Elucidation of the buildup mechanism of eumelanin particles and specific isolation of intermediates

真黑素是一种具有特殊材料性能的生物颜料，如防辐射、清除自由基、顺磁性、受控药物释放和混合电导率。黑色素的堆积包括分子和超分子方面。分子方面是很好理解的。然而，最终粒子的超分子积聚大多是未知的。这在很大程度上是由于与该系统相关的特定挑战，因为完整的合成包括三个主要的重叠方面：单体合成、聚合和超分子粒子形成。此外，每个方面都包括几个反应步骤。在自己的初步研究中，首次获得了关于颗粒形成的结果。很明显，集结由四个不同的层级组成。特定的颗粒类型是非常单分散的，并且可以通过每个大小一个数量级的大小变化来区分。在此基础上，提出了一个完整构筑过程的机理，并将其作为工作假设包含在本方案中。本项目的目的是完整地阐明真黑素的超分子构筑。此外，希望在适用的量内对这种堆积中的每种颗粒类型进行具体分离。这是通过三重指导原则实现的，包括(I)用于参数控制和现场分析的定制反应器，(Ii)时间分辨散射法，和(Iii)显微镜。首先，将用这种方法研究各种参数和前驱体对超分子聚集的影响，以获得对过程的控制。这应允许加速、减速或抑制积聚中的每一步。此外，每个积聚步骤的潜在机制将被完整地阐明，以获得对整个过程的深入了解。合并后的结果将最终实现每种颗粒类型的克量的稳定分离，用于未来在创新材料中的应用。

Eumelanin is a biological pigment with extraordinary materials properties like radiation protection, radical scavenging, paramagnetism, controlled drug release, and hybrid electrical conductivity. The buildup of melanin pigments includes a molecular and a supramolecular aspect. The molecular aspect is quite well understood. The supramolecular buildup to the final particles however, is mostly unknown. This is to a great extent due to the specific challenges, connected to this system, as the complete synthesis consists of three major, overlapping aspects: Monomer synthesis, polymerization, and supramolecular particle formation. Moreover, each aspect consists of several reaction steps.First results on the particle formation have been gained in own preliminary research. It became clear that the buildup consists of four distinct, hierarchical levels. The specific particle types are quite monodisperse and are distinguishable by size variations of one order of magnitude each. Based on this, a mechanism for the complete buildup process was proposed, which is included in this proposal as working hypothesis.The aim of this project is a complete elucidation of the supramolecular buildup of eumelanin. Additionally, specific isolation of every particle type within this buildup in applicable amounts is aspired. This is realized by a three-fold guiding principle consisting of (i) a tailor-made reactor for parameter control and in situ analytics, (ii) time resolved scattering methods, and (iii) microscopy.First, influences of the various parameters and precursors on the supramolecular buildup will be investigated with this approach, to gain control over the process. This shall allow for acceleration, deceleration, or inhibition of each step within the buildup. Moreover, the underlying mechanisms of each buildup-step will be elucidated completely, to gain a deep understanding of the entire process. The combined results will finally enable stable isolation of gram-amounts of every particle type for future application in innovative materials.