https://sam.ensam.eu:443 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Wed, 17 Jun 2026 01:12:21 GMT 2026-06-17T01:12:21Z http://hdl.handle.net/10985/10537 Influence of viscoelastic properties of an hyaluronic acid-based hydrogel on viability of mesenchymal stem cells EDDHAHAK, Anissa; ZIDI, Mustapha BACKGROUND : The present research is involved in the framework of the biotherapy using mesenchymal stem cells (MSCs). Here, MSC encapsulation in a hydrogel based on hyaluronic acid (HA) is investigated to optimize the composition of the biomaterial. M E T H O D S : Several formulations candidates of the hydrogel (9 in total) are postulated as a scaffold for the 3D MSC culture in order to investigate their potential to mimic the in vivo cellular environment. Rheological measurements in oscillation mode of complex modulus and complex viscosity are performed on the different hydrogels. Biological tests are carried out for the measurement of the cell viability of MSC encapsulated in the hydrogels. R E S U LT S : Rheological and biological findings are correlated together in order to establish relationships between the viscoelastic properties of the hydrogel and the cellular viability of MSC. C O N C L U S I O N S : In the light of the viaility results, the composition of the hydrogel was related to the MSC proliferation. Thus, such relations are useful tools for scientists offering them more flexibility in the design of their hydrogels while ensuring an acceptable level of MSC viability. Thu, 01 Jan 2015 00:00:00 GMT http://hdl.handle.net/10985/10537 2015-01-01T00:00:00Z EDDHAHAK, Anissa ZIDI, Mustapha BACKGROUND : The present research is involved in the framework of the biotherapy using mesenchymal stem cells (MSCs). Here, MSC encapsulation in a hydrogel based on hyaluronic acid (HA) is investigated to optimize the composition of the biomaterial. M E T H O D S : Several formulations candidates of the hydrogel (9 in total) are postulated as a scaffold for the 3D MSC culture in order to investigate their potential to mimic the in vivo cellular environment. Rheological measurements in oscillation mode of complex modulus and complex viscosity are performed on the different hydrogels. Biological tests are carried out for the measurement of the cell viability of MSC encapsulated in the hydrogels. R E S U LT S : Rheological and biological findings are correlated together in order to establish relationships between the viscoelastic properties of the hydrogel and the cellular viability of MSC. C O N C L U S I O N S : In the light of the viaility results, the composition of the hydrogel was related to the MSC proliferation. Thus, such relations are useful tools for scientists offering them more flexibility in the design of their hydrogels while ensuring an acceptable level of MSC viability. http://hdl.handle.net/10985/12275 Experimental study of the miscibility of ABS/PC polymer blends and investigation of the processing effect AID, Sara; EDDHAHAK, Anissa; ORTEGA, Zaida; FROELICH, Daniel; TCHARKHTCHI, Abbas In the challenging prospect of developing new materials by mixing different polymers to reach a synergetic performance, the present research focuses on the study of the miscibility of two polymers: The acrylonitrile butadiene styrene (ABS) composed of a dispersed elastomeric (polybutadiene rubber) polymer embedded in a SAN thermoplastic matrix, and the polycarbonate (PC). It shall be noted that obtaining miscible polymer blends is often a difficult task because of the large size of their molecular chains and the high interfacial tension between the polymer phases. Until now, the most numerous researches developed in this field involve polymer blends obtained by compatibilization techniques in order to improve the interfacial adhesion between initial polymers. The aim of this work is to study the miscibility between ABS and PC. First, two different methods were used to mix the polymers: the twin-screw extrusion and the dissolution in a common solvent tetrahydrofuran (THF). Then, physicochemical, microscopic observation and rheological characterization were performed on samples of mixtures obtained by both extrusion processing and dissolution method. The measurement of glassy transition temperature (Tg) by differential scanning calorimetry measurements (DSC) and dynamical mechanical thermal analysis (DMTA) have shown a partial miscibility between the two polymers. Sun, 01 Jan 2017 00:00:00 GMT http://hdl.handle.net/10985/12275 2017-01-01T00:00:00Z AID, Sara EDDHAHAK, Anissa ORTEGA, Zaida FROELICH, Daniel TCHARKHTCHI, Abbas In the challenging prospect of developing new materials by mixing different polymers to reach a synergetic performance, the present research focuses on the study of the miscibility of two polymers: The acrylonitrile butadiene styrene (ABS) composed of a dispersed elastomeric (polybutadiene rubber) polymer embedded in a SAN thermoplastic matrix, and the polycarbonate (PC). It shall be noted that obtaining miscible polymer blends is often a difficult task because of the large size of their molecular chains and the high interfacial tension between the polymer phases. Until now, the most numerous researches developed in this field involve polymer blends obtained by compatibilization techniques in order to improve the interfacial adhesion between initial polymers. The aim of this work is to study the miscibility between ABS and PC. First, two different methods were used to mix the polymers: the twin-screw extrusion and the dissolution in a common solvent tetrahydrofuran (THF). Then, physicochemical, microscopic observation and rheological characterization were performed on samples of mixtures obtained by both extrusion processing and dissolution method. The measurement of glassy transition temperature (Tg) by differential scanning calorimetry measurements (DSC) and dynamical mechanical thermal analysis (DMTA) have shown a partial miscibility between the two polymers. http://hdl.handle.net/10985/18008 On the miscibility of PVDF/PMMA polymer blends: Thermodynamics, experimental and numerical investigations AID, Sara; EDDHAHAK, Anissa; ORTEGA, Zaida; CHAABANI, Sana; TCHARKHTCHI, Abbas; KHELLADI, Sofiane In this paper the miscibility of PVDF/PMMA blends was studied using different approaches: experimental tests, thermodynamics and numerical simulation. The first part of this study is devoted to the experimental work and aims to investigate the miscibility of blends by different experimental techniques. First, blends of PVDF/PMMA at different ratios were compounded and characterized using physico-chemical and rheological methods. The effect of PMMA content on the crystallization behavior of PVDF in the blend was experimentally investigated. At a second stage, the thermodynamic interaction parameter of Flory-Huggins was evaluated as a function of the PMMA proportion in the blends based on the experimental data related to the PVDF melting point and enthalpy. Besides, a numerical method has been developed using Fluent Ansys software to describe the coalescence phenomenon under different scenarios of viscosity ratios and grain sizes of polymers. The confrontation of the code simulation results with the experimental and thermodynamic approaches has shown a good agreement for reproducing the behavior of miscible polymers as well as their aptitude to form a homogeneous blend. Tue, 01 Jan 2019 00:00:00 GMT http://hdl.handle.net/10985/18008 2019-01-01T00:00:00Z AID, Sara EDDHAHAK, Anissa ORTEGA, Zaida CHAABANI, Sana TCHARKHTCHI, Abbas KHELLADI, Sofiane In this paper the miscibility of PVDF/PMMA blends was studied using different approaches: experimental tests, thermodynamics and numerical simulation. The first part of this study is devoted to the experimental work and aims to investigate the miscibility of blends by different experimental techniques. First, blends of PVDF/PMMA at different ratios were compounded and characterized using physico-chemical and rheological methods. The effect of PMMA content on the crystallization behavior of PVDF in the blend was experimentally investigated. At a second stage, the thermodynamic interaction parameter of Flory-Huggins was evaluated as a function of the PMMA proportion in the blends based on the experimental data related to the PVDF melting point and enthalpy. Besides, a numerical method has been developed using Fluent Ansys software to describe the coalescence phenomenon under different scenarios of viscosity ratios and grain sizes of polymers. The confrontation of the code simulation results with the experimental and thermodynamic approaches has shown a good agreement for reproducing the behavior of miscible polymers as well as their aptitude to form a homogeneous blend. http://hdl.handle.net/10985/15460 A review of microencapsulated and composite phase change materials: Alteration of strength and thermal properties of cement-based materials DRISSI, Sarra; LING, Tung Chai; MO, Kim Hung; EDDHAHAK, Anissa Due to the population growth and the increased reliance on cooling and heating systems, buildings have become the largest energy consumer worldwide. The use of phase change material (PCM) has shown great potential to reduce the annual cooling and heating load by up to 50%. Nowadays, the direct incorporation of PCM in cement-based materials (CBM) is creating a considerable debate in the research community with