D'Acierno Francesco, Capron Isabelle
UR1268 Biopolymères Interactions Assemblages, INRAE, F-44316 Nantes, France.
Carbohydr Polym. 2023 Nov 1;319:121159. doi: 10.1016/j.carbpol.2023.121159. Epub 2023 Jun 28.
Cellulose nanocrystals (CNCs) are hydrophilic nanoparticles that cannot be dispersed in non-polar solvents or hydrophobic polymer matrices. Here, we demonstrate the tunable modification of CNC surfaces by physical adsorption of tannic acid (TA) and two alkyl cellulose derivatives (ACDs), methyl cellulose (MC) and ethyl cellulose (EC), while maintaining their sustainable nature. We compare the impact of ACD adsorption when mixed with CNCs to CNCs precoated with tannic acid (CNC@TA), varying ACD weight fractions in CNC suspensions. Our results show that CNC@ACD and CNC@TA@ACD aqueous suspensions display good colloidal stability in water, while their surface properties are altered. We use a wide range of analytical techniques to characterize these suspensions, with a focus on their interaction with water. The two selected ACDs adsorb on both CNCs and CNC@TA at low fractions (ACD ≤ 10 % w/w), followed by an intermediate region of saturation between 10 % and 30 % w/w. At fractions above 30 % w/w, we observe the formation of CNC- or CNC@TA-reinforced ACD composites. Most samples can be redispersed in water upon freeze-drying, except for EC-rich samples redispersible in toluene. Our facile method for preparing ACD-coated CNCs allows for the creation of a range of nanomaterials with modulable wetting and emulsification properties.
纤维素纳米晶体（CNCs）是亲水性纳米颗粒，不能分散在非极性溶剂或疏水性聚合物基质中。在此，我们展示了通过单宁酸（TA）以及两种烷基纤维素衍生物（ACD），即甲基纤维素（MC）和乙基纤维素（EC）的物理吸附对CNC表面进行可调谐修饰，同时保持其可持续性。我们将与CNCs混合时ACD吸附的影响与预先用单宁酸包覆的CNCs（CNC@TA）进行比较，在CNC悬浮液中改变ACD的重量分数。我们的结果表明，CNC@ACD和CNC@TA@ACD水悬浮液在水中表现出良好的胶体稳定性，同时其表面性质发生了改变。我们使用多种分析技术来表征这些悬浮液，重点是它们与水的相互作用。两种选定的ACD在低分数（ACD≤10% w/w）下吸附在CNCs和CNC@TA上，随后在10%至30% w/w之间存在一个中间饱和区域。在分数高于30% w/w时，我们观察到形成了CNC或CNC@TA增强的ACD复合材料。除了富含EC的样品可在甲苯中重新分散外，大多数样品在冷冻干燥后可在水中重新分散。我们制备ACD包覆CNCs的简便方法允许创建一系列具有可调润湿性和乳化性能的纳米材料。
