Although most of the rare earth metals were discovered in Sweden, the industrialisation started in the Austrian Empire. This was due to the fact that the Swedish chemist Jons Fridrik Bahr (1815–1875) from Uppsala went to Heidelberg in Germany in 1855 to analyse some rare earth minerals by the spectroscope discovered recently by chemistry professor Robert Bunsen (1811– 1899) and his colleague ph...

The volume transition induced by monovalent-divalent cation exchange of fully neutralized polyacrylate hydrogels was investigated in aqueous NaCl solutions. The variation of the osmotic swelling pressure, shear modulus, and mixing pressure was measured when Na(+) ions were substituted by divalent or trivalent cations. Alkali metal salts move freely throughout the entirely network, and alkaline ...