[PHYS-09]Casein-stabilized emulsions: effect of crosslinking density

Sodium caseinate (SC) particles of different crosslinking density are synthesized and used as emulsifiers. It turns out crosslinking SC decreased its interfacial ability, forming emulsions with larger droplets. When combined with oleophilic surfactants, SC can be used to stabilize double emulsions (DEs). SC with a higher crosslinking density tends to form DEs of better storage stability in terms of the preservation of double droplets.

Continue reading

[PHYS-08]Parametrization of flexible polarizable water model using genetic algorithm

Electronic polarizability is crucial for simulating interfacial systems in presence of ions. One of the most popular polarizable water model, based on Drude oscillators, is SWM4-NDP.1 However, being a rigid water model, it cannot be directly used to calculate vibration spectra or participate in reactions. In this work, we use a genetic algorithm to optimize polarizable flexible water models with Drude oscillators. Our current best water model has good accurate thermodynamic and transport properties such as the dielectric constant, solvation free energy of water, and self-diffusion constant.

Continue reading

[PHYS-07]Ion transport in microporous anion exchange membranes

Anion exchange membrane (AEM) fuel cell is a leading candidate to replace the aging alkaline fuel cell technology and a much cheaper alternative to proton exchange membrane fuel cell because of the possible utilization of nonnoble catalysts. A major challenge of using AEMs is the trade-off between conductivity and chemical/mechanical stability.1 Using diblock copolymers that combine the properties of different polymer blocks is a promising solution. In our research, we investigate crosslinked diblock copolymers with incorporating polymer of intrinsic microporosity by molecular dynamics simulation to understand the mechanism(s) of charge transport in these membranes.

Continue reading

[PHYS-06]Hindered diffusion near fluid-solid interfaces

We carried out molecular dynamics (MD) simulations to calculate the hindered diffusion constants of particle as a function of distance from the wall and then we compared our results with the classical hydrodynamics calculations by Brenner and Faxen. We showed that the diffusion constants in the perpendicular direction calculated in MD is roughly consistent with the hydrodynamic results by Brenner. However, the discrepancy grows as the particle gets very close to the wall where molecular details matter. We found that there is an underlying difference in the interaction range of wall interaction with the particle predicted by MD and hydrodynamics.

Continue reading

[ORG-16]Octabenzo[8]circulene-based network for application in lithium ion battery

This study explores a new type of carbon-rich material, which is constructed by linking negatively curved nanographene into a covalent network and thus can in some degree mimic theoretical carbon schwarzites for application in lithium ion batteries. The negatively curved nanographene studied herein is octabenzo[8]circulene, which is found to possess excellent symmetry as well as two-dimensional π-π interaction. Polymerization of the tetrabromo derivative of octabenzo[8]circulene by the nickel-mediated Yamamoto coupling reaction enables a new carbon-rich anode material for lithium ion batteries, which exhibits a discharge capacity as high as 830 mAh·g−1 with 74% retention after 100 cycles.

Continue reading

[ORG-15]Synthetic studies of low-symmetry phthalocyanines with cleavable linkers

We report herein methodological studies to prepare a series of isomerically pure phthalocyanines with various symmetries (e.g. D2h, C2h, C2v, and Cs) in a controlled manner using cleavable linkers, and the resulting deprotected analogues with free functional groups which enable further functionalization. The structural and spectroscopic features of these interesting compounds will also be reported and discussed in this presentation.

Continue reading