Optimizing Nanocellulose Production via Acid Hydrolisis And Mechanical Methods and Its use as Nanofiller For Biomedical Applications

LEANDRO LUDUEÑA; MELINA BRACONE; JIMENA SOLEDAD GONZALEZ; VERA ALEJANDRA ALVAREZ

Espoo-Helsinki

Conferencia; IX Iberoamerican Conference on Pulp and Paper Research, CIADICYP Espoo/Helsinki,Finlandia; 2016

Nanocellulose is an attractive emerging material for biomedical applications due to its renewable nature, anisotropic shape, excellent mechanical properties, and good biocompatibility, among others. Hydrogels are soft materials, capable of holding large amounts of water in their networks maintaining their shape. They are potential candidates for a wide range of biomedical applications. In particular, PVA hydrogels are biocompatible, natural and non-toxic but exhibit low mechanical properties. Nanocellulose can be incorporated to produce nanocomposites with improved mechanical performanceand durability. The aim of this study was first to optimize the obtaining of nanocellulose from microcrystalline cellulose in a first steps and from natural fibers in second one, by two different techniques: acid hydrolysis (studying the temperature and time of the procedure and also the acid concentration) and mechanical method, by means of an ultrasound tip (an ecofriendly procedure). The as obtained nanocelluose fibers were characterized by Field Emission Scanning Electron Microscopy (FESEM), Fourier transform Infrared Spectroscopy (FTIR), Thermogravimetric analysis (TGA) and X-Ray diffraction (XRD).Once nanocellulose fibers were obtained and characterized and the best conditions were selected, PVA based hydrogels modified with nanocellulose for biomedical applications were synthesized and also characterized. PVA/Nanocellulose fibers (NCF) hydrogels with several CNW contents (0, 1, 3, 5 and 7 wt.%) were successfully obtained by freezing-thawing (F-T) technique. It was found that the addition of the NCF modified the chemical structure of the gel, mainly acting as nucleation sites favoring the crystal formation around the nanofillers during the crosslinking process. On the other hand, it was established that the excellent compatibility between the matrix and filler (both hydrophilic) is responsible for the increment on the mechanical and barrier properties of the composite hydrogels. In addition, their function as barriers against bacterial penetration showed that they could protect the wound from further infection; hence it could accelerate the healing process of wound. All obtained results, but mainly the mechanical, barrier and antimicrobial properties, indicate that the composite hydrogels with 03 wt.% of NCF are promising materials to be used as wound dressing.Actually, other polymer gels reinforced with nanocellulose for biomedical applications and several nanocomposites based on biodegradable polymers and nanocellulose for packaging are being obtained and characterized, among other applications.