Silva Caroline E P, Bernardes Juliana S, Loh Watson
Institute of Chemistry, University of Campinas (UNICAMP), Caixa Postal 6154, 13083-970 Campinas, SP, Brazil; Brazilian Nanotechnology National Laboratory (LNNano), CNPEM, 13083-970 Campinas, SP, Brazil.
Brazilian Nanotechnology National Laboratory (LNNano), CNPEM, 13083-970 Campinas, SP, Brazil; Center for Natural and Human Sciences, Federal University of ABC, Santo André, SP 09210-580, Brazil.
Carbohydr Polym. 2023 Feb 15;302:120354. doi: 10.1016/j.carbpol.2022.120354. Epub 2022 Nov 15.
Nanocellulose is a well-known stabilizer for several colloidal dispersions, including emulsions and solid nanoparticles, replacing surfactants, polymers, and other additives, and therefore providing more minimalistic and eco-friendly formulations. However, could this ability be extended to stabilize oil droplets and inorganic nanoparticles simultaneously in the same colloidal system? This work aimed to answer this question. We evaluated both cationic and anionic nanofibrillated celluloses to stabilize both titanium dioxide nanoparticles and oil droplets. The resulting suspensions held their macroscopic stability for up to 2 months, regardless of pH or surface charge. Cryo-TEM images revealed a complex network formation involving nanofibers and TiO nanoparticles, which agrees with the high viscosity values and gel-like behavior found in rheology measurements. We propose that the formation of this network is responsible for the simultaneous stabilization of oil droplets and TiO nanoparticles, and that this may be used as a formulation tool for other complex systems.
纳米纤维素是几种胶体分散体系（包括乳液和固体纳米颗粒）中广为人知的稳定剂，可替代表面活性剂、聚合物和其他添加剂，从而提供更简约且环保的配方。然而，这种能力能否扩展到在同一胶体体系中同时稳定油滴和无机纳米颗粒呢？这项工作旨在回答这个问题。我们评估了阳离子和阴离子纳米纤化纤维素对二氧化钛纳米颗粒和油滴的稳定作用。所得悬浮液在长达2个月的时间内保持宏观稳定性，不受pH值或表面电荷的影响。低温透射电子显微镜图像显示形成了一个涉及纳米纤维和二氧化钛纳米颗粒的复杂网络，这与流变学测量中发现的高粘度值和凝胶状行为相符。我们认为，这个网络的形成是油滴和二氧化钛纳米颗粒同时稳定的原因，并且这可作为其他复杂体系的一种配方工具。
