Meltable Biopolymers with magnetic micro segments

新型可熔化和磁性生物材料将被研究，其中包含确定的磁性纳米颗粒的分布模式和片段。通过将多糖与脂肪酸进行酯化反应，合成了熔点可调的生物聚合物。另外，一方面引入了可以光化学交联的不饱和官能团。另一方面，能够实现可逆交联的功能是人们感兴趣的中心。特别是，允许Diels-Alder和Retro-Diels-Alder反应的系统将被调查。这些可逆和不可逆的可熔性生物聚合物衍生物可以负载磁性纳米颗粒。在磁性掺杂材料上对聚合物基质进行局部限制的诱导交联。通过交联，可以在材料中创建具有屏障效应的亚结构。在热处理过程中，这些屏障具有显著更高的粘度或根本不会融化。通过熔融基质与外部磁场梯度的相互作用，磁性颗粒迁移到分段边界并在那里聚集。这使得磁性纳米颗粒可以通过熔融的基质被特定地引导。以这种方式，可以在具有由交联剂预定的磁性纳米颗粒的分布图案的生物聚合物基质中产生多个磁梯度。对粘度和颗粒运动的研究将显示阻挡层如何影响以及如何控制碎片的形成。根据这种颗粒-基质相互作用的数据，将开发出新系统中纳米颗粒迁移率的数学模型。研究了具有磁性微段的固体生物聚合物在交变磁场中的熔融行为。将研究将这些生物聚合物用于执行器等微技术系统的可能性。

Novel meltable and magnetic biomaterials will be studied that contain defined distribution pattern and segments of magnetic nanoparticles. Biopolymers with adjustable melting points are synthesized by esterification of the polysaccharides with fatty acids. Additionally, unsaturated functional groups are introduced that can be photochemically crosslinked, on one hand. On the other, functions that enable a reversible cross-linking are in the center of interest. In particular, systems allowing Diels-Alder and retro-Diels-Alder reactions will be investigated. These reversible and irreversible meltable biopolymer derivatives can be loaded with magnetic nanoparticles. A locally limited, induced crosslinking of the polymer matrix is carried out on the magnetically doped materials. Through the crosslinking, substructures can be created in the material that have a barrier effect. During thermal treatment, these barriers have a significantly higher viscosity or do not melt at all. By interaction of the molten matrix with an external magnetic field gradient, the magnetic particles migrate to the segment boundary and concentrate there. This allows the magnetic nanoparticles to be specifically directed through the molten matrix. In this way, multiple magnetic gradients can be generated in the biopolymer matrix having a distribution pattern of the magnetic nanoparticles that is predetermined by the crosslinking. Studies on viscosity and particle motion will show how the barrier effect and how the formation of the segments can be controlled. A mathematical model for the mobility of nanoparticles in the novel systems will be developed from the data for this particle-matrix interaction. The melting behavior in the alternating magnetic field is investigated on solid biopolymers with magnetic microsegments. The possibility of using these biopolymers in micro-technological systems such as actuators will be investiaged.