The preparation and characterization of double-layer microcapsules used for the self-healing of resin matrix composites
The preparation and characterization of double-layer microcapsules used for the self-healing of resin matrix composites
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DOI：
10.1039/c2jm34195f
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发表时间：
2012-11
影响因子：
--
通讯作者：
Ru Tian;X. Fu;Yudong Zheng;Xin Liang;Qiaoli Wang;Ying Ling;B. Hou
中科院分区：
文献类型：
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作者：
Ru Tian;X. Fu;Yudong Zheng;Xin Liang;Qiaoli Wang;Ying Ling;B. Hou
在这项工作中，二氨基二苯砜（DDS）被用作固化剂，吸附在单层微胶囊的外围，Ag-80作为三聚氰胺甲醛树脂（MF）内的固化剂。双层微胶囊是通过原位聚合用 MF 包裹颗粒（DDS 修饰的单层微胶囊）制成的。这些双层微胶囊在周围基质破裂时同时释放愈合剂和固化剂，增加了两种药剂之间的接触率，从而提高了愈合效率。 DDS吸附对双层微胶囊的形成和最终形貌起着重要作用。当使用30%Tween 80和70%Span 80组成的复合分散剂时，分散的DDS颗粒均匀、细小。当pH值在3.5至4.5之间时，分散的DDS和MF(Ag-80)微胶囊具有相反的表面电荷，并且由于静电相互作用而倾向于聚集在一起。通过扫描电子显微镜（SEM）观察微胶囊的形貌。通过红外光谱（FTIR）证明了愈合剂和胶囊失效前固化剂的共存和稳定性。采用纳米压痕技术研究了双层微胶囊的力学性能。结果表明，微胶囊比基体更早破裂修复裂纹，且固化后的微胶囊的力学性能与树脂基体相似。
In this work, diaminodiphenyl sulfone (DDS) was used as a curing agent adsorbed at the periphery of single-layer microcapsules with Ag-80 as the healing agent within melamine-formaldehyde resin (MF). The double-layer microcapsules were made by encapsulating the particulates (the single-layer microcapsules decorated with DDS) with MF via in situ polymerization. These double-layer microcapsules simultaneously release healing agent and curing agent upon the fracture of the surrounding matrix, which increases the rate of contact between the two agents, and thus improves the healing efficiency. DDS adsorption plays an important role in the formation and final morphology of the double-layer microcapsules. When using a compound dispersant consisting of 30% Tween 80 and 70% Span 80, the particulates of dispersed DDS were homogeneous and fine. When the pH value was between 3.5 and 4.5, the dispersed DDS and MF (Ag-80) microcapsules had opposite surface charges, and tended to come together due to electrostatic interactions. The morphologies of the microcapsules were observed by scanning electron microscopy (SEM). The co-existence and stability of the healing agent and the curing agent before capsule failure were demonstrated by infrared spectrometry (FTIR). The mechanical properties of the double-layer microcapsules were investigated by nanoindentation. The results indicated that the microcapsules fractured earlier than the matrix to repair a crack, and the mechanical properties of the cured microcapsules were similar to those of the resin matrix.