Borgström J, Piculell L, Viebke C, Talmon Y
University of Lund, Sweden.
Int J Biol Macromol. 1996 Apr;18(3):223-9. doi: 10.1016/0141-8130(95)01081-5.
Cryo-transmission electron microscopy (cryo-TEM), viscometry and optical rotation have been used to study the microstructure of dilute solutions of helical kappa-carrageenan under varied electrolyte composition (0.1 M of NaI, CsI and mixtures of the two salts). Microfibers (300-400 nm in length) were observed above a critical cesium content, while below that no microstructure was seen in the micrographs. A drastic increase in the specific viscosity and an onset of thermal hysteresis in the optical rotation above the same critical cesium content provide clear evidence of aggregate formation. This leads to the conclusion that the observed microfibers are aggregates consisting of several helices. At high proportions of cesium, further aggregation of the microfibers was observed by cryo-TEM.
冷冻透射电子显微镜（cryo-TEM）、粘度测定法和旋光法已被用于研究在不同电解质组成（0.1 M的NaI、CsI以及两种盐的混合物）下螺旋κ-卡拉胶稀溶液的微观结构。在临界铯含量以上观察到微纤维（长度为300 - 400 nm），而在该含量以下，显微照片中未观察到微观结构。在相同临界铯含量以上，比粘度急剧增加且旋光出现热滞后现象，这为聚集体形成提供了明确证据。由此得出结论，观察到的微纤维是由几个螺旋组成的聚集体。在高比例铯的情况下，通过冷冻透射电子显微镜观察到微纤维进一步聚集。
