1
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Mousavi Z, Heuzey MC, Carreau PJ. Compatibilized polylactide/polyamide 11 blends containing multiwall carbon nanotubes: Morphology, rheology, electrical and mechanical properties. POLYMER 2023. [DOI: 10.1016/j.polymer.2023.125906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
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2
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Abstract
PNIPAM (poly(N-isopropylacrylamide)), a well-studied thermo-responsive polymer, undergoes conformational transition around 32 °C. On the other hand, cellulose nanocrystals (CNCs), as a promising and biocompatible material, has rarely been introduced to the PNIPAM-based fibrous hydrogel system. CNCs' impact on the temperature responsive behaviors of hydrogels, either in single layer or bilayer hydrogel systems, is yet to be investigated. In this work, stable well dispersed PNIPAM/CNC suspensions (with various CNC proportions) are prepared and electrospun into nanofiber membranes. The corresponding hydrogels are then obtained via UV-induced crosslinking. CNCs are found to exert a significant constraint effect on hydrogel swelling when it exceeded 5 wt% but a negligible effect on contraction. The difference between hydrogels with various CNC proportions regarding their temperature responsive behaviors is utilized to fabricate bilayer hydrogels. These bilayer samples are capable of generating 3D geometries when they come into contact with water for the first time via anisotropic swelling between the two layers and changing their dimension reversibly in the following swelling and contraction. In addition, these geometries are found to be highly tunable via the finely tuned thickness ratio between the two layers. This promising feature would significantly extend the application of these materials in tissue engineering where a controllable geometry of the culture substrate is of great importance.
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Affiliation(s)
- Yinghao Xu
- CREPEC, Department of Chemical Engineering, Polytechnique Montréal, P. O. Box 6079, Station Centre-Ville, Montreal, Quebec, H3C 3A7, Canada.
| | - Abdellah Ajji
- CREPEC, Department of Chemical Engineering, Polytechnique Montréal, P. O. Box 6079, Station Centre-Ville, Montreal, Quebec, H3C 3A7, Canada.
| | - Marie-Claude Heuzey
- CREPEC, Department of Chemical Engineering, Polytechnique Montréal, P. O. Box 6079, Station Centre-Ville, Montreal, Quebec, H3C 3A7, Canada.
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3
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Zhang C, Wang CS, Therriault D, Heuzey MC. Development of aqueous protein/polysaccharide mixture-based inks for 3D printing towards food applications. Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2022.107742] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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4
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Girard M, Bertrand F, Tavares JR, Heuzey MC. Rheological insights on the evolution of sonicated cellulose nanocrystal dispersions. Ultrason Sonochem 2021; 78:105747. [PMID: 34534796 PMCID: PMC8449047 DOI: 10.1016/j.ultsonch.2021.105747] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/30/2021] [Accepted: 09/01/2021] [Indexed: 06/13/2023]
Abstract
Cellulose nanocrystals (CNCs) are promising biomaterials, but their tendency to agglomerate when dried limits their use in several applications. Ultrasonication is commonly used to disperse CNCs in water, bringing enough energy to the suspension to break agglomerates. While the optimized parameters for sonication are now well defined for small volumes of low concentration CNC suspensions, a deeper understanding of the influence of the dispersing process is needed to work with larger volumes, at higher concentrations. Herein, rheology is used to define the distribution and dispersion states upon ultrasonication of a 3.2 wt% CNC suspension. After considering the importance of the measurement sampling volume, the behavior of a more concentrated suspension (6.4 wt%) is examined and compared with a never-dried suspension of the same concentration to validate the dispersion state.
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Affiliation(s)
- Mélanie Girard
- Research Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, Polytechnique Montreal, Montreal, Quebec H3C 3A7, Canada; Research Center for Industrial Flow Processes (URPEI), Polytechnique Montreal, Montreal, Quebec H3C 3A7, Canada
| | - François Bertrand
- Research Center for Industrial Flow Processes (URPEI), Polytechnique Montreal, Montreal, Quebec H3C 3A7, Canada
| | - Jason R Tavares
- Research Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, Polytechnique Montreal, Montreal, Quebec H3C 3A7, Canada
| | - Marie-Claude Heuzey
- Research Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, Polytechnique Montreal, Montreal, Quebec H3C 3A7, Canada.
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Mohammadi M, Heuzey MC, Carreau PJ, Taguet A. Interfacial localization of CNCs in PLA/PBAT blends and its effect on rheological, thermal, and mechanical properties. POLYMER 2021. [DOI: 10.1016/j.polymer.2021.124229] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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6
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Wang CS, Virgilio N, Carreau PJ, Heuzey MC. Understanding the Effect of Conformational Rigidity on Rheological Behavior and Formation of Polysaccharide-Based Hybrid Hydrogels. Biomacromolecules 2021; 22:4016-4026. [PMID: 34510906 DOI: 10.1021/acs.biomac.1c00803] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The importance of conformational rigidity on macroscopic rheological properties was revealed using two model polysaccharides, namely, xanthan gum and hyaluronic acid. Xanthan gum has a rigid tertiary conformation due to its ordered double-helical structure, and the interactions between the tertiary structures result in the formation of a network/quaternary structure. In comparison, hyaluronic acid possesses a relatively flexible tertiary conformation due to its secondary random coil structure. Xanthan gum exhibits a much stronger shear thinning and more solidlike behavior compared to hyaluronic acid, owing to its network/quaternary structure. The rigid tertiary structure and the presence of a network/quaternary structure also endow xanthan gum with better resistance against environmental changes (e.g., salt and/or urea addition, temperature change) compared to hyaluronic acid. The network/quaternary structure allows xanthan gum to form gels with chitosan via electrostatic interactions when using the vapor-induced gelation technique, which is not possible for hyaluronic acid due to its flexible tertiary conformation under similar conditions.
