Controllable Cooperative Self-Assembly of PS-b-PAA/PS-b-P4VP Mixture by Tuning the Intercorona Interaction
Controllable Cooperative Self-Assembly of PS-b-PAA/PS-b-P4VP Mixture by Tuning the Intercorona Interaction
复制标题
通过调节间电晕相互作用实现 PS-b-PAA/PS-b-P4VP 混合物的可控协同自组装
DOI：
10.1021/acs.jpcb.6b00273
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发表时间：
2016-06-23
影响因子：
3.3
通讯作者：
Jiang, Wei
中科院分区：
文献类型：
--
作者：
Geng, Zhen;Cheng, Zhongkai;Jiang, Wei
研究了两亲聚苯乙烯-嵌段-聚丙烯酸(PS144-b-PAA(22))和聚苯乙烯-嵌段-聚(4-乙烯基吡啶)(PS144-b-P4VP(33))两嵌段共聚物在DMF/H2O混合溶剂中的协同自组装。如果单独使用，这两种共聚物都会自组装成小球形胶束(SSM)。然而，这两种共聚物的等摩尔混合物协同自组装成囊泡。研究发现，泡囊的形成是由于PAA和P4VP链之间的复杂相互作用，包括未电离的丙烯酸单元和吡啶单元之间的氢键以及电离的丙烯酸单元和质子化的吡啶单元之间的电子吸引。由于PAA和P4VP链之间的相互作用依赖于pH值，因此可以很容易地通过添加HCl或NaOH来调节协同自组装的形态。当H+或OH-加入量较高时，冠间相互作用是排斥的，共聚物混合物倾向于形成SSMS(碱性条件)或柱状胶束(酸性条件)，而当H+或OH-加入量较低时，由于冠间相互作用是吸引的，它更倾向于聚集成囊泡。有趣的是，无论是高Er加入量还是低OH-加入量，都可以得到相同的自组装聚集体的形貌，这是由于随着HCl或NaOH的加入，冠间相互作用的非单调变化。目前的研究表明，主导协同自组装形态的是日冕间的相互作用，而不是化学条件。
The cooperative self-assembly of amphiphilic polystyrene-block-poly(acrylic acid) (PS144-b-PAA(22)) and polystyrene-block-poly(4-vinylpyridine) (PS144-b-P4VP(33)) diblock copolymers in DMF/H2O mixtures has been investigated. Both copolymers self assemble into small spherical micelles (SSMs) if used individually. However, the equimolar mixture of these two copolymers cooperatively self-assembles into vesicles. It is found that the formation of vesicles is attributed to the complex interactions between PAA and P4VP chains, including the hydrogen bonds between un-ionized acrylic acid units and pyridine units as well as the electronic attractions between ionized acrylic acid units and protonated pyridine units. Since these interactions between PAA and P4VP chains depend on pH value, the cooperatively self-assembled morphology can be easily tuned by the addition of HCl or NaOH. At high addition of H+ or OH-, the intercorona interaction is repulsive and the copolymer mixture tends to form SSMs (basic condition) or cylindrical micelles (acidic condition), whereas it prefers to aggregate into vesicles at low addition of H+ or OH- because the intercorona interaction is attractive. Interestingly, the same morphology of the self-assembled aggregates can be obtained either at high Er addition or at low OH- addition, which from the nonmonotonic variation of the intercorona interaction along with the addition of HCl or NaOH. The current study implies that it is the intercorona interaction rather than the chemical condition that dominates the cooperatively self-assembled morphology.