壳聚糖-鞘和甲壳素-核纳米纤维。
Chitosan-sheath and chitin-core nanowhiskers.
机构信息
Grupo de Materiais Poliméricos e Compósitos (GMPC) - Department of Chemistry, Maringá State University, Av. Colombo, 5790, Maringá, Paraná 87020-900, Brazil; Fiber and Polymer Science, University of California, Davis, One Shields Avenue, Davis, California 95616, USA.
Grupo de Materiais Poliméricos e Compósitos (GMPC) - Department of Chemistry, Maringá State University, Av. Colombo, 5790, Maringá, Paraná 87020-900, Brazil.
出版信息
Carbohydr Polym. 2014 Jul 17;107:158-66. doi: 10.1016/j.carbpol.2014.02.046. Epub 2014 Feb 25.
Chitosan-sheath and α-chitin-core nanowhiskers (CsNWs) have been successfully generated by surface deacetylation of chitin nanowhiskers (CtNWs) in the never-dried state. Acid hydrolysis (3N HCl, 30 mL/g, 104°C) of pure chitin derived from crab shell yielded 65% 4-10nm thick, 16 nm wide and 214 nm long chitin whiskers (CtNWs) that were 86% crystalline and 81% acetylated. Surface deacetylation of CtNWs was robust in their never-dried state in 50% NaOH at a moderate 50°C for 6h, yielding 92% CsNWs. All deacetylated CsNWs retain the same α-chitin crystalline core at reduced 50% crystallinity and similar dimensions (4-12 nm thick, 15 nm wide, 247 long) as CtNWs, but reduced 60% acetylation reflecting the deacetylated surface layers. Progressive surface deacetylation was evident by the increased IP as well as increased positive charges under acidic pH and reduced negative charges at alkaline pH with increasing reaction time.
壳聚糖-鞘和α-壳聚糖核纳米纤维（CsNWs）已通过从未干燥状态的壳聚糖纳米纤维（CtNWs）的表面脱乙酰成功生成。纯蟹壳衍生壳聚糖的酸水解（3N HCl，30 mL/g，104°C）得到了 65%的 4-10nm 厚、16nm 宽和 214nm 长的壳聚糖纳米纤维（CtNWs），其结晶度为 86%，乙酰化度为 81%。在从未干燥状态的 50%NaOH 中，在温和的 50°C 下反应 6 小时，CtNWs 可以实现稳健的表面脱乙酰，得到 92%的 CsNWs。所有脱乙酰的 CsNWs 在降低的 50%结晶度下保留相同的α-壳聚糖晶核，且尺寸相似（4-12nm 厚、15nm 宽、247nm 长），但乙酰化度降低了 60%，反映了脱乙酰的表面层。随着反应时间的增加，通过增加 IP 以及在酸性 pH 下增加正电荷和在碱性 pH 下减少负电荷，可以明显看出渐进的表面脱乙酰。
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