Materials Synthesis and Modification

The application of SCCO2 to the synthesis and modification of well-defined polymers has enormous potential and as such has been extensively investigated. One of the earliest reactions studied was fluoropolymer synthesis. 

Fluoropolymers could not be prepared in hydrocarbon solvents and earlier routes to them had employed ozone-depleting chlorofluorocarbon (CFC) solvents. The C02-philic nature of both the monomers and the resulting polymers allowed a homogeneous polymerization reaction to be performed. DuPont now 

Supercritical drying and particle formation processes are also important areas in SCCO2 based materials chemistry. Some of the particle processing methods available, such as precipitation with compressed antisolvent (PCA), are shown schematically in Chapter 9. 

Using SCF processes such as these, polymers and inorganic materials have been formed into films, fibres and spherical particles. For example, mesoporous silicate films and mesoporous silica hollow spheres have both been recently prepared using SCCO2 based technologies.  

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The enormous potential of enzymes has been recently applied to polymer material synthesis and modifications. This recent application has made biocatalysis a popular topic for polymeric research in academia and industry. Enzyme catalysis has provided a new synthetic strategy for useful polymers most of which are otherwise very difficult to produce by conventional chemical catalysis. This paper overviews our recent work on the use of a variety of eu2ymes in the synthesis of novel pegylated multifunctional polymers for applications in drug and gene delivery. 

L. Dai, A. W. H. Mau, Controlled synthesis and modification of carbon nanotubes and C60 Carbon nanostructures for advanced polymeric composite materials, Advanced Materials, vol. 13, pp. 899-913, 2001. 

Fleet GWJ (1993) Sugar lactones as useful starting materials. In Krohn K, Kirst HA, Maas H (eds) Antibiotics and antiviral compounds chemical synthesis and modifications. VCH Verlagsgesellschaf, Weinheim, pp 333-342 Isbell HS (1963) Meth Carbohydr Chem 2 13-15... 

We are concerned with both homogeneous gas-phase chemistry and heterogeneous surface chemistry. Certainly in combustion, gas-phase chemistry is usually dominant. However, there may be good reason to be concerned with heterogeneous chemistry, for example, on the relatively cool walls of a combustion chamber. Moreover there are emerging materials-synthesis and surface-modification techniques that depend on flame-surface interactions. 

In this paper, a summary of these previous results on the synthesis and modification of metal and complex hydrides by ball milling is presented. More information about the applied methods and the properties of the materials can be found in the original publications. 

Synthesis and preparation process affects some propenies of ceria-based materials such as formed phase, panicle size, surt ace area, catalytic activities, and OSC etc. Therefore, many studies on synthesis, preparation, and modification have been carried out to develop the ceria-based materials of high catalytic activities, OSC, and thermal durability. In this chapter, conventional processes and recent advances in the synthesis and modification of the ceria-based materials are reviewed with the dependence of these methods on the characteristics of the materials. 

Synthesis and modification of basic mesoporous materials for the selective etherification of glycerol. 

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