EL APRENDIZAJE BASADO EN EQUIPOS O POR SUS SIGLAS EN INGLÉS CONOCIDO COMO: TEAM BASED LEARNING (TBL), ES UNA METODOLOGÍA DE APRENDIZAJE ACTIVA, DONDE EL ESTUDIANTADO CONSTRUYE EL CONOCIMIENTO A PARTIR DE TAREAS QUE DESARROLLAN EN EQUIPOS DINÁMICOS, ASUMIENDO UN ROL PARTICIPATIVO. ESTA METODOLOGÍA FUE APLICADA EN ESTUDIANTES DE PREGRADO DEL CURSO DE BALANCES DE MATERIA Y ENERGÍA PERTENECIENTES AL PROGRAMA DE INGENIERÍA CIVIL QUÍMICA DE LA UNIVERSIDAD DEL BÍO-BÍO, CHILE. TBL FUE IMPLEMENTADO CON EL PROPÓSITO DE FACILITAR EL TRABAJO EN EQUIPO, Y MEJORAR EL DESEMPEÑO DEL ESTUDIANTADO CON RESPECTO A LAS TRADICIONALES CLASES MAGISTRALES. EL TRABAJO FUE DESARROLLADO EN LA ÚLTIMA UNIDAD TEMÁTICA DEL CURSO PARA LOS AÑOS 2014 Y 2016 Y FUE CONTRASTADO CON LOS RESULTADOS ALCANZADOS EN LOS AÑOS 2015 Y 2017, AÑOS EN LOS CUALES NO SE APLICÓ LA METODOLOGÍA. LOS RESULTADOS EVIDENCIAN QUE LAS CALIFICACIONES FINALES PROMEDIO PARA EL CURSO ALCANZARON SU VALOR MÁS ALTO EN EL AÑO 2016 (4.9), AÑO EN EL CUAL SE IMPLEMENTÓ LA METODOLOGÍA POR SEGUNDA VEZ. DE IGUAL MANERA LAS CALIFICACIONES EN ESTA UNIDAD FUERON EN PROMEDIO 6.5 Y 6.6 PARA LOS AÑOS 2014 Y 2016 FRENTE A 6.0 Y 4.9 PARA LOS AÑOS 2015 Y 2017 RESPECTIVAMENTE (EN UNA ESCALA DE PUNTUACIONES QUE TIENE COMO VALOR MÍNIMO 1.0 HASTA UN MÁXIMO DE 7.0). LOS RESULTADOS DEL CUESTIONARIO DE PERCEPCIÓN REVELAN QUE LA METODOLOGÍA FACILITA EL TRABAJO EN EQUIPO, FORMANDO UN AMBIENTE COOPERATIVO DE TRABAJO, DONDE MÁS DEL 90% DEL ESTUDIANTADO MANIFESTÓ ESTAR CONFORME CON LA METODOLOGÍA.

IN THE LAST YEARS, CHILE HAS INCREASED THE PRODUCTION OF BLUEBERRIES; CONSEQUENTLY, A LARGE NUMBER OF LIGNOCELLULOSIC RESIDUES DERIVED FROM THE HARVESTING AND PRUNING ARE BEING GENERATED. THESE RESIDUES ARE COMMONLY BURNED, THEREFORE INCREASING CO2 EMISSIONS. THIS STUDY FOCUSES ON THE EXTRACTION OF TWO ADDED-VALUE PRODUCTS FROM BLUEBERRY PRUNING RESIDUES (BPRS), CELLULOSE NANOCRYSTALS (CNC-IL) ISOLATED USING IONIC LIQUID (IL) 1-ETHYL-3-METHYLIMIDAZOLIUM [EMIM][CL], AND CARBOXYLATED NANOCELLULOSE (TOCNC), ISOLATED WITH (2,2,6,6-TETRAMETHYLPIPERIDINE-1-YL) OXYL OR TEMPO REAGENT COMBINED WITH A MECHANICAL DISINTEGRATION PROCESS. THESE PRODUCTS WERE CHARACTERIZED BY ZETA POTENTIAL (?), FTIR, XRD, TGA, AFM, AND CONDUCTOMETRIC TITRATION. RESULTS SHOW OVAL-SHAPED CNC-IL PARTICLES WITH LENGTHS OF 46.1?±?9.3?NM; MEANWHILE, TOCNC WERE ROD-LIKE SHAPED PARTICLES, WITH LENGTHS OF 120.3?±?30.6?NM. THESE BPRS SHOWED A PROMISING POTENTIAL TO PRODUCE CELLULOSE NANOCRYSTALS (CNCS) WITH DIFFERENT SURFACE PROPERTIES, OPENING A NEW ALTERNATIVE FOR THE PRODUCTION OF CELLULOSE NANOMATERIALS (CNMS) WITH PROMISING APPLICATIONS IN COLLOIDAL FORMULATIONS, COATINGS, AMONG OTHERS.

