Organic/inorganic nanocomposites prepared by mechanical smashing of agglomerated silica ultrafine particles in molten thermoplastic resin

Abstract

A new approach for the preparation of organic/inorganic nanocomposites was investigated in which nano-sized silica particles without surface modification were dispersed by the mechanical smashing of strength-controlled porous silica agglomerates in molten resin during direct melt-compounding. The method consists of two stages. The first stage involves preparation of the strength-controlled agglomerated silica nanoparticles with pore structure, and the second stage involves meltcompounding of a thermoplastic resin with the silica agglomerates prepared in the first stage. In the first stage, on the basis of the theory of stability of an aqueous colloidal silica solution, the pore structure and the fracture strength of the silica agglomerate could be controlled by pH-control and electrolyte ion-addition to the colloidal solutions of silica nanoparticles. In the next stage, primary silica nanoparticles could be dispersed in some matrix resins such as a poly(ethylene-ran-vinyl alcohol) and polystyrene uniformly by the proposed mechanical approach by the use of the high shear stress acting on porous silica agglomerates inside these melt-compounded resins. Organic/inorganic nanocomposites 983 Dimensionless Interaction Energy, E T / kT Distance between Two Particle Surfaces, H / nm Conditions of colloidal silica solution KBr-addition pH-control Figure 4. Effects of KBr-addition and pH-control on dimensionless energy versus distance profile of DLVO interaction between two silica particles with d p,Silica ¼ 12 nm at the beginning stage of the evaporation step of aqueous solvent at 353 K. Organic/inorganic nanocomposites 987 Figure 11. SEM micrographs of selected areas of silica nanoparticle-dispersed PS composites (volume fraction of silica, V f,Silica ¼ (a) 0.025, (b) 0.049 and (c) 0.098). Bright spots in the circles are examples of dispersed primary silica particles.

Graphene oxide modified with PMMA via ATRP as a reinforcement filler

“…16,17 In fact, it has been shown that a considerable improvement in polymer nanocomposite mechanical properties can be achieved by adding nanosized fillers, such as SiO 2 and ZnO, at low volume content, i.e. in the range 1-5 vol%, [18][19][20] which is very important due to the high cost of nanosized fillers.…”

Development of Fabrication Methods of Filler/Polymer Nanocomposites: With Focus on Simple Melt-Compounding-Based Approach without Surface Modification of Nanofillers

“…Therefore, the author’s research group has focused on the fracture strength of agglomerates of the dispersed nanoparticles (required stress for the breakdown of the agglomerates into nano-sized primary particles) [60,61,62,63,64,65,66]. For this method, the preparation stage of the strength-controlled agglomerates with a porous structure (the first stage) was combined with the melt-compounding process (the second stage).…”

“…On the basis of the chemistry of colloidal silica [84] and the DLVO (Derjaguin-Landau-Verwey-Overbeek) theory on the stability of a colloidal dispersion system [86,87], the packing structure of the agglomerate was controlled, ensuring open packing with a large amount of porosity. In the following section, the experimental techniques and the main findings of the previous studies carried out by the author and coworkers [60,61,62,63,64] are reviewed together with the results on the dispersion state of silica particles into various polymers by melt-compounding each polymer with the prepared agglomerates.…”

Morphology of the Conducting Poly-N-vinylcarbazole-coated Silica Gel Nanocomposites

“…Tanahashi et al 16 pointed out that the application of nanosized fillers demonstrated the potential to improve the general performance of thermoplastic polymers fundamentally. It has been shown that a considerable improvement of mechanical properties can be achieved by adding a low volume content of nanosized fillers, somewhere in the range of 1 -5 vol %.…”

“…The formation of the conducting PVK with dark green color, in which the polymer chain is formed exclusively by bonds between benzene rings, is possible. [12][13][14][15][16] It has been reported that blending polymer with inorganic materials is considered as a powerful method to produce new materials called polymercomposites or filled polymers. However, due to the significant development in nanotechnologies in the recent years, nanoinorganic materials such as SiO2, Al2O3 and TiO 2 have brought much attention to this research field.…”