Angstrom laboratory

INORGANIC CHEMISTRY, THE ANGSTROM LABORATORY, UPPSALA UNIVERSITY, BOX 538, S-751 21 UPPSALA, SWEDEN... 

Bengt NOLANG The Angstrom Laboratory Department of Materials Chemistry Uppsala University Uppsala (Sweden)... 

Department of Physics, Chalmers University of Technology, S-412 96 Gote-borg, Sweden. Present address The Angstrom Laboratory, Uppsala University, Box 534, Uppsala, SE-751 21, Sweden... 

Department of Chemistry, Angstrom Laboratory, Institute of Theoretical Chemistry, Uppsala University, Box 518, SE-751 20 Uppsala, Sweden e-mail Erkki.Brandas kemi.uu.se... 

Prof. Erkki J. Brandas Department of Chemistry Angstrom Laboratory Institute for Theoretical Chemistry SE-751 20 Uppsala University Sweden... 

Gunnar A. Niklasson Department of Materials Science The Angstrom Laboratory... 

Stenbjorn Styring Department of Chemistry - Angstrom Laboratory, Uppsala University, Uppsala, Sweden... 

KRISTINA EDSTROM, TORBJORN GUSTAFSSON and JOSH THOMAS Angstrom Advanced Battery Centre, Department of Materials Chemistry, Angstrom Laboratory, Uppsala University, Box 538, SE-751 21 Uppsala, Sweden E-mail Josh.Thomas mkem.uu.se... 

X-rays have wavelengths in the angstrom range, are sufficiently energetic to penetrate solids, and are well suited to probe their internal structure. XRD is used to identify bulk phases, to monitor the kinetics of bulk transformations, and to estimate particle sizes. An attractive feature is that the technique can be applied in situ. We will first discuss XRD as done in the laboratory and then discuss newer applications of XRD as are available by using synchrotron radiation. The theory of X-ray diffraction is given in textbooks of solid state physics [1,2] and in specialized books [3-6]. 

Because the particles must be very small, not more than a few hundred angstroms for most substances, there have been few laboratory observations of structure in ultraviolet extinction spectra of small, nonmetallic particles. Particles of the required size are difficult to make. Grinding them from the bulk, with the attendant problem of separation, is almost hopeless. Various smokes can be made, MgO particularly easily, but not of all substances that might be of interest. 

The presence of proteoglycans in the extrafibrillar compartment would result in water depletion in the intrafibrillar compartment when the salinity of the synovial joint, or of the bath in laboratory experiments, is decreased. Therefore there should be mechanisms that retain intrafibrillar water within fibrils. Here, hydration forces that act at short distances, a few angstroms, are postulated to be the main factor that limit the exchangeability of intrafibrillar water. 

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