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Synthetic, layered nano-particles for polymeric nanocomposites (PNC's)Utracki, L. A.; Sepehr, M.; Boccaleri, E.Contact us / Contactez nous: nparc.cisti@nrc-cnrc.gc.ca.http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=fr L'accès à ce site Web et l'utilisation de son contenu sont assujettis aux conditions présentées dans le site Web page / page Web http://dx.doi.org/10.1002/pat.852 http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?action=rtdoc&an=15774991&lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?action=rtdoc&an=15774991&lang=fr LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D'UTILISER CE SITE WEB. READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE.Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en This review discusses preparation and use of the synthetic layered nanoparticles in polymer matrices, i.e., in the polymeric nanocomposites (PNCs). Several types of synthetic or semi-synthetic layered materials are considered, namely the phyllosilicates (clays), silicic acid (magadiite), layered double hydroxides (LDHs), zirconium phosphates (ZrPs), and di-chalcogenides. The main advantage of synthetic clays is their chemical purity (e.g. absence of amorphous and gritty contaminants, as well as arsenic, iron, and other heavy metals), white to transparent color that assures reproducibly of brightly colored products, as well as a wide range of aspect ratios, p ¼ 20 to £6000. Several large scale production facilities have been established. The synthetic clay and LDH industries are oriented toward big volume markets: catalysis, foodstuff, cosmetics, pharmaceuticals, toiletry, etc. The use of these materials in PNCs is limited to synthetic clays and LDHs, mainly for reinforcement, permeability control, reduction of flammability, and stabilization, e.g. during dehydrohalogenation of chlorinated macromolecules. The use of lamellar ZrPs and di-chalcogenides is at the laboratory stage of functional polymeric systems development, e.g. for electrically conductive materials, catalysts or support for catalysts, in photochemistry, molecular and chiral recognition, or in fuel cell technologies, etc. Copyright # 2007 John Wiley & Sons, Ltd.KEYWORDS: polymeric nanocomposites; nanoparticles; clay; layered double hydroxides; matrix POLYMERS FOR ADVANCED TECHNOLOGIES Polym. Adv. Technol. 2007; 18: 1-37 Published online in Wiley InterScience (www.interscience.wiley.com) DOI: 10.1002/pat.852 AUTHORS' BIOGRAPHIESDr Leszek A. Utracki was born and educated (up to Habilitation) in Poland. After the post-doctoral stage at USC in Los Angeles with Robert Simha he settled in Canada. His passionate research interest has been within the field of thermodynamics, rheology and processing of multicomponent, multiphase polymeric systems. During the 55 years in the profession he has published several hundred articles, book chapters, books, patents, etc., which has placed him on the ISI li...

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The theoretical and experimental data on the breakup of droplets are reviewed. Several factors influence development of droplets: flow type and its intensity, viscosity ratio, elasticity of polymers, composition, thermodynamic interactions, time, etc. For Newtonian systems undergoing small, linear deformation, both the viscosity ratio and the capillary number control deformability of drops. On the other hand, the breakup process can be described by the dimensionless breakup time and the critical capillary number. Drops are more efficiently broken in elongational flow than in shear, especially when the viscosity ratio A 2 3. The drop deformation and breakup seems to be more difficult in viscoelastic systems than in Newtonian ones. There is no theory able to describe the deformability of viscoelastic droplet suspended in a viscoelastic or even Newtonian medium. The effect of droplets coalescence on the final morphology ought to be considered, even at low concentration of the dispersed phase, (bd 2 0.005. Several drop breakup and coalescence theories were briefly reviewed. However, they are of little direct use for quantitative prediction of the polymer blend morphology during compounding in a twin-screw extruder. Their value is limited to serving as general guides to the process modeling. 32, No. 24

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Most polymer blends are immiscible and need to be compatibilized. The compatibilization must accomplish: (i) optimization of the interfacial tension; (ii) stabilize the morphology against high stresses during forming; and (iii) enhance adhesion between the phases in the solid state. Compatibilization is accomplished either by addition of a compatibilizer or by reactive processing. This review will focus on the three aspects: description of the interphase, compatibilization by addition and reactive compatibilization.

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