Structural Description of the Interface of Pickering Emulsions Stabilized by Cellulose Nanocrystals
Structural Description of the Interface of Pickering Emulsions Stabilized by Cellulose Nanocrystals
复制标题
DOI：
10.1021/acs.biomac.5b01413
复制
发表时间：
2016-02-01
影响因子：
6.2
通讯作者：
Capron, Isabelle
中科院分区：
文献类型：
--
作者：
Cherhal, Fanch;Cousin, Fabrice;Capron, Isabelle
本研究中使用的棉纤维素纳米晶体（CNC）是具有纳米级尺寸（195 nm长，23 nm宽和6 nm厚）的棒状颗粒，能够稳定皮克林乳液。用小角中子散射（SANS）方法研究了CNC在油水界面上的吸附，并考察了CNC浓度在2 ~ 5 g/L范围内的变化。对于带电和不带电的CNC，分别确定了7和18 nm的乳液液滴周围的界面CNC层的平均厚度，而不管它们在悬浮液中的浓度如何。这表明CNC颗粒作为表面密度变化的单层存在。使用几种相衬变化，中子波矢量（Q）与强度的依赖性表明，CNC仅通过CNC的表面与油相接触，而不浸入油中，因为在整个Q范围内观察到Porod行为，表明油表面在纳米尺度下没有变形。这一结果促进了CNC的（2 0 0）晶面直接与界面相互作用的假设。
The cotton cellulose nanocrystals (CNCs) used in this study are rod-like particles with dimensions in the nanoscale (195 nm long, 23 nm width and 6 nm thick) able to stabilize Pickering emulsions. The adsorption of CNCs at an oil-water interface has been investigated by small angle neutron scattering (SANS) with and without surface charge, and varying CNC concentration from 2 to 5 g/L. Average thicknesses of the interfacial CNC layer around the emulsion droplets of 7 and 18 nm were determined for charged and uncharged CNC, respectively, regardless of their concentration in suspension. This suggests that CNC particles lie as a monolayer varying in surface density. Using several phase contrast variations, the neutron wave vector (Q) dependence with the intensity showed that CNCs are in contact with the oil phase only via the surface of the CNC and not immersed in oil since the Porod behavior is observed over the whole Q-range revealing no deformation of the oil surface at a nanometer scale. This result promotes the postulate that the (2 0 0) crystalline plane of the CNC directly interacts with the interface.