Micro- and Nano-assembly of Composite Particles by Electrostatic Adsorption

Abstract

This work reports on a novel controlled nanocomposite fabrication technique which is applicable for material design via a micro- and nano-assembly method. The principle is based on the use of electrostatic adsorption of the surface charge-modified particles via layer-by-layer assembly. The polarity and the zeta potential of the surface charge was controlled using polycation and polyanion, while the zeta potential strength was controlled via the number of alternating coating layers which was determined using zeta potential measurement. A systematic study was conducted to demonstrate the feasibility of composite material assembly via electrostatic adsorption using alumina (Al 2 O 3 ) and silica (SiO 2 ) composite as a study model, which was carried out as a function of surface zeta potential, surface coverage percentage, and processing time. The considerable potential of this technique for composite material design is also further demonstrated with controlled assembly involving different materials in various structural forms such as fiber, whisker, nanosheets, and even irregular-shaped foam-like structured urethane. The composite materials designed using this EA method possess good potentials to be utilized for various applications such as mechanical property control, composite ceramic films formation, selective laser sintering, and rechargeable metal-air battery. Electronic supplementary material The online version of this article (10.1186/s11671-019-3129-1) contains supplementary material, which is available to authorized users.

Design of Heat-Conductive hBN–PMMA Composites by Electrostatic Nano-Assembly

“…Then, the oppositely charged PMMA particles (positive) and hBN nanosheets (negative) in aqueous solution were mixed and stirred to obtain the electrostatically assembled hBN/PMMA composite particles. The coverage amount of additive particles (hBN or PMMA) on intended primary particles (PMMA or hBN) was adjusted in vol.% according to previous reported work [14].The suspension was then dried to obtain the composite powder. For the heat distribution evaluation of the hBN/PMMA composite obtained, the composite powders were pressed into pellets using a hot press with a pressure of 100 MPa at 200 • C for 15 min.…”

“…In order to preserve the sheet-like structure of hBN sheets, electrostatic nano-assembly (EA) was used in this study. Previously, our group demonstrated the feasibility of an EA method for fabricating various composite materials [14]. The composites were used for applications such as IR shielding [5], optical property-controlled ceramic composite films [15], selective laser sintering [16], mechanical property control of carbon-based alumina composite [17], and fabrication of the negative electrode for rechargeable Fe-air batteries [18].…”

“…Moreover, the mixing is conducted at room temperature with minimal energy consumption compared to high-energy-consuming equipment such as mechanical ball-milling, heated roller mixing [6], and chemical vapor deposition [10]. The EA method also allows the efficient usage of the raw materials, which helps to reduce wastage due to the good recovery rate of the composites while maintaining the shape and structure of the raw materials [14].…”

Hierarchical Assemblies of Polymer Particles through Tailored Interfaces and Controllable Interfacial Interactions

“…[ 145–147 ] Second, multiscale assemblies by using particles of various length scale can be fabricated by applying one type of particles on the surface of others through electrostatic interactions as well as other interfacial interactions. [ 148 ] In this case, it is possible to tune the size, shape, and density of the assembling particles on the surface of host particles which is useful for tunable assembly product. A third, a single‐step microfluidic formation of the microscale particles and their assemblies with embedded droplets/nanoparticles can be formed by double or triple (multiple) emulsion through droplet‐based microfluidics.…”

Formation of porous Al₂O₃–SiO₂ composite ceramics by electrostatic assembly

“…One solution is to use homogeneously designed precursor composite particles, obtained by electrostatic assembly. This method has been used for feasible controlled composite particles formation, 3) aerosol deposited film with desired optical properties, 4) efficient thermal conductive composite materials 5) and infrared filtering composite materials. 6) In this study, composite particles consisting of alumina (Al 2 O 3 ) and silica (SiO 2 ) with different coverage percentages were fabricated and sintered in order to investigate the feasible formation of porous Al 2 O 3 SiO 2 ceramics without the use of any pore-forming agent.…”