Microphase separation of stimuli-responsive interpenetrating network microgels investigated by scattering methods
Microphase separation of stimuli-responsive interpenetrating network microgels investigated by scattering methods
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DOI：
10.1016/j.jcis.2021.03.178
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发表时间：
2021-04-17
影响因子：
9.9
通讯作者：
Chertovich, Alexander, V
中科院分区：
文献类型：
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作者：
Kozhunova, Elena Yu;Rudyak, Vladimir Yu;Chertovich, Alexander, V
聚合物刺激响应型微凝胶在各种应用中得到了应用。对其内部结构的认识对于进一步完善和扩大范围具有重要意义。在选择性溶剂存在的条件下，互穿网络(IPN)微凝胶可能具有强烈的内部结构不均匀甚至微相分离的显著特征。在本研究中，我们首次使用静态光散射(SLS)和小角X射线散射(SAXS)技术相结合的方法，在宽广的Q值范围内收集了聚(N-异丙基丙烯酰胺)-聚丙烯酸IPN微凝胶水分散体的结构因子。我们研究了溶剂质量对微凝胶构象的影响，结果表明，在选择性溶剂中，这样的体系经历了微相分离：在较差的溶剂条件下，子网络在好的溶剂条件下形成致密的小聚集体，在大的溶胀的子网络内形成致密的小聚集体。我们提出了用于IPN微凝胶结构因子解释的微结构球模型，并通过粗粒度分子动力学计算机模拟进行了额外的分析和验证。(C)2021爱思唯尔公司版权所有。
Polymer stimuli-responsive microgels find their use in various applications. The knowledge of its internal structure is of importance for further improvement and expanding the scope. Interpenetrating network (IPN) microgels may possess a remarkable feature of strongly non-uniform inner architecture, even microphase separation, in conditions of a selective solvent. In this research, we, for the first time, use a combination of static light scattering (SLS) and small-angle X-ray scattering (SAXS) techniques to collect the structure factors of aqueous dispersions of poly(N-isopropylacrylamide)-polyacrylic acid IPN microgels on the broad scale of q values. We study the influence of solvent quality on microgel conformations and show that in a selective solvent, such a system undergoes microphase separation: the sub-network in a poor solvent conditions forms dense small aggregates inside the large swollen sub-network in a good solvent. We propose the microstructured sphere model for the IPN microgel structure factor interpretation and perform additional analysis and verification through coarse-grained molecular dynamics computer simulations.(c) 2021 Elsevier Inc. All rights reserved.