Centre de Recherche sur les Macromolécules Végétales (CERMAV, UPR-CNRS 5301) affiliated with Université Joseph Fourier, 38041 Grenoble Cedex 9, France.
Langmuir. 2010 Feb 16;26(4):2325-32. doi: 10.1021/la902743y.
This work discusses the self-assembly properties of thermoresponsive hybrid oligosaccharide-block-poly(N-isopropylacrylamide) copolymer systems: maltoheptaose-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 (1) 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.
这项工作讨论了热响应性杂化寡糖-嵌段-聚（N-异丙基丙烯酰胺）共聚物体系的自组装特性：麦芽七糖-嵌段-聚（N-异丙基丙烯酰胺）（Mal（7）-b-PNIPAM（n））共聚物。这些在不同摩尔质量和体积分数的系统是通过铜（I）催化的 1,3-偶极氮丙啶/炔烃环加成反应，即所谓的“点击”化学，合成的，其中包括一个炔基功能化的麦芽七糖（1）和具有末端叠氮基团的聚（N-异丙基丙烯酰胺）（N（3）-PNIPAM（n）），通过原子转移自由基聚合（ATRP）制备。而 N（3）-PNIPAM（n）的浊点（T（cp））取决于聚合度，范围从 36.4 到 51.5 摄氏度，而得到的二嵌段共聚物的浊点范围从 39.4 到 73.9 摄氏度。由于 PNIPAM 在高于 T（cp）的水中的疏水性，这些系统的自组装是有利的。虽然 N（3）-PNIPAM（n）呈现出具有 500nm 平均直径的多分散球形形状，但在二嵌段共聚物体系中可以得到具有约 300nm 直径的明确的囊泡形态。这些结果是通过静态和动态光散射以及成像技术，如透射电子显微镜实验得到和证实的。
