ISSN:
1573-4846
Keywords:
SAXS
;
TEM
;
nanocomposites
;
hybrid materials
;
surface modification
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Transmission electron microscopy (TEM) and small angle X-ray scattering (SAXS) were used to characterize the morphology of thermoplastic nanocomposites. These materials were based on a thermoplastic matrix of a copolymer of methylmethacrylate (MMA) and 2-hydroxyethylmethacrylate (HEMA) with spherical 10 nm silica particles as a filler (filler content 2, 5 and 10 vol%, respectively). Depending on the surface modification of the particles, it was possible to control the aggregation tendency of the primary filler particles. With uncoated particles large aggregates about 100 nm in size could be observed by TEM. For nanocomposites containing particles coated with methacryloxypropyltrimethoxysilane (MPTS), TEM showed that the particles were better dispersed in the polymer matrix only forming aggregates comprised of two or three primary particles. In comparison to the TEM results, the volume weighted particle size distribution calculated from SAXS for the systems with uncoated particles is monomodal and shows particle sizes in the range of primary particles whereas the systems with MPTS coated particles revealed a bimodal size distribution with particle sizes comparable to those measured with TEM. To obtain complete information about the morphology of the nanocomposites above the critical upper limit of detectable scattering vectors (particle sizes 〉50 nm) SAXS has to be supported by TEM, whereas in the nanosize range below the critical limit both methods exhibit an excellent correspondence.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1008602118194
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