See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles. Applications ofNanochitin in Multidimensional Materials AK 5.1. Application of Nanochitins as Building Blocks AL 5.1.1. Nanochitin as a Pickering Stabilizer AL 5.

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This work investigates multifunctional composite films synthesized with cellulose nanofibers (CNFs) and poly­(vinyl alcohol) (PVA). First, TEMPO-oxidized CNFs were modified in the heterogeneous phase with benzophenone, diisocyanate, and epoxidized soybean oil via esterification reactions. A thorough characterization was carried out via elemental analysis as well as FT-IR and X-ray photoelectron spectroscopies and solid-state NMR. Following, the surface-modified CNFs were combined with PVA to endow composite films with UV-absorbing capabilities while increasing their thermomechanical strength and maintaining a high light transmittance. Compared to neat PVF films, the tensile strength, Young modulus, and elongation of the films underwent dramatic increases upon addition of the reinforcing phase (maximum values of ∼96 MPa, ∼ 714 MPa, and ∼350%, respectively). A high UV blocking performance, especially in the UVB region, was observed for the introduced multifunctional PVA films at CNF loadings below 5 wt %. The trade-off between modified nanofibril function as interfacial reinforcement and aggregation leads to an optimum loading. The results indicate promising applications, for example, in active packaging.

An energy-efficient method has been developed to prepare 3-5 nm-wide carboxyl-functionalized cellulose nanofibers (CNFs) from pulp fiber by a simple one-pot swelling followed by esterification process. Tetrabutylammonium acetate (TBAA)/dimethyl sulfoxide (DMSO) binary solvent is used as the swelling agent and the esterification medium admixed with maleic anhydride. All steps are performed at room temperature and no post-mechanical treatment is needed. The highly efficient defibrillation of pulp fiber to CNFs is thought to be due to two factors: 1) swelling in TBAA/DMSO effectively loosens the structure of cellulose supermolecules by breaking the intra- and intermolecular hydrogen bonds between cellulose chains; and 2) the carboxyl groups grafted onto the cellulose molecules by esterification prohibit the reformulation of hydrogen bonds between cellulose chains and therefore stabilize the disperse CNFs with uniform diameter in solution. Other than acid anhydride, no catalyst is added for the esterification, which facilitates the recycling and reuse of the binary solvent. This energy-efficient one-pot method could facilitate the large-scale manufacture of bio-based nanomaterials.

A silica-supported peroxycarboxylic acid oxidant, 2-percarboxyethyl silica (SiO2@(CH2)2COOOH), was successfully prepared and used for the epoxidation of fatty acid methyl esters (FAMEs) and vegetable oils. Among the oxidants prepared under different conditions, C-SiO2@(CH2)2COOOH (TEOS:CTES = 2:1) had the highest surface area, pore volume, and peroxide value. It also exhibited the highest activity for the epoxidation reactions. For methyl linoleate, 92.76% yield of epoxidized product was obtained at room temperature. Other unsaturated FAMEs with 1 and 3 double bonds were also efficiently converted to their epoxides. Moreover, the oxidant was also successfully applied to the epoxidation of vegetable oils, olive oil, and linseed oil with high product yield at room temperature. Finally, the used oxidant was regenerated through a simple oxidation process with H2O2 and recycled at least 5 times without much drop in the reactivity.