使用动态光散射DLS详细研究了聚合物水凝胶MC-co-MA的pH和热响应行为,扫描电镜,SEM,核磁共振(1HNMR)和流变学来评估构象变化,膨胀-收缩,稳定性,纳米粒子在几种温度下的流动能力和扩散过程。此外,用丙烯酸MC和丙烯酰胺MA官能化的聚合物体系用氯化钙CaCl2溶液进行滴定过程,以分析其对平均粒径Dz的影响,聚合物结构和分子内和分子间相互作用,以便提供响应性聚合物网络,其可以用作具有若干益处的用于药物递送的可能的纳米载体。结果证实,敏感水凝胶的结构变化高度依赖于羧基(-COOH)和酰胺(-CONH2)官能团的相应临界溶解温度CST以及钙离子Ca2对形成或破坏的影响氢键,以及聚合物链之间产生的静电排斥力的降低,有助于颗粒团聚现象。温度导致聚合物链的重排,影响水凝胶的粘弹性。此外,评估了纳米粒子的扩散系数D,显示出与形态之间的亲密关系,形状,尺寸和温度,导致较大粒径的扩散较慢,相反,随着聚合物尺寸的减小,介质中的扩散增加。因此,水凝胶对环境中的pH和温度变化表现出明显的响应。在这项研究中,在不同的分析条件下观察到聚合物纳米粒子的功能和行为,这揭示了显着的结构变化,并进一步证明了纳米颗粒有望用于药物递送应用的高潜力。因此,这些结果引发了人们对各种科学的浓厚兴趣,工业和技术领域。
The pH- and thermo-responsive behavior of polymeric hydrogels MC-co-MA have been studied in detail using dynamic light scattering DLS, scanning electron microscopy SEM, nuclear magnetic resonance (1H NMR) and rheology to evaluate the conformational changes, swelling-shrinkage, stability, the ability to flow and the diffusion process of nanoparticles at several temperatures. Furthermore, polymeric systems functionalized with acrylic acid MC and acrylamide MA were subjected to a titration process with a calcium chloride CaCl2 solution to analyze its effect on the average particle diameter Dz, polymer structure and the intra- and intermolecular interactions in order to provide a responsive polymer network that can be used as a possible nanocarrier for drug delivery with several benefits. The results confirmed that the structural changes in the sensitive hydrogels are highly dependent on the corresponding critical solution temperature CST of the carboxylic (-COOH) and amide (-CONH2) functional groups and the influence of calcium ions Ca2+ on the formation or breaking of hydrogen bonds, as well as the decrease in electrostatic repulsions generated between the polymer chains contributing to a particle agglomeration phenomenon. The temperature leads to a re-arrangement of the polymer chains, affecting the viscoelastic properties of the hydrogels. In addition, the diffusion coefficients D of nanoparticles were evaluated, showing a closeness among with the morphology, shape, size and temperature, resulting in slower diffusions for larger particles size and, conversely, the diffusion in the medium increasing as the polymer size is reduced. Therefore, the hydrogels exhibited a remarkable response to pH and temperature variations in the environment. During this research, the functionality and behavior of the polymeric nanoparticles were observed under different analysis conditions, which revealed notable structural changes and further demonstrated the nanoparticles promising high potential for drug delivery applications. Hence, these results have sparked significant interest in various scientific, industrial and technological fields.