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Affiliation(s)
- Chang-Sheng Wang
- Research Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, Polytechnique Montréal, Montréal, Québec H3C 3A7, Canada
| | - Nick Virgilio
- Research Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, Polytechnique Montréal, Montréal, Québec H3C 3A7, Canada
| | - Pierre J Carreau
- Research Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, Polytechnique Montréal, Montréal, Québec H3C 3A7, Canada
| | - Marie-Claude Heuzey
- Research Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, Polytechnique Montréal, Montréal, Québec H3C 3A7, Canada
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7
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Abriat C, Gazil O, Heuzey MC, Daigle F, Virgilio N. The Polymeric Matrix Composition of Vibrio cholerae Biofilms Modulate Resistance to Silver Nanoparticles Prepared by Hydrothermal Synthesis. ACS Appl Mater Interfaces 2021; 13:35356-35364. [PMID: 34286588 DOI: 10.1021/acsami.1c07455] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Biofilms represent the dominant microbial lifestyle in nature. These complex microbial communities in which bacteria are embedded in a self-produced protective polymeric extracellular matrix, display an enhanced resistance to antimicrobials and thus represent a major health challenge. Although nanoparticles have proven to be effective against bacteria, the interactions between nanoparticles and the polymeric biofilm matrix are still unclear. In this work, silver nanoparticles (AgNPs) were used on mature biofilms formed by the pathogen Vibrio cholerae, and their effects on the biofilm microstructure were evaluated. Bacteria cells within mature biofilms showed an increased tolerance to AgNPs, with their elimination requiring a concentration nine times higher than planktonic cells. Mutant strains not able to form a pellicle biofilm were four times more susceptible to AgNPs than the wild-type strain forming a strong biofilm. Moreover, electron microscopy analysis revealed that AgNPs interacted with the extracellular matrix components and disrupted its microstructure. Finally, two major proteins, Bap1 and RbmA, appeared to mediate the biofilm bacterial resistance to AgNPs. This work highlights the role of the polymeric biofilm matrix composition in resistance to AgNPs. It underlines how crucial it is to understand and characterize the interactions between nanoparticles and the biofilm matrix, in order to design appropriate metallic nanoparticles efficient against bacterial biofilms.
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Affiliation(s)
- Clémence Abriat
- CREPEC, Department of Chemical Engineering, Polytechnique Montréal, Montréal, Québec H3T1J4, Canada
- Department of Microbiology, Infection and Immunology, Université de Montréal, Montréal, Québec H3C3J7, Canada
| | - Olivier Gazil
- CREPEC, Department of Chemical Engineering, Polytechnique Montréal, Montréal, Québec H3T1J4, Canada
| | - Marie-Claude Heuzey
- CREPEC, Department of Chemical Engineering, Polytechnique Montréal, Montréal, Québec H3T1J4, Canada
| | - France Daigle
- Department of Microbiology, Infection and Immunology, Université de Montréal, Montréal, Québec H3C3J7, Canada
| | - Nick Virgilio
- CREPEC, Department of Chemical Engineering, Polytechnique Montréal, Montréal, Québec H3T1J4, Canada
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8
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Mohammadi M, Heuzey MC, Carreau PJ, Taguet A. Morphological and Rheological Properties of PLA, PBAT, and PLA/PBAT Blend Nanocomposites Containing CNCs. Nanomaterials (Basel) 2021; 11:nano11040857. [PMID: 33801672 PMCID: PMC8065413 DOI: 10.3390/nano11040857] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 03/22/2021] [Accepted: 03/24/2021] [Indexed: 11/16/2022]
Abstract
Morphological and rheological properties of poly(lactic acid), PLA (semicrystalline and amorphous), and poly(butylene adipate-co-terephthalate), PBAT, and their blends (75 wt%/25 wt%; PLA/PBAT) were investigated in the presence of cellulose nanocrystals (CNCs) prepared from solution casting followed by melt mixing. For the solution casting step, the CNCs were either incorporated into the matrix, the dispersed phase, or both. The dispersion and distribution of the CNCs in the neat polymers and localization in their blends were analyzed via scanning electron microscopy (SEM) and atomic force microscopy (AFM). The highly dispersed CNCs in the solution cast nanocomposites were agglomerated after melt mixing. In the blends with 1 wt% CNCs, the nanoparticles were mostly localized on the surface of the PBAT droplets irrespective of their initial localization. The rheological behavior of the single polymer matrix nanocomposites and their blends was determined in dynamic and transient shear flow in the molten state. Upon melt mixing the complex viscosity and storage modulus of the solution cast nanocomposites decreased markedly due to re-agglomeration of the CNCs. Under shearing at 0.1 s−1, a significant droplet coalescence was observed in the neat blends, but was prevented by the presence of the CNCs at the interface in the blend nanocomposites.
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Affiliation(s)
- Mojtaba Mohammadi
- Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, École Polytechnique de Montréal, Montreal, QC H3T 1J4, Canada; (M.M.); (M.-C.H.)
| | - Marie-Claude Heuzey
- Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, École Polytechnique de Montréal, Montreal, QC H3T 1J4, Canada; (M.M.); (M.-C.H.)
| | - Pierre J. Carreau
- Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, École Polytechnique de Montréal, Montreal, QC H3T 1J4, Canada; (M.M.); (M.-C.H.)
