Crystal structures, polymers morphologies

Electrodeposition is a unique, versatile technique for fabrication of metal oxide, polymer, and composite electrodes for electrochemical supercapacitors. Composition, crystal structure, and morphology of the deposits can be easily manipulated by adjusting the electrodeposition parameters to achieve improved capacitive behavior. Current progress, however, is far from the commercial expectations for electrochemical supercapacitors. 

Volume 16. Polymers—Part A Molecular Structure and Dynamics Part B Crystal Structure and Morphology Part C Physical Properties Edited by R. A. Fava... 

S.Z.D. Cheng, and B. Lotz, Nucleation control in polymer crystallization structural and morphological probes in different length- and time-scales for selection processes, Phil. Trans. Ro. Soc. London, A-Mathemat. Phys. and Engr. Sci 361, 517-536 (2003). 

In a real polymer system, the chain will attempt to crystallize in the lowest energy state. The lowest energy state for a polymer such as poly(methylene) will be an extended all-trans structure. Studies of single crystals of poly(methylene) formed from dilute solution resemble the predicted structure of a single crystal however, there are a number of other factors which will influence the nature of the crystal structure or morphology observed. It is appropriate to divide polymers into various types depending on their chemical repeat unit. 

Sebastian Munoz-Guerra completed his Ph.D in Organic Chemistry in 1974 at the University of Seville. After postdoctoral work on crystal structure and morphology of non-conventional nylons, he initiated research on synthesis and characterization of bio-based polymers and copolymers. Since 1987, he is full Professor in Chemical Engineering at the Technical University of Catalonia in Barcelona. His current research is focussed on the development of polyesters, polyamides and polyurethanes derived from carbohydrates with special attention paid to industrial aromatic polyesters, as well as on modification of microbial biopolymers with therapeutic interest. He has authored more than 200 peer reviewed papers and several book chapters, and has been granted more than 15 patents on these issues. 

In this chapter we shall be concerned with the basic principles that govern the crystallization behavior of flexible long-chain molecules. The more-rigid type of polymers will be discussed in Chapter 5. The subject matter divides itself naturally into several interrelated subdivisions. These include thermodynamics of crystallization, kinetics and mechanisms of crystallization, structure and morphology, and microscopic and macroscopic properties. We shall discuss each of these topics in terms of fundamental physical and chemical concepts. There is an interrelation among the various aspects of polymer crystallization as is indicated by the chart given in Fig. 4.1. 

Part A Molecular Structure and Dynamics, Academic Press, 1980 L. Marton, C. Marton (Ed.) Methods of Experimental Physics Vol.16, Polymers Part B Crystal Structure and Morphology, Academic Press, 1980 L. Marton, C. Marton (Ed.) Methods of Experimental Physics Vol.16, Polymers Part C Physical Properties, Academic Press, 1980 V. J. McBrierty, K. J. Packer Cambridge Solid State Science Series, Nuclear Magnetic Resonance in Solid Polymers, Cambridge University Press, 1993... 

Fava, R. A. (ed.) (1980) Methods of Experimental Physics, Vol. 16, Part B Polymers Crystal Structure and Morphology. Academic Press, New York. 

XRD patterns from polymers can be analyzed at various levels, based on the quality of the data and the intended use of the results. Earlier efforts were focused on determining the crystal structure, lamellar morphology, and in improving the methods to determine the crystallinity and orientation. Later efforts were focused on determining the nature of the lattice distortions and the nature of the noncrystalline phases. With the availability of synchrotrons, fast 2D detectors, software tools to analyze the data, future effort will more likely be toward understanding the evolution of these structures with time and temperature. While the analysis and interpretation of WAXS data is now straightforward, there is opportunity to improve the analysis and interpretation of the SAXS data. 

Wang B, Li CY, Hanzlicek J, Cheng SZD, GeU PH, Gre-bowicz J, Ho R-M. Poly(trimethylene teraphthalate) crystal structure and morphology in different length scales. Polymer 2001 42 7171-7180. 

INFLUENCE OF FOREIGN SURFACE ON THE CRYSTAL STRUCTURE AND MORPHOLOGY OF POLYMERS... 

The purpose of this chapter is to provide a context as to how the foreign surface can affect the crystallization process of a polymer. It contains a brief introduction on the possible influences of foreign surfaces on the crystallization kinetics of polymers and the resultant unique crystal structure and morphology of polymers in contact with different surfaces. The advantages of surface-induced polymer crystallization to fabricate polymeric materials with improved property or enhanced efficiency is described with some elaborately selected examples. 

The straightforward dependence of properties on the crystal structure and morphology of semicrystalline polymers provides an opportunity to tailor the properties of these... 

Gan Z, Kuwabara K, Abe H, Iwata T, Doi Y. The role of polymorphic crystal structure and morphology in enzymatic degradation of melt-crystallized poly (butylene adipate) films. Polym Degrad Stab 2005 87 191-199. 

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