Aggregation behavior of pluronic F127 solutions in presence of chitosan/clay nanocomposites examined by dynamic light scattering
Aggregation behavior of pluronic F127 solutions in presence of chitosan/clay nanocomposites examined by dynamic light scattering
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DOI：
10.1016/j.jcis.2019.02.031
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发表时间：
2019-04-15
影响因子：
9.9
通讯作者：
D'Angelo, Giovanna
中科院分区：
文献类型：
--
作者：
Branca, Caterina;D'Angelo, Giovanna
假设：虽然一些研究已经探索了不同条件下普朗尼克水溶液的动力学，但人们对纳米颗粒存在下普朗尼克共聚物的动力学特性知之甚少。了解和理解此类系统的基本动力学行为对于优化高性能多功能结构的配方至关重要。实验：在目前的工作中，使用动态光散射（DLS）来研究存在插层壳聚糖/粘土纳米复合材料的 Pluronic F127 水溶液的动力学性质的温度依赖性；为了进行比较，还对Pluronic水溶液以及具有相同共聚物浓度的Pluronic/壳聚糖和Pluronic/蒙脱石二元体系进行了研究。结果：DLS结果表明，Pluronic溶液具有快速和慢速扩散过程的特征。较快的扩散与胶束之间的单聚体交换有关，而较慢的扩散则归因于随着温度升高而发生脱水的胶束簇的存在。从这些观察开始，分析了基于普朗尼克/水系统的动力学，并且根据溶液温度，观察到的衰变归因于不同大小的实体。 DLS 的研究结果为复杂聚合状态的共存提供了强有力的证据，使我们能够更好地了解所研究系统的架构。 (C) 2019 Elsevier Inc. 保留所有权利。
Hypothesis: Although several researches have explored the dynamics of pluronic aqueous solutions under different conditions, little is known about the dynamical properties of pluronic copolymers in presence of nanoparticles. Knowing and understanding the fundamental dynamical behavior of such systems is crucial to optimize the formulation of high performance multifunctional structures.Experiments: In the present work, dynamic light scattering (DLS) is used to investigate the temperature dependence of the dynamical properties of Pluronic F127 aqueous solutions in presence of intercalated chitosan/clay nanocomposites; for comparison, the pluronic aqueous solution and the binary systems pluronic/chitosan and pluronic/montmorillonite having the same copolymer concentration were also investigated.Findings: DLS results show that the pluronic solution is characterized by a fast and a slow diffusion process. The faster diffusion is associated with the unimers interchange between micelles whereas the slower one is ascribed to the presence of micellar clusters that undergo dehydration as the temperature increases. Starting from these observations, the dynamics of the pluronic-based/water systems was analyzed and, depending upon solution temperature, the observed decays were attributed to differently sized entities. The DLS findings give strong evidence for the coexistence of complex states of aggregation allowing us to get a better insight into the architecture of the investigated systems. (C) 2019 Elsevier Inc. All rights reserved.