- Correspondence:
| | - Aurélie Taguet
- Polymers Composites and Hybrids (PCH), IMT Mines Ales, 30319 Ales, France;
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9
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Girard M, Vidal D, Bertrand F, Tavares JR, Heuzey MC. Evidence-based guidelines for the ultrasonic dispersion of cellulose nanocrystals. Ultrason Sonochem 2021; 71:105378. [PMID: 33186861 PMCID: PMC7786632 DOI: 10.1016/j.ultsonch.2020.105378] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/25/2020] [Accepted: 10/20/2020] [Indexed: 05/28/2023]
Abstract
Nanoparticles possess unique, size-driven properties. However, they can be challenging to use as they easily agglomerate - their high surface area-to-volume ratio induces strong interparticle forces, generating agglomerates that are difficult to break. This issue prevails in organic particles as well, such as cellulose nanocrystals (CNCs); when in their dried form, strong hydrogen bonding enhances agglomeration. Ultrasonication is widely applied to prepare CNC suspensions, but the methodology employed is non-standardized and typically under-reported, and process efficiency is unknown. This limits the ability to adapt dispersion protocols at industrial scales. Herein, numerical simulations are used in conjunction with validation experiments to define and optimize key parameters for ultrasonic dispersion of CNCs, allowing an operating window to be inferred.
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Affiliation(s)
- Mélanie Girard
- Research Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, Polytechnique Montreal, Montreal, Quebec H3C 3A7, Canada; Research Center for Industrial Flow Processes (URPEI), Polytechnique Montreal, Montreal, Quebec H3C 3A7, Canada.
| | - David Vidal
- Research Center for Industrial Flow Processes (URPEI), Polytechnique Montreal, Montreal, Quebec H3C 3A7, Canada; Department of Mechanical Engineering, Polytechnique Montreal, Montreal, Quebec H3C 3A7, Canada.
| | - François Bertrand
- Research Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, Polytechnique Montreal, Montreal, Quebec H3C 3A7, Canada; Research Center for Industrial Flow Processes (URPEI), Polytechnique Montreal, Montreal, Quebec H3C 3A7, Canada.
| | - Jason R Tavares
- Research Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, Polytechnique Montreal, Montreal, Quebec H3C 3A7, Canada.
| | - Marie-Claude Heuzey
- Research Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, Polytechnique Montreal, Montreal, Quebec H3C 3A7, Canada.
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10
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Bruel C, Queffeulou S, Carreau PJ, Tavares JR, Heuzey MC. Orienting Cellulose Nanocrystal Functionalities Tunes the Wettability of Water-Cast Films. Langmuir 2020; 36:12179-12189. [PMID: 32986430 DOI: 10.1021/acs.langmuir.0c01799] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Cellulose nanocrystal (CNC)-based materials display apparently erratic wetting behaviors with contact angle (CA) variations as large as 30° from sample to sample. This work hypothesizes that it is the orientation of CNC amphiphilic functionalities at the interface with air that causes the variability in CA. By exploiting relationships with the Hansen solubility parameter theory, a set of surface tension parameters is proposed for both the polar and the non-polar surfaces of cellulose Iβ nanocrystals. These coefficients elucidate the wettability of CNC materials by establishing a correlation between the wetting properties of the air/sample interface and its chemical composition in terms of non-polar moieties. Advancing/receding CA experiments suggest that, while spin-coating CNC suspensions yield purely polar films, oven-casting them produces amphiphilic surfaces. We proposed a mechanism where the state of dispersion (individual or agglomerated) in which CNCs reach the air/water interface during casting is the determining factor: while individual nanocrystals find it more stable to orient their non-polar surfaces toward the interface, the aspect ratio of CNC agglomerates favors an orientation of their polar surfaces. This represents the first compelling evidence of CNC orientation at an interface and can be applied to Pickering emulsions and nanocomposites and to the production of CNC materials with tuned wettability.
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Affiliation(s)
- Charles Bruel
- Research Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, Polytechnique Montréal, P.O. Box 6079, Stn Centre-Ville, Montreal, Quebec H3C 3A7, Canada
| | - Salomé Queffeulou
- Research Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, Polytechnique Montréal, P.O. Box 6079, Stn Centre-Ville, Montreal, Quebec H3C 3A7, Canada
| | - Pierre J Carreau
- Research Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, Polytechnique Montréal, P.O. Box 6079, Stn Centre-Ville, Montreal, Quebec H3C 3A7, Canada
| | - Jason R Tavares
- Research Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, Polytechnique Montréal, P.O. Box 6079, Stn Centre-Ville, Montreal, Quebec H3C 3A7, Canada
| | - Marie-Claude Heuzey
- Research Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, Polytechnique Montréal, P.O. Box 6079, Stn Centre-Ville, Montreal, Quebec H3C 3A7, Canada
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11
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Bruel C, Davies TS, Carreau PJ, Tavares JR, Heuzey MC. Self-assembly behaviors of colloidal cellulose nanocrystals: A tale of stabilization mechanisms. J Colloid Interface Sci 2020; 574:399-409. [DOI: 10.1016/j.jcis.2020.04.049] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 04/10/2020] [Accepted: 04/10/2020] [Indexed: 11/30/2022]
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12
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Abriat C, Enriquez K, Virgilio N, Cegelski L, Fuller GG, Daigle F, Heuzey MC. Mechanical and microstructural insights of Vibrio cholerae and Escherichia coli dual-species biofilm at the air-liquid interface. Colloids Surf B Biointerfaces 2020; 188:110786. [DOI: 10.1016/j.colsurfb.2020.110786] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 12/16/2019] [Accepted: 01/08/2020] [Indexed: 10/25/2022]
