Rheological investigation of the structural properties and aging effects in the agarose/co-solute mixture
Rheological investigation of the structural properties and aging effects in the agarose/co-solute mixture
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DOI：
10.1016/s0144-8617(02)00327-2
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发表时间：
2003-07-01
影响因子：
11.2
通讯作者：
Mitchell, JR
中科院分区：
文献类型：
--
作者：
Deszczynski, M;Kasapis, S;Mitchell, JR
采用小变形动态振荡、大变形压缩和蠕变试验研究了琼脂糖在蔗糖和葡萄糖浆50：50混合物中的结构特性。共溶质的含量在混合物中从10%至93%变化。增加糖的添加量逐渐将多糖的无定形、脆性网络转变为热稳定性增强的“橡胶状”结构。在饱和的固体水平下，存在从琼脂糖网络的凝胶状特征到共溶质的连续相的液体状响应的相转化。后者在冷却时经历玻璃化，从而表现出机械玻璃化转变区和玻璃态。随着时间的推移，琼脂糖螺旋的残留发展和最终的三维连接将高粘度液体恢复为橡胶状凝胶，表现出相当大的屈服应变（140%变形）。这项工作相比，糖/多糖的混合物在文献中，以合理化的基本分子过程和定义的普遍影响。(C)2003爱思唯尔科技有限公司版权所有。
Small deformation dynamic oscillation, large deformation compression and creep testing were carried out to examine the structural properties of agarose in the presence of 50:50 preparations of sucrose and glucose syrup. The content of co-solute varied from 10 to 93% in the mixture. Increasing additions of sugar transform gradually the enthalpic, brittle networks of the polysaccharide to 'rubbery' structures of enhanced thermal stability. At saturated levels of solids there is a phase inversion from the gel-like characteristics of the agarose network to the liquid-like response of the continuous phase of co-solute. The latter undergoes vitrification upon cooling thus exhibiting the mechanical glass transition region and the glassy state. Given time, vestigial development and eventual three-dimensional linkage of agarose helices reverts the high viscosity liquids to rubbery gels exhibiting considerable yield strain (140% deformation). The work is compared to sugar/polysaccharide mixtures in the literature with the view to rationalizing underlying molecular processes and defining universal effects. (C) 2003 Elsevier Science Ltd. All rights reserved.