Wood Technology and Wood Chemistry, Georg-August-Universität Göttingen, Büsgenweg 4, D-37077 Göttingen, Germany.
Center of Excellence for Polysaccharide Research, Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University of Jena, Humboldtstr. 10, D-07743 Jena, Germany.
Nanoscale. 2016 Jan 7;8(1):648-57. doi: 10.1039/c5nr05862g.
Stimuli-responsive nanoparticles (NPs) based on sustainable polymeric feedstock still need more exploration in comparison with NPs based on synthetic polymers. In this report, stimuli-responsive NPs from novel ionic cellulose derivatives were prepared via a facile nanoprecipitation. Cellulose 10-undecenoyl ester (CUE) with a degree of substitution (DS) of 3 was synthesized by esterification of cellulose with 10-undecenoyl chloride. Then, CUE was modified by photo-induced thiol-ene reactions, in order to obtain organo-soluble ionic cellulose derivatives with DSs of ∼3, namely cellulose 11-((3-carboxyl)ethylthio)undecanoate (CUE-MPA), cellulose 11-((2-aminoethyl)thio)undecanoate (CUE-CA), cellulose 11-(2-(2-(diethylamino)ethyl)thio)undecanoate (CUE-DEAET) and cellulose 11-(2-(2-(dimethylamino)ethyl)thio)undecanoate (CUE-DMAET). CUE-MPA could be transformed into NPs with average diameters in the range of 80-330 nm, but these NPs did not show particular stimuli-responsive properties. Moreover, the dropping technique resulted in smaller NPs than a dialysis technique. Stable NPs with average diameters in the range of 90-180 nm showing pH-responsive and switchable sizes were obtained from CUE-DEAET and CUE-DMAET possessing tertiary amines using nanoprecipitation. Thus, altering the terminal functional groups will be a new approach to prepare stimuli-responsive cellulose-derived polymeric NPs.
基于可持续聚合物原料的刺激响应性纳米颗粒（NPs）与基于合成聚合物的 NPs 相比仍需要更多的探索。在本报告中，通过简单的纳米沉淀法制备了基于新型离子纤维素衍生物的刺激响应性 NPs。通过纤维素与 10-十一烯酰氯酯化合成取代度（DS）为 3 的纤维素 10-十一烯酸酯（CUE）。然后，通过光诱导的硫醇-烯反应对 CUE 进行修饰，以获得具有 DS 约 3 的可溶有机离子纤维素衍生物，即纤维素 11-（3-羧乙基硫代）十一酸酯（CUE-MPA）、纤维素 11-（2-氨基乙基）硫代）十一酸酯（CUE-CA）、纤维素 11-（2-（2-（二乙基氨基）乙基）硫代）十一酸酯（CUE-DEAET）和纤维素 11-（2-（2-（二甲氨基）乙基）硫代）十一酸酯（CUE-DMAET）。CUE-MPA 可转化为平均直径在 80-330nm 范围内的 NPs，但这些 NPs 没有表现出特殊的刺激响应特性。此外，与透析技术相比，滴注技术会导致更小的 NPs。通过纳米沉淀法从具有叔胺的 CUE-DEAET 和 CUE-DMAET 中获得了平均直径在 90-180nm 范围内的稳定 NPs，这些 NPs 具有 pH 响应性和可切换的尺寸。因此，改变末端官能团将成为制备刺激响应性纤维素衍生聚合物 NPs 的新方法。