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Abriat C, Virgilio N, Heuzey MC, Daigle F. Microbiological and real-time mechanical analysis of Bacillus licheniformis and Pseudomonas fluorescens dual-species biofilm. Microbiology (Reading) 2019; 165:747-756. [DOI: 10.1099/mic.0.000819] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Clemence Abriat
- Department of Chemical Engineering, Polytechnique Montréal, CREPEC, Montréal, Québec, Canada
- Department of Microbiology, Infection and Immunology, Université de Montréal, Montréal, Québec, Canada
| | - Nick Virgilio
- Department of Chemical Engineering, Polytechnique Montréal, CREPEC, Montréal, Québec, Canada
| | - Marie-Claude Heuzey
- Department of Chemical Engineering, Polytechnique Montréal, CREPEC, Montréal, Québec, Canada
| | - France Daigle
- Department of Microbiology, Infection and Immunology, Université de Montréal, Montréal, Québec, Canada
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Bruel C, Tavares JR, Carreau PJ, Heuzey MC. The structural amphiphilicity of cellulose nanocrystals characterized from their cohesion parameters. Carbohydr Polym 2019; 205:184-191. [DOI: 10.1016/j.carbpol.2018.10.026] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 10/08/2018] [Accepted: 10/09/2018] [Indexed: 11/25/2022]
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Beuguel Q, Tavares JR, Carreau PJ, Heuzey MC. Ultrasonication of spray- and freeze-dried cellulose nanocrystals in water. J Colloid Interface Sci 2018; 516:23-33. [DOI: 10.1016/j.jcis.2018.01.035] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 01/08/2018] [Accepted: 01/09/2018] [Indexed: 12/24/2022]
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Affiliation(s)
- Chang-Sheng Wang
- Centre de Recherche sur les Systèmes Polymères et Composites à Haute Performance (CREPEC); Department of Chemical Engineering; Polytechnique Montréal; Montréal Québec H3C 3A7 Canada
| | - Nick Virgilio
- Centre de Recherche sur les Systèmes Polymères et Composites à Haute Performance (CREPEC); Department of Chemical Engineering; Polytechnique Montréal; Montréal Québec H3C 3A7 Canada
| | - Paula M. Wood-Adams
- CREPEC; Department of Mechanical and Industrial Engineering; Concordia University; Montréal Québec H3G 1M8 Canada
| | - Marie-Claude Heuzey
- Centre de Recherche sur les Systèmes Polymères et Composites à Haute Performance (CREPEC); Department of Chemical Engineering; Polytechnique Montréal; Montréal Québec H3C 3A7 Canada
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Wang CS, Virgilio N, Wood-Adams P, Heuzey MC. A mechanism for the synergistic gelation properties of gelatin B and xanthan gum aqueous mixtures. Carbohydr Polym 2017; 175:484-492. [DOI: 10.1016/j.carbpol.2017.08.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 08/03/2017] [Indexed: 10/19/2022]
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Wu Q, Maire M, Lerouge S, Therriault D, Heuzey MC. 3D Printing of Microstructured and Stretchable Chitosan Hydrogel for Guided Cell Growth. ACTA ACUST UNITED AC 2017. [DOI: 10.1002/adbi.201700058] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Qinghua Wu
- Department of Chemical Engineering; Polytechnique de Montréal; C.P. 6079, succ. Centre-Ville Montréal H3C 3A7 Québec, Québec Canada
| | - Marion Maire
- École de Technologie Supérieure (ÉTS); The University of Montreal Hospital Research Centre (CRCHUM); 1100 Rue Notre-Dame O Montréal H3C 1K3 Québec Canada
| | - Sophie Lerouge
- École de Technologie Supérieure (ÉTS); The University of Montreal Hospital Research Centre (CRCHUM); 1100 Rue Notre-Dame O Montréal H3C 1K3 Québec Canada
| | - Daniel Therriault
- Laboratory for Multiscale Mechanics (LM2); Polytechnique de Montréal; C.P. 6079, succ. Centre-Ville Montréal H3C 3A7 Québec Canada
| | - Marie-Claude Heuzey
- Department of Chemical Engineering; Polytechnique de Montréal; C.P. 6079, succ. Centre-Ville Montréal H3C 3A7 Québec, Québec Canada
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Affiliation(s)
- Gilles Lenfant
- Department of Chemical Engineering; CREPEC, Polytechnique Montreal; Montreal QC, H3T 1J4 Canada
| | - Marie-Claude Heuzey
- Department of Chemical Engineering; CREPEC, Polytechnique Montreal; Montreal QC, H3T 1J4 Canada
| | - Theo G. M. van de Ven
- Department of Chemistry; Pulp and Paper Research Center; McGill University; Montreal QC, H3A 2A7 Canada
| | - Pierre J. Carreau
- Department of Chemical Engineering; CREPEC, Polytechnique Montreal; Montreal QC, H3T 1J4 Canada
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Arkoun M, Daigle F, Heuzey MC, Ajji A. Mechanism of Action of Electrospun Chitosan-Based Nanofibers against Meat Spoilage and Pathogenic Bacteria. Molecules 2017; 22:E585. [PMID: 28383516 PMCID: PMC6154008 DOI: 10.3390/molecules22040585] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 03/27/2017] [Accepted: 03/28/2017] [Indexed: 02/07/2023] Open
Abstract
This study investigates the antibacterial mechanism of action of electrospun chitosan-based nanofibers (CNFs), against Escherichia coli, Salmonella enterica serovar Typhimurium, Staphylococcus aureus and Listeria innocua, bacteria frequently involved in food contamination and spoilage. CNFs were prepared by electrospinning of chitosan and poly(ethylene oxide) (PEO) blends. The in vitro antibacterial activity of CNFs was evaluated and the susceptibility/resistance of the selected bacteria toward CNFs was examined. Strain susceptibility was evaluated in terms of bacterial type, cell surface hydrophobicity, and charge density, as well as pathogenicity. The efficiency of CNFs on the preservation and shelf life extension of fresh red meat was also assessed. Our results demonstrate that the antibacterial action of CNFs depends on the protonation of their amino groups, regardless of bacterial type and their mechanism of action was bactericidal rather than bacteriostatic. Results also indicate that bacterial susceptibility was not Gram-dependent but strain-dependent, with non-virulent bacteria showing higher susceptibility at a reduction rate of 99.9%. The susceptibility order was: E. coli > L. innocua > S. aureus > S. Typhimurium. Finally, an extension of one week of the shelf life of fresh meat was successfully achieved. These results are promising and of great utility for the potential use of CNFs as bioactive food packaging materials in the food industry, and more specifically in meat quality preservation.
