Disputas: Neda Beheshtivadeghani

Master Sci. Neda Beheshtivadeghani ved Kjemisk institutt vil forsvare sin avhandling for graden ph.d. (philosophiae doctor): Structural, Dynamical, and Rheological Features of Polymer-Based Complex Systems

Prøveforelesning

Se prøveforelesning

Bedømmelseskomité

Lecturer PhD Søren Hvidt , Department of Chemistry, Roskilde University, Denmark
Docent PhDAndra Dedinaite , Department of Chemistry, Royal Institute of Technology, Lund University, Stockholm, Sweden
Associate Professor Trond Vidar Hansen, School of Pharmacy, University of Oslo

Leder av disputas:  Professor Tyge Greibrokk

Veileder:  Prof. Bo Nyström og Dr. Anna-Lena Kjøniksen

Sammendrag

Polymers are giant high-molar-mass substances constructed from multitudes of discrete building blocks, called monomer residues. Plastics, fibers, rubber, protein, DNA, adhesives, coatings and paints, wool, cotton, and cellulose are well-known examples of materials belonging to the fascinating world of polymer chemistry. Our modern life has been so profoundly affected by polymers that we would encounter difficulties avoiding their manifold usages. The polymer hydroxyethylcellulose (HEC) that belongs to the class of biopolymers (naturally occurring, biosynthesized polymers) have been the main subject of research in this work. Solution of HEC can be used as a thickening agent for various cosmetic and personal care formulations, in painting, for enhanced oil recovery applications, as well as in pharmaceuticals and industrial products as rheology modifier or as drug carrier. The aim of this study was to investigate how we can tune the viscosity of a polymer solution in order to achieve the desired viscosity depending on the application. This can be achieved by changing different conditions such as concentration, temperature, and addition of other materials (co-solutes) to polymer solution. Another biopolymer that has been studied in this work, is dextran. Dextran is widely used in medicine as expander or substitute for blood plasma and as an anticoagulant. The results demonstrated that depending on the amount of cosolute we can enhance or decrease the viscosity of these polymers and obtain the desired rheology. Block sopolymers, in which various polymers with different structures are connected to each other, are an interesting class of research due to their complex structure and the ability to mimic the basic properties of biological systems. The self-assembly of a new block copolymer in the form of micelles has been investigated. The results reveal that the size of different polymer blocks constituing the copolymer has a strong impact on its physical property.

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Publisert 29. mars 2012 15:18 - Sist endret 13. apr. 2012 10:13