Thermoresponsive Vesicular Morphologies Obtained by Self-Assemblies of Hybrid Oligosaccharide-block-poly(N-isopropylacrylamide) Copolymer Systems
Thermoresponsive Vesicular Morphologies Obtained by Self-Assemblies of Hybrid Oligosaccharide-block-poly(N-isopropylacrylamide) Copolymer Systems
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DOI：
10.1021/la902743y
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发表时间：
2010-02-16
期刊：
影响因子：
3.9
通讯作者：
Borsali, Redouane
中科院分区：
文献类型：
--
作者：
Otsuka, Issei;Fuchise, Keita;Borsali, Redouane
本文研究了温度响应性低聚糖-嵌段-聚（N-异丙基丙烯酰胺）共聚物体系：麦芽七酶-嵌段-聚（N-异丙基丙烯酰胺）（Mal（7）-b-PNIPAM（n））共聚物的自组装性质。采用Cu（I）催化的炔基官能化麦芽七糖（I）与通过原子转移自由基聚合（ATRP）制备的具有末端叠氮基的聚（N-异丙基丙烯酰胺）（N-3-PNIPAM（n））之间的1，3-偶极叠氮/炔环加成（所谓的“点击”化学），合成了不同摩尔质量和体积分数的那些体系。根据聚合度，N-3-PNIPAM（n）的浊点（T-cp）为36.4 ~ 51.5 ℃，而二嵌段共聚物的浊点（T-cp）为39.4 ~ 73.9 ℃。由于PNIPAM在高于T-cp的水中的疏水性，这种系统的自组装是有利的。虽然N-3-PNIPAM（n）呈现平均直径为500 nm的多分散球形形状，但在二嵌段共聚物体系中获得了直径约为300 nm的定义明确的囊泡形态。这些结果得到了证实，使用静态和动态光散射以及成像技术，如透射电子显微镜实验。
This work discusses the self-assembly properties of thermoresponsive hybrid oligosaccharide-block-poly(N-isopropylacrylamide) copolymer systems: maltoheptase-block-poly(N-isopropylacrylamide) (Mal(7)-b-PNIPAM(n)) copolymers. Those systems at different molar masses and volume fractions were synthesized Using Cu(I)-catalyzed 1,3-dipolar azide/alkyne cycloaddition, so-called "click" chemistry, between an alkynyl-functionalized maltoheptaose (I) and poly(N-isopropylacrylamide) having a terminal azido group (N-3-PNIPAM(n)) prepared by atom transfer radical polymerization (ATRP). While the cloud point (T-cp) of the N-3-PNIPAM(n) ranged from 36.4 to 51.5 degrees C depending on the degree of polymerization, those obtained of the diblock copolymers ranged from 39.4 to 73.9 degrees C. The self-assembly of such systems is favored due to the hydrophobicity of the PNIPAM in water above the T-cp. While the N-3-PNIPAM(n) present polydisperse globular shape with a mean diameter of 500 nm, well-defined vesicular morphologies with an approximate diameter of 300 nm are obtained in diblock copolymer systems. These results were obtained and confirmed using static and dynamic light scattering as well as imaging techniques such as transmission electron microscope experiments.