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Affiliation(s)
- Mounia Arkoun
- CREPEC Department of Chemical Engineering, École Polytechnique de Montréal, P.O. Box 6079, Station Centre-Ville, Montréal, QC H3C 3A7, Canada.
| | - France Daigle
- Department of Microbiology, Infectiology and Immunology, Pavillon Roger-Gaudry, Université de Montréal, C.P. 6128, Centre-ville, Montréal, QC H3C 3J7, Canada.
| | - Marie-Claude Heuzey
- CREPEC Department of Chemical Engineering, École Polytechnique de Montréal, P.O. Box 6079, Station Centre-Ville, Montréal, QC H3C 3A7, Canada.
| | - Abdellah Ajji
- CREPEC Department of Chemical Engineering, École Polytechnique de Montréal, P.O. Box 6079, Station Centre-Ville, Montréal, QC H3C 3A7, Canada.
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Arias A, Sojoudiasli H, Heuzey MC, Huneault MA, Wood-Adams P. Rheological study of crystallization behavior of polylactide and its flax fiber composites. J Polym Res 2017. [DOI: 10.1007/s10965-017-1210-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Ardila N, Daigle F, Heuzey MC, Ajji A. Effect of Chitosan Physical Form on Its Antibacterial Activity Against Pathogenic Bacteria. J Food Sci 2017; 82:679-686. [DOI: 10.1111/1750-3841.13635] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 12/15/2016] [Accepted: 12/27/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Nury Ardila
- CREPEC, Dept. of Chemical Engineering; Polytechnique Montréal; P.O. Box 6079, Station Centre-Ville Montréal Québec Canada H3C 3A7
| | - France Daigle
- Dept. of Microbiology, Infectiology and Immunology, Pavillon Roger-Gaudry; Univ. de Montréal; P.O. Box 6128, Station Centre-ville Montréal Québec Canada H3C 3J7
| | - Marie-Claude Heuzey
- CREPEC, Dept. of Chemical Engineering; Polytechnique Montréal; P.O. Box 6079, Station Centre-Ville Montréal Québec Canada H3C 3A7
| | - Abdellah Ajji
- CREPEC, Dept. of Chemical Engineering; Polytechnique Montréal; P.O. Box 6079, Station Centre-Ville Montréal Québec Canada H3C 3A7
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Ardila N, Daigle F, Heuzey MC, Ajji A. Antibacterial Activity of Neat Chitosan Powder and Flakes. Molecules 2017; 22:molecules22010100. [PMID: 28067839 PMCID: PMC6155679 DOI: 10.3390/molecules22010100] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 12/21/2016] [Accepted: 01/03/2017] [Indexed: 12/30/2022] Open
Abstract
This study investigates the antibacterial activity of neat chitosan powder and flakes against three different bacterial species, Escherichia coli, Listeria innocua and Staphylococcus aureus, which are frequent causes of food spoilage. The effect of chitosan concentration and purity, as well as the influence of temperature, ionic strength (salt) and impact of a solid physical support in the medium are examined. Results show that the antibacterial activity of neat chitosan: (i) requires partial solubilisation; (ii) can be promoted by environmental factors such as adequate temperature range, ionic strength and the presence of a solid physical support that may facilitate the attachment of bacteria; (iii) depends on bacterial species, with a sensitivity order of E. coli > L. innocua > S. aureus; and (iv) increases with chitosan concentration, up to a critical point above which this effect decreases. The latter may be due to remaining proteins in chitosan acting as nutrients for bacteria therefore limiting its antibacterial activity. These results on the direct use of chitosan powder and flakes as potential antimicrobial agents for food protection at pH values lower than the chitosan pKa (6.2-6.7) are promising.
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Affiliation(s)
- Nury Ardila
- Research Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, Polytechnique Montréal, P.O. Box 6079, Station Centre-Ville, Montréal, QC H3C 3A7, Canada.
| | - France Daigle
- Department of Microbiology, Infectiology and Immunology, Pavillon Roger-Gaudry, Université de Montréal, P.O. Box 6128, Station Centre-ville, Montréal, QC H3C 3J7, Canada.
| | - Marie-Claude Heuzey
- Research Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, Polytechnique Montréal, P.O. Box 6079, Station Centre-Ville, Montréal, QC H3C 3A7, Canada.
| | - Abdellah Ajji
- Research Center for High Performance Polymer and Composite Systems (CREPEC), Department of Chemical Engineering, Polytechnique Montréal, P.O. Box 6079, Station Centre-Ville, Montréal, QC H3C 3A7, Canada.
