In Situ SAXS Measurement and Molecular Dynamics Simulation of Magnetic Alignment of Hexagonal LLC Nanostructures

Abstract

The alignment of nanostructures in materials such as lyotropic liquid crystal (LLC) templated materials has the potential to significantly improve their performances. However, accurately characterising and quantifying the alignment of such fine structures remains very challenging. In situ small angle X-ray scattering (SAXS) and molecular dynamics were employed for the first time to understand the hexagonal LLC alignment process with magnetic nanoparticles under a magnetic field. The enhanced alignment has been illustrated from the distribution of azimuthal intensity in the samples exposed to magnetic field. Molecular dynamics simulations reveal the relationship between the imposed force of the magnetic nanoparticles under magnetic field and the force transferred to the LLC cylinders which leads to the LLC alignment. The combinational study with experimental measurement and computational simulation will enable the development and control of nanostructures in novel materials for various applications.

Controlling Anti-Penetration Performance by Post-Grafting of Fluorinated Alkyl Chains onto Polystyrene-block-poly(vinyl methyl siloxane)

“…Factors such as weight fractions of PS and PDMS, , solvents’ selectivity, plasticizers, and topologies of block polymers of PS and PDMS were reported to significantly affect the morphology. , For this study, we focus on the influence of the fluorinated alkyl chain length on the morphology of PS- b -PVMS. As shown in Figure b, the SAXS profile of PS- b -PVMS shows that its morphology matches that of hexagonally packed cylinders (HEX) as the relative values of q / q * are 1, √4, and √7, which are the (1,0), (2,0), and (2,1) peaks of the hexagonal lattice, respectively . For PS- b -P­(CF 3 -VMS), its SAXS profile shows more peaks with q / q * of 1, √3, √4, √7, √9, and √13, which are the (1,0), (1,1), (2,0), (2,1), (3,0), and (3,1) peaks of a HEX, respectively .…”

“…As shown in Figure 3b, the SAXS profile of PS-b-PVMS shows that its morphology matches that of hexagonally packed cylinders (HEX) as the relative values of q/q* are 1, √4, and √7, which are the (1,0), (2,0), and (2,1) peaks of the hexagonal lattice, respectively. 59 For PS-b-P(CF 3 -VMS), its SAXS profile shows more peaks with q/q* of 1, √3, √4, √7, √9, and √13, which are the (1,0), (1,1), (2,0), (2,1), (3,0), and (3,1) peaks of a HEX, respectively. 60 Compared with PSb-PVMS, the SAXS results show that PS-b-P(CF 3 -VMS) has a morphology of more ordered HEX, which may be explained by the limitation of the flexibility of the PVMS backbone after the introduction of CF 3 that can limit the deformation of its microdomain.…”

Mathematical Simulation of Nanofiltration Process: State of Art Review

“…As in the case of CFD, the molecular dynamics methods require a significant number of calculations, therefore, for its effective application, it is reasonable to use special software. In the considered period, the most applied program products include GROMACS 94,[120][121][122][123][124] , NAMD 125,126 , and Materials Studio 119,127 . Also, for the force field analysis, such software as OPLS 121,124 , CHARMM 126 , and COMPASS 119 was used.…”

“…In the considered period, the most applied program products include GROMACS 94,[120][121][122][123][124] , NAMD 125,126 , and Materials Studio 119,127 . Also, for the force field analysis, such software as OPLS 121,124 , CHARMM 126 , and COMPASS 119 was used.…”

“…In addition to the above-mentioned study 120 , the potential of Lennard-Jones was considered by Sofos et al 131 It has been noted by the authors previously 7 that CBM methods are often used to account for the influence of membrane materials. In the considered period during the NF process simulation, in some works, several materials were investigated, including cellulose derivatives 122 , polybenzimidazole 124 , and novel materials such as graphene 120,125 , liquid crystals 126 , and the membranes from nanotubes 127 .…”