Self-organization of amphiphilic copolymers into nanoparticles:: Study by 1H NMR longitudinal relaxation time
Self-organization of amphiphilic copolymers into nanoparticles:: Study by 1H NMR longitudinal relaxation time
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DOI：
10.1081/ma-200035422
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发表时间：
2004-11-01
期刊：
影响因子：
--
通讯作者：
Watterson, AC
中科院分区：
文献类型：
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作者：
Chen, MH;Kumar, R;Watterson, AC
用核磁共振纵向弛豫时间（T-1）研究了一种新型两亲性聚乙二醇聚合物1的聚集和纳米粒子的形成。两亲性聚合物在水溶液和有机溶剂中的质子核磁共振T-1值呈现不同的变化趋势，这可能与分子链的迁移率有关。据观察，疏水链上的质子的T-1弛豫时间随着在水介质中的浓度的增加而减小，并稳定在临界胶束浓度（CMC）以上。在水介质中，疏水链上质子的T-1弛豫时间的稳定化是由于疏水侧链在由于疏水相互作用而形成的纳米球的核中的聚集而发生的。然而，在有机溶剂中，两亲性聚合物的疏水和亲水链上的质子的T-1没有显示出任何粒子形成的证据。因此，侧链质子的受限运动可以指示在水溶液中形成纳米颗粒，而在有机溶液中不形成这种颗粒。
The aggregation and nanoparticle formation of a novel amphiphilic polymer 1 based on polyethylene glycol has been studied by H-1 NMR longitudinal relaxation time (T-1). The T-1 of proton NMR, which may be associated with the mobility of molecular chains showed different trends when the amphiphilic polymer was dissolved in aqueous and organic solvents. It was observed that the T-1 relaxation time of protons on hydrophobic chains decreases with the increase in concentration in aqueous media and stabilizes above the critical micelle concentration (CMC). The stabilization of T-1 relaxation time of protons on hydrophobic chains in aqueous media occurs because of the aggregation of hydrophobic side chains in the core of nanospheres formed due to hydrophobic interactions. However, in organic solvent, the T-1 of protons on hydrophobic as well as hydrophilic chain of amphiphilic polymer did not show any evidence of particle formation. Thus, the restricted motion of the side-chain protons may be indicative of nanoparticle formation in aqueous solution and non-formation of such particles in organic Solution.