RESUMEN
A protein/CaCO3/chitin nanofiber complex was prepared from crab shells by a simple mechanical treatment with a high-pressure water-jet (HPWJ) system. The preparation process did not involve chemical treatments, such as removal of protein and calcium carbonate with sodium hydroxide and hydrochloric acid, respectively. Thus, it was economically and environmentally friendly. The nanofibers obtained had uniform width and dispersed homogeneously in water. Nanofibers were characterized in morphology, transparency, and viscosity. Results indicated that the shell was mostly disintegrated into nanofibers at above five cycles of the HPWJ system. The chemical structure of the nanofiber was maintained even after extensive mechanical treatments. Subsequently, the nanofiber complex was found to improve the growth of tomatoes in a hydroponics system, suggesting the mechanical treatments efficiently released minerals into the system. The homogeneous dispersion of the nanofiber complex enabled easier application as a fertilizer compared to the crab shell flakes.
Asunto(s)
Exoesqueleto/química , Carbonato de Calcio/química , Quitina/química , Nanofibras/química , Proteínas/química , Animales , Braquiuros/metabolismo , Solanum lycopersicum/efectos de los fármacos , Solanum lycopersicum/crecimiento & desarrollo , Microscopía Electrónica de Rastreo , Nanofibras/toxicidad , Nanofibras/ultraestructura , Desarrollo de la Planta/efectos de los fármacos , Espectroscopía Infrarroja por Transformada de Fourier , Estrés MecánicoRESUMEN
Esterification with maleic anhydride significantly improved the mechanical disintegration of chitin into uniform 10-nm nanofibers. Nanofibers with 0.25° of esterification were homogeneously dispersed in basic water due to the carboxylate salt on the surface. Esterification proceeded on the surface and did not affect the relative crystallinity. A cast film of the esterified chitin nanofibers was highly transparent, since the film was free from light scattering.