Monte Carlo simulations are performed to study the phase diagram of liquid crystals formed by bent-core molecules with a strong transverse dipole moment deviating from their angular bisector.The results show that the ...Monte Carlo simulations are performed to study the phase diagram of liquid crystals formed by bent-core molecules with a strong transverse dipole moment deviating from their angular bisector.The results show that the strong dipolar interaction,after suppressing uniaxial phases,encourages biaxiality,which leads to a Landau point or even to a Landau line in the phase diagram,inducing a more stable biaxial nematic phase.It is also found that a deviation of dipole moment from the angular bisector also suppresses uniaxiality in the small bend-angle regime.展开更多
We present the results of molecular dynamics simulations of net positively charged fullerene nanoparticles in salt- free and salt-added solution. The aggregation of fullerene （C60）-like nanoparticle and counterion a...We present the results of molecular dynamics simulations of net positively charged fullerene nanoparticles in salt- free and salt-added solution. The aggregation of fullerene （C60）-like nanoparticle and counterion are studied in detail as a function of temperatures and a finite salt concentration. Our simulations show that the strong conformation changes as temperature changes. The net positively-charged nanoparticles do not repel each other but are condensed under proper temperatures. If salts are added, the aggregated nanoparticles will be disaggregated due to the Debye screening effect.展开更多
Stretched polymers will lose their possible configurations if they are mixed with nanoparticles or touch a hard wall, which leads to a strong depletion attraction responsible for the enrichment of nanoparticles near s...Stretched polymers will lose their possible configurations if they are mixed with nanoparticles or touch a hard wall, which leads to a strong depletion attraction responsible for the enrichment of nanoparticles near substrates. Moreover, it is found that there exists a sacrifice mechanism in confined pure polymer samples or polymer-nanoparticle mixtures, that part of the polymers, in order to reach a minimum free energy for the total system, are adsorbed on hard walls even though they lose their conformation. The current study provides a simple yet effective approach for the design of thin polymer composites.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 10974162 and 11074208.
文摘Monte Carlo simulations are performed to study the phase diagram of liquid crystals formed by bent-core molecules with a strong transverse dipole moment deviating from their angular bisector.The results show that the strong dipolar interaction,after suppressing uniaxial phases,encourages biaxiality,which leads to a Landau point or even to a Landau line in the phase diagram,inducing a more stable biaxial nematic phase.It is also found that a deviation of dipole moment from the angular bisector also suppresses uniaxiality in the small bend-angle regime.
基金Project supported by the Natural Science Foundation of Fujian Province of China(Grant No.2012J05008)
文摘We present the results of molecular dynamics simulations of net positively charged fullerene nanoparticles in salt- free and salt-added solution. The aggregation of fullerene （C60）-like nanoparticle and counterion are studied in detail as a function of temperatures and a finite salt concentration. Our simulations show that the strong conformation changes as temperature changes. The net positively-charged nanoparticles do not repel each other but are condensed under proper temperatures. If salts are added, the aggregated nanoparticles will be disaggregated due to the Debye screening effect.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10974162 and 11074208)
文摘Stretched polymers will lose their possible configurations if they are mixed with nanoparticles or touch a hard wall, which leads to a strong depletion attraction responsible for the enrichment of nanoparticles near substrates. Moreover, it is found that there exists a sacrifice mechanism in confined pure polymer samples or polymer-nanoparticle mixtures, that part of the polymers, in order to reach a minimum free energy for the total system, are adsorbed on hard walls even though they lose their conformation. The current study provides a simple yet effective approach for the design of thin polymer composites.
