Agarose is a natural polymer extracted from algae that has the property of forming physical gels in aqueous solutions when heat is removed from the system. This property holds considerable potential considering its applications in food and pharmaceutical industries, especially for DNA analysis. In this article, different concentrations of agarose in aqueous solutions were submitted to a progressive change in temperature, in order to obtain more or less organized structures of macromolecules. During this process, dynamic light scattering (DLS) and rheological measurements were performed. For scattering measurements, the Kohrausch–William–Watts (KWW) equation was adjusted to the data to obtain the average relaxation rate of the process. Mathematical adjustments were made for both techniques, aiming to study the helix–coil transition of polymeric chains during the temperature change, relating them by calculating the apparent activation energy of the process. Both approaches showed that apparent active energy tends to decrease for dilute solutions and at high temperatures. Given the results with DLS and rheology, we identify similar points of the aggregate formation through the shape of the activation energy curves. However, we also verified that the activation energy values suffer influence according to the nature of the measure. Graphical abstract Graphical abstract

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通过流变学和 DLS 分析研究琼脂糖聚集体的形成

琼脂糖是一种从藻类中提取的天然聚合物，当从系统中去除热量时，它具有在水溶液中形成物理凝胶的特性。考虑到其在食品和制药行业的应用，尤其是 DNA 分析，这一特性具有相当大的潜力。在这篇文章中，水溶液中不同浓度的琼脂糖被置于温度的逐渐变化中，以获得或多或少有组织的大分子结构。在此过程中，进行了动态光散射 (DLS) 和流变测量。对于散射测量，根据数据调整 Kohrausch-William-Watts (KWW) 方程以获得过程的平均弛豫率。对这两种技术进行了数学调整，旨在研究温度变化过程中聚合物链的螺旋-螺旋转变，通过计算该过程的表观活化能将它们联系起来。两种方法都表明，在稀溶液和高温下，表观活性能量趋于降低。鉴于 DLS 和流变学的结果，我们通过活化能曲线的形状确定了聚集体形成的相似点。然而，我们还验证了活化能值会受到测量性质的影响。图形摘要图形摘要 我们通过活化能曲线的形状识别聚集体形成的相似点。然而，我们还验证了活化能值会受到测量性质的影响。图形摘要图形摘要 我们通过活化能曲线的形状识别聚集体形成的相似点。然而，我们还验证了活化能值会受到测量性质的影响。图形摘要图形摘要