Tuning Diblock Copolymer Particle Packing Symmetry with Variable Molecular Weight Core-Homopolymers
Tuning Diblock Copolymer Particle Packing Symmetry with Variable Molecular Weight Core-Homopolymers
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DOI：
10.1021/acs.macromol.2c01267
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发表时间：
2022-09
期刊：
影响因子：
5.5
通讯作者：
A. J. Mueller;A. Lindsay;Ashish Jayaraman;S. Weigand;T. Lodge;M. Mahanthappa;F. Bates
中科院分区：
文献类型：
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作者：
A. J. Mueller;A. Lindsay;Ashish Jayaraman;S. Weigand;T. Lodge;M. Mahanthappa;F. Bates
我们报告了二嵌段共聚物颗粒堆积对称性对比率 α =Nhomo/Ncore 的敏感性，其中 Nhomo 和 Ncore 分别是均聚物和核嵌段聚合度。将体积分数fO=0.15、0.16和0.20的三种聚(环氧乙烷)-b-聚(丙烯酸2-乙基己酯)(OA)二嵌段共聚物与α=0.23、0.42、0.80和1.00表征的均聚物共混。小角 X 射线散射揭示了作为 α、总体颗粒核心体积分数 (fcore) 和温度函数的丰富相行为。 BCC、HCP 和 Frank-Kasper σ、C14、C15 和十二角准晶相均已被鉴定。 “干刷”均聚物分布（α = 0.80 和 1.00）有利于 C14 和 C15 相，在高均聚物负载量下进行宏观相分离。颗粒核心中的“湿刷”均聚物分布 (α = 0.42) 导致在更大的浓度下产生较窄的 σ 或 C15 窗口和圆柱体。类溶剂膨胀 (α = 0.23) 有利于广泛的 σ 相形成。
We report the sensitivity of diblock copolymer particle packing symmetry to the ratio α =Nhomo/Ncore, whereNhomoandNcoreare the respective homopolymer and core-block degrees of polymerization. Three poly(ethylene oxide)-b-poly(2-ethylhexyl acrylate) (OA) diblock copolymers withOvolume fractionsfO= 0.15, 0.16, and 0.20 were blended withOhomopolymers characterized by α = 0.23, 0.42, 0.80, and 1.00. Small-angle X-ray scattering revealed rich phase behavior as a function of α, the overall particle core volume fraction (fcore), and temperature. BCC, HCP, and Frank–Kasper σ, C14, C15, and dodecagonal quasicrystal phases, were all identified. “Dry-brush” homopolymer distribution (α = 0.80 and 1.00) favor C14 and C15 phases with macrophase separation at high homopolymer loadings. “Wet-brush” homopolymer distributions in the particle cores (α = 0.42) lead to narrow σ or C15 windows and cylinders at greaterOconcentrations. Solvent-like swelling (α = 0.23) favors widespread σ phase formation.