Synthesis and assembly of nanomaterials under magnetic fields

Abstract

Traditionally, magnetic field has long been regarded as an important means for studying the magnetic properties of materials. With the development of synthesis and assembly methods, magnetic field, similar to conventional reaction conditions such as temperature, pressure, and surfactant, has been developed as a new parameter for synthesizing and assembling special structures. To date, magnetic fields have been widely employed for materials synthesis and assembly of one-dimensional (1D), two-dimensional (2D) or three-dimensional (3D) aggregates. In this review, we aim to provide a summary on the applications of magnetic fields in this area. Overall, the objectives of this review are: (1) to theoretically discuss several factors that refer to magnetic field effects (MFEs); (2) to review the magnetic-field-induced synthesis of nanomaterials; the 1D structure of various nanomaterials, such as metal oxides/sulfide, metals, alloys, and carbon, will be described in detail. Moreover, the MFEs on spin states of ions, magnetic domain and product phase distribution will be also involved; (3) to review the alignment of carbon nanotubes, assembly of magnetic nanomaterials and photonic crystals with the help of magnetic fields; and (4) to sketch the future opportunities that magnetic fields can face in the area of materials synthesis and assembly.

3D hybrid–porous carbon derived from carbonization of metal organic frameworks for high performance supercapacitors

“…The change in the TGA curve shows the evaporation of CO, CO 2 , NO, Zn [21]. The reduced metal Zinc (Boiling point 908 C) is easily vaporized by heating at 950 C and the mass does not change after 950 C [14,15]. Unlike the other MOFs such as Iron series and Cobalt series, Zinc evaporated from the carbon matrix at high temperature played a pore-forming role, leaving a unique pore structure.…”

Cooperative Ordering and Kinetics of Cellulose Nanocrystal Alignment in a Magnetic Field

“…[20][21][22] Given that CNCs are not colloidally stable in such media, coupled with the fact that organic solvents are discouraged in industrial processing, magnetic alignment may offer a more feasible route to produce controllably aligned CNC materials. [23][24][25] Sugiyama et al were the first to show that the magnetic dipole of individual C-O, C-H, and O-H bonds, and their relative orientations in the cellulose polymer chain, led to a material with anisotropic diamagnetic susceptibility. 26 Furthermore, it was observed that the diamagnetic susceptibility is smaller in the direction parallel to the polymer chain axis compared to the perpendicular direction, characterizing cellulose more specifically as a negative diamagnetic anisotropic material.…”

Fabrication and characterization of 1 D Fe3O4/P(NIPAM–MAA–MBA) nanochains with thermo- and pH-responsive shell for controlled release for phenolphthalein

“…), which can be widely applied in biomedical and biotechnological fields such as controlled drug delivery and enzyme immobilization [4][5][6]. Among them, poly(N-isopropylacrylamide) (PNI-PAM) gained much attention because it undergo a phase transition from a hydrophilic, water-swollen state to a hydrophobic, globular state when heated above its volume phase transition temperature (VPTT) at 32°C in water [7][8][9][10][11].…”