Selzer Lukas, Odenbach Stefan
Institute of Mechatronic Engineering, Chair of Magnetofluiddynamics, Measuring and Automation Technology, Technische Universität Dresden, George-Bähr-Str. 3, 01062 Dresden, Germany.
Gels. 2023 Feb 25;9(3):182. doi: 10.3390/gels9030182.
Hydrogels are functional smart materials which can be tailored by modifying their chemical composition. Further functionalization can be achieved by incorporating magnetic particles into the gel matrix. In this study, a hydrogel with magnetite micro-particles is synthesized and characterized by rheological measurements. Inorganic clay is used as the crosslinking agent, which additionally prevents the sedimentation of the micro-particles during the synthesis of the gel. The mass fractions for the magnetite particles in the synthesized gels range from 10% to 60% in the initial state. Rheological measurements are performed in different degrees of swelling using temperature as a stimulus. The influence of a homogeneous magnetic field is analyzed by a step-wise activation and deactivation during dynamic mechanical analysis. For the evaluation of the magnetorheological effect in the steady states a procedure is developed, which takes occurring drift effects into account. Using the magnetic flux density, the particle volume fraction and the storage modulus as independent parameters, a general product approach is deployed for a regression analysis of the dataset. In the end, an empirical law for the magnetorheological effect in nanocomposite hydrogels can be found.
水凝胶是一种功能性智能材料，可以通过改变其化学成分进行定制。通过将磁性颗粒掺入凝胶基质中，可以实现进一步的功能化。在本研究中，合成了一种含有磁铁矿微粒的水凝胶，并通过流变学测量对其进行了表征。无机粘土用作交联剂，此外还可防止微粒在凝胶合成过程中沉降。合成凝胶中磁铁矿颗粒的初始质量分数范围为10%至60%。使用温度作为刺激因素，在不同溶胀程度下进行流变学测量。在动态力学分析过程中，通过逐步激活和去激活来分析均匀磁场的影响。为了评估稳态下的磁流变效应，开发了一种考虑到发生的漂移效应的程序。使用磁通密度、颗粒体积分数和储能模量作为独立参数，采用一般乘积法对数据集进行回归分析。最终，可以找到纳米复合水凝胶中磁流变效应的经验定律。
