Polymer nanocomposites morphologies

Keywords Nanocellulose, polymer, nanocomposite, morphology, properties, compatibility,... 

Scanning Electron Microscopy (SEM) and Optical Microscopy In addition to TEM, other types of microscopy can provide details of polymer nanocomposite morphology. With SEM and optical microscopy, the analysis... 

Probing polymer nanocomposite morphology by small angle neutron scattering. Pramana Journal of Physics, 71, 947-952. 

Provided in this chapter is an overview on the fundamentals of polymer nanocomposites, including structure, properties, and surface treatment of the nanoadditives, design of the modifiers, modification of the nanoadditives and structure of modified nanoadditives, synthesis and struc-ture/morphology of the polymer nanocomposites, and the effect of nanoadditives on thermal and fire performance of the matrix polymers and mechanism. Trends for the study of polymer nanocomposites are also provided. This covers all kinds of inorganic nanoadditives, but the primary focus is on clays (particularly on the silicate clays and the layered double hydroxides) and carbon nanotubes. The reader who needs to have more detailed information and/or a better picture about nanoadditives and their influence on the matrix polymers, particularly on the thermal and fire performance, may peruse some key reviews, books, and papers in this area, which are listed at the end of the chapter. 

Samyn, F., Bourbigot, S., Jama, C., Bellayer, S., Nazare, S., Hull, R., Castrovinci, A., and Camino, G. (2008) Crossed characterisation of polymer-layered silicate (PLS) nanocomposite morphology TEM, x-ray diffraction, rheology and solid-state nuclear magnetic resonance measurements, European Polymer Journal 44(6) 1642-1653. 

CNT nanocomposites morphological and structural analysis is often done by TEM but an extensive imaging is required then to ensure a representative view of the material. Moreover, carbon based fillers have very low TEM contrast when embedded in a polymer matrix. The application of microscopy techniques is very useful to control the status of CNTs at any time during the preparation process of CNT/polymer nanocomposites, and moreover, to gain insights on parameters important for a better understanding the performance of the final nanocomposite material based on CNTs. 

Most of the previous studies on flame retardation of polymer nanocomposites are focused on the relationship between macroscopic morphologies of chars and the flammability properties. Fang et al. studied the relationship between evolution of the microstructure, viscoelasticity and graphitization degree of chars and the flammability of polymers during combustion (68). The flame retar-dancy of ABS/clay /MWNTs nanocomposites was strongly affected by the formation of a network structure. Flammability properties... 

Transmission electron spectroscopy (TEM) studies of the co-deposited thin films revealed a continuos polymer phase with a largely inter-dispersed SiOj regions on a 5-50 nm scale, confirming the nanocomposite morphology. As mentioned in section 3.1.3, parylene thin films obtained are typically highly crystalline. In contrast, SiO is an amorphous material. From X-ray diffraction analyses, it was observed that by increasing the relative amount of polymer in the nanocomposite, the crystallinity was... 

Polymer nanocomposites and polymer blends are an extremely important class of materials due to the expected synergistic enhancement of properties and potential multi-functionality. However, the immiscibility of most of the polymers results in poor interfacial interaction between the individual components which severely affects the hnal properties. A deeper insight into the spatial heterogeneity and morphology of the individual components at a microscopic level and their inhuence on the macroscopic properties is important for their rational design (such as choice and volume fraction of individual components, surface chemistry, and processing... 

This chapter reports the results of the literature that concerns the photooxidation of polymer nanocomposites. The published studies concern various polymers (PP, epoxy, ethylene-propylene-diene monomer (EPDM), PS, and so on) and different nanofillers such as organomontmorillonite or layered double hydroxides (LDH) were investigated. It is worthy to note that a specific attention was given to the interactions with various kinds of stabilizers and their efficiency to protect the polymer. One of the main objectives was to understand the influence of the nanofiller on the oxidation mechanism of the polymer and on the ageing of the nanocomposite material. Depending on the types of nanocomposite that were studied, the influence of several parameters such as morphology, processing conditions, and nature of the nanofiller was examined. 

A chapter focusing on the use of nanocomposites in electrochemical devices is presented by Schoonman, Zavyalov, and Pivkina. A wide range of metal (metal ox-ide)/polymer nanocomposites has been synthesized using Al, Sn, Zn, Pd, and Ti as a metal source and poly-para-xylylene (PPX) as a polymeric matrix. The properties of the nanocomposites were studied by comparing structure, morphology, electrical properties, oxidation kinetics, and electrochemical parameters. 

Polymer Nanocomposites The morphology and dispersion state of a filler-like sepiolite (lamella and fiber type) were determined using STEM [66]. 

The first report of TEMT on block copolymer nanostructures, by Spontak [164], appeared in 1988. This was followed by three morphological smdies carried out in the 1990s [165-167]. Only recently has TEMT become more popular in characterizing polymer nanostructures, including block copolymers [134, 164, 167-173], nanocomposites [174, 175], and polymer nanocomposites [176]. Kawase et al. [177] recently presented a protocol to perform complete rotation (i.e., 90°) on a Zr02/polymer nanocomposite, by which they achieved truly quantitative TEMT for the first time. 

The synthesis approaches for fabrication of hollow spheres of different semiconductor materials through irradiation route in large scale and under mild conditions could be of interest for both applications and fundamental studies. Indeed, it has been found that the combination of ionizing radiation and microemulsion can afford more unique conditions to control the composition, morphology, and size of NPs. Compared with other routes of building hollow spheres, radiation chemical approach is a one-step facile and effective method and has potential to produce various inorganic/polymer nanocomposite hollow spheres with potential applications in the fields of materials science and biotechnology. 

Anderson, K. L., Sinsawat, A., Vaia, R. A., and Farmer, B. L., Control of silicate nanocomposite morphology in binary fluids coarse-grained molecular dynamics simulations, J. Polym. Sci. B, 43, 1014-1024(2005). 

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