Stable Dispersions of Hybrid Nanoparticles Induced by Stereocomplexation between Enantiomeric Poly(lactide) Star Polymers
Stable Dispersions of Hybrid Nanoparticles Induced by Stereocomplexation between Enantiomeric Poly(lactide) Star Polymers
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DOI：
10.1021/la202110w
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发表时间：
2011-09-06
期刊：
影响因子：
3.9
通讯作者：
He, C. B.
中科院分区：
文献类型：
--
作者：
Tan, B. H.;Hussain, H.;He, C. B.
我们报告的形成和表征的混合纳米粒子在溶液中形成的对映异构体的聚（丙交酯）混合星星聚合物通过立体络合的稳定分散体。以多面体低聚倍半硅氧烷（POSS）为大分子引发剂，通过丙交酯的开环聚合，合成了以POSS纳米笼为核，聚L-丙交酯（PLLA）或聚d-丙交酯（PDLA）为臂的星形杂化聚合物。在固态下，差示扫描量热法和广角X-射线散射测量证实了POSS-star-PLLA和POSS-star-PDLA（50：50，wt %）的混合物中立体复合物的形成。在四氢呋喃（THF）中的相同混合物的溶液中，立体络合导致形成杂化纳米颗粒。纳米粒子的形成和老化和浓度的影响的详细帐户已提交。观察到，在低浓度下，立体络合的纳米颗粒在45天内保持稳定，并且对稀释不敏感，表明在溶液中形成稳定的混合纳米颗粒分散体。相比之下，通过弱疏溶剂相互作用形成的单个POSS-星形-PLLA或POSS-星形-PDLA在THF中的聚集体倾向于在稀释时崩解成较小的聚集体。利用PLLA-PDLA立体络合与适当的分子设计可以是一种通用的路线，以开发稳定的有机/无机混合纳米粒子分散体。
We report the formation and characterization of stable dispersions of hybrid nanoparticles in solution formed via stereocomplexation of enantiomeric poly(lactide) hybrid star polymers. The hybrid starlike polymers, having polyhedral oligomeric silsesquioxane (POSS) nanocages as the core and either poly(L-lactide) (PLLA) or poly(d-lactide) (PDLA) as the arms, are synthesized via ring-opening polymerization of lactide using octafunctional POSS as the macroinitiator. In the solid state, differential scanning calorimetry and wide-angle X-ray scattering measurements confirmed the formation of the stereocomplex in the mixture of POSS-star-PLLA and POSS-star-PDLA (50:50, wt %). In a solution of the same mixture in tetrahydrofuran (THF), sterocomplexation leads to formation of hybrid nanaoparticles. Detailed accounts of the nanoparticle formation and influence of aging and concentration have been presented. It was observed that at low concentration the stereocomplexed nanaoparticles remain stable over 45 days and are not sensitive to dilution, suggesting the formation of a stable hybrid nanoparticle dispersion in solution. In contrast, the aggregates of the individual POSS-star-PLLA or POSS-star-PDLA in THF, formed via weak solvophobic interactions, tended to disintegrate into smaller aggregates on dilution. Exploiting the PLLA-PDLA stereocomplexation with an appropriate molecular design can be a versatile route to develop stable organic/inorganic hybrid nanoparticle dispersions.