Nakajima Tasuku, Fukuda Yuki, Kurokawa Takayuki, Sakai Takamasa, Chung Ung-Il, Gong Jian Ping
Faculty of Advanced Life Science, Hokkaido University, N10W8, Kita-ku, Sapporo, Hokkaido, 060-0810, Japan.
School of Science, Hokkaido University, N10W8, Kita-ku, Sapporo, Hokkaido, 060-0810, Japan.
ACS Macro Lett. 2013 Jun 18;2(6):518-521. doi: 10.1021/mz4002047. Epub 2013 May 30.
To investigate the effect of inhomogeneity in the first network on the enormously high toughness of double network (DN) gels, we fabricated DN gels with a nearly homogeneous first network structure (named St-TPEG/PAAm DN gels) based on tetra-PEG (TPEG) gels via a molecular stent method. The St-TPEG/PAAm DN gels also show excellent mechanical properties and yielding-like phenomena comparable to conventional DN gels. This result demonstrates that the inhomogeneity within the first network is not essential for the specific toughening mechanism of DN gels. On the other hand, the St-TPEG/PAAm DN gels and conventional DN gels undergo substantially different fracture processes before the yielding point. This suggests the importance of a "homogenization process" for the yielding of DN gels. Since the St-TPEG/PAAm DN gels consist of a well-defined first network, they may serve as model DN gels in the future for further studies on fracture processes of DN gels.
为了研究第一个网络中的不均匀性对双网络（DN）凝胶极高韧性的影响，我们通过分子支架法基于四聚乙二醇（TPEG）凝胶制备了具有近乎均匀的第一个网络结构的DN凝胶（命名为St-TPEG/PAAm DN凝胶）。St-TPEG/PAAm DN凝胶也表现出与传统DN凝胶相当的优异力学性能和类屈服现象。这一结果表明，第一个网络内的不均匀性对于DN凝胶的特定增韧机制并非必不可少。另一方面，St-TPEG/PAAm DN凝胶和传统DN凝胶在屈服点之前经历了截然不同的断裂过程。这表明“均匀化过程”对DN凝胶的屈服很重要。由于St-TPEG/PAAm DN凝胶由定义明确的第一个网络组成，它们未来可能作为模型DN凝胶用于进一步研究DN凝胶的断裂过程。
