Self-organization of diblock and triblock copolymers of poly(L-lactide) and poly(oxyethylene) into nanostructured bands and their network system. proposition of a doubly twisted chain conformation of poly(L-lactide)
Self-organization of diblock and triblock copolymers of poly(L-lactide) and poly(oxyethylene) into nanostructured bands and their network system. proposition of a doubly twisted chain conformation of poly(L-lactide)
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DOI：
10.1021/ma010056t
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发表时间：
2001-05
期刊：
影响因子：
5.5
通讯作者：
Tomoko Fujiwara;M. Miyamoto;Y. Kimura;T. Iwata;Y. Doi
中科院分区：
文献类型：
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作者：
Tomoko Fujiwara;M. Miyamoto;Y. Kimura;T. Iwata;Y. Doi
合成了单分散的聚乳酸-嵌段-聚氧乙烯（PLLA-PEG）和聚乳酸-嵌段-聚氧乙烯-嵌段-聚乳酸（PLLA-PEG-PLLA），并在水溶液中成功地制备了它们的纳米粒子。两种颗粒的二嵌段和三嵌段共聚物的纳米级的大小，由疏水性PLLA和亲水性PEG的核心和外壳，分别。PLLA-PEG-PLLA颗粒的尺寸随着介质中聚合物浓度的增加而增加，而PLLA-PEG颗粒的尺寸与聚合物浓度无关。当这些颗粒在云母基底上浇铸和热处理时，通过原子力显微镜观察，在两种共聚物的表面上形成了具有1 - 2 nm厚度的带结构。PLLA-PEG的能带结构显示彼此平行排列，而PLLA-PEG-PLLA的能带结构形成了一个特征性的网络系统，类似于在动物组织中观察到的神经元系统。透射电子显微镜
Monodispersed poly(l-lactide)-block-poly(oxyethylene) (PLLA−PEG) and poly(l-lactide)-block-poly(oxyethylene)-block-poly(l-lactide) (PLLA−PEG−PLLA) were synthesized, and their nanoparticles were successfully prepared in an aqueous medium. Both particles of the di- and triblock copolymers were nanoscale in size, consisting of hydrophobic PLLA and hydrophilic PEG in the core and shell, respectively. The size of the PLLA−PEG−PLLA particles increased with increasing polymer concentration in the medium, while that of the PLLA−PEG particles was constant irrespective of the polymer concentration. When these particles were cast and heat-treated on a mica substrate, band structures having 1−2 nm thickness were formed on the surface for both copolymers as observed by atomic force microscopy. The band structures of PLLA−PEG showed parallel alignment with each other, while those of PLLA−PEG−PLLA formed a characteristic network system resembling the neuron system observed in animal tissues. Transmission electron microg...