Gels formed from amino-acid derivatives, their novel rheology as probed by bulk and particle tracking rheological methods
Gels formed from amino-acid derivatives, their novel rheology as probed by bulk and particle tracking rheological methods
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DOI：
10.1016/j.jnnfm.2014.09.008
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发表时间：
2015-08-01
影响因子：
3.1
通讯作者：
Aufderhorst-Roberts, A.
中科院分区：
文献类型：
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作者：
Frith, W. J.;Donald, A. M.;Aufderhorst-Roberts, A.
我们讨论了使用动态光散射粒子微流变学探测Fmoc-酪氨酸凝胶形成的微观结构的长度尺度依赖性。过去使用染料扩散对这些系统的研究表明，Fmoc-酪氨酸能够形成凝胶，如果分子足够大，则该凝胶可以捕获分子，这与由Fmoc-苯丙氨酸形成的那些凝胶不同（萨顿等人，2009年）。这一结果似乎与凝胶微观结构的显微研究不一致，后者表明孔隙率的长度尺度比所使用的分子探针大得多。在这里，我们使用粒子探针为基础的微流变学研究的孔隙率的凝胶在更大的长度尺度上比可能使用分子扩散研究，并表明，有相当多的证据，更大规模的结构存在于凝胶。特别是，我们看到，在任何时候都没有粒子探针为基础的微流变学再现的凝胶体的性质，也有很强的依赖性的探针行为的粒度。这两个结果都表明凝胶中存在粒度级的微观结构特征。(C)2014 Elsevier B.V.
We discuss the use of dynamic light scattering based particle micro-rheology to probe the lengthscale dependence of the microstructures formed by Fmoc-tyrosine gels. Past studies on these systems using dye diffusion have shown that Fmoc-tyrosine is capable of forming gels that can entrap molecules if they are large enough, unlike those gels formed by Fmoc-phenylalanine (Sutton et al., 2009). This result seems at odds with microscopic studies of the gel microstructure, which indicate porosity on much larger lengthscales than the molecular probes used. Here, we use particle probe based micro-rheology to investigate the porosity of the gels on larger lengthscales than is possible using molecular diffusion studies and show that there is considerable evidence of larger scale structures present in the gel. In particular we see that at no point does particle probe based micro-rheology reproduce the bulk properties of the gels, and also that there is strong dependence of the probe behaviour on particle size. Both of these results indicate the presence of microstructural features in the gel that are of the order of the particle size. (C) 2014 Elsevier B.V.