Tailored polymers as nucleation templates for the synthesis of fluorescing nanodiamonds

该项目将建立一个强大的协议，通过聚合物模板工艺控制合成亚10纳米荧光纳米金刚石（ND）。所述聚合物将包含金刚烷型类金刚石位点以促进有效的成核和生长，以及杂原子携带部分（主要是N，但也有Si、Ge）以实现杂原子空位缺陷（位置、数量）的受控注入。·种子聚合物将应用于高压高温（HPHT）工艺中，以使用来自“反应性烃”（异十六烷/二十四烷）的碳供应来生长ND，如已知的用于小分子模板和我们用于聚合物模板化ND的初步结果。·空缺将通过与当地团体合作进行的电子束照射或离子束处理来引入。退火将根据标准程序在真空中或在惰性气氛下在约800 °C的温度下进行。·我们将首先通过电子显微镜分析所获得的ND，然后通过光学显微镜上的吸收和荧光光谱来研究所产生的NV（和SiV，GeV）中心的性质，光致发光量子产率和寿命，以获得有关缺陷浓度的信息。对于最有前途的样品，我们将转向自相关技术，并与量子光学研究所合作研究具有单一色心的样品的磁光效应。聚合物方法允许模板单元的高局部浓度，控制其位置以及精确掺入缺陷。与小分子模板相比，ND的产率和质量将大大提高。该项目的具体目标是，在复杂性增加：1。（杂）金刚烷基单体及其聚合物的制备将进行具有限定的单峰和窄摩尔质量分布的种子大分子和各种含N、Si和Ge的金刚烷基单体的聚合，以提供用于HPHT过程的理想成核位点。2.生产具有多个色心的高荧光和稳定的ND将在聚合物模板中掺入受控量的氮杂-、硅杂-和锗金刚烷基以控制杂原子空位中心。对于NV中心，我们将检查是否可以通过控制电子束加速电压和退火温度来控制NV中心（NV 0或NV-）的性质。3.具有单一色心的小ND的产生分别用氮杂-、硅杂-或锗金刚烷或衍生物的端基官能化将允许我们每个聚合物模板单元仅引入一种杂原子物质以最终合成具有单一色心的几纳米范围内的纳米金刚石，该方法将被确立为自下而上合成荧光纳米金刚石的新黄金标准。

• The project will establish a robust protocol for the controlled synthesis of sub-10-nm fluorescing nanodiamonds (NDs) by a polymer templating process. The polymers will comprise adamantane-type diamondoid sites to facilitate efficient nucleation and growth as well as heteroatom-carrying moieties (mainly N but also Si, Ge) to achieve controlled implantation of heteroatom-vacancy defects (location, number). • The seed polymers will be applied in a high pressure high temperature (HPHT) process to grow NDs using carbon supply from “reactive hydrocarbons” (isocetane/tetracosane) as known for small molecular templates and as we used for the preliminary results on polymer templated NDs. • Vacancies will be introduced by electron beam irradiation or ion beam treatment performed in collaboration with local groups. Annealing will be done at temperatures around 800 °C in vacuum or under inert atmosphere in accordance to standard procedures. • We will analyze the obtained NDs first by electron microscopy and then by absorption and fluorescence spectra on an optical microscope to investigate the nature of the produced NV (and SiV, GeV) centers, photoluminescence quantum yield and lifetime to gain information about the concentration of defects. For the most promising samples, we will turn to autocorrelative techniques and investigate magneto-optical effects on samples with single colour centers in collaboration with the Institute for Quantum Optics. The polymeric approach allows a high local concentration of templating units with control over their location as well as precise incorporation of defects. The yield and quality of the NDs will be strongly improved compared to small molecular templates. The specific goals of this project are, increasing in complexity:1. Preparation of (hetero-)adamantyl monomers and their polymersPolymerization of seed macromolecules with defined monomodal and narrow molar mass distribution and a variety of N, Si, and Ge containing adamantyl monomers will be performed to present ideal nucleation sites for the HPHT process. 2. Production of highly fluorescing and stable NDs with multiple colour centersA controlled amount of aza-, sila- and germaadamantyl will be incorporated into the polymeric templates to steer the heteroatom-vacancy centers. For NV centers we will examine if we can control the nature of the NV center (NV0 or NV-) by controlling the electron-beam acceleration voltage and the annealing temperature. 3. Generation of small NDs with single colour centersEnd group functionalization with aza-, sila-, or germaadamantane or derivatives, respectively, will allow us to incorporate only one heteroatom species per polymeric templating unit to ultimately synthesize nanodiamonds in the range of a few nanometers with single colour centers, which are important as quantum sensors.The process shall be established as a new gold standard for the bottom-up synthesis of fluorescing nanodiamonds.