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Affiliation(s)
- Thibault Jauzein
- Chemical Engineering Department, Polytechnique Montréal; CREPEC; 2500 Chemin de Polytechnique Montréal H3T1J4 Québec Canada
| | - Michel A. Huneault
- Chemical and Biotechnological Engineering Departement; Université de Sherbrooke; 2500 Boulevard de l'Université Sherbrooke Québec J1K 2R1 Canada
| | - Marie-Claude Heuzey
- Chemical Engineering Department, Polytechnique Montréal; CREPEC; 2500 Chemin de Polytechnique Montréal H3T1J4 Québec Canada
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Abstract
The occurrence of surface defects in TPO injected foam parts has been investigated. Unlike typical flow marks such as tiger stripes that affect the surface quality of injected bulk parts, jetting and silver streaks are the major problems encountered with the TPO foamed parts. Systematic experiments are performed to study the effect of rheological properties and key injection parameters, such as melt temperature, mold cooling, and injection speed on the occurrence of the surface defects. Premature cell nucleation before the injection of the melt into the mold is believed to be the main cause of the surface defects. Therefore, methods that avoid injection of a two-phase mixture into the mold and force cell nucleation to take place strictly in the mold are considered to improve the surface quality of the parts.
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Affiliation(s)
- Ming-Cheng Guo
- Center for Applied Research on Polymers and Composites (CREPEC) Department of Chemical Engineering, Ecole Polytechnique PO Box 6079, Stn Centre-Ville, Montreal, Quebec H3C 3A7, Canada
| | - Antoine Santoni
- Center for Applied Research on Polymers and Composites (CREPEC) Department of Chemical Engineering, Ecole Polytechnique PO Box 6079, Stn Centre-Ville, Montreal, Quebec H3C 3A7, Canada
| | - Marie-Claude Heuzey
- Center for Applied Research on Polymers and Composites (CREPEC) Department of Chemical Engineering, Ecole Polytechnique PO Box 6079, Stn Centre-Ville, Montreal, Quebec H3C 3A7, Canada
| | - Pierre J. Carreau
- Center for Applied Research on Polymers and Composites (CREPEC) Department of Chemical Engineering, Ecole Polytechnique PO Box 6079, Stn Centre-Ville, Montreal, Quebec H3C 3A7, Canada
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Abstract
Chitosan-based conventional and Pickering oil-in-water (O/W) emulsions with very fine droplet size (volume average diameter, dv, as low as 1.7 μm) and long-term stability (up to 5 months) were ultrasonically generated at different pH values without the addition of any surfactant or cross-linking agent. The ultrasonication treatment was found to break and disperse chitosan agglomerates effectively (particularly at pH ≥ 4.5) and also reduce the chitosan molecular weight, benefiting its emulsification properties. The emulsion stability and emulsion type could be controlled by chitosan solution pH. Increasing pH from 3.5 to 5.5 led to the formation of conventional emulsions with decreasing droplet size (dv from 14 to 2.1 μm) and increasing emulsion stability (from a few days to 2 months). These results can be explained by the increase of dynamic interfacial pressure, which results from the conformation transition of chitosan molecules from an extended state to a more flexible structure as pH increases. At pH = 6.5 (the acid dissociation constant (pKa) of chitosan), the chitosan molecules self-assembled into well-dispersed nanoparticles (dv = 82.1 nm) with the assistance of ultrasonication, which resulted in a Pickering emulsion with the smallest droplet size (dv = 1.7 μm) and highest long-term stability (up to 5 months) because of the presence of chitosan solid nanoparticles at the oil/water interface. The key originality of this study is the elucidation of the role of pH in the formation of conventional and Pickering chitosan-based O/W emulsions with the assistance of ultrasonication. Our results suggest that chitosan possesses great potential to be used as an effective pH-controlled emulsifier and stabilizer without the need of other additives.
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Affiliation(s)
- Xiao-Yan Wang
- Department of Chemical Engineering, CREPEC, Polytechnique Montréal , PO Box 6079, Station Centre-Ville, Montréal, QC Canada H3C 3A7
| | - Marie-Claude Heuzey
- Department of Chemical Engineering, CREPEC, Polytechnique Montréal , PO Box 6079, Station Centre-Ville, Montréal, QC Canada H3C 3A7
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Abstract
Food-grade colloidal particles or complexes made from natural polymers via noncovalent interactions can be good candidates for applications in food and non-food industries.
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Affiliation(s)
- Xiao-Yan Wang
- Department of Chemical Engineering
- CREPEC
- Polytechnique Montréal
- Montréal
- Canada
| | - Marie-Claude Heuzey
- Department of Chemical Engineering
- CREPEC
- Polytechnique Montréal
- Montréal
- Canada
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Abstract
A multifunctional 3D liquid sensor made of a PLA/MWCNT nanocomposite and shaped as a freeform helical structure was fabricated by solvent-cast 3D printing. The 3D liquid sensor featured a relatively high electrical conductivity, the functionality of liquid trapping due to its helical configuration, and an excellent sensitivity and selectivity even for a short immersion into solvents.
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Affiliation(s)
- Shuang-zhuang Guo
- Laboratory of Multi-scale Mechanics, Mechanical Engineering Department, Research Center for High Performance Polymer and Composite Systems (CREPEC), École Polytechnique de Montreal, C.P. 6079, succ. Centre-Ville, Montreal, QC H3C 3A7, Canada.
