Search for dissertations about: "counterions"

Showing result 16 - 20 of 39 swedish dissertations containing the word counterions.

  2. 16. Polymer Gels: Modeling the Swelling Behavior

    Author : Stefanie Schneider; Fysikalisk kemi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Fysikalisk kemi; Physical chemistry; Polymerteknik; biopolymers; Polymer technology; binding isotherms; polyelectrolyte-surfactant interactions; discontinuous volume transition; gel swelling; Monte Carlo simulation; polyelectrolyte gels;

    Abstract : This thesis is concerned with the swelling behavior of polyelectrolyte gels. The thesis can be divided into two parts. Part one deals with the modeling and computer simulation of the gel swelling. READ MORE

  4. 17. Charged Polymers: From DNA to Polyampholytes

    Author : Malek O Khan; Beräkningskemi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; computational steering; DNA condensation; ion correlations; electrostatic interactions; colloidal stability; polyampholytes; Monte Carlo simulations; polyelectrolytes; Theoretical chemistry; quantum chemistry; Teoretisk kemi; kvantkemi;

    Abstract : Three main themes are outlined in this thesis: Polyelectrolytes/DNA : In a living cell, DNA molecules have a compact conformation in order to fit in, while in a test tube they will take on an expanded cylindrical shape, due to the negative phosphate groups along the DNA molecule. With the help of computer simulations it has been shown that like-charged monomers of a poly- electrolyte can attract each other if the counterions are taken into account. READ MORE

  5. 18. Metal‐Free Arylations of Oxygen and Nitrogen Nucleophiles : Applications of Diaryliodonium Salts

    Author : Elin Stridfeldt; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; arylation; aryloxyamines; cyclization; diaryliodonium salts; O-aryloximes; sigmatropic rearrangement;

    Abstract : This thesis concerns development of new methods for metal‐free arylations in organic synthesis. The protocols discussed in the thesis are based on a class of hypervalent iodine compounds called diaryliodonium salts. These reagents are known to transfer aryl moieties to suitable nucleophiles. READ MORE

  6. 19. NMR studies of DNA structure and counterion behaviour

    Author : Lorens van Dam; Gary Drobny; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physical Chemistry; fysikalisk kemi;

    Abstract : DNA is a polymer of nucleotides, each nucleotide consisting of a negatively charged phosphate group, a ribose sugar unit, and a purine or pyrimidine base. The secondary structure of DNA is commonly a double-helix with Watson-Crick paired bases. Several secondary structures, all with these features, are observed for DNA. READ MORE

  7. 20. Studies on structure and mechanism at formation of solid solutions and solid dispersions of hydrophobic drugs in polymers

    Author : Marie Wulff; Uppsala universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Pharmaceutical chemistry; Farmaceutisk kemi; Pharmaceutical chemistry; Farmaceutisk kemi; Physical and Inorganic Pharmaceutical Chemistry; fysikalisk och oorganisk farmaceutisk kemi;

    Abstract : The aim of the studies was to investigate the structures formed and mechanisms involved, when a hydrophobic drug is dispersed in a polymer carrier. The effect of different additives, like surfactants and cyclodextrins, was evaluated. The dispersions were prepared by the melting method. READ MORE