Mesophase products, microstructure

Understanding the factors that govern the formation of mesogens will assist in determining the processing conditions for the production of materials with specified amounts, sizes, and distribution of such crystalline microstructures. Mesophases can be local or permeate the entire structure. They can be large or small, and present in a random or more ordered arrangement. 

Chemical and plastic behavior of the carbonaceous mesophase, which is the liquid crystalline phase where the microstructure of coke and many other carbon products is established... 

The properties of manufactured graphites are determined by the microstructure of the carbonaceous mesophase which is formed during pyrolysis, usually between the temperatures of 370 C and 500°C. The characteristics of the final product can be measured in a qualitative way by examination of the mesophase micro-structure. Several coal liquid asphaltene and petroleum pitch samples have been screened in this way to determine their suitability as precursors for graphite materials. The physical and chemical properties of the mesophase formed from the samples and their pyrolyses residues were studied(1). It was found that the phenolic oxygen present either in the precursor or by addition during heat treatment suppresses mesophase formation by crosslinking and preventing the development of fluidity(2J>... 

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