RESUMEN
Naturally derived polymers, such as cellulose or chitin, are materials with increasing interest for a sustainable future. Considering the pollution associated with plastics recycling, natural and fully biocompatible materials like cellulose and chitin are becoming increasingly more relevant for sustainable engineering applications. Chitin and highly deacetylated chitin (chitosan) are already implemented in a wide range of materials applications, especially in biomedical fields. One interesting aspect of chitin is that the majority of industrially produced chitin is extracted from shrimp exoskeleton. However, other arthropods can also be investigated as a source of chitin. In this work, we focus on the extraction of chitin and preparation of chitosan from a beetle specie: Mecynorhina torquata. This includes characterization of the native Mecynorhina torquata surfaces and all intermediate surfaces throughout the chitosan extraction procedure. The final product, prepared chitosan, is also characterized using IR, SEM, ash content, and deacetylation degree. In addition, spectacular iridescent surfaces of Mecynorhina torquata are highlighted at the intermediate steps during chitin extraction. Finally, as proof of concept, the isolated chitosan is used to form hydrogel.
Asunto(s)
Quitina/química , Quitina/aislamiento & purificación , Quitosano/química , Quitosano/aislamiento & purificación , Escarabajos/química , Alginatos/química , Animales , Materiales Biocompatibles/química , Rastreo Diferencial de Calorimetría , Femenino , Hidrogeles/química , Espectroscopía de Resonancia Magnética , Masculino , Microscopía Electrónica de Rastreo , Polímeros/química , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie , Termogravimetría , Difracción de Rayos XRESUMEN
In the animal kingdom, macroscopic variations in size, color, and even hairiness are frequently observed between male and female, making the sex of various species easy to discern. In the case of insects, similar variances also exist. While direct observation is a quick and efficient way to differentiate between sexes, there are also variations which are unseen to the naked eye and occur on a micro- or nanoscopic scale. Sometimes, these micro/nanoscopic variations can lead to significant variations in surface properties as a function of sex. Such is the case for the Mecynorhina polyphemus confluens (Kraatz, 1890). In this work, we characterize these micro- and nanoscale differences, and describe their impact on the surface properties (e.g. wettability). It is found that water interacts quite differently with the surface of the cuticle of Mecynorhina polyphenus confluens, depending on the specimen sex. On a female, water spreads readily across the elytra indicating hydrophilic behavior. However, on the surface of the male elytra, strong hydrophobicity is observed. Microscopic observations reveal differences in microscale surface morphology across the male and female cuticle. These observations contribute to a better, global understanding of the wettability behavior observed on M. polyphemus confluens.