paper, we at first predict the structure of a heptane/butanol/sodium dodecyl sulfate droplet in water that self-assembled to form a microemulsion through the molecular dynamics (MD) simulation and subsequently investigate the thermodynamic equilibrium of solute partitioning using COSMOmic. To our knowledge, this is the first time that the MD/COSMOmic approach is used for predicting solute partitioning in a microemulsion. The predicted partition coefficients are compared to experimental values derived from retention measurements of the same microemulsion. We show that the experimental data of droplet–water partition coefficients (K droplet/w) can be reliably predicted by the method that combines MD simulations with COSMOmic.

show abstract

Molecular dynamics simulations of branched polyethyleneimine in water-in-heptanol micelles stabilized by zwitterionic surfactants

Cited by 15 publications

References 38 publications

Using Microemulsions: Formulation Based on Knowledge of Their Mesostructure

Using Microemulsions: Formulation Based on Knowledge of Their Mesostructure

pH-Dependent Conformations for Hyperbranched Poly(ethylenimine) from All-Atom Molecular Dynamics

In Silico Prediction of the Thermodynamic Equilibrium of Solute Partition in Multiphase Complex Fluids: A Case Study of Oil–Water Microemulsion

Contact Info

Product

Resources

About