A facile bottom-up route to self-assembled biogenic chitin nanofibers

Chitin Nanofiber Transparent Paper for Flexible Green Electronics

“…[36,51] It is notable that for ChNF paper the peak corresponding to the intersheet diffraction appears in between (2θ = 8.2°), which suggests that our ChNF paper may possess crystallographic characteristics of both chitin polymorphs. [41,44] Further indication of the coexistence of both crystals is also revealed from FT-IR analysis (Figure 2d), in which the ChNF paper has an absorption spectrum intermediate between the two chitin polymorphs. In general, β-chitin is characterized by a single broad absorption peak at around 1630 cm −1 that springs from the intramolecular C O···HO hydrogen bonds ( Figure S4, Supporting Information).…”

“…[36,37] Such a top-down approach is often combined with specific chemical treatments, such as TEMPO-mediated oxidation, to promote the individualization of ChNF. [38,39] Meanwhile, in a bottomup route, Zhang and co-workers recently demonstrated a pure chitin transparent paper fabricated by coagulating ChNF (regeneration) from a chitin solution dissolved in NaOH/urea/ water; [40] for this type of method nonaqueous solvent systems, such as LiCl/DMAc [41] and CaCl 2 /MeOH [42] are also available. Building on these previous efforts, we introduce here a new version of transparent paper made with bottom-up self-assembled ChNF.…”

“…[44,49] This solvent evaporation-induced self-assembly (EISA) of ChNF is different from other bottom-up ChNF regeneration methods in that the EISA route does not require any coagulation process that indispensably uses antisolvents to recrystallize ChNF. [40][41][42] Figure 2b shows cross-sectional scanning electron microscopy (SEM) images of the ChNF paper, which reveals that the ChNF are oriented horizontally in-plane making up a nonporous as-casted transparent ChNF paper and (f) a plane origami from a ChNF paper (both scale bars = 2 cm). g) A digital photograph of a graphic image depicting 'squid pen chitin-derived flexible green electronics' printed on a ChNF paper using a normal color laser-jet printer (scale bar = 1 cm).…”

A polysaccharide bioprotonic field-effect transistor

“…1b,c) is a polysaccharide chitin derivative of particular interest for the prospect of bionanoprotonics. Most chitin derivatives are biodegradable, nontoxic, and physiologically inert 28 . Palladium is chosen as the contact material for its ability to form proton-conducting PdH x on exposure to hydrogen 27 .…”

Fabrication of nanofibrous scaffolds for tissue engineering applications

“…These studies proposed that the position of aromatic moieties is a signifi cant determinant for supramolecular self-assembling conformations. Self-assembled chitin fi bers with diameters of 3 nm and 10 nm could be also obtained from dissolving in hexafl uoro-2-propanol (HFIP) and LiCl/N,N-dimethylacetamide (DMAC), respectively (Zhong et al , 2010 ). These observations demonstrated that nanofi ber assembly occurs at a critical concentration and fi ber morphology can be controlled by solution concentration and solution evaporation rate.…”