Tomić S, Vuletić T, Babić S Dolanski, Krca S, Ivanković D, Griparić L, Podgornik R
Institut za fiziku, 10000 Zagreb, Croatia.
Phys Rev Lett. 2006 Sep 1;97(9):098303. doi: 10.1103/PhysRevLett.97.098303.
The fundamental length scales in semidilute Na-DNA aqueous solutions have been investigated by dielectric spectroscopy. The low- and the high-frequency relaxation modes are studied in detail. The length scale of the high-frequency relaxation mode at high DNA concentrations can be identified with the de Gennes-Pfeuty-Dobrynin correlation length of polyelectrolytes in semidilute solution, whereas at low DNA concentrations and in the low added salt limit the length scale shows an unusual exponent reminiscent of semidilute polyelectrolyte chains with hydrophobic backbone. The length scale of the low-frequency relaxation mode corresponds to a Gaussian chain composed of correlation blobs in the low added salt limit, and to the Odijk-Skolnick-Fixman value of the single chain persistence length in the high added salt limit.
通过介电谱研究了半稀Na-DNA水溶液中的基本长度尺度。详细研究了低频和高频弛豫模式。在高DNA浓度下，高频弛豫模式的长度尺度可以用半稀溶液中聚电解质的德热纳-费蒂-多布林因相关长度来确定，而在低DNA浓度和低添加盐极限下，长度尺度显示出一个不寻常的指数，让人联想到具有疏水主链的半稀聚电解质链。低频弛豫模式的长度尺度在低添加盐极限下对应于由相关团块组成的高斯链，在高添加盐极限下对应于单链持久长度的奥迪克-斯科尔尼茨克-菲克斯曼值。
