摘要: The poly(vinyl alcohol)–iodine blue color reaction in dilute aqueous solution has been investigated, and extinctions at the absorption maximum have measured as a function of concentrations polymer, iodine, iodide ions, boric acid. Depending upon conditions, main can be made to appear any wavelength between 580 700 mμ, with longest wavelengths highest per vinyl alcohol group showing up high acid concentrations. Poly(vinyl alcohol) samples from various sources displayed, under identical great differences staining intensities. This ascribed regularity polymer chain structures. To account for behavior towards iodine wide variety well number irreversible or only slowly reversible phenomena, model mechanism PVA–iodine complex formation is proposed involving dual process helix intramolecular association. There evidence indicate that full saturation 12 residues supported by one molecule form single turn which enwraps atom, out long polyiodide nested interior helix.
sci-hub.se 参考文章(0)