摘要
手性小分子诱导嵌段共聚物手性组装是构筑手性可控螺旋结构的一种有效方法,但是目前对手性小分子引导螺旋结构形成的机制还没有明确认识。文中利用具有不同化学结构的手性掺杂剂与聚1,4-丁二烯-b-聚环氧乙烷(PBd-b-PEO)共组装,研究了手性小分子化学结构的差异对螺旋结构形成的影响。通过小角散射、透射电镜和圆二色光谱证明了苹果酸和扁桃酸诱导嵌段共聚物中PEO形成螺旋相结构,而酒石酸二苄酯和二乙酰基酒石酸由于氢键位点和取代基效应无法诱导形成螺旋相结构。组装体由于聚合物结构变化和手性分子聚集态变化而呈现不同的手性信号变化规律。通过分子模拟分析了共组装体系中氢键缔合体的稳定性,从能量角度解释了手性分子结构对聚合物形成螺旋结构的影响。
Chiral additive-driven self-assembly of block copolymer is an effective method to construct helical nanostructure with controlled handedness.However,the effect of the small chiral molecules on the formation of helical structure is still unclear.In this work,small chiral molecules with different chemical structures were used to co-assemble with poly(1,4-butadiene)-b-poly(ethylene oxide)(PBd-b-PEO).Small angle X-ray scattering,TEM and circular dichroism(CD)were utilized to verify that the chiral malic acid(MA)and mandelic acid(MDA)can induce the PEO phase to form a helical structure at solid film state,while the chiral tartaric acid dibenzyl ester(DBTA)and diacetyl tartaric acid(DATA)cannot induce a helical phase due to the hydrogen bonding sites and the effect of their substituents.The assembly shows distinct CD signals based on the change of the polymer structure and the aggregation of chiral molecules.On the basis of molecular simulation,the stability of the hydrogen bond association in co-assembled system was analyzed,and the effect of chiral additives on the helical self-assembly of block copolymer was explained.
作者
梁鸿宇
李庆祥
陆学民
路庆华
Hongyu Liang;Qingxiang Li;Xuemin Lu;Qinghua Lu(School of Chemistry and Chemical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2021年第1期59-66,共8页
Polymer Materials Science & Engineering
基金
国家自然科学基金资助项目(21975156)。
关键词
嵌段共聚物
螺旋组装
手性
分子模拟
block copolymer
helix
chirality
molecular simulation
