Sökning: "pore shape"

Visar resultat 16 - 20 av 52 avhandlingar innehållade orden pore shape.

1. 16. Towards a responsive functional material: Modification of porosity and grafting of poly(N-isopropylacrylamide) in mesoporous silica SBA-15

   Författare :Nina Reichhardt; Fysikalisk kemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mesoporous silica; SBA-15; intrawall pores; PNIPAAM; lower critical solution temperature; water sorption calorimetry; gas sorption;

   Sammanfattning : Mesoporous silica materials, such as SBA-15, have potential as biocompatible carriers for pharmaceutical applications as well as mini-reactors in e.g. catalysis. This potential arises from their well-defined porous structure on the nanometre scale accompanied by a high internal surface area (800 - 1000 m2/g). LÄS MER

3. 17. Membrane mechanisms during exo- and endocytosis in excitable cells

   Författare :Gianvito Arpino; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :;

   Sammanfattning : Excitable cells, like endocrine cells and neurons release hormones and transmitters through exocytosis to mediate many important functions, such as stress responses, immune responses, control of blood glucose, and synaptic transmission that mediates communication between neurons in the brain. This process relies on delicate endocytic mechanisms, to retrieve vesicular membranes and proteins previously fused at the plasma membrane and thus maintains the ability of exocytosis for excitable cells. LÄS MER

4. 18. Structural and Morphological Studies of Mesoporous Crystals

   Författare :Kristina Lund; Osamu Terasaki; Sven Lidin; Lars Eriksson; Mika Lindén; Stockholms universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Chemistry; Kemi; Structural Chemistry; strukturkemi;

   Sammanfattning : Mesoporous silica and carbon have been synthesised and characterised by X-ray diffraction (XRD), transmission and scanning electron microscopy (TEM and SEM) and nitrogen adsorption. Surface structure, size and shape (morphology) of particles have been of special interest in this work. LÄS MER

5. 19. Nuclear magnetic resonance studies of water self-diffusion in porous systems

   Författare :Daniel Topgaard; Fysikalisk kemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diffusion diffraction; nonfreezing; anisotropy; tortuosity; cross relaxation; emulsion; starch; cellulose; porous material; water; NMR; self-diffusion; Physical chemistry; Fysikalisk kemi;

   Sammanfattning : Proton nuclear magnetic resonance (NMR) was used to study the self-diffusion of water in porous systems that respond to a change in water content in order to elucidate the porous structure and the properties of the confined water. In the carbohydrate systems cellulose fibers and starch granules, water is free to move throughout the porous objects, albeit with a rate reduced from the value of the bulk liquid, The reduction is related to the tortuosity of the pore space filled by water. LÄS MER

7. 20. Microstructure and liquid mass transport control in nanocomposite materials

   Författare :Christoffer Abrahamsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; magnetic alignment; permeability; colloidal gels; microgels; bond water; clay; flow; microstructure; nanocomposites; poly N-isopropylacrylamide ; porous materials; liquid mass transport; diffusion; diffusion NMR; particle aggregation; phase behavior; silica;

   Sammanfattning : Some of the biggest problems currently facing the world are closely tied to unsolved technological challenges in the material sciences. Many materials have a porous microstructure that controls their overall properties. LÄS MER