High-Strength Nanostructured Films Based on Well-Preserved α-Chitin Nanofibrils Disintegrated from Insect Cuticles
2020 (English)In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 21, no 2, p. 604-612Article in journal (Refereed) Published
Abstract [en]
The α-chitin nanofibril is an alternative to nanocellulose as a building-block for strong films and other nanomaterials. The hypothesis of high film strength for films based on mildly treated insect cuticles was tested. Fibrils from the cuticle of Ruspolia differens (a long-horned bush cricket grasshopper locally known as senene) are disintegrated by a mild process, subsequently characterized by transmission electron microscopy, NMR, Fourier transform infrared spectroscopy, and XRD, and used to prepare strong and transparent films. A mild process (with 20% NaOH treatment for 2 weeks and at room temperature) was used to largely remove the strongly bound protein associated with chitin. The purpose was to reduce chitin degradation. The native structure of chitin was indeed well preserved and close to the native state, as is supported by data for degree of acetylation, molar mass, crystallinity, and crystallite dimensions. The diameter of the smallest chitin fibrils was as small as 3-7 nm (average 6 nm) with lengths larger than or around 1 μm. A stable and well-dispersed colloidal chitin fibril suspension in water was achieved. A nanostructured chitin film prepared by filtration showed high optical transmittance (∼90%) and very high tensile strength (220 MPa). The high tensile strength was attributed to the well-preserved chitin structure, high intrinsic fibril strength, and high colloidal stability of the fibril suspension. Strong, transparent insect chitin films offer interesting alternatives to nanocellulose films because of different resource origins, surface chemistries, and potential antimicrobial properties.
Place, publisher, year, edition, pages
American Chemical Society , 2020. Vol. 21, no 2, p. 604-612
Keywords [en]
Acetylation, Cellulose, Crystallinity, Fourier transform infrared spectroscopy, High resolution transmission electron microscopy, Nanocellulose, Nanofibers, Sodium hydroxide, Surface chemistry, Suspensions (fluids), Tensile strength, Anti-microbial properties, Chitin degradation, Colloidal Stability, Crystallite dimension, Degree of acetylation, High-tensile strength, Nanocellulose films, Nanostructured Films, Chitin
National Category
Polymer Technologies
Identifiers
URN: urn:nbn:se:kth:diva-268456DOI: 10.1021/acs.biomac.9b01342ISI: 000513091100032PubMedID: 31742385Scopus ID: 2-s2.0-85076238936OAI: oai:DiVA.org:kth-268456DiVA, id: diva2:1422883
Note
QC 20200409
2020-04-092020-04-092022-06-26Bibliographically approved