Structure and Properties of Multiwall Carbon Nanotubes/Polystyrene Composites Prepared via Coagulation Precipitation Technique

Abstract

Coagulation technique was applied for preparation of multiwall carbon nanotube- (MWNT-)containing polystyrene (PSt) composite materials with different MWNT loading (0.5–10 wt.%). Scanning and transmission electron microscopies were used for investigation of the morphology and structure of produced composites. It was shown that synthesis of MWNT/PSt composites using coagulation technique allows one to obtain high dispersion degree of MWNT in the polymer matrix. According to microscopy data, composite powder consists of the polystyrene matrix forming spherical particles with diameter ca. 100–200 nm, and the surface of MWNT is strongly wetted by the polymer forming thin layer with 5–10 nm thickness. Electrical conductivity of MWNT/PSt composites was investigated using a four-probe technique. Observed electrical percolation threshold of composite materials is near to 10 wt.%, mainly due to the insulating polymer layer deposited on the surface of nanotubes. Electromagnetic response of prepared materials was investigated in broadband region (0.01–4 and 26–36 GHz). It was found that MWNT/PSt composites are almost radiotransparent for low frequency region and possess high absorbance of EM radiation at higher frequencies.

Anisotropic thermal conductivity of polypropylene composites filled with carbon fibers and multiwall carbon nanotubes

“…The preparation of the CF/MWNT composite in PP was performed by coagulation precipitation technique as follows. A calculated amount of milled CFs and MWNTs was placed into a PP solution in o ‐xylene with PP concentration 10 wt% with a filler concentration 100 g/l.…”

Influence of Carbon Nanotube Spatial Distribution on Electromagnetic Properties of Nanotube–Polymer Composites

“…Modeling the adhesion of PMMA and PE matrices to the MWCNT surface using HyperChem 8.0 (molecular mechanics, MM þ force field) showed that adhesion of the PE matrix is 1.5-2 times higher as compared to the PMMA matrix. This provides a more uniform distribution of nanotubes, which is achieved in the case of the PE matrix [29] ( Figure 1H). The optical microscopy images show the initial nanotubes are mostly distributed uniformly within the PE matrix, without a significant number of aggregates, while the milled nanotubes show even a relatively greater number of the observed MWCNT aggregates.…”

Influence of mixing methods on the properties of high density polyethylene nanocomposites with different carbon nanoparticles

“…Due to its low viscosity, the method tends to facilitate the dispersion of nanoparticles in the polymer matrix, which may or may not be associated with high energy sonication devices, and mechanical agitation to promote exfoliation/dispersion of nanoparticles and assist in achieving a state of homogeneous dispersion. This method has been very efficient in dispersing nanoparticles, but in general, large quantities of solvent compared to the mass of the nanocomposite obtained are required [4,5]. In addition, from the best of our knowledgement, there are a few works that had prepared nanocomposites using solution mixing techniques [6][7][8][9][10] with HDPE as a matrix, very probably due to time consumption of the method and the fact that organic solvents in general are employed.…”