Nanogel Degradation at Soft Interfaces and in Bulk: Tracking Shape Changes and Interfacial Spreading
Nanogel Degradation at Soft Interfaces and in Bulk: Tracking Shape Changes and Interfacial Spreading
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DOI：
10.1021/acs.macromol.2c02470
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发表时间：
2023-02-16
期刊：
影响因子：
5.5
通讯作者：
Kuksenok，Olga
中科院分区：
文献类型：
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作者：
Palkar，Vaibhav;Thakar，Devanshu;Kuksenok，Olga
通过中尺度模拟，我们描述了悬浮在单一溶剂中的纳米凝胶和吸附在两种不相容流体之间的液-液界面上的纳米凝胶的受控降解过程。可控降解是我们感兴趣的，因为它可以用来动态地调整这些软颗粒的大小、形状和传输特性。对于吸附在液-液界面上的纳米凝胶，控制降解可以提供一种在纳米尺度上动态调整界面特性的手段。为了描述降解过程，我们跟踪了残余纳米凝胶的结构特征，如其旋转半径和形状各向异性，以及破碎碎片的时空分布。我们使用耗散粒子动力学方法与修正的段排斥势的一种改编形式。我们确定了反凝胶点，并用系统中有限数量的聚合物前驱体表征了该点的结垢。此外，我们表征了聚合物-溶剂相互作用对降解过程中纳米凝胶形状和有效尺寸演变的影响。研究表明，纳米凝胶吸附在液-液界面上，其扩散程度受相对降解程度的控制。我们证明，根据软界面的性质，破碎的碎片可以分散到其中一个相或吸附在界面上，从而在纳米尺度上增强界面覆盖并控制界面性质。我们的研究为使用受控降解来动态调整纳米载体的形状和液-液界面的纳米级形貌提供了见解。
Via mesoscale simulations, we characterize the process of controlled degradation of nanogels suspended in a single solvent and those adsorbed at the liquid–liquid interface between two incompatible fluids. Controlled degradation is of interest since it can be used to dynamically tailor size, shape, and transport properties of these soft particles. For the nanogels adsorbed at the liquid–liquid interfaces, controlled degradation can provide a means to dynamically tailor interfacial properties on the nanoscale. To characterize the degradation process, we track the structural characteristics of the remnant nanogel, such as its radius of gyration and shape anisotropy, and spatiotemporal distribution of the broken-off fragments. We use the dissipative particle dynamics approach with an adapted form of the modified segmental repulsive potential. We identify the reverse gel point and characterize the scaling of this point with the finite number of polymer precursors in the system. Furthermore, we characterize the effects of polymer–solvent interactions on the evolution of shape and effective size of the nanogel during the degradation process. We show that for the nanogel adsorbed onto the liquid–liquid interface, the extent of spreading is controlled by the relative extent of degradation. We demonstrate that depending on the properties of the soft interface, broken-off fragments can either disperse into one of the phases or adsorb onto the interface, enhancing the interfacial coverage and controlling interfacial properties on the nanoscale. Our study provides insights into using controlled degradation to dynamically tune shapes of nanocarriers and nanoscale topography at the liquid–liquid interfaces.