DSpace Angular :: Browsing by Author "Cabrera-Barjas, Gustavo"

Browsing by Author "Cabrera-Barjas, Gustavo"

Now showing 1 - 15 of 15

Biocomoposites of polylactic acid/poly(butylene adipate-co-terephthalate) blends loaded with quinoa husk agro-waste: thermal and mechanical properties
(2022) Ponce, Giovanni; Rodriguez-Llamazares, Saddys; Rivera, Patricia Castano; Castano, Johanna; Oporto-Velasquez, Gloria; Sabando, Constanza; Ide, Walter; Nesic, Aleksandra; Cabrera-Barjas, Gustavo
Quinoa husk (QH) is often discarded without being utilized. This study investigates an alternative route for this agro-waste resource as a raw material in the preparation of bioplastic composites. The effect of QH on the mechanical and thermal properties of thermoplastic poly(lactic acid)/poly(butylene adipate-co-terephthalate) (PLA/PBAT) blends was evaluated. The composites were prepared by melting compounding. The content of quinoa husk in composite materials varied from 0-30 wt%. The results demonstrated that addition of quinoa husk in PLA/PBAT blend induced slight increase in crystalline phase of PLA, which was evidenced by FTIR and DSC analysis. However, it reduced the mechanical and thermal properties of materials. The 30 wt% load of quinoa husk in formulation led to decreased tensile strength (by 45.5%), elongation at break (by 85.8%), thermal stability (by 23.5%) and flexural strength (by 36%) of final biocomposite material, when compared to the control biopolymer blend. Although addition of quinoa husk in bioplastic material did not improve mechanical properties, load of 20 wt% QH in PLA/PBAT still provided satisfied tensile strength of 19 MPa and flexural strength of 27 MPa, showing that quinoa husk can add value to lignocellulosic by-product/agro waste, particularly decreasing the cost and increasing the sustainability of bioplastic materials for use in the agriculture industry.
Comparative Study of Three Dyes' Adsorption onto Activated Carbon from Chenopodium quinoa Willd and Quillaja saponaria
(2022) Abril, Diana; Ferrer, Victor; Mirabal-Gallardo, Yaneris; Cabrera-Barjas, Gustavo; Segura, Cristina; Marican, Adolfo; Pereira, Alfredo; Duran-Lara, Esteban F.; Valdes, Oscar
The present study shows porous activated carbon obtained from Chenopodium quinoa Willd and Quillaja saponaria and their use as potential adsorbents to remove three types of dyes from aqueous solutions. The adsorption results were compared with commercial charcoal to check their efficiency. All porous carbon materials were activated using carbon dioxide and steam and fully characterized. Moreover, the steam-activated samples exhibited a high total pore volume with a BET surface area of around 800 m(2) g(-1). Batch adsorption experiments showed that commercial charcoal is the charcoal that offered the best adsorption efficiency for tartrazine and sunset yellow FCF. However, in the case of crystal violet, all activated carbons obtained from Chenopodium quinoa Willd and Quillaja saponaria showed the best captures, outperforming commercial charcoal. Molecular dockings of the dyes on the commercial charcoal surface were performed using AutoDock Vina. The kinetic results of the three isotherm's models for the present data follow the order: Langmuir similar to Freundlich > Temkin.
Condensed tannins from Pinus radiata bark: Extraction and their nanoparticles preparation in water by green method
(2024) Cabrera-Barjas, Gustavo; Butto-Miranda, Nicole; Nesic, Aleksandra; Moncada-Basualto, Mauricio; Segura, Rodrigo; Bravo-Arrepol, Gaston; Escobar-Avello, Danilo; Moeini, Arash; Riquelme, Sebastian; Neira-Carrillo, Andronico
This work reports for the first time the production of condensed tannin nanoparticles stable in water via modification with glycine betaine. Pine bark, as a byproduct from the paper industry, was used as a source of condensed tannins of high molecular weight. Different glycine betaine concentrations were tested to produce condensed tannin nanoparticles, and the obtained nanoparticles were subjected to several characterization techniques (Dynamic Light Scattering, Field emission scanning electron microscopy, Zeta potential, Fourier transform infrared spectroscopy-Attenuated total reflectance, thermogravimetric analysis). The results showed that the highest stability possessed nanoparticles with 40 wt% glycine betaine. The average particle size distribution evaluated by scanning microscopy was 124 nm. Besides, the glycine betaine-modified condensed tannin nanoparticles demonstrated higher thermal stability with the starting degradation temperature at 238 degrees C. Finally, obtained nanoparticles showed an antioxidant capacity of 34,209 +/- 2194 mu mol ET/100 g and low cytotoxicity towards healthy human cells, representing the high potential to be used as a carrier of active compounds in agriculture, food, drug and medical sector.
Eco-Friendly Design of Chitosan-Based Films with Biodegradable Properties as an Alternative to Low-Density Polyethylene Packaging
(2024) Fiallos-Nunez, Johanna; Cardero, Yaniel; Cabrera-Barjas, Gustavo; Garcia-Herrera, Claudio M.; Inostroza, Matias; Estevez, Miriam; Espana-Sanchez, Beatriz Liliana; Valenzuela, Loreto M.
Biopolymer-based films are a promising alternative for the food packaging industry, in which petrochemical-based polymers like low-density polyethylene (LDPE) are commanding attention because of their high pollution levels. In this research, a biopolymer-based film made of chitosan (CS), gelatin (GEL), and glycerol (GLY) was designed. A Response Surface Methodology (RSM) analysis was performed to determine the chitosan, gelatin, and glycerol content that improved the mechanical properties selected as response variables (thickness, tensile strength (TS), and elongation at break (EAB). The content of CS (1.1% w/v), GEL (1.1% w/v), and GLY (0.4% w/v) in the film-forming solution guarantees an optimized film (OPT-F) with a 0.046 +/- 0.003 mm thickness, 11.48 +/- 1.42 mPa TS, and 2.6 +/- 0.3% EAB. The OPT-F was characterized in terms of thermal, optical, and biodegradability properties compared to LDPE films. Thermogravimetric analysis (TGA) revealed that the OPT-F was thermally stable at temperatures below 300 degrees C, which is relevant to thermal processes in the food industry of packaging. The reduced water solubility (WS) (24.34 +/- 2.47%) and the improved biodegradability properties (7.1%) compared with LDPE suggests that the biopolymer-based film obtained has potential applications in the food industry as a novel packaging material and can serve as a basis for the design of bioactive packaging.
Effect of cellulose nanofibrils on vancomycin drug release from chitosan nanocomposite films
(2023) Cabrera-Barjas, Gustavo; Becheran, Liliam; Valdes, Oscar; Giordano, Ady; Segura-del Rio, Rodrigo; Bravo-Arrepol, Gaston; Duran-Lara, Esteban F.; Cea, Juan; Berg, Alex; Castanos, Johana; Rodriguez-Llamazares, Saddys; Fuentes, Gaston; Katsarov, Plamen; Lukova, Paolina; Delattre, Cedric
Overuse of antibiotic drugs usually leads to the further development of resistance to targeted bacteria. In this context, a controlled release system could be a solution to achieve higher drug efficiency without overdosing and drug resistance. In this work, nanocomposite films based on chitosan (CHI) reinforced with cellulose nanofibrils (CNF) for antibiotic release were prepared and characterized. Several nanocomposite films containing vancomycin hydrochloride and different amounts of CNF (5, 10, and 20 wt%) were prepared by the solvent casting method. Spectroscopic (FTIR), thermal (TG), morphological (SEM), mechanical, and swelling analyses of the films were performed to study the effect of nanofibers content on the nanocomposite properties. A good dispersion of CNF and the model drug was observed in the CHI matrix. FTIR spectroscopy confirmed the interaction between the film components (CNF and CHI). Film swelling capacity decreased with an increase of CNF content in the film formulation, whereas stiffness and tensile strength of the film increased. In addition, vancomycin release at pH = 7.4 was studied, and it was observed that controlled slower release could be achieved by tuning the CNF content in the chitosan film. The results confirm that these films could be useful for pharmaceutical purposes where the controlled release of drugs is required.
