| Texto completo | |
| Autor(es): |
Bai, Long
[1, 2, 3, 4]
;
Kamarainen, Tero
[1]
;
Xiang, Wenchao
[1]
;
Majoinen, Johanna
[1]
;
Seitsonen, Jani
[5]
;
Grande, Rafael
[1]
;
Huan, Siqi
[1, 2, 3, 4]
;
Liu, Liang
[6]
;
Fan, Yimin
[6]
;
Rojas, Orlando J.
[1, 2, 3, 4, 7]
Número total de Autores: 10
|
| Afiliação do(s) autor(es): | [1] Aalto Univ, Dept Bioprod & Biosyst, FI-00076 Aalto - Finland
[2] Univ British Columbia, Bioprod Inst, Dept Chem & Biol Engn, Vancouver, BC V6T 1Z3 - Canada
[3] Univ British Columbia, Dept Chem, Vancouver, BC V6T 1Z3 - Canada
[4] Univ British Columbia, Dept Wood Sci, Vancouver, BC V6T 1Z3 - Canada
[5] Aalto Univ, Dept Appl Phys, FI-00076 Aalto - Finland
[6] Nanjing Forestry Univ, Coll Chem Engn, Jiangsu Key Lab Biomass Based Green Fuel & Chem, Jiangsu Coinnovat Ctr Efficient Proc & Utilizat F, Nanjing 210037 - Peoples R China
[7] Nanjing Forestry Univ, Coll Chem Engn, Nanjing 210037, Jiangsu - Peoples R China
Número total de Afiliações: 7
|
| Tipo de documento: | Artigo Científico |
| Fonte: | ACS NANO; v. 14, n. 6, p. 6921-6930, JUN 23 2020. |
| Citações Web of Science: | 1 |
| Resumo | |
The complex nature of typical colloids and corresponding interparticle interactions pose a challenge in understanding their selfassembly. This specifically applies to biological nanoparticles, such as those obtained from chitin, which typically are hierarchical and multidimensional. In this study, we obtain chitin nanocrystals by one-step heterogeneous acid hydrolysis of never-dried crab residues. Partial deacetylation facilitates control over the balance of electrostatic charges (xi-potential in the range between +58 and +75 mV) and therefore affords chitin nanocrystals (DE-ChNC) with axial aspect (170-350 nm in length), as determined by cryogenic transmission electron microscopy and atomic force microscopy. We find that the surface amines generated by deacetylation, prior to hydrolysis, play a critical role in the formation of individual chitin nanocrystals by the action of a dual mechanism. We directly access the twisting feature of chitin nanocrystals using electron tomography (ET) and uncover the distinctive morphological differences between chitin nanocrystals extracted from nondeacetylated chitin, ChNC, which are bundled and irregular, and DE-ChNC (single, straight nanocrystals). Whereas chitin nanocrystals obtained from dried chitin precursors are known to be twisted and form chiral nematic liquid crystals, our ET measurements indicate no dominant twisting or handedness for the nanocrystals obtained from the never-dried source. Moreover, no separation into typical isotropic and anisotropic phases occurs after 2 months at rest. Altogether, we highlight the critical role of drying the precursors or the nanopolysaccharides to develop chirality. (AU) | |
| Processo FAPESP: | 17/20891-8 - Fabricação de microfibras compósitas de celulose oxidada (tempo) por complexação interfacial |
| Beneficiário: | Rafael Grande |
| Modalidade de apoio: | Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado |