Wood Technology and Wood Chemistry, Georg-August-University of Goettingen, Büsgenweg 4, 37077 Göttingen, Germany.
Wood Technology and Wood Chemistry, Georg-August-University of Goettingen, Büsgenweg 4, 37077 Göttingen, Germany; College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang, Jiangxi 330022, PR China.
J Colloid Interface Sci. 2018 Mar 1;513:629-637. doi: 10.1016/j.jcis.2017.11.079. Epub 2017 Nov 29.
Hydrophobic particles with static water contact angles larger than 90° are more like to stabilize W/O Pickering emulsions. In particular, high internal phase Pickering emulsions (HIPEs) are of great interest for diverse applications. However, W/O HIPEs have rarely been realized using sustainable biopolymers. Herein, we used stearoylated microcrystalline cellulose (SMCC) to stabilize W/O Pickering emulsions and especially, W/O HIPEs. Moreover, these W/O HIPEs can be further used as platforms for the preparation of porous materials, such as porous foams.
Stearoylated microcrystalline cellulose (SMCC) was prepared by modifying MCC with stearoyl chloride under heterogeneous conditions. Using SMCC as emulsifiers, W/O medium and high internal phase Pickering emulsions (MIPEs and HIPEs) with various organic solvents as continuous phases were prepared using one-step and two-step methods, respectively. Polystyrene (PS) foams were prepared after polymerization of oil phase using HIPEs as templates and their oil/water separation capacity were studied.
SMCC could efficiently stabilize W/O Pickering emulsions and HIPEs could only be prepared via the two-step method. The internal phase volume fraction of the SMCC-stabilized HIPEs reached as high as 89%. Diverse internal phase volume fractions led to distinct inner structures of foams with closed or open cells. These macroporous polystyrene (PS) foams demonstrated great potential for the effective absorption of organic solvents from underwater.
静态水接触角大于 90°的疏水颗粒更有可能稳定 W/O Pickering 乳液。特别是，高内相比 Pickering 乳液（HIPE）在各种应用中非常有吸引力。然而，使用可持续的生物聚合物很少实现 W/O HIPE。在此，我们使用硬脂酰化微晶纤维素（SMCC）稳定 W/O Pickering 乳液，特别是 W/O HIPE。此外，这些 W/O HIPE 可以进一步用作制备多孔材料（如多孔泡沫）的平台。
硬脂酰化微晶纤维素（SMCC）通过在非均相条件下用硬脂酰氯修饰 MCC 制备。使用 SMCC 作为乳化剂，分别使用一步法和两步法制备了以各种有机溶剂为连续相的 W/O 中相与高内相比 Pickering 乳液（MIPE 和 HIPE）。使用 HIPE 作为模板聚合油相后制备聚苯乙烯（PS）泡沫，并研究了其油水分离能力。
SMCC 可以有效地稳定 W/O Pickering 乳液，并且只能通过两步法制备 HIPE。SMCC 稳定的 HIPE 的内部相体积分数高达 89%。不同的内部相体积分数导致泡沫的内部结构不同，有闭孔或开孔。这些大孔聚苯乙烯（PS）泡沫在有效吸收水下有机溶剂方面表现出巨大的潜力。