Extracted Eucalyptus globulus Bark Fiber as a Potential Substrate for Pinus radiata and Quillaja saponaria Germination
(2024) Ferrer-Villasmil, Victor; Fuentealba, Cecilia; Reyes-Contreras, Pablo; Rubilar, Rafael; Cabrera-Barjas, Gustavo; Bravo-Arrepol, Gaston; Escobar-Avello, Danilo
This study aimed to explore alternative substrates for growing forest species using eucalyptus bark. It evaluated the potential of extracted Eucalyptus globulus fiber bark as a substitute for commercial growing media such as coconut fiber, moss, peat, and compost pine. We determined the physicochemical parameters of the growing media, the germination rate, and the mean fresh and dry weights of seedlings. We used the Munoo-Liisa Vitality Index (MLVI) test to evaluate the phytotoxicity of the bark alone and when mixed with commercial substrates. Generally, the best mixture for seed growth was 75% extracted eucalyptus bark fiber and 25% commercial substrates. In particular, the 75E-25P (peat) mixture is a promising substitute for seedling growth of Pinus radiata, achieving up to 3-times higher MLVI than the control peat alone. For Quillaja saponaria, the best growth substrate was the 50E-50C (coconut fiber) mixture, which had the most significant MLVI values (127%). We added chitosan and alginate-encapsulated fulvic acid phytostimulants to improve the performance of the substrate mixtures. The fulvic acid, encapsulated or not, significantly improved MLVI values in Q. saponaria species and P. radiata in concentrations between 0.05 and 0.1% w/v. This study suggests that mixtures with higher levels of extracted fiber are suitable for growing forest species, thus promoting the application of circular economy principles in forestry.
Forest by-Product Valorization: Pilot-Scale Pinus radiata and Eucalyptus globulus Bark Mixture Extraction
(2023) Santos, Jorge; Escobar-Avello, Danilo; Fuentealba, Cecilia; Cabrera-Barjas, Gustavo; Gonzalez-Alvarez, Julia; Martins, Jorge M.; Carvalho, Luisa H.
One of the most important by-products generated in the forestry industry is the bark obtained during the debarking process. Pine (Pinus radiata D. Don) and eucalyptus (Eucalyptus globulus L.) are the main important tree species exploited in the Chilean forestry industry. The bark of P. radiata D. Don is an interesting source of extracts, rich in condensed tannins, with potential uses in biopolymer and bioadhesive preparation. Conversely, the E. globulus bark extracts are rich in hydrolyzable tannins with few applications. Nevertheless, the forest industry generates a high volume of these by-products, simultaneously. Then, it is interesting to determine a suitable process for the joint valorization of both forest by-products at a large scale. In this work, alkaline extraction (NaOH and Na2SO3) was performed at a pilot scale of a mixture of E. globulus and P. radiata barks prepared at different ratios (0%-100%). The effect of bark mixture composition on the resulting extract's properties was evaluated. All extracts were characterized according to their chemical composition by FTIR-ATR, MALDI-TOF, and molecular weight distribution (GPC). In addition, the Stiasny number was tested to determine the potential use of extracts in bioadhesive formulation. The self-condensation reaction of resulting extracts was studied using Dynamic Mechanical Analysis (DMA) and Automated Bond Evaluation System (ABES) techniques. Results show a good interaction between condensed and hydrolyzable tannins from both species' barks. It also demonstrated the potential application of the obtained extracts, for a bark ratio of 50:50, in the formulation of bioadhesives for particleboard manufacture. The obtained product showed a similar performance to that of the bioadhesive formulated with the extract obtained using only P. radiata bark.
Influence of chitin nanofibers and gallic acid on physical-chemical and biological performances of chitosan-based films
(2024) Cabrera-Barjas, Gustavo; Albornoz, Karin; Belchi, Maria Dolores Lopez; Giordano, Ady; Bravo-Arrepol, Gaston; Moya-Elizondo, Ernesto; San Martin, Juan; Valdes, Oscar; Nesic, Aleksandra
In this work, chitosan films loaded with gallic acid and different content of chitin nanofibers were prepared and subjected to different characterization techniques. The results showed that the inclusion of gallic acid to chitosan films caused moderate decrease in water vapor permeability (by 29 %) and increased tensile strength of films (by 169 %) in comparison to the neat chitosan films. Furthermore, it was found that the addition of chitin nanofibers up to 30 % into chitosan/gallic acid films additionally improved tensile strength (by 474 %) and reduced plasticity of films (by 171 %), when compared to the chitosan/gallic acid films. Increased concentration of chitin nanofibers in films reduced the overall water vapor permeability of films by 51 %. In addition, gallic acid and chitin nanofibers had synergic effect on high chitosan film's antioxidant and antifungal activity toward Botrytis cinerea (both above 95 %). Finally, chitosan/gallic acid/chitin nanofibers films reduced decay incidence of strawberries, increased total soluble solid content, and promoted high production of some polyphenols during cold storage, in comparison to the control chitosan films and uncoated strawberry samples. Hence, these results suggest that chitosan/gallic acid/chitin nanofibers can present eco-sustainable approach for preservation of strawberries, giving them additional nutritional value.
