Mandal Joydeb, Varunprasaath R S, Yan Wenqing, Divandari Mohammad, Spencer Nicholas D, Dübner Matthias
Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, CH-8093 Zurich, Switzerland. Email:
Indian Institute of Science, Bangalore, India.
RSC Adv. 2018 Jun 3;8(36):20048-20055. doi: 10.1039/c8ra03073a. Epub 2018 May 31.
An investigation of the polymerisation of 2-hydroxyethyl methacrylate (HEMA) by means of surface-initiated atom transfer radical polymerisation (SI-ATRP) has been carried out using a quartz crystal microbalance, with multiple reinitiations under continuous flow of the reaction mixture. The SI-ATRP kinetics of HEMA were studied continuously by means of changes in the frequency, varying conditions including temperature and solvent composition, as well as monomer and catalyst concentrations, showing the influence of key reaction parameters on SI-ATRP kinetics. Such experiments enabled the design of a polymerisation protocol that leads to a reasonably fast but well-controlled growth of poly(HEMA) brushes. Furthermore, only a minor change in growth rate was observed when the polymerisation was stopped and reinitiated multiple times (essential for block synthesis), demonstrating the living nature of the SI-ATRP reaction under such conditions. The clean switching of reaction mixtures in the flow-based QCM has been shown to be a powerful tool for real-time studies of surface-initiated polymerisation reactions, and a promising approach for the precise fabrication of block-containing brush structures.
利用石英晶体微天平，通过表面引发原子转移自由基聚合（SI-ATRP）对甲基丙烯酸2-羟乙酯（HEMA）的聚合反应进行了研究，反应混合物在连续流动下进行多次再引发。通过频率变化、改变包括温度和溶剂组成以及单体和催化剂浓度等条件，持续研究了HEMA的SI-ATRP动力学，显示了关键反应参数对SI-ATRP动力学的影响。此类实验使得能够设计出一种聚合方案，该方案能实现聚（HEMA）刷的合理快速且可控生长。此外，当聚合反应停止并多次重新引发时（这对于嵌段合成至关重要），仅观察到生长速率有微小变化，这证明了在此类条件下SI-ATRP反应的活性特征。基于流动的石英晶体微天平中反应混合物的清洁切换已被证明是用于表面引发聚合反应实时研究的有力工具，也是精确制造含嵌段刷结构的一种有前景的方法。
