Dissipative Particle Dynamics Simulation on Vesicles Self-Assembly Controlled by Terminal Groups

Abstract

Block copolymer vesicles have been widely used in the field of drug delivery, microreactors, and cell membrane mimetics. Introducing terminal groups to the block copolymer can control the structures of vesicles, which is important for improving the application of vesicles. In this paper, the effects of terminal groups on the structure of vesicles were studied by dissipative particle dynamics simulation. We considered different locations, hydrophobicity, and numbers of terminal groups. When the terminal group located at the end of a hydrophobic block, the increase of wall thickness and the decrease of cavity size of vesicles were observed with the hydrophobicity of the terminal group increasing. In contrast, when the terminal group located at the end of the hydrophilic block, with the hydrophobicity of terminal groups increasing, the vesicular cavity size increased but the wall thickness of vesicles remained nearly unchanged. Finally, increasing the number of terminal groups lead to a decrease of cavity size and an increase of wall thickness of vesicles. The hydrophobic changes of polymer molecules are regarded as the origin of the structural changes of vesicles. This simulation study supplies a potential approach that controls the structures of vesicles and is expected to facilitate its further applications.

Quantum Chemical Study of the Carbon Dioxide-Philicity of Surfactants: Effects of Tail Functionalization

“…As shown in Figure 11a,b, CO 2 actually interacts with the fourth carbon atom, which is at the end of the molecule. Based on our previous study, 51,58,64 this structure is detrimental to the stability of reverse micelles in scCO 2 . Therefore, oxidative surfactants have adverse effects on surfactant CO 2 -philicity, while in polymer systems, oxidation is a good way to improve CO 2 -philicity.…”

“…Molecular simulation has recently been widely employed to evaluate the nanoscale interaction among molecules. − Molecular dynamics simulations of the structural properties of various surfactants at the scCO 2 /water interface have shown that fluorinated surfactants can be used as stable cosolvents to disperse nanoparticles in scCO 2 and that the strong electron dipole of the carbon–fluorine bond can improve the CO 2 -philicity of the surfactant. , Stone et al studied the behavior of DiH8 and DiF8 surfactants at the water/CO 2 interface , and found that fluorinated surfactants (DiF8) typically have larger free volumes. According to our preliminary study, the functionalization of the surfactant tail is key to improving the CO 2 -philicity, and the vast majority of surfactants possess alkane chain segments. Although the CO 2 -philicities of surfactants have been studied by molecular dynamics simulation, the relationship between the structural properties of CO 2 -philic surfactants and their interaction strength with CO 2 requires further clarification.…”

“…36,39 Stone et al studied the behavior of DiH8 and DiF8 surfactants at the water/CO 2 interface 49,50 and found that fluorinated surfactants (DiF8) typically have larger free volumes. According to our preliminary study, 51 the functionalization of the surfactant tail is key to improving the CO 2 -philicity, and the vast majority of surfactants possess alkane chain segments. Although the CO 2 -philicities of surfactants have been studied by molecular dynamics simulation, the relationship between the structural properties of CO 2 -philic surfactants and their interaction strength with CO 2 requires further clarification.…”

A Ligand‐Directed Spatial Regulation to Structural and Functional Tunability in Aggregation‐Induced Emission Luminogen‐Functionalized Organic–Inorganic Nanoassemblies

“…In these simulations, the interaction parameter between the same type of beads was fixed at α ii = 25. [ 19 ] Given that all the building units are water insoluble and referring to the hydrophobic parameter (ClogP), [ 20 ] the interaction parameters among PMAO, AIEgens, AuNP, alkylamine, and water were fixed at α BW = 35.0, α CW = 65.0, α GW = 55.0, and α AW = 40.0, and the interaction parameters among PMAO, AIEgens, AuNPs, alkylamine, and chloroform were fixed at α BD = 25.0, α CD = 25.0, α GD = 30.0, and α AD = 25.0. We then set α AC = α BC = α GC = 35.0 to describe the incompatibility among PMAO, alkylamine, AuNPs, and AIEgens, and set α AG = α BG = 30.0 to describe the incompatibility among alkylamine, PMAO, and AuNPs ( Table 1 ).…”

Simulations of morphology control of self‐assembled amphiphilic surfactants

“…Most of the existing studies have focused on understanding equilibrium or near-equilibrium self-assembly. Researchers have identified a number of molecular properties (e.g., chemical identity, 14,15 segment length ratio [15][16][17][18][19][20][21] ) as well as environmental variables (e.g., solvent quality [22][23][24][25][26] ) that give rise to the plethora of self-assembled structures described above. This work has significantly improved our understanding of the fundamental chemistry and physics of amphiphilic self-assembly, and provides invaluable guidance for creating tailor-made structures for desired applications.…”