期刊
ACS APPLIED MATERIALS & INTERFACES
卷 13, 期 27, 页码 32510-32519出版社
AMER CHEMICAL SOC
DOI: 10.1021/acsami.1c07259
关键词
Janus particles; Janus emulsions; catalysis; polymers; self-assembly
资金
- MaxPlanck Society through the Emmy-Noether program of the German Research Foundation [ZE 1121/3-1]
- Experiment! program of the Volkswagen (VW) foundation
Janus particles have a strong tendency to directionally assemble and segregate to interfaces, offering advantages as colloidal analogues of molecular surfactants to enhance stability of multiphasic mixtures. A novel one-step synthetic approach for generating amphiphilic polymer Janus particles with highly uniform and tunable wettability contrasts has been developed, utilizing reconfigurable bi-phasic Janus emulsions as particle scaffolds. This versatile method allows for fine-tuning of internal droplet geometry and the generation of Janus particles with adjustable wettability profiles.
Janus particles exhibit a strong tendency to directionally assemble and segregate to interfaces and thus offer advantages as colloidal analogues of molecular surfactants to improve the stability of multiphasic mixtures. Investigation and application of the unique adsorption properties require synthetic procedures that enable careful design and reliable control over the particles' asymmetric chemistry and wettability profiles with high morphological uniformity across a sample. Herein, we report on a novel one-step synthetic approach for the generation of amphiphilic polymer Janus particles with highly uniform and tunable wettability contrasts, which is based on using reconfigurable bi-phasic Janus emulsions as versatile partide scaffolds. Two phase-separated acrylate oils were used as the constituent droplet phases and transformed into their solidified Janus partide replicas via UV-induced radical polymerization. Using Janus emulsions as particle precursors offers the advantage that their internal droplet geometry can be fine-tuned by changing the force balance of surface tensions acting at the individual interfaces via surfactants or the volume ratio of the constituent phases. In addition, preassembled functional surfactants at the droplet interfaces can be locked in position upon polymerization, which enables both access toward postfunctionalization reaction schemes and the generation of highly uniform Janus particles with adjustable wettability profiles. Depending on the particle morphology and wettability, their interfacial position can be adjusted, which allows us to stabilize either air bubbles-in-water or water droplets-in-air (liquid marbles). Motivated by the interfacial activity of the particles and particularly the longevity of the resulting particle-stabilized air-in-water bubbles, we explored their ability to promote the delivery of oxygen inside a liquid-phase reaction medium, namely, for the heterogeneous Au-NP-mediated catalytic oxidation of D-glucose. We observed a 2.2-fold increase in the reaction rate attributed to the increase of the local concentration of oxygen around catalysts, thus showcasing a new strategy to overcome the limited solubility of gases in aqueous reaction media.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据