CHILE IS THE SECOND LARGEST GLOBAL PRODUCER OF BLUEBERRIES, WHICH ARE HARVESTED IN THE SOUTH-CENTRAL REGION. AS A RESULT OF THE EXPONENTIAL PRODUCTION GROWTH, A LARGE AMOUNT OF LIGNOCELLULOSIC BIOMASS IS GENERATED FROM PRUNING AND LEFT ON THE GROUND AS WASTE. AS AN ALTERNATIVE TO THE CURRENT INCINERATION PRACTICES AND THEIR NEGATIVE AIR POLLUTION EFFECTS, THIS STUDY PROPOSED VALUE-ADDED UTILIZATION OF THESE AGROINDUSTRY RESIDUES. THE CHEMICAL COMPOSITIONS (CELLULOSE, HEMICELLULOSE, LIGNIN, EXTRACTIVES, AND ASH) OF THE PRUNING RESIDUES FROM BLUEBERRY BRANCHES AND TRUNKS WERE ANALYZED. THE CELLULOSE CONTENTS FROM THE BRANCHES AND TRUNKS WERE SIMILAR AT 52% AND 51%, RESPECTIVELY. HOWEVER, THE X-RAY DIFFRACTION ANALYSIS INDICATED IMPORTANT DIFFERENCES IN THEIR CRYSTALLINITY INDEX, WITH 52% AND 84%, RESPECTIVELY. COMPARED WITH THE CELLULOSE OBTAINED FROM THE TRUNKS, CELLULOSE FROM THE BRANCHES WAS LESS THERMALLY STABLE, POSSIBLY DUE TO THE PRESENCE OF RESIDUAL LIGNIN AND HEMICELLULOSE. ACCORDING TO THE RESULTS, IT IS EXPECTED THAT THE AGRO-INDUSTRIAL RESIDUES FROM PRUNING OF THE CHILEAN BLUEBERRY BUSHES (BRANCHES AND TRUNKS) MIGHT BE OF USE AS A POTENTIAL PLATFORM FOR BIOPRODUCTS, SUCH AS CELLULOSE MATERIALS IN ORDER TO REPLACE SYNTHETIC OR UNSUSTAINABLE MATERIALS.

CHUSQUEA QUILA OR ?QUILA?, IS ONE OF THE MOST ABUNDANT LESSER-KNOWN SPECIES FROM CHILE, AND FOR MANY YEARS IT HAS CREATED PROBLEMS FOR FARMERS IN THE SOUTHERN PART OF THIS COUNTRY. IN THIS STUDY, IT WAS EXAMINED AS A PROMISING RESOURCE FOR HIGH-TECH MATERIALS. THE CHEMICAL AND PHYSICAL PROPERTIES WERE DETERMINED BY ASTM STANDARDS. THE EXTRACTIVES, ASH CONTENT, LIGNIN, AND ALPHA-CELLULOSE WERE 4.55%, 2.17%, 13.78%, AND 54.65%, RESPECTIVELY. THE HIGHER HEATING VALUE AND BASIC DENSITY OBTAINED WERE 5,106 KCAL/KG AND 290 KG/M3, RESPECTIVELY. THE MOISTURE CONTENT WAS STUDIED DURING FOUR SEASONS AND FOUND TO BE THE HIGHEST IN WINTER (73%). REGARDING THE NANOMECHANICAL PROFILES, HARDNESS VARIED FROM 0.16 GPA IN THE CORTEX TO 0.21 GPA IN THE NODULE. THE AVERAGE ELASTIC MODULUS IN THE NODULE AND INTERNODE WAS 12.5 GPA, WHILE IN THE CORTEX IT WAS 7.45 GPA. CONSIDERING THE HIGH CELLULOSE CONTENT AND STRUCTURAL FEATURES OF THE LIGNOCELLULOSIC MATRIX, IT COULD BE POSSIBLE TO EXTRACT CELLULOSE FIBERS FOR COMMERCIAL USE AND CRUDE LIGNIN FOR TESTING NEW APPLICATIONS. THUS, THE ENTIRE QUILA STRUCTURE IS A POTENTIAL BIOMASS RESOURCE.

