Intra-molecular phase segregation in a single polyelectrolyte chain
Intra-molecular phase segregation in a single polyelectrolyte chain
复制标题
单聚电解质链中的分子内相分离
DOI：
--
复制
发表时间：
2001
期刊：
影响因子：
--
通讯作者：
K. Yoshikawa
中科院分区：
文献类型：
--
作者：
S. Takagi;K. Tsumoto;K. Yoshikawa
我们在平均场理论的框架下，考虑了小的可移动离子的影响，对多价阳离子诱导的聚电解质链的崩塌转变进行了理论研究。对于足够长的链，折叠转变是一个从盘绕到分离和从分离到崩溃的两步过程，其中分离状态是指在平衡状态下单个聚合物链中拉长的螺旋部分和崩溃的致密部分共存。这些相变被认为反映了自由能双极小值的两个态之间的竞争，即介观体系中的一阶相变。利用荧光显微镜单链观察的实验技术，我们监测了单个巨型DNA的折叠转变。实验结果表明，单DNA分子中确实存在两步折叠转变。离子的平移熵可能起到一定的作用。
We performed a theoretical study on the collapse transition of a single polyelectrolyte chain induced by multivalent cations, under the framework of the mean-field theory by taking into account the effect of small mobile ions. For a sufficiently long chain, the folding transition is found to be a two-step process; from coil to segregated and from segregated to collapsed, where the segregated state means the coexistence of an elongated coil part and a collapsed compact part in a single polymer chain in the equilibrium state. These transitions are considered to reflect competition between two states with double minima in the free energy; i.e., a first-order phase transition in a mesoscopic system. With the experimental technique of single chain observation by fluorescence microscopy, we monitored the folding transition of individual giant DNAs. The results of this experiment indicate the actual existence of the two-step folding transition in single DNA molecules. The translational entropy of ions may play a...
影响因子：
5.6
作者：
WIDOM, J;BALDWIN, RL
通讯作者：
BALDWIN, RL