In situ observation of heterogeneous melting of poly[(R)-3-hydroxybutyrate] single crystals by temperature-controlled atomic force microscopy
In situ observation of heterogeneous melting of poly[(R)-3-hydroxybutyrate] single crystals by temperature-controlled atomic force microscopy
复制标题
温控原子力显微镜原位观察聚[(R)-3-羟基丁酸酯]单晶的非均相熔融
DOI：
10.1016/s0141-3910(03)00082-x
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发表时间：
2003
影响因子：
5.9
通讯作者：
Y. Doi
中科院分区：
文献类型：
--
作者：
M. Fujita;T. Iwata;Y. Doi
利用温控原子力显微镜（TC-AFM）原位跟踪了聚[（R）-3-羟基丁酸酯]（P（3 HB））板条状单晶在退火过程中的形态变化，以阐明单个单晶的热稳定性或链迁移率。采用两种不同晶化条件下制备的溶液生长单晶，研究了晶化温度对退火行为的影响。退火过程中观察到显着的形态变化，在温度高于原始结晶温度。TC-AFM观察已经揭示，通过热处理，偶尔会形成横过晶体宽度（平行于b轴）的层状表面上的脊和沿着晶体长轴（平行于a轴）的裂纹。在较高的退火温度下，沿b轴的许多缺口经常形成在晶体的侧面沿着。凹口的形成可能是由于层状晶体内有缺陷或不太完美的区域的优先熔化。随着退火温度的升高，缺口沿沿着b轴方向扩展，整个晶体变窄，晶体中心出现空洞。等温退火实验表明，P（3 HB）晶体的熔化是从侧面逐渐进行的。结果表明，P（3 HB）单晶中存在沿a轴和b轴沿着方向的不完全区域，晶体侧面的区域更容易熔化。
Morphological changes of lath-shaped single crystals of poly[(R)-3-hydroxybutyrate] (P(3HB)) during annealing were followed in situ by a temperature-controlled atomic force microscopy (TC-AFM) in order to elucidate thermal stability or chain-mobility within the individual single crystal. Two kinds of the solution-grown single crystals prepared under different crystallization conditions were used to also investigate the influence of crystallization temperature on the annealing behavior. The significant morphological changes during annealing were observed at temperatures above the original crystallization temperature. The TC-AFM observations have revealed that ridges on the lamellar surface running across the crystal width (parallel to the b-axis), and cracks along the long axis of the crystal (parallel to the a-axis) are occasionally formed by thermal treatment. At a higher annealing temperature, numerous notches along the b-axis were frequently formed at the lateral sides of crystal. The notch formation may be due to preferential melting of the defective or less perfect regions within the lamellar crystal. The whole crystal became narrow while the notches progressed along b-axis, and some cavities developed at the central portion of the crystal as annealing temperature was elevated. The isothermal annealing experiment has demonstrated that the melting of P(3HB) crystals gradually progresses from the lateral outer faces. On the basis of the results, it has been concluded that the less perfect regions along the a-axis and b-axis exist within the P(3HB) single crystal, and that melting of the regions at the lateral sides of crystal is more easily initiated.
影响因子：
4.6
作者：
Y. Kikkawa;Y. Inoue;H. Abe;T. Iwata;Y. Doi
通讯作者：
Y. Kikkawa;Y. Inoue;H. Abe;T. Iwata;Y. Doi
影响因子：
5.5
作者：
KUNIOKA, M;DOI, Y
通讯作者：
DOI, Y