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Matet M, Heuzey MC, Ajji A, Sarazin P. Plasticized chitosan/polyolefin films produced by extrusion. Carbohydr Polym 2015; 117:177-184. [DOI: 10.1016/j.carbpol.2014.09.058] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 09/11/2014] [Accepted: 09/16/2014] [Indexed: 11/16/2022]
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Affiliation(s)
- Qingkai Meng
- Department of Chemical Engineering
and Research Center for High Performance Polymer and Composite Systems
(CREPEC), Polytechnique Montreal, C.P. 6079, succ. Centre-Ville, Montreal, QC H3C
3A7, Canada
| | - Marie-Claude Heuzey
- Department of Chemical Engineering
and Research Center for High Performance Polymer and Composite Systems
(CREPEC), Polytechnique Montreal, C.P. 6079, succ. Centre-Ville, Montreal, QC H3C
3A7, Canada
| | - Pierre J. Carreau
- Department of Chemical Engineering
and Research Center for High Performance Polymer and Composite Systems
(CREPEC), Polytechnique Montreal, C.P. 6079, succ. Centre-Ville, Montreal, QC H3C
3A7, Canada
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Guo SZ, Heuzey MC, Therriault D. Properties of polylactide inks for solvent-cast printing of three-dimensional freeform microstructures. Langmuir 2014; 30:1142-1150. [PMID: 24410099 DOI: 10.1021/la4036425] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Solvent-cast printing is a highly versatile microfabrication technique that can be used to construct various geometries such as filaments, towers, scaffolds, and freeform circular spirals by the robotic deposition of a polymer solution ink onto a moving stage. In this work, we have performed a comprehensive characterization of the solvent-cast printing process using polylactide (PLA) solutions by analyzing the flow behavior of the solutions, the solvent evaporation kinetics, and the effect of process-related parameters on the crystallization of the extruded filaments. Rotational rheometry at low to moderate shear rates showed a nearly Newtonian behavior of the PLA solutions, while capillary flow analysis based on process-related data indicated shear thinning at high shear rates. Solvent vaporization tests suggested that the internal diffusion of the solvent through the filaments controlled the solvent removal of the extrudates. Different kinds of three-dimensional (3D) structures including a layer-by-layer tower, nine-layer scaffold, and freeform spiral were fabricated, and a processing map was given to show the proper ranges of process-related parameters (i.e., polymer content, applied pressure, nozzle diameter, and robot velocity) for the different geometries. The results of differential scanning calorimetry revealed that slow solvent evaporation could increase the ability of PLA to complete its crystallization process during the filament drying stage. The method developed here offers a new perspective for manufacturing complex structures from polymer solutions and provides guidelines to optimize the various parameters for 3D geometry fabrication.
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Affiliation(s)
- Shuang-Zhuang Guo
- Laboratory of Multiscale Mechanics, Mechanical Engineering Department Center for Applied Research on Polymers and composites (CREPEC), École Polytechnique de Montréal , C.P. 6079, succ. Centre-Ville, Montreal, QC H3C 3A7, Canada
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Guo SZ, Gosselin F, Guerin N, Lanouette AM, Heuzey MC, Therriault D. Solvent-cast three-dimensional printing of multifunctional microsystems. Small 2013; 9:4118-22. [PMID: 23824963 DOI: 10.1002/smll.201300975] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 04/14/2013] [Indexed: 05/05/2023]
Abstract
The solvent-cast direct-write fabrication of microstructures is shown using a thermoplastic polymer solution ink. The method employs the robotically controlled microextrusion of a filament combined with a rapid solvent evaporation. Upon drying, the increased rigidity of the extruded filament enables the creation of complex freeform 3D shapes.
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Affiliation(s)
- Shuang-Zhuang Guo
- Laboratory of Multiscale Mechanics, Mechanical Engineering Department, Center for Applied Research on Polymers and composites (CREPEC), École Polytechnique de Montréal, C.P. 6079, succ. Centre-Ville, Montreal, QC H3C 3A7, Canada
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Matet M, Heuzey MC, Pollet E, Ajji A, Avérous L. Innovative thermoplastic chitosan obtained by thermo-mechanical mixing with polyol plasticizers. Carbohydr Polym 2013; 95:241-51. [PMID: 23618266 DOI: 10.1016/j.carbpol.2013.02.052] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 02/26/2013] [Indexed: 11/30/2022]
Abstract
Chitosan shows a degradation temperature lower than its melting point, which prevents its development in several applications. One way to overcome this issue is the plasticization of the carbohydrate. In this work plasticized chitosan was prepared by a thermo-mechanical kneading approach. The effects of different non-volatile polyol plasticizers (glycerol, xylitol and sorbitol) were investigated. The microstructure and morphology were determined using FTIR, XRD, TEM and SEM in order to understand the plasticization mechanism. Sorbitol, which is the highest molecular weight polyol used, resulted in plasticized chitosan with the highest thermal, mechanical and rheological properties. On the other hand, the sample plasticized with glycerol, the lowest molecular weight polyol, had the most important amorphous phase content and the lowest thermal, mechanical and rheological properties. Also, when the polyol content increased in the formulation, the plasticized chitosan was more amorphous and consequently its processability easier, while its properties decreased.
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Affiliation(s)
- Marie Matet
- CREPEC, Department of Chemical Engineering, Polytechnique Montreal, P.O. Box 6079, Station Centre-Ville, Montreal, Quebec, Canada H3C 3A7
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Abstract
The influence of reactive compatibilization on the foaming behavior of thermoplastic olefin blends of polypropylene and a metallocene-catalyzed ethylene octene copolymer was investigated. A batch setup was used to foam the samples using carbon dioxide as blowing agent. Solubility measurements were performed to determine the relative amount of gas concentration in the pressurized polymers before foaming. A microscopic method based on the back-scattered electron imaging technique was used to determine the respective locations of the bubbles and the dispersed elastomeric domains in the polypropylene matrix. It was shown that the bubbles are preferentially formed in the dispersed elastomeric domains. A clear relationship was established between the microstructure of the blends prepared with different levels of compatibilizer and the final cellular morphology of the microcellular thermoplastic olefin foams. The initial morphology of the blends was also altered by quiescent coarsening as well as shear-induced phase coalescence, and the impact of the morphological transitions on the cellular structure of the resulting foams was investigated. Dynamic shear and transient measurements of elongation were performed to characterize the viscoelastic behavior of the thermoplastic olefins. It was shown that the addition of a compatibilizer resulted in enhanced viscoelastic properties at low frequencies as well as increased levels of strain hardening, especially at low strain rates. The reactive compatibilization could significantly improve the melt foamability through control of the blend microstructure as well as enhancement of the melt rheological properties.
