Designing bijels formed by solvent transfer induced phase separation with functional nanoparticles
Designing bijels formed by solvent transfer induced phase separation with functional nanoparticles
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DOI：
10.1039/c9sm00289h
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发表时间：
2019-04-28
期刊：
影响因子：
3.4
通讯作者：
Haase, Martin F.
中科院分区：
文献类型：
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作者：
Boakye-Ansah, Stephen;Schwenger, Matthew S.;Haase, Martin F.
通过溶剂转移诱导相分离 (STrIPS) 形成的双连续界面堵塞乳液凝胶 (bijels) 是新型软材料，在分离、医疗保健或催化方面具有潜在应用。为了促进它们的应用，需要用各种表面化学纳米粒子来制造 STrIPS bijels 的方法。在这里，我们研究了具有不同润湿性（从部分疏水性到极度亲水性）纳米颗粒的 STrIPS bijels 的形成。为此，二氧化硅纳米粒子的表面润湿性通过带有疏水或亲水端基的配体的官能化来调节。我们表明，具有丙烯酸酯基团的部分疏水性颗粒本身可以赋予 STrIPS bijels 短期稳定性。然而，为了实现长期稳定性，需要使用阳离子表面活性剂。部分疏水颗粒需要短链表面活性剂以实现形态稳定性，而甘油官能化亲水颗粒需要双链阳离子表面活性剂。表面活性剂浓度的变化会产生具有可控域尺寸的各种 STrIPS bijel 形态。最后，我们表明纳米粒子上的官能团促进界面交联，以增强 STrIPS bijels。我们的研究为使用各种固体颗粒（无论其表面润湿性如何）来制造在皮克林界面催化和错流微反应器中具有潜在应用的双杰尔斯奠定了基础。
Bicontinuous interfacially jammed emulsion gels (bijels) formed via solvent transfer induced phase separation (STrIPS) are new soft materials with potential applications in separations, healthcare, or catalysis. To facilitate their applications, means to fabricate STrIPS bijels with nanoparticles of various surface chemistries are needed. Here, we investigate the formation of STrIPS bijels with nanoparticles of different wettabilities, ranging from partially hydrophobic to extremely hydrophilic. To this end, the surface wettability of silica nanoparticles is tailored by functionalization with ligands bearing either hydrophobic or hydrophilic terminal groups. We show that partially hydrophobic particles with acrylate groups can impart short-term stability to STrIPS bijels on their own. However, to enable long-term stability, the use of cationic surfactants is needed. Partially hydrophobic particles require short chain surfactants for morphological stability while glycerol-functionalized hydrophilic particles require double chain cationic surfactants. Variation of the surfactant concentration results in various STrIPS bijel morphologies with controllable domain sizes. Last, we show that functional groups on the nanoparticles facilitate interfacial cross-linking for the purposes of reinforcing STrIPS bijels. Our research lays the foundation for the use of a wide variety of solid particles, irrespective of their surface wettabilities, to fabricate bijels with potential applications in Pickering interfacial catalysis and as cross-flow microreactors.