Sökning: "sol-gel synthesis"

Visar resultat 6 - 10 av 25 avhandlingar innehållade orden sol-gel synthesis.

1. 6. Carbothermal synthesis of nano-structured metal, carbides and nitrides, using solution processed precursors; from precursor to product

   Författare :Sarmad Naim Katea; Gunnar Westin; Hilmar Vidarsson; Sanjay Mathur; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Solution-based chemical processing; sol-gel; ceramic powders; transition metal carbides and nitrides; sintering; nickel binder; mechanical properties; Chemistry with specialization in Inorganic Chemistry; Kemi med inriktning mot oorganisk kemi;

   Sammanfattning : This thesis describes how solution chemical based carbothermal syntheses can be used for the synthesis of nanostructured zirconium carbide and nitride nanophase powders as well as a nickel-metal coating on NbC for use as a sintering agent. The focus is on the development of novel synthesis routes using atomic or small nanoscale level mixing of the metal oxide and carbon source in the starting precursors, enabling the use of lower synthesis temperatures and non-agglomerated nanosized powders. LÄS MER

3. 7. From Current Collectors to Electrodes : Aluminium Rod Structures for Three-dimensional Li-ion Micro-battery Applications

   Författare :Gabriel Oltean; Kristina Edström; Leif Nyholm; Erik Kelder; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; 3D micro-batteries; aluminium; titanium oxide; current collectros; negative electrodes; electrodepostion; electrophoretic depostion; sol-gel synthesis;

   Sammanfattning : The potential use of 3D aluminium nanorod structures as current collectors and negative electrodes for 3D Li-ion micro-batteries was studied based on the use of relatively simple and cost-effective electrochemical and sol-gel deposition techniques.Aluminium rod structures were synthesised by galvanostatic electrodeposition using commercial porous membranes as templates. LÄS MER

4. 8. 3D Magnetic Photonic Crystals : Synthesis and Characterization

   Författare :Mei Fang; K.Venkat Rao; Lyubov Belova; Rajeev Ahuja; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; magnetic photonic crystals; photonic band gaps; Fe3O4 nanoparticles; silica; Optical physics; Optisk fysik; Materials science; Teknisk materialvetenskap;

   Sammanfattning : This thesis presents the synthesis methods and the characterizations of magnetic Fe3O4 nanoparticles, silica spheres with Fe3O4 nanoparticles embedded, and three dimensional magnetic photonic crystals (MPCs) prepared from the spheres. The structure, material composition, magnetic and optical properties, photonic band gaps (PBGs), as well as how these properties depend on the concentration of the magnetic nanoparticles, are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), superconducting quantum interference device (SQUID), Faraday rotation (FR) and optical spectrophotometers. LÄS MER

5. 9. Colloidal synthesis of metal oxide nanocrystals and thin films

   Författare :Fredrik Söderlind; Per-Olov Käll; Kajsa Uvdal; Mats Johnsson; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; nanoparticles; synthesis; contrast agents; functionalization; thin films; Chemistry; Kemi;

   Sammanfattning : A main driving force behind the recent years’ immense interest in nanoscience and nanotechnology is the possibility of achieving new material properties and functionalities within, e.g., material physics, biomedicine, sensor technology, chemical catalysis, energy storing systems, and so on. LÄS MER

7. 10. Structure and Dynamics of Silica Dispersions and Gels

   Författare :Jonas Nordström; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; aging; Photon correlation spectroscopy; sodium silicate; lithium electrolytes; water glass; fumed silica; sol-gel transition;

   Sammanfattning : This thesis deal with the sol-gel transition of two quite different systems, both based on silica. The overall aim is to understand what interactions lead to this sol-gel transition and how the structure and dynamics change as a result of this.The first project concern the gelation of water glass, also known as alkaline sodium silicate solutions. LÄS MER