HYDROGELS OF TEMPO-OXIDIZED NANOCELLULOSE WERE STABILIZED FOR DRY-JET WET SPINNING USING A SHELL OF CELLULOSE DISSOLVED IN 1,5-DIAZABICYCLO[4.3.0]NON-5-ENIUM PROPIONATE ([DBNH][CO2ET]), A PROTIC IONIC LIQUID (PIL). COAGULATION IN AN ACIDIC WATER BATH RESULTED IN CONTINUOUS CORE-SHELL FILAMENTS (CSFS) THAT WERE TOUGH AND FLEXIBLE WITH AN AVERAGE DRY (AND WET) TOUGHNESS OF ?11 (2) MJ·M-3 AND ELONGATION OF ?9 (14) %. THE CSF MORPHOLOGY, CHEMICAL COMPOSITION, THERMAL STABILITY, CRYSTALLINITY, AND BACTERIAL ACTIVITY WERE ASSESSED USING SCANNING ELECTRON MICROSCOPY WITH ENERGY-DISPERSIVE X-RAY SPECTROSCOPY, LIQUID-STATE NUCLEAR MAGNETIC RESONANCE, FOURIER TRANSFORM INFRARED SPECTROSCOPY, THERMOGRAVIMETRIC ANALYSIS, PYROLYSIS GAS CHROMATOGRAPHY-MASS SPECTROMETRY, WIDE-ANGLE X-RAY SCATTERING, AND BACTERIAL CELL CULTURING, RESPECTIVELY. THE COAXIAL WET SPINNING YIELDS PIL-FREE SYSTEMS CARRYING ON THE SURFACE THE CELLULOSE II POLYMORPH, WHICH NOT ONLY ENHANCES THE TOUGHNESS OF THE FILAMENTS BUT FACILITIES THEIR FUNCTIONALIZATION.

FORESTRY INDUSTRIES IN CHILE ARE FACING AN IMPORTANT CHALLENGE-DIVERSIFYING THEIR PRODUCTS USING GREEN TECHNOLOGIES. IN THIS STUDY, THE POTENTIAL USE OF IONIC LIQUIDS (ILS) TO DISSOLVE AND HYDROLYZE EUCALYPTUS WOOD (MIX OF EUCALYPTUS NITENS AND EUCALYPTUS GLOBULUS) KRAFT PULP WAS STUDIED. THE BLEACHED HARDWOOD KRAFT PULP (BHKP) FROM A CHILEAN PULP MILL WAS USED TOGETHER WITH FIVE DIFFERENT ILS: 1-BUTYL-3-METHYLIMIDAZOLIUM CHLORIDE [BMIM][CL], 1-BUTYL-3-METHYLIMIDAZOLIUM ACETATE [BMIM][AC], 1-BUTYL-3-METHYLIMIDAZOLIUM HYDROGEN SULFATE [BMIM][HSO4], 1-ETHYL-3-METHYLIMIDAZOLIUM CHLORIDE [EMIM][CL], 1-ETHYL-3-METHYLIMIDAZOLIUM ACETATE [EMIM][AC]. EXPERIMENTALLY, ONE VACUUM REACTOR WAS DESIGNED TO STUDY THE DISSOLUTION/HYDROLYSIS PROCESS FOR EACH ILS; PARTICULARLY, THE CELLULOSE DISSOLUTION PROCESS USING [BMIM][CL] WAS STUDIED PROPOSING ONE MOLECULAR DYNAMIC MODEL. EXPERIMENTAL CHARACTERIZATION USING ATOMIC FORCE MICROSCOPY, CONDUCTOMETRIC TITRATION, AMONG OTHER TECHNIQUES SUGGEST THAT ALL ILS ARE CAPABLE OF CELLULOSE DISSOLUTION AT DIFFERENT LEVELS; IN SOME CASES, THE DISSOLUTION EVOLVED TO PARTIAL HYDROLYSIS APPEARING CELLULOSE NANOCRYSTALS (CNC) IN THE FORM OF SPHERICAL AGGREGATES WITH A DIAMETER OF 40-120 NM. MOLECULAR DYNAMICS SIMULATIONS SHOWED THAT THE [BMIM][CL] ANIONS TEND TO INTERACT ACTIVELY WITH CELLULOSE SITES AND WATER MOLECULES IN THE DISSOLUTION PROCESS. THE RESULTS SHOWED THE POTENTIAL OF SOME ILS TO DISSOLVE/HYDROLYZE THE CELLULOSE FROM CHILEAN EUCALYPTUS, MAINTAINING REACTIVE FORMS.

