Chitosan-sheath and chitin-core nanowhiskers.
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.
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.
Antonio G B
AG
Pereira
Grupo de Materiais Poliméricos e Compósitos (GMPC) - Department of Chemistry, Maringá State University, Av. Colombo, 5790, Maringá, Paraná 87020-900, Brazil.
Edvani C
EC
Muniz
Fiber and Polymer Science, University of California, Davis, One Shields Avenue, Davis, California 95616, USA. Electronic address: ylhsieh@ucdavis.edu.
You-Lo
YL
Hsieh
D000107:Acetylation; D002686:Chitin / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D043942:Nanotubes / Q000737:chemistry*; D013499:Surface Properties
D002686:Chitin; D048271:Chitosan
Chitin; Chitosan; Deacetylation; Nanowhiskers; Surface modification