Preparation and characterization of bionanocomposites based on protein and cellulose nanocrystals by continuous casting

Cette thèse étudie la production et la caractérisation de films bionanocomposites de gélatine-cellulose nanocristaux (CNCs) destinés aux emballages alimentaires multifonctionnels. L’évolutivité des films de gélatine/CNCs a été obtenue par casting continu, et les paramètres rhéologiques des solutions filmogènes et la température de séchage nécessaire pour produire 12 m de film/h ont été établis. Le processus de casting continu s'est avéré avantageux par rapport au processus de casting conventionnel. Les tests de traction, l'analyse thermogravimétrique et l'analyse de perméabilité à la vapeur d'eau ont montré que les films de gélatine/CNCs laminés produits continuellement ont eu une meilleure performance que ceux obtenus par casting conventionnel. Les propriétés physiques et structurelles des gélatine/CNCs modulé par des interactions électrostatiques changés par le pH ont été étudiées. La fonction des CNCs a été étendue avec succès par la fonctionnalisation avec rosin (r-CNCs), qui a produit des nanocharges antimicrobiennes. Des tests de traction et des analyses antimicrobiennes ont montré que les r-CNCs servent d’agent antibactériens dans les films à base de gélatine. Sans cela, les films souffriraient autrement de propriétés physiques et biologiques limitées. L'acide tannique a été utilisé avec succès comme antioxydant et additif antibactérien, comme une autre perspective pour développer le potentiel des films de gélatine/CNCs comme matériel d'emballage. L'acide tannique non oxydé a favorisé les interactions non covalentes et intermoléculaires entre la gélatine, les CNCs et l'acide tannique. Ces interactions physico-chimiques ont montré une plus grande influence sur les propriétés antioxydantes et physiques des films gélatine/CNCs-acide tannique. Cette thèse donne une compréhension globale de la façon dont la CNCs peut être exploitée pour développer des films biodégradables à base de gélatine avec des propriétés améliorées ou des fonctionnalités supplémentaires. Le casting continu a été appliqué afin d’augmenter la production de films de gélatine/CNCs, ce que rend les films hautement souhaitables pour les applications d'emballage.This Ph.D. thesis covers the production and characterization of gelatin-cellulose nanocrystals (CNCs) bionanocomposite films intended for multifunctional food packaging. The up-scalability of the gelatin/CNCs films was attained by continuous casting and the rheological parameters of the film-forming solutions and drying temperature required to produce 12 m film/h were established. The continuous casting processing was proven to be advantageous when compared to the bench solution casting method. Tensile tests, thermogravimetric analysis, and water vapor permeability analysis showed that the continuously cast gelatin/CNCs films had exceptionally better performance than the films obtained by bench casting. The physical and structural properties of the gelatin/CNCs bionanocomposites as tailored by pH-dependent electrostatic interactions were investigated. The suitability of CNCs was successfully extended by functionalization with rosin (r-CNCs), thus giving rise to antimicrobial reinforcing agents. Tensile tests and antimicrobial analysis showed that r-CNCs served as bacterial nanofillers in gelatin-based films, which otherwise would suffer from limited physical and biological properties. Plant-derived tannic acid was successfully used as an antioxidant and bactericidal additive, as another perspective of extending the potential of the gelatin/CNCs films as a packaging material. Non-oxidized tannic acid favored non-covalent interactions and intermolecular connections between gelatin, CNCs, and tannic acid. These physico chemical interactions showed to have a greater influence on the antioxidant and physical properties of gelatin/CNCs/Tannic acid films. This thesis provides a comprehensive understanding of how CNCs can be explored to develop biodegradable films based on gelatin with enhanced properties or extra functionalities. A continuous solution casting was applied for scaling up the production of gelatin/CNCs-based films making them highly desirable for packaging applications

Préparation et caractérisation de bionanocomposites à base de protéines et nanocristaux de cellulose par casting continu

This Ph.D. thesis covers the production and characterization of gelatin-cellulose nanocrystals (CNCs) bionanocomposite films intended for multifunctional food packaging. The up-scalability of the gelatin/CNCs films was attained by continuous casting and the rheological parameters of the film-forming solutions and drying temperature required to produce 12 m film/h were established. The continuous casting processing was proven to be advantageous when compared to the bench solution casting method. Tensile tests, thermogravimetric analysis, and water vapor permeability analysis showed that the continuously cast gelatin/CNCs films had exceptionally better performance than the films obtained by bench casting. The physical and structural properties of the gelatin/CNCs bionanocomposites as tailored by pH-dependent electrostatic interactions were investigated. The suitability of CNCs was successfully extended by functionalization with rosin (r-CNCs), thus giving rise to antimicrobial reinforcing agents. Tensile tests and antimicrobial analysis showed that r-CNCs served as bacterial nanofillers in gelatin-based films, which otherwise would suffer from limited physical and biological properties. Plant-derived tannic acid was successfully used as an antioxidant and bactericidal additive, as another perspective of extending the potential of the gelatin/CNCs films as a packaging material. Non-oxidized tannic acid favored non-covalent interactions and intermolecular connections between gelatin, CNCs, and tannic acid. These physico chemical interactions showed to have a greater influence on the antioxidant and physical properties of gelatin/CNCs/Tannic acid films. This thesis provides a comprehensive understanding of how CNCs can be explored to develop biodegradable films based on gelatin with enhanced properties or extra functionalities. A continuous solution casting was applied for scaling up the production of gelatin/CNCs-based films making them highly desirable for packaging applications.Cette thèse étudie la production et la caractérisation de films bionanocomposites de gélatine-cellulose nanocristaux (CNCs) destinés aux emballages alimentaires multifonctionnels. L’évolutivité des films de gélatine/CNCs a été obtenue par casting continu, et les paramètres rhéologiques des solutions filmogènes et la température de séchage nécessaire pour produire 12 m de film/h ont été établis. Le processus de casting continu s'est avéré avantageux par rapport au processus de casting conventionnel. Les tests de traction, l'analyse thermogravimétrique et l'analyse de perméabilité à la vapeur d'eau ont montré que les films de gélatine/CNCs laminés produits continuellement ont eu une meilleure performance que ceux obtenus par casting conventionnel. Les propriétés physiques et structurelles des gélatine/CNCs modulé par des interactions électrostatiques changés par le pH ont été étudiées. La fonction des CNCs a été étendue avec succès par la fonctionnalisation avec rosin (r-CNCs), qui a produit des nanocharges antimicrobiennes. Des tests de traction et des analyses antimicrobiennes ont montré que les r-CNCs servent d’agent antibactériens dans les films à base de gélatine. Sans cela, les films souffriraient autrement de propriétés physiques et biologiques limitées. L'acide tannique a été utilisé avec succès comme antioxydant et additif antibactérien, comme une autre perspective pour développer le potentiel des films de gélatine/CNCs comme matériel d'emballage. L'acide tannique non oxydé a favorisé les interactions non covalentes et intermoléculaires entre la gélatine, les CNCs et l'acide tannique. Ces interactions physico-chimiques ont montré une plus grande influence sur les propriétés antioxydantes et physiques des films gélatine/CNCs-acide tannique. Cette thèse donne une compréhension globale de la façon dont la CNCs peut être exploitée pour développer des films biodégradables à base de gélatine avec des propriétés améliorées ou des fonctionnalités supplémentaires. Le casting continu a été appliqué afin d’augmenter la production de films de gélatine/CNCs, ce que rend les films hautement souhaitables pour les applications d'emballage

Préparation et caractérisation de bionanocomposites à base de protéines et nanocristaux de cellulose par casting continu

This Ph.D. thesis covers the production and characterization of gelatin-cellulose nanocrystals (CNCs) bionanocomposite films intended for multifunctional food packaging. The up-scalability of the gelatin/CNCs films was attained by continuous casting and the rheological parameters of the film-forming solutions and drying temperature required to produce 12 m film/h were established. The continuous casting processing was proven to be advantageous when compared to the bench solution casting method. Tensile tests, thermogravimetric analysis, and water vapor permeability analysis showed that the continuously cast gelatin/CNCs films had exceptionally better performance than the films obtained by bench casting. The physical and structural properties of the gelatin/CNCs bionanocomposites as tailored by pH-dependent electrostatic interactions were investigated. The suitability of CNCs was successfully extended by functionalization with rosin (r-CNCs), thus giving rise to antimicrobial reinforcing agents. Tensile tests and antimicrobial analysis showed that r-CNCs served as bacterial nanofillers in gelatin-based films, which otherwise would suffer from limited physical and biological properties. Plant-derived tannic acid was successfully used as an antioxidant and bactericidal additive, as another perspective of extending the potential of the gelatin/CNCs films as a packaging material. Non-oxidized tannic acid favored non-covalent interactions and intermolecular connections between gelatin, CNCs, and tannic acid. These physico chemical interactions showed to have a greater influence on the antioxidant and physical properties of gelatin/CNCs/Tannic acid films. This thesis provides a comprehensive understanding of how CNCs can be explored to develop biodegradable films based on gelatin with enhanced properties or extra functionalities. A continuous solution casting was applied for scaling up the production of gelatin/CNCs-based films making them highly desirable for packaging applications.Cette thèse étudie la production et la caractérisation de films bionanocomposites de gélatine-cellulose nanocristaux (CNCs) destinés aux emballages alimentaires multifonctionnels. L’évolutivité des films de gélatine/CNCs a été obtenue par casting continu, et les paramètres rhéologiques des solutions filmogènes et la température de séchage nécessaire pour produire 12 m de film/h ont été établis. Le processus de casting continu s'est avéré avantageux par rapport au processus de casting conventionnel. Les tests de traction, l'analyse thermogravimétrique et l'analyse de perméabilité à la vapeur d'eau ont montré que les films de gélatine/CNCs laminés produits continuellement ont eu une meilleure performance que ceux obtenus par casting conventionnel. Les propriétés physiques et structurelles des gélatine/CNCs modulé par des interactions électrostatiques changés par le pH ont été étudiées. La fonction des CNCs a été étendue avec succès par la fonctionnalisation avec rosin (r-CNCs), qui a produit des nanocharges antimicrobiennes. Des tests de traction et des analyses antimicrobiennes ont montré que les r-CNCs servent d’agent antibactériens dans les films à base de gélatine. Sans cela, les films souffriraient autrement de propriétés physiques et biologiques limitées. L'acide tannique a été utilisé avec succès comme antioxydant et additif antibactérien, comme une autre perspective pour développer le potentiel des films de gélatine/CNCs comme matériel d'emballage. L'acide tannique non oxydé a favorisé les interactions non covalentes et intermoléculaires entre la gélatine, les CNCs et l'acide tannique. Ces interactions physico-chimiques ont montré une plus grande influence sur les propriétés antioxydantes et physiques des films gélatine/CNCs-acide tannique. Cette thèse donne une compréhension globale de la façon dont la CNCs peut être exploitée pour développer des films biodégradables à base de gélatine avec des propriétés améliorées ou des fonctionnalités supplémentaires. Le casting continu a été appliqué afin d’augmenter la production de films de gélatine/CNCs, ce que rend les films hautement souhaitables pour les applications d'emballage

Préparation et caractérisation de bionanocomposites à base de protéines et nanocristaux de cellulose par casting continu

This Ph.D. thesis covers the production and characterization of gelatin-cellulose nanocrystals (CNCs) bionanocomposite films intended for multifunctional food packaging. The up-scalability of the gelatin/CNCs films was attained by continuous casting and the rheological parameters of the film-forming solutions and drying temperature required to produce 12 m film/h were established. The continuous casting processing was proven to be advantageous when compared to the bench solution casting method. Tensile tests, thermogravimetric analysis, and water vapor permeability analysis showed that the continuously cast gelatin/CNCs films had exceptionally better performance than the films obtained by bench casting. The physical and structural properties of the gelatin/CNCs bionanocomposites as tailored by pH-dependent electrostatic interactions were investigated. The suitability of CNCs was successfully extended by functionalization with rosin (r-CNCs), thus giving rise to antimicrobial reinforcing agents. Tensile tests and antimicrobial analysis showed that r-CNCs served as bacterial nanofillers in gelatin-based films, which otherwise would suffer from limited physical and biological properties. Plant-derived tannic acid was successfully used as an antioxidant and bactericidal additive, as another perspective of extending the potential of the gelatin/CNCs films as a packaging material. Non-oxidized tannic acid favored non-covalent interactions and intermolecular connections between gelatin, CNCs, and tannic acid. These physico chemical interactions showed to have a greater influence on the antioxidant and physical properties of gelatin/CNCs/Tannic acid films. This thesis provides a comprehensive understanding of how CNCs can be explored to develop biodegradable films based on gelatin with enhanced properties or extra functionalities. A continuous solution casting was applied for scaling up the production of gelatin/CNCs-based films making them highly desirable for packaging applications.Cette thèse étudie la production et la caractérisation de films bionanocomposites de gélatine-cellulose nanocristaux (CNCs) destinés aux emballages alimentaires multifonctionnels. L’évolutivité des films de gélatine/CNCs a été obtenue par casting continu, et les paramètres rhéologiques des solutions filmogènes et la température de séchage nécessaire pour produire 12 m de film/h ont été établis. Le processus de casting continu s'est avéré avantageux par rapport au processus de casting conventionnel. Les tests de traction, l'analyse thermogravimétrique et l'analyse de perméabilité à la vapeur d'eau ont montré que les films de gélatine/CNCs laminés produits continuellement ont eu une meilleure performance que ceux obtenus par casting conventionnel. Les propriétés physiques et structurelles des gélatine/CNCs modulé par des interactions électrostatiques changés par le pH ont été étudiées. La fonction des CNCs a été étendue avec succès par la fonctionnalisation avec rosin (r-CNCs), qui a produit des nanocharges antimicrobiennes. Des tests de traction et des analyses antimicrobiennes ont montré que les r-CNCs servent d’agent antibactériens dans les films à base de gélatine. Sans cela, les films souffriraient autrement de propriétés physiques et biologiques limitées. L'acide tannique a été utilisé avec succès comme antioxydant et additif antibactérien, comme une autre perspective pour développer le potentiel des films de gélatine/CNCs comme matériel d'emballage. L'acide tannique non oxydé a favorisé les interactions non covalentes et intermoléculaires entre la gélatine, les CNCs et l'acide tannique. Ces interactions physico-chimiques ont montré une plus grande influence sur les propriétés antioxydantes et physiques des films gélatine/CNCs-acide tannique. Cette thèse donne une compréhension globale de la façon dont la CNCs peut être exploitée pour développer des films biodégradables à base de gélatine avec des propriétés améliorées ou des fonctionnalités supplémentaires. Le casting continu a été appliqué afin d’augmenter la production de films de gélatine/CNCs, ce que rend les films hautement souhaitables pour les applications d'emballage

Preparation and characterization of cellulose nanocrystals/cellulose acetate composites

Orientador: Maria do Carmo GonçalvesDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de QuímicaResumo: Nesse trabalho, nanocristais de celulose (CNC) foram obtidos por hidrólise de fibras de algodão, utilizando-se três diferentes ácidos: ácido sulfúrico, clorídrico e fosfórico. Micrografias obtidas por microscopia eletrônica de varredura (SEM) e transmissão (TEM) confirmaram que as condições de hidrólise empregadas foram adequadas para isolar seus nanocristais. No entanto, foi também possível observar a presença de uma pequena fração de fibras não totalmente hidrolisadas em todas as amostras analisadas. Imagens de microscopia óptica por luz polarizada (PLM) revelaram que o processo de secagem por liofilização dos CNC conduz à formação de aglomerados com dimensões micrométricas. Modificações químicas nas superfícies dos CNC, empregando-se ácido acético e cloreto de hexanoíla, foram conduzidas com o objetivo de diminuir o seu caráter hidrofílico. As modificações foram confirmadas por espectroscopia na região do infravermelho e por imagens de PLM das suspensões dos CNC. Compósitos de acetato de celulose (CA), reforçados com CNC, foram preparados por extrusão, utilizando-se dois procedimentos para a incorporação da carga na matriz: mistura direta e masterbatch, sendo esse último conduzido na tentativa de evitar a etapa de liofilização, onde ocorre a formação de aglomerados de nanocristais. Ensaios mecânicos mostraram que não houve aumento significativo nas propriedades mecânicas para os compósitos preparados por mistura direta. Entretanto, compósitos preparados por masterbatch apresentaram aumento no módulo de Young em torno de 5% e 14%, para composições contendo 10 e 15 % nanocristais em massa, respectivamente. Esses resultados evidenciam a importância das condições de hidrólise para obtenção das nanopartículas, como também da escolha do método de preparação do compósito de forma a promover a menor formação de aglomerados e melhor dispersão da carga na matrizAbstract: In this work, cotton fiber cellulose nanocrystals (CNC) were obtained by acid hydrolysis using three different acids: sulfuric acid, hydrochloric acid and phosphoric acid. Scanning (SEM) and transmission (TEM) electron micrographs confirmed that the acid hydrolysis conditions used were efficient to isolate their nanocrystals. However, in all samples analyzed, it was possible to observe the presence of some partially hydrolyzed fibers. Polarized Light Microscopy (PLM) showed that the freeze-drying process led to the formation of small CNC agglomerates with micron dimensions. CNC surface functionalization was carried out with the purpose of reducing the hydrophilic character, by using acetic acid and hexanoyl chloride. Chemical modifications at the surface were confirmed by infrared spectroscopy and the hydrophilic character decrease was confirmed by PLM images of the functionalized CNC. Cellulose acetate composites, reinforced with CNC, were obtained by melt extrusion using two techniques for the introduction of reinforcing agent: direct mixing and masterbatch. The latter were carried out prevent CNC agglomeration formation due to the freeze-drying process. Mechanical tests showed that there was no significant increase in of the composites prepared by direct mixing mechanical properties. However, composites prepared from masterbatch showed a 5% and 14% increase in Young's modulus for 10 and 15 wt% CNC content, respectively. These results show the importance of the hydrolysis conditions on the nanoparticle synthesis, as well as the choice of an appropriate reinforcing agent load method so as to avoid agglomeration and increase load dispersion in the matrixMestradoMestra em Químic

Morphological Investigation Of Cellulose Acetate/cellulose Nanocrystal Composites Obtained By Melt Extrusion

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Composites were prepared from cellulose acetate (CA) and cellulose nanocrystals (CNC) by melt extrusion using two methods for the introduction of CNC: direct mixing and predispersion in CA solution. CNC were isolated using hydrochloric acid to increase thermal stability allowing the composites to be processed above 150 degrees C. The effect of CNC dispersion on the composites morphology, thermal, and mechanical properties was investigated. Field emission scanning electron microscopy and transmission electron microscopy results indicated that the predispersion method allows better CNC dispersion and distribution when compared to the direct mixture method. In addition, predispersion promotes preferential CNC orientation in relation to the injection flow. The predispersion method also showed a 14% Young's modulus increase in composites containing 15 wt % CNC while no significant change was observed when using the direct mixing. The results obtained in this work show that, to achieve the percolation threshold, nanoparticle distribution is as important as their content. (C) 2016 Wiley Periodicals, Inc.13344Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)National Institute of Science, Technology and Innovation in Complex Functional Materials (Inomat/INCT)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Morphological investigation of cellulose acetate/cellulose nanocrystal composites obtained by melt extrusion

Composites were prepared from cellulose acetate (CA) and cellulose nanocrystals (CNC) by melt extrusion using two methods for the introduction of CNC: direct mixing and predispersion in CA solution. CNC were isolated using hydrochloric acid to increase thermal stability allowing the composites to be processed above 150 °C. The effect of CNC dispersion on the composites morphology, thermal, and mechanical properties was investigated. Field emission scanning electron microscopy and transmission electron microscopy results indicated that the predispersion method allows better CNC dispersion and distribution when compared to the direct mixture method. In addition, predispersion promotes preferential CNC orientation in relation to the injection flow. The predispersion method also showed a 14% Young's modulus increase in composites containing 15 wt % CNC while no significant change was observed when using the direct mixing. The results obtained in this work show that, to achieve the percolation threshold, nanoparticle distribution is as important as their content.13344CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPSem informaçãoSem informaçãoSem informaçã

Propriedades reológicas de soluções filmogênicas de gelatina e nanocristais de celulose para produção de filmes biodegradáveis por casting contínuo

International audienceMost studies for the production of protein-based films make use of the classical casting technique. However, this technique requires relatively long drying times and obtains films with small dimensions, which makes this technique impractical on an industrial scale. In this work, we propose to study a suitable formulation to produce large-scale biodegradable gelatin films by continuous casting, as well as to investigate the effect of the addition of CNCs on the physical properties of the obtained films. Gelatin/CNCs films produced by continuous casting exhibited homogeneity and continuity, and absence of fractures and insoluble particles on the surface. In addition, the addition of 1% by mass of CNCs to the gelatin bionanocomposite led to an increase in elongation at break of 148%, compared to the pure gelatin film. The results show that gelatin/CNCs films have a high performance, and that the use of continuous casting is a compatible large-scale processing method for the production of biodegradable films from gelatin.A maioria dos estudos para produção de filmes à base de proteínas faz uso da técnica clássica de casting. No entanto, esta técnica requer tempos de secagem relativamente longos e obtém filmes com pequenas dimensões, o que torna essa técnica impraticável em escala industrial. Neste trabalho, propomos estudar uma formulação adequada para produzir filmes biodegradáveis de gelatina em larga escala por casting contínuo, bem como investigar o efeito da adição de CNCs nas propriedades físicas dos filmes obtidos. Os filmes de gelatina/CNCs produzidos por casting contínuo exibiram homogeneidade e continuidade, e ausência de fraturas e partículas insolúveis na superfície. Além disso, a adição de 1% em massa de CNCs ao bionanocompósito de gelatina levou a um aumento no alongamento a ruptura de 148%, em comparação com o puro filme de gelatina. Os resultados mostram que os filmes de gelatina/CNCs apresentam um alto desempenho, e que o uso de casting contínuo é um método de processamento em larga escala compatível para a produção de filmes biodegradáveis a partir de gelatina