Department of Chemistry, Biotechnology, and Chemical Engineering, Graduate School of Science and Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan.
Department of Chemistry, Biotechnology, and Chemical Engineering, Graduate School of Science and Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan.
Int J Biol Macromol. 2020 Aug 15;157:680-686. doi: 10.1016/j.ijbiomac.2019.11.225. Epub 2019 Nov 29.
This study investigated the preparation of chitin-based fluorescent hollow particles by Pickering emulsion polymerization of styrene using bifunctional chitin nanofibers (ChNFs) as stabilizer, giving CNF-based composite particles, followed by solubilizing out inner polystyrene. In addition to the introduction of anionic maleyl groups on ChNFs to improve dispersibility in aqueous ammonia, polymerizable methacryl groups were substituted on ChNFs as second functionalization to provide ability in copolymerization with styrene for stabilization of hollow structures. Consequently, after the formation of styrene-in-water Pickering emulsion using the bifunctional ChNFs as stabilizer, radical polymerization was conducted in the presence of potassium persulfate as an initiator to produce the composite particles. The hollow particles were then fabricated by solubilizing out inner polystyrene with toluene, which stably dispersed in water. Encapsulation of a fluorescent dye, pyrene, into the cavity of the hollow particles was achieved by hydrophobic interaction with polystyrene present on the inner walls, which could be released by treatment of the resulting fluorescent hollow particles with surfactant, oleyl alcohol, in water. The same Pickering emulsion polymerization system was also performed in the presence of a pyrene derivative having a polymerizable group to obtain fluorescent composite/hollow particles with pyrene moieties covalently bound to polystyrene.
本研究通过使用双功能壳聚糖纳米纤维（ChNFs）作为稳定剂的苯乙烯 Pickering 乳液聚合制备了基于壳聚糖的荧光空心粒子，得到了基于 CNF 的复合粒子，然后溶解出内部聚苯乙烯。除了在壳聚糖纳米纤维上引入阴离子马来酰基以提高在氨水中的分散性外，还在壳聚糖纳米纤维上取代了可聚合的甲基丙烯酰基作为二次功能化，以提供与苯乙烯共聚的能力，从而稳定空心结构。因此，在用双功能 ChNFs 作为稳定剂形成苯乙烯/水 Pickering 乳液后，在过硫酸钾作为引发剂的存在下进行自由基聚合，以制备复合粒子。然后，通过用甲苯溶解内部聚苯乙烯来制备空心粒子，所得空心粒子在水中稳定分散。通过与存在于内壁上的聚苯乙烯的疏水相互作用，将荧光染料芘包封到空心粒子的空腔中，所得荧光空心粒子通过在水中用表面活性剂油醇处理，可以将其释放。在存在具有聚合基团的芘衍生物的情况下，也进行了相同的 Pickering 乳液聚合体系，以获得共价结合有聚苯乙烯的芘部分的荧光复合/空心粒子。