ISOLATED LIGNANS OF ARAUCARIA ARAUCANA (MOLINA) K. KOCH PROVIDE WOOD PROTECTION AGAINST ATTACK BY THE XYLOPHAGOUS FUNGUS PLEUROTUS OSTREATUS (JACQ.) P. KUMM
(2023) Bravo-Arrepol, Gaston; Torres, Solange; Perez, Claudia; Gonzalez-Ramirez, Mariela; Figueroa, Fabian; Cabrera-Barjas, Gustavo; Aranda, Mario; Tiezzi, Antonio; Gavin, Jose; Paz, Cristian; Becerra, Jose
Araucaria araucana (Molina) K. Koch is an evergreen conifer endemic of Southern Chile and it is considered a sacred tree by the Pehuenche originary people. A. araucana is endangered in the red book. The knots wood of A. araucana are resistant to biological degradation, due to producing a high amount of lignans, even after the decomposition of the tree is possible to find its knots in the forest. In the present study the chemical composition of three wood tissue of A. araucana; knotwood, stemwood, and branches were analyzed by HPTLC-MS, GC-MS, and NMR. Three lignans were purified and identified as eudesmin (1), ((1S,2R,3R) 1,2,3,4tetrahydrona phthalene-2,3-diyl) dimethanol (2) and secoisolarisiresinol (3). Folin-Ciocalteu, DPPH and resistance to biodegradation assays were evaluated to extracts from compressed wood zones. Eudesmin was identified as the principal lignan in knots with a 0.5%w/w and outperformed the fungicide Nipacide (R) P511 in protecting wood against xylophage fungi Pleurotus ostreatus (Jacq.) P. Kumm.
Polyphenolic Composition and Antioxidant Activity (ORAC, EPR and Cellular) of Different Extracts of Argylia radiata Vitroplants and Natural Roots
(2022) Giordano, Ady; Morales-Tapia, Pablo; Moncada-Basualto, Mauricio; Pozo-Martinez, Josue; Olea-Azar, Claudio; Nesic, Aleksandra; Cabrera-Barjas, Gustavo
Plant biochemistry studies have increased in recent years due to their potential to improve human health. Argylia radiata is an extremophile plant with an interesting polyphenolic profile. However, its biomass is scarce and occasionally available. Argylia in vitro biomass was obtained from tissue culture and compared with in vivo roots regarding its polyphenolic and flavonoid content. Different solvents were used to prepare extracts from the in vitro tissue of callus and aerial plant organs and in vivo roots. UPLC-MS/MS was used to assess the chemical composition of each extract. ORAC-FL and scavenging of free radicals (DPPH and OH) methods were used to determine the antioxidant capacity of extracts. Furthermore, the biological activity of the extracts was established using the cellular antioxidant activity method. The vitroplants were a good source of polyphenols (25-68 mg GAE/100 g tissue FW), and methanol was the most efficient solvent. Eight polyphenolic compounds were identified, and their antioxidant properties were investigated by different chemical methods with EPR demonstrating its specific scavenging activity against free radicals. All extracts showed cellular dose-dependent antioxidant activity. The methanolic extract of vitroplants showed the highest cellular antioxidant activity (44.6% and 51%) at 1 and 10 mu g/mL of extract, respectively. Vitroplants of A. radiata are proposed as a biotechnological product as a source of antioxidant compounds with multiple applications.
