Morphology evolution in superheated crystal monolayer of low molecular weight poly(ethylene oxide) on mica surface
Morphology evolution in superheated crystal monolayer of low molecular weight poly(ethylene oxide) on mica surface
复制标题
DOI：
10.1016/j.polymer.2006.05.013
复制
发表时间：
2006-07
期刊：
影响因子：
4.6
通讯作者：
D. Zhu;Yi-Xin Liu;A. Shi;E. Chen
中科院分区：
文献类型：
--
作者：
D. Zhu;Yi-Xin Liu;A. Shi;E. Chen
利用原子力显微镜（AFM）和热相结合的方法，研究了云母表面过热的聚环氧乙烷（PEO）晶体单层的形态演变。PEO的数平均分子量（Mn）为4250g/mol，多分散性为1.03。当三折叠链晶体[IF(3)]的整个外围加厚为两折叠链晶体[IF(2)]的“坝”时，就得到了过热的单层。IF(3)晶体受到IF(2)“坝”的侧向约束，在其无约束熔化温度（Tm）下保持不变。在过热条件下，内部IF(3)晶体展开，形成厚度介于IF(3)和IF(2)晶体折叠长度之间的区域，并伴有空穴形成。在成核后，孔洞迅速扩大其面积，并在IF(2)晶体“坝”所包围的区域内长距离迁移。
Using atomic force microscopy (AFM) coupled with a hot stage, we studied the morphological evolution of superheated poly(ethylene oxide) (PEO) crystal monolayer on the mica surface. The PEO possesses a number average molecular weight (Mn) of 4250g/mol and a polydispersity of 1.03. The superheated monolayer was obtained when the entire periphery of a triply-folded chain crystal [IF(3)] was thickened to be a twice-folded chain crystal [IF(2)] ‘dam’. The IF(3) crystal was laterally confined by the IF(2) ‘dam’ and remained unchanged at its unconfined melting temperature (Tm). In superheated conditions, the interior IF(3) crystal unfolded, resulting in domains with a thickness in between the fold lengths of the IF(3) and the IF(2) crystals accompanied by hole formation. After its nucleation, the hole enlarged its area quickly and migrated long distances within the area bounded by the IF(2) crystal ‘dam’.