Structure Characterization of Tetra-PEG Gel by Small-Angle Neutron Scattering
Structure Characterization of Tetra-PEG Gel by Small-Angle Neutron Scattering
复制标题
DOI：
10.1021/ma802280n
复制
发表时间：
2009-02-24
期刊：
影响因子：
5.5
通讯作者：
Shibayama, Mitsuhiro
中科院分区：
文献类型：
--
作者：
Matsunaga, Takuro;Sakai, Takamasa;Shibayama, Mitsuhiro
用小角中子散射(SANS)研究了四臂聚乙二醇凝胶(PEG四臂)形成的新型生物相容性、易制备性和高强度水凝胶的结构。由于Tetra-PEG凝胶是由两种末端分别具有不同官能团的四臂聚乙二醇大单体，即胺基和琥珀酰亚胺基酯基团交叉末端偶联而成，所以偶联反应仅发生在带有不同官能团的聚乙二醇链之间。SANS结果表明，多臂高斯链的理论散射函数和Ornstein-Zernike函数分别能很好地描述四臂聚乙二醇大分子水溶液和四聚乙二醇凝胶。令人惊讶的是，在Tetra-PEG凝胶中没有观察到明显的交联性过度散射，这表明它的网络结构非常均匀。对非化学计量比的Tetra-PEG凝胶的研究表明，力学性能减弱，网络中的悬链(缺陷)增加。结果表明，Tetra-PEG凝胶具有非常均匀的网络结构，很可能模仿了类钻石结构，这是Tetra-PEG凝胶具有优异力学性能的原因之一。
The structure of Tetra-PEG gel, a new class of biocompatible, easy-made, and high-strength hydrogel consisting of a four-arm polyethylene glycol (PEG) network, has been investigated by means of small-angle neutron scattering (SANS). Since the Tetra-PEG gel is prepared by cross-end-coupling two kinds of four-arm PEG macromers having different functional groups at the ends, i.e., amine group and succinimidyl ester group respectively, the coupling reaction occurs exclusively between PEG chains carrying different functional groups. SANS results showed that the four-arm PEG macromer aqueous solutions and Tetra-PEG gels were successfully described by the theoretical scattering function for multiarm Gaussian chains and the Ornstein-Zernike function, respectively. Surprisingly, no noticeable excess scattering that originated from cross-linking was observed in Tetra-PEG gels, suggesting that its network structure is extremely uniform. Investigations on nonstoichiometric Tetra-PEG gels showed weakening of the mechanical properties as well as an increase of dangling chains (defects) in the network. It is concluded that Tetra-PEG gels have an extremely uniform network structure, probably mimicking a diamond-like structure, and this is one of the reasons for the advanced mechanical properties of Tetra-PEG gels.