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Affiliation(s)
- Amirhossein Maani
- CREPEC, Department of Chemical Engineering, École Polytechnique de Montréal, Montreal, Quebec, Canada
| | - Hani E Naguib
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Marie-Claude Heuzey
- CREPEC, Department of Chemical Engineering, École Polytechnique de Montréal, Montreal, Quebec, Canada
| | - Pierre J Carreau
- CREPEC, Department of Chemical Engineering, École Polytechnique de Montréal, Montreal, Quebec, Canada
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Hébert JS, Wood-Adams P, Heuzey MC, Dubois C, Brisson J. Morphology of polylactic acid crystallized during annealing after uniaxial deformation. ACTA ACUST UNITED AC 2012. [DOI: 10.1002/polb.23231] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Ghanbari A, Heuzey MC, Carreau PJ, Ton-That MT. Morphology and properties of polymer/organoclay nanocomposites based on poly(ethylene terephthalate) and sulfopolyester blends. POLYM INT 2012. [DOI: 10.1002/pi.4331] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Meng Q, Heuzey MC, Carreau PJ. Control of thermal degradation of polylactide/clay nanocomposites during melt processing by chain extension reaction. Polym Degrad Stab 2012. [DOI: 10.1016/j.polymdegradstab.2012.01.030] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Affiliation(s)
- Mehdi Pakravan
- CREPEC, Department of Chemical Engineering, Ecole Polytechnique de Montreal, P.O. Box 6079, Station
Centre-Ville, Montreal, Quebec, Canada H3C 3A7
| | - Marie-Claude Heuzey
- CREPEC, Department of Chemical Engineering, Ecole Polytechnique de Montreal, P.O. Box 6079, Station
Centre-Ville, Montreal, Quebec, Canada H3C 3A7
| | - Abdellah Ajji
- CREPEC, Department of Chemical Engineering, Ecole Polytechnique de Montreal, P.O. Box 6079, Station
Centre-Ville, Montreal, Quebec, Canada H3C 3A7
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Abstract
Core-shell structured PEO-chitosan nanofibers have been produced using a coaxial electrospinning setup. PEO and chitosan solutions, both in an aqueous acetic acid solvent, were used as the inner (core) and outer (shell) layer, respectively. Uniform-sized defect-free nanofibers of 150-190 nm diameter were produced. In addition, hollow nanofibers could be obtained subsequent to PEO washing of the membranes. The core-shell nanostructure and existence of chitosan on the shell layer were confirmed by TEM images obtained before and after washing the PEO content with water. The presence of chitosan on the surface of the composite nanofibers was further supported by XPS studies. The chitosan and PEO compositions in the nanofibrous mats were determined by TGA analysis, which were similar to their ratio in the feed solutions. The local compositional homogeneity of the membranes and the efficiency of the washing step to remove PEO were also verified by FTIR. In addition, DSC and XRD were used to characterize the crystalline structure and morphology of the co-electrospun nonwoven mats. The prepared coaxial nanofibers (hollow and solid) have several potential applications due to the presence of chitosan on their outer surfaces.
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Affiliation(s)
- Mehdi Pakravan
- CREPEC, Department of Chemical Engineering, Ecole Polytechnique de Montreal, PO Box 6079, Station Centre-Ville, Montreal, Quebec, Canada H3C 3A7
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Shahbikian S, Carreau PJ, Heuzey MC, Ellul MD, Nadella HP, Cheng J, Shirodkar P. Rheology/morphology relationship of plasticized and nonplasticized thermoplastic elastomers based on ethylene-propylene-diene-terpolymer and polypropylene. POLYM ENG SCI 2011. [DOI: 10.1002/pen.21806] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Hadj Henni A, Schmitt C, Tremblay MÉ, Hamdine M, Heuzey MC, Carreau P, Cloutier G. Hyper-frequency viscoelastic spectroscopy of biomaterials. J Mech Behav Biomed Mater 2011; 4:1115-22. [PMID: 21783120 DOI: 10.1016/j.jmbbm.2011.03.020] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Revised: 03/14/2011] [Accepted: 03/15/2011] [Indexed: 01/26/2023]
Abstract
With the emergence of new biomaterials and elastography imaging techniques, there is a need for innovative instruments dedicated to viscoelasticity measurements. In this work, we introduce a novel hyper-frequency viscoelastic spectroscopy (HFVS) technique dedicated to characterize soft media subjected to mid-to-very-high frequency stress ranges (or, equivalently, to probe short-to-very-short relaxation times). HFVS, which has been implemented in an analytical instrument performing non-contact measurements in less than 1 s between 10 and 1000 Hz, is a suitable tool to study viscoelasticity for bio-applications. In this context, HFVS has been compared to classical oscillatory rheometry on several classes of soft materials currently encountered in tissue repair, bioengineering and elastography imaging on a frequency range between 10 and 100 Hz. After having demonstrated the good correspondence between HFVS and rheometry, this study has been completed by exploring the sensitivity of HFVS to physicochemically induced variations of viscoelasticity. HFVS opens promising perspectives in the challenging field of biomaterial science and for viscoelasticity-based quality control of materials.
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Affiliation(s)
- Anis Hadj Henni
- Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center, Montreal, QC, Canada.
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Yuryev Y, Wood-Adams P, Heuzey MC, Dubois C, Brisson J. Crystallization of polylactide films: An atomic force microscopy study of the effects of temperature and blending. POLYMER 2008. [DOI: 10.1016/j.polymer.2008.02.023] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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