Dynamic Behavior Of Hydrophobic Molecules In Aqueous Ubder Electric Field

Hydrophobic molecules in water usually produce a series of unexpected phenomena under the influence of hydrophobic interaction.The hydrophobic gas dissolved in the aqueous solution will form a nano-layer at the interface due to the hydrophobic interaction,and the existence of nano-bubbles at the interface is also observed in the experiment.Hydrophobic interaction can also cause hydrophobic collapse of large hydrophobic molecules.A polymer in aqueous solution will fold into a random coil due to hydrophobic interaction.However,while the conformational transformation of the polymer in the aqueous solution will directly affect the properties of the polymer materials.Both during the process of nanobubbles at the interface and the hydrophobic collapse of the polymer,water always exist.Water molecules are polar molecules,the dynamic behavior of water molecules will be affected by external electric field,which affects the absorption of gases and the collapse of polymers.However,it is difficult to understand the effect of electric field on the dynamic behavior of hydrophobic molecules in the water on the molecular scale due to the complexity and uncertainty of the experimental operation.With the development of science and technology,the ability of computer computing has been greatly improved.All-atomic molecular dynamics simulation(MDS)method has become an important means to understand the micro-mechanism at the molecular scale.In the present work,the dynamics behavior of hydrophobic molecules in aqueous environment under electric field at the molecular scale is studied by MDS.The research work is carried out from two main aspects: electric field induced gas dissolution in aqueous solution and interfacial water induced carbon chain unfolding in aqueous solution.Gas dissolution or accumulation regulating in an aqueous environment is important but difficult in in chemistry,physics and biology.Here,we studied the dissolution/accumulation of gas molecules in aqueous solutions by MDS.It was found that the distribution of gas molecules at the solid–water interface is regulated by the direction of the external electric field.Gas molecules attach and accumulate to the interface with an electric field parallel to the interface,while the gas molecules depart and dissolve into the aqueous solutions with a vertical electric field.This finding reveals a new mechanism of regulating gas accumulation and dissolution in aqueous solutions and can have tremendous applications in the synthesis of drugs,the design of microfluidic device,and the extraction of natural gas.The folding and unfolding of the carbon chain,which is the basic constitutional unit of polymers,are important to the performance of the material.However,it is difficult to regulate conformational transition of the carbon chain,especially in an aqueous environment.In this paper,we propose a strategy that can use electric field to regulate the conformational transition of the carbon chain in water based on the MDS.It is shown that the unfolded carbon chain will spontaneously collapse into the folded state,while the folded carbon chain will unfold with an external electric field.The demonstrated method of regulating conformational transition of the carbon chain in water in this study has great potential in drug molecule design and new polymer material development.In summary,the dynamic behavior of hydrophobic molecules in water under electric field is a complex dynamic process.The research work in this paper only takes some different types of hydrophobic molecules as models to discuss the microscopic mechanism of the dynamic behavior of hydrophobic molecules in water under electric field,which provides a new idea for the regulation of hydrophobic molecules in water.