Mitsumata Tetsu
Graduate School of Science and Technology, Niigata University.
Yakugaku Zasshi. 2018;138(4):497-501. doi: 10.1248/yakushi.17-00201-2.
We investigated the electric and viscoelastic properties for the aqueous solution of cyanobacterial megamolecules, named sacran. Sacran is an anionic polyelectrolyte that has carboxylate and sulfate groups on the saccharide chain. The electric conductivity and shear viscosity demonstrated three crossover concentrations; overlap concentration at 0.004 wt%, entanglement concentration at 0.02 wt%, and gelation concentration at 0.1 wt%. The decrease in the charge density of the sacran chains reduces the repulsive force between the chains and this would cause transformation from the dilute to condensed states. At extremely low flow rates, sacran demonstrated a behavior called negative thixotropy in which the shear viscosity increased over time. In this review, the conformation of sacran chain in pure water is discussed and its negative thixotropy is briefly described.
我们研究了名为“Sacran”的蓝藻大分子水溶液的电学和粘弹性性质。Sacran是一种阴离子聚电解质，在糖链上具有羧基和硫酸根基团。电导率和剪切粘度表现出三个交叉浓度；重叠浓度为0.004 wt%，缠结浓度为0.02 wt%，凝胶化浓度为0.1 wt%。Sacran链电荷密度的降低会减少链间的排斥力，这将导致从稀态到凝聚态的转变。在极低流速下，Sacran表现出一种称为负触变性的行为，即剪切粘度随时间增加。在这篇综述中，讨论了Sacran链在纯水中的构象，并简要描述了其负触变性。
