A Study of Physical and Covalent Hydrogels Containing pH-Responsive Microgel Particles and Graphene Oxide
A Study of Physical and Covalent Hydrogels Containing pH-Responsive Microgel Particles and Graphene Oxide
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DOI：
10.1021/la5032015
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发表时间：
2014-11-11
期刊：
影响因子：
3.9
通讯作者：
Saunders, Brian R.
中科院分区：
文献类型：
--
作者：
Cui, Zhengxing;Milani, Amir H.;Saunders, Brian R.
在这项研究中，我们将低浓度的氧化石墨烯（GO）与微凝胶（MG）颗粒混合，形成复合双交联微凝胶（DX MG/GO）凝胶。 MG颗粒包含具有侧链甲基丙烯酸缩水甘油酯单元的聚(丙烯酸乙酯-共聚-甲基丙烯酸-共聚-1,4-丁二醇二丙烯酸酯)。 MG/GO 混合分散体形成单交联 MG 的物理凝胶（称为 SX MG/GO），随后加热通过自由基反应生成 DX MG/GO 凝胶。使用动态流变学和静态压缩测量研究了 GO 浓度对 SX MG/GO 和 DX MG/GO 凝胶机械性能的影响。 SX MG/GO 物理凝胶是可注射和可模制的。当仅约 DX MG/GO 凝胶的模量增加时，其模量增加了 4-6 倍。包含 1.0 wt% 的 GO。等应变模型用于描述模量随 DX MG/GO 组成的变化。 GO 的加入极大地改变了凝胶的应力消散和屈服机制。 GO 充当高表面积、高模量填料，并且随着 GO 浓度的增加，在负载分布中发挥越来越大的作用。有人提出 MG 域分散在渗透的 GO 网络中。将模量数据与已发布的不含 GO 的 DX MG 的模量数据进行比较表明，包含 GO 为该胶体凝胶系列提供了前所未有的模量随网络体积分数增加的速度。此外，DX MG/GO 凝胶具有生物相容性，结果表明这些新系统未来可能会应用作为用于软组织修复的可注射负载支持凝胶。
In this study we mixed low concentrations of graphene oxide (GO) with microgel (MG) particles and formed composite doubly cross-linked microgels (DX MG/GO) gels. The MG particles comprised poly(ethyl acrylate-co-methacrylic acid-co-1,4-butanediol diacrylate) with pendant glycidyl methacrylate units. The MG/GO mixed dispersions formed physical gels of singly cross-linked MGs (termed SX MG/GO), which were subsequently heated to produce DX MG/GO gels by free-radical reaction. The influence of the GO concentration on the mechanical properties of the SX MG/GO and DX MG/GO gels was investigated using dynamic rheology and static compression measurements. The SX MG/GO physical gels were injectable and moldable. The moduli for the DX MG/GO gels increased by a factor of 4-6 when only ca. 1.0 wt % of GO was included. The isostrain model was used to describe the variation of modulus with DX MG/GO composition. Inclusion of GO dramatically altered the stress dissipation and yielding mechanisms for the gels. GO acted as a high surface area, high modulus filler and played an increasing role in load distribution as the GO concentration increased. It is proposed that MG domains were dispersed within a percolated GO network. Comparison of the modulus data with those published for GO-free DX MGs showed that inclusion of GO provided an unprecedented rate of modulus increase with network volume fraction for this family of colloid gels. Furthermore, the DX MG/GO gels were biocompatible and the results imply that there may be future applications of these new systems as injectable load supporting gels for soft tissue repair.