IN THE FINAL PROCESS OF THE BLEACHED KRAFT PULP THERE ARE SOME CELLULOSE FIBERS THAT ARE SEPARATED FROM THE MAIN FIBERS STREAM; THESE FIBERS ARE REJECTED AND CONSIDERED AS A LOW QUALITY FIBERS, THESE FIBERS ARE KNOWN AS REJECTED FIBER (RF). IN THE PRESENT WORK THE POTENTIAL USE OF THESE FIBERS FOR CELLULOSE NANOCRYSTALS (CNCS) SYNTHESIS WAS STUDIED. THE PHYSICAL AND CHEMICAL PROPERTIES OF SYNTHESIZED CNCS WERE CHARACTERIZED THROUGH DIFFERENT TECHNIQUES SUCH AS ATOMIC FORCE MICROSCOPY (AFM), SCANNING ELECTRON MICROSCOPY (SEM), X-RAY DIFFRACTION (XRD), FOURIER-TRANSFORM INFRARED SPECTROSCOPY (FTIR), AND THERMOGRAVIMETRIC ANALYSIS (TGA). RESULTS DEMONSTRATE THE FEASIBILITY OF CNCS SYNTHESIS WITH A YIELD OF 28.1% AND 36.9%, AND CRYSTALLINITY OF 73.5% AND 82.7%. FINALLY, THE MORPHOLOGY AND SYNTHESIS CONDITIONS SUGGEST THAT THIS INDUSTRIAL REJECT FIBER (RF) COULD BE USED AS A SOURCE FOR THE CNCS PRODUCTION, THUS ADDING VALUE TO THE KRAFT PROCESS AND OPENING NEW POSSIBILITIES FOR INNOVATION IN THE PULP INDUSTRY.

CELLULOSE NANOFIBER FILMS (CNFF) WERE TREATED VIA A WELDING PROCESS USING IONIC LIQUIDS (ILS). ACID-BASE-CONJUGATED ILS DERIVED FROM 1,5-DIAZABICYCLO[4.3.0]NON-5-ENE [DBN] AND 1-ETHYL-3-METHYLIMIDAZOLIUM ACETATE ([EMIM][OAC]) WERE UTILIZED. THE REMOVAL EFFICIENCY OF ILS FROM WELDED CNFF WAS ASSESSED USING LIQUID-STATE NUCLEAR MAGNETIC RESONANCE (NMR) SPECTROSCOPY AND FOURIER TRANSFORM INFRARED SPECTROSCOPY (FTIR). THE MECHANICAL AND PHYSICAL PROPERTIES OF CNFF INDICATED SURFACE PLASTICIZATION OF CNFF, WHICH IMPROVED TRANSPARENCY. UPON TREATMENT, THE AVERAGE CNFF TOUGHNESS INCREASED BY 27%, AND THE FILMS REACHED A YOUNGS MODULUS OF ?5.8 GPA. THESE FIRST ATTEMPTS FOR IL """"""""WELDING"""""""" SHOW PROMISE TO TUNE THE SURFACES OF BIOBASED FILMS, EXPANDING THE SCOPE OF PROPERTIES FOR THE PRODUCTION OF NEW BIOBASED MATERIALS IN A GREEN CHEMISTRY CONTEXT. THE RESULTS OF THIS WORK ARE HIGHLY RELEVANT TO THE FABRICATION OF CNFFS USING IONIC LIQUIDS AND RELATED SOLVENTS.

CELLULOSE NANOFIBER FILMS (CNFF) WERE TREATED VIA A WELDING PROCESS USING IONIC LIQUIDS (ILS). ACID-BASE-CONJUGATED ILS DERIVED FROM 1,5-DIAZABICYCLO[4.3.0]NON-5-ENE [DBN] AND 1-ETHYL-3-METHYLIMIDAZOLIUM ACETATE ([EMIM][OAC]) WERE UTILIZED. THE REMOVAL EFFICIENCY OF ILS FROM WELDED CNFF WAS ASSESSED USING LIQUID-STATE NUCLEAR MAGNETIC RESONANCE (NMR) SPECTROSCOPY AND FOURIER TRANSFORM INFRARED SPECTROSCOPY (FTIR). THE MECHANICAL AND PHYSICAL PROPERTIES OF CNFF INDICATED SURFACE PLASTICIZATION OF CNFF, WHICH IMPROVED TRANSPARENCY. UPON TREATMENT, THE AVERAGE CNFF TOUGHNESS INCREASED BY 27%, AND THE FILMS REACHED A YOUNGS MODULUS OF ?5.8 GPA. THESE FIRST ATTEMPTS FOR IL """"WELDING"""" SHOW PROMISE TO TUNE THE SURFACES OF BIOBASED FILMS, EXPANDING THE SCOPE OF PROPERTIES FOR THE PRODUCTION OF NEW BIOBASED MATERIALS IN A GREEN CHEMISTRY CONTEXT. THE RESULTS OF THIS WORK ARE HIGHLY RELEVANT TO THE FABRICATION OF CNFFS USING IONIC LIQUIDS AND RELATED SOLVENTS.