Preparation and Characterization of Lignin Nanoparticles from Different Plant Sources
(2024) Ortega-Sanhueza, Isidora; Girard, Victor; Ziegler-Devin, Isabelle; Chapuis, Hubert; Brosse, Nicolas; Valenzuela, Francisca; Banerjee, Aparna; Fuentealba, Cecilia; Cabrera-Barjas, Gustavo; Torres, Camilo; Mendez, Alejando; Segovia, Cesar; Pereira, Miguel
This article presents new research on producing lignin nanoparticles (LNPs) using the antisolvent nanoprecipitation method. Acetone (90%) served as the lignin solvent and water (100%) as the antisolvent, using five types of lignins from various sources. Comprehensive characterization techniques, including NMR, GPC, FTIR, TEM, and DLS, were employed to assess both lignin and LNP properties. The antioxidant activity of the LNPs was evaluated as well. The results demonstrated the successful formation of spherical nanoparticles below 100 nm with initial lignin concentrations of 1 and 2%w/v. The study highlighted the crucial role of lignin purity in LNP formation and colloidal stability, noting that residual carbohydrates adversely affect efficiency. This method offers a straightforward, environmentally friendly approach using cost-effective solvents, applicable to diverse lignin sources. The innovation of this study lies in its demonstration of a cost-effective and eco-friendly method to produce stable, nanometric-sized spherical LNPs. These LNPs have significant potential as reinforcement materials due to their reinforcing capability, hydrophilicity, and UV absorption. This work underscores the importance of starting material purity for optimizing the process and achieving the desired nanometric dimensions, marking a pioneering advancement in lignin-based nanomaterials.
Pretreated Eucalyptus globulus and Pinus radiata Barks: Potential Substrates to Improve Seed Germination for a Sustainable Horticulture
(2023) Escobar-Avello, Danilo; Ferrer, Victor; Bravo-Arrepol, Gaston; Reyes-Contreras, Pablo; Elissetche, Juan P.; Santos, Jorge; Fuentealba, Cecilia; Cabrera-Barjas, Gustavo
Commercial forest plantations in Chile are dominated by pine (Pinus radiata) and eucalyptus (Eucalyptus globulus). Tree bark is the main by-product of the forestry industry and has low value, but great potential for use as an agricultural substrate. However, the direct use of bark fibers may cause plant phytotoxicity due to the presence of polyphenolic and other compounds. This study aims to evaluate the physicochemical properties of E. globulus and P. radiata bark after water extraction treatments. The phytotoxicity of the resulting extracted bark alone and that mixed with commercial substrates (coconut fiber, moss, peat, and composted pine) at different ratios (25 to 75 wt%) were assessed using the Munoo-Liisa vitality index (MLVI) test. For all treatments, the seed germination and growth of radish (Raphanus sativus) and Chinese cabbage (Brassica rapa) species were evaluated and compared to a commercial growing medium (peat) as a control. The optimal mixture for seed growth was determined to be 75% extracted E. globulus bark fiber and 25% commercial substrates such as peat (P), coconut fiber (C), moss (M), and composted pine (CP), as indicated by the MLVI and germination results. Two phytostimulant products, chitosan and alginate-encapsulated fulvic acid, were added to the best substrate mixture, with the purpose of improving their performance. Encapsulated fulvic acid at 0.1% w/v was effective in promoting plant growth, while chitosan at all of the concentrations studied was effective only for mixture 75E-25CP. The mixture of E. globulus fiber and commercial substrates, containing a high proportion of water-extracted fiber (75%), shows the potential to be used in the growth of horticultural crops and in the plant nursery industry.
Stress Dependent Biofilm Formation and Bioactive Melanin Pigment Production by a Thermophilic Bacillus Species from Chilean Hot Spring
(2022) Marin-Sanhueza, Cathalina; Echeverria-Vega, Alex; Gomez, Aleydis; Cabrera-Barjas, Gustavo; Romero, Romina; Banerjee, Aparna
Thermophilic bacteria able to survive extreme temperature stress are of great biotechnological interest due to their extracellular production of bioactive molecules as a part of a survival strategy, or by intracellular modifications. In the present study, thermophilic Bacillus haynesii CamB6, isolated from a Chilean hot spring, was studied for the formation of different stress response molecules. The polymeric pigment produced by the bacterial strain was characterized by different physicochemical techniques. On exposure to ranges of temperature (50-60 degrees C), pH (5.0-7.0), and sources of nitrogen and carbon (1-5 g center dot L-1), the bacteria responded with a biofilm network formation in a hydrophobic polystyrene surface. Biofilm formation under fed-batch conditions was also statistically validated. The bacteria showed a planktonic pellicle network formation in the presence of induced hypoxia and salinity stress (19.45 g center dot L-1) under static conditions. Salinity stress also resulted in the intracellular response of brown pigment production. The pigment was structurally and functionally characterized by UV-Vis absorbance and the presence of different characteristic peaks via FTIR analysis (bacterial pyomelanin fingerprints) were assessed. A high thermal stability and TGA profile indicated the brown pigment was a probable pyomelanin candidate. Micropyrolysis (Py-GC/MS) showed that isoprene, pyrrole, benzene, pyridine, and their derivatives were the major components detected. In addition, acetic acid, indole, phenol, and its derivatives were observed. The absence of sulfocompounds in the pyrolyzed products agreed with those reported in the literature for pyomelanin. The pigment surface morphology was analyzed via SEM, and the elemental composition via EDS also demonstrated the similarity of the brown pigment to that of the melanin family. The pyomelanin pigment was observed to be bioactive with promising antioxidant capacity (H2O2, Fe2+) compared to the standard antioxidant molecules. In conclusion, B. haynesii CamB6 demonstrated the formation of several biomolecules as a stress response mechanism that is bioactive, showing its probable biotechnological applications in future.
