http://hdl.handle.net/10316/21135 Sat, 07 Mar 2020 13:52:08 GMT 2020-03-07T13:52:08Z http://hdl.handle.net/10316/88902 Title: Influence of initial chemical composition and characteristics of pulps on the production and properties of lignocellulosic nanofibers Authors: Ehman, N V; Lourenço, A. F.; McDonagh, B H; Vallejos, M E; Felissia, F.E.; Ferreira, Paulo Jorge Tavares; Chinga-Carrasco, G; Area, M.C. Abstract: This work aimed to study the influence of the initial chemical composition (glucans, lignin, xylan, and mannans), intrinsic viscosity, and carboxylate groups of pulps on the production process and final properties of lignocellulosic nanofibers (LCNF). Pulps of pine sawdust, eucalyptus sawdust, and sugarcane bagasse subjected to conventional pulping and highly oxidized processes were the starting materials. The LCNF were obtained by TEMPO mediated oxidation and mechanical fibrillation with a colloidal grinder. The nanofibrillation degree, chemical charge content, rheology, laser profilometry, cristallinity and atomic force microscopy were used to characterize the LCNF. The carboxylate groups, hemicelluloses and lignin of the initial pulps were important factors that affected the production process of LCNF. The results revealed that intrinsic viscosity and carboxylate groups of the initial pulps affected LCNF production process, whereas lignin and hemicelluloses influenced the viscosity of LCNF aqueous suspensions, the roughness of LCNF films, and the carboxylate groups content of LCNF. Wed, 15 Jan 2020 00:00:00 GMT http://hdl.handle.net/10316/88902 2020-01-15T00:00:00Z http://hdl.handle.net/10316/80420 Title: Impregnation of cinnamaldehyde into cassava starch biocomposite films using supercritical fluid technology for the development of food active packaging Authors: de Souza, Ana Cristina; Dias, Ana M A; Sousa, Hermínio C; Tadini, Carmen C Abstract: In this work, supercritical solvent impregnation (SSI) has been tested for the incorporation of natural compounds into biocomposite materials for food packaging. Cinnamaldehyde, with proved antimicrobial activity against fungi commonly found in bread products, was successfully impregnated on biocomposite cassava starch based materials using supercritical carbon dioxide as solvent. Different process experimental conditions were tested (pressure, impregnation time and depressurization rate) at a fixed temperature (35 °C) in order to study their influence on the amount of impregnated cinnamaldehyde as well as on the morphology of the films. Results showed that all conditions permitted to impregnate antimicrobial active amounts superior to those previously obtained using conventional incorporation methods. Moreover, a significant decrease of the equilibrium water vapor sorption capacity and water vapor permeability of the films was observed after SSI processing which is a clear advantage of the process, considering the envisaged applications. Sat, 15 Feb 2014 00:00:00 GMT http://hdl.handle.net/10316/80420 2014-02-15T00:00:00Z http://hdl.handle.net/10316/80418 Title: Enzymatic treatment applied as a final stage inE. globuluskraft pulp bleaching Authors: Sousa, Joana IT; Moura, Ana IG; Evtuguin, Dmitry V; Carvalho, M Graça VS Fri, 01 Jan 2016 00:00:00 GMT http://hdl.handle.net/10316/80418 2016-01-01T00:00:00Z http://hdl.handle.net/10316/80417 Title: Settling Suspensions Flow Modelling: A Review Authors: Silva, Rui; Garcia, Fernando A. P.; Faia, Pedro M. G. M.; Rasteiro, Maria G. Thu, 01 Jan 2015 00:00:00 GMT http://hdl.handle.net/10316/80417 2015-01-01T00:00:00Z