Search results for "Partial specific volume"
showing 3 items of 3 documents
Die bestimmung von sedimentationskoeffizient, diffusions-koeffizient und molekulargewicht von α-amylasen nach der methode des aktivitätstransportes
1965
Abstract Sedimentation and diffusion coefficients determined by optical methods on pure (crystallized) enzymes are compared with those obtained by activity measurements on the unpurified enzymes. On performing the experiments under suitable conditions, results of the two methods are in good agreement. The calculation of the molecular weights of the unpurified enzymes is somewhat uncertain because the partial specific volume in most cases is not accurately known.
1984
Sedimentation coefficients of S of polystyrene covering a broad range of molecular weights M, are measured in toluene and 2-butanone in the semidilute regime. The results are compared with literature data using a plot of S · NA · η/(1 − νρ) = M · η/f versus concentration c, allowing experiments in different solvents of different density ρ and viscosity η to be compared (ν: partial specific volume of polymer; f: friction coefficient; NA: Avogadro number). According to scaling theory for concentrations higher than a critical concentration c, linear plots are to be expected. This is true for the theta-solvent cyclohexane, but for the theta-solvent cyclopentane as well as for the thermodynamica…
Partielle spezifische volumina von m.m′-ditolyl und seinen oligomeren
1969
Das partielle spezifische Volumen von m.m′-Ditolyl in Toluol wurde durch Dichtemessungen uber den gesamten Konzentrationsbereich bei 25°C bestimmt. Das hieraus berechnete molare Uberschusvolumen betragt −0,21 cm3/Mol bei einem Volumenbruch von 0,5. Die partiellen spezifischen Volumina von Oligomeren des m.m′-Ditolyls wurden in einem niedrigen Konzentrationsbereich in Toluol, Benzol und Trichlorathylen bei 25°C bestimmt. Sie sind in erster Naherung dem Molekulargewicht umgekehrt proportional. The partial specific volume of m.m′-ditolyl in toluene was determined by means of density measurement over the entire range of concentrations at 25°C. The molar excess volume computed hereof turns out t…