Sulfated Polysaccharide Extracted from the Green Algae Codium bernabei: Physicochemical Characterization and Antioxidant, Anticoagulant and Antitumor Activity
(2022) Figueroa, Fabian A.; Abdala-Diaz, Roberto T.; Perez, Claudia; Casas-Arrojo, Virginia; Nesic, Aleksandra; Tapia, Cecilia; Duran, Carla; Valdes, Oscar; Parra, Carolina; Bravo-Arrepol, Gaston; Soto, Luis; Becerra, Jose; Cabrera-Barjas, Gustavo
Codium bernabei is a green alga that grows on Chilean coasts. The composition of its structural polysaccharides is still unknown. Hence, the aim of this work is to isolate and characterize the hot water extracted polysaccharide fractions. For this purpose, the water extracts were further precipitated in alcohol (TPs) and acid media (APs), respectively. Both fractions were characterized using different physicochemical techniques such as GC-MS, GPC, FTIR, TGA, and SEM. It is confirmed that the extracted fractions are mainly made of sulfated galactan unit, with a degree of sulfation of 19.3% (TPs) and 17.4% (ATs) and a protein content of 3.5% in APs and 15.6% in TPs. Other neutral sugars such as xylose, glucose, galactose, fucose, mannose, and arabinose were found in a molar ratio (0.05:0.6:1.0:0.02:0.14:0.11) for TPs and (0.05:0.31:1.0:0.03:0.1:0.13) for ATs. The molecular weight of the polysaccharide samples was lower than 20 kDa. Both polysaccharides were thermally stable (Tonset > 190 degrees C) and showed antioxidant activity according to the ABTS(center dot+) and DPPH tests, where TPs fractions had higher scavenging activity (35%) compared to the APs fractions. The PT and APTTS assays were used to measure the anticoagulant activity of the polysaccharide fractions. In general, the PT activity of the TPs and APs was not different from normal plasma values. The exception was the TPs treatment at 1000 mu g mL(-1) concentration. The APTTS test revealed that clotting time for both polysaccharides was prolonged regarding normal values at 1000 mu g mL(-1). Finally, the antitumor test in colorectal carcinoma (HTC-116) cell line, breast cancer (MCF-7) and human leukemia (HL-60) cell lines showed the cytotoxic effect of TPs and APs. Those results suggest the potential biotechnological application of sulfate galactan polysaccharides isolated from a Chilean marine resource.
Synthesis and Properties of Poly(imides) and Poly(imides)/Ionic Liquid Composites Bearing a Benzimidazole Moiety
(2019) Terraza, Claudio A.; Ortiz, Pablo; Tagle, Luis H.; Perez, German; Saldias, Cesar; Rodriguez-Gonzalez, Fidel E.; Cabrera-Barjas, Gustavo; Catalan, Henry; Tundidor-Camba, Alain; Coll, Deysma
Three new aromatic poly(imides) containing benzimidazole units in the backbone were synthesized and characterized by several spectroscopic techniques. Flexible spacer groups were incorporated into the poly(imides) structure to improve their solubility in organic solvents and their oxidative stabilization. All poly(imides) were thermally stable (T-d5% > 512 degrees C) and had the ability to form dense flexible films. Novel composite films were successfully prepared by loading poly(imide) with ionic liquid ([Bmim]Br) at different concentrations up to 25 wt.%. The resulting materials were characterized according to their morphology and elemental composition (SEM-EDX), water uptake capability, contact angle, and oxidative degradation resistance. Results suggested that poly(imide)/ionic liquid composites would be excellent candidates for future proton conductivity measurements.

Browsing by Author "Cabrera-Barjas, Gustavo"

Results Per Page

Sort Options