regards to the proper selection and the beneficial utilization of PCM (microencapsulated or composite) in CBM. Therefore, this paper reviews the pros and cons of using microencapsulated and composite PCM in CBM by highlighting the mechanisms involved in the mechanical strength loss and thermal properties enhancement. Generally, a high thermal energy storage CBM was obtained. However, PCM exhibited a negative effect on the compressive strength of CBM. In view of the literature review, the compressive strength reduction varies considerably with no clear trend which is understandable in view of the differences in mix designs as well as the variety of materials used in each study. Finally, an up-to-date PCM case studies, gaps and future directions are also presented to provide a reliable basis and helpful reference for the future development of eco-friendly and energy-efficient building materials containing PCM. Tue, 01 Jan 2019 00:00:00 GMT http://hdl.handle.net/10985/15460 2019-01-01T00:00:00Z DRISSI, Sarra LING, Tung Chai MO, Kim Hung EDDHAHAK, Anissa Due to the population growth and the increased reliance on cooling and heating systems, buildings have become the largest energy consumer worldwide. The use of phase change material (PCM) has shown great potential to reduce the annual cooling and heating load by up to 50%. Nowadays, the direct incorporation of PCM in cement-based materials (CBM) is creating a considerable debate in the research community with regards to the proper selection and the beneficial utilization of PCM (microencapsulated or composite) in CBM. Therefore, this paper reviews the pros and cons of using microencapsulated and composite PCM in CBM by highlighting the mechanisms involved in the mechanical strength loss and thermal properties enhancement. Generally, a high thermal energy storage CBM was obtained. However, PCM exhibited a negative effect on the compressive strength of CBM. In view of the literature review, the compressive strength reduction varies considerably with no clear trend which is understandable in view of the differences in mix designs as well as the variety of materials used in each study. Finally, an up-to-date PCM case studies, gaps and future directions are also presented to provide a reliable basis and helpful reference for the future development of eco-friendly and energy-efficient building materials containing PCM. http://hdl.handle.net/10985/12274 Predictive coalescence modeling of particles from different polymers: application to PVDF and PMMA pair AID, Sara; EDDHAHAK, Anissa; ORTEGA, Zaida; FROELICH, Daniel; TCHARKHTCHI, Abbas This paper aims to study the coalescence phenomenon of two different polymers PVDF and PMMA. The paper is divided in two parts: the first part is devoted to the experimental work, and the second one focuses on the modeling of the coalescence phenomenon. The first step was a physicochemical and rheological characterization. Then, the coalescence tests have been performed on droplets derived from PVDF and PMMA polymers using a polarized light optical microscope combined with a hot stage. The effect of several significant parameters like temperature and particle size was investigated. The second part of this study is focused on the modeling of the coalescence phenomenon based on the well-known Bellehumeur model. The latter has been commonly used to describe the coalescence phenomenon between identical grains. The novelty of the present work consists in the extension of the coalescence model to wider describe the coalescence phenomenon between grains of different polymers. In addition, probabilistic analysis was performed in order to investigate the effect of the parameters governing the coalescence model, namely the viscosity, the surface tension and the relaxation time. The results have shown a good compromise between the experimental results and the predictive generalized Bellehumeur model. Sun, 01 Jan 2017 00:00:00 GMT http://hdl.handle.net/10985/12274 2017-01-01T00:00:00Z AID, Sara EDDHAHAK, Anissa ORTEGA, Zaida FROELICH, Daniel TCHARKHTCHI, Abbas This paper aims to study the coalescence phenomenon of two different polymers PVDF and PMMA. The paper is divided in two parts: the first part is devoted to the experimental work, and the second one focuses on the modeling of the coalescence phenomenon. The first step was a physicochemical and rheological characterization. Then, the coalescence tests have been performed on droplets derived from PVDF and PMMA polymers using a polarized light optical microscope combined with a hot stage. The effect of several significant parameters like temperature and particle size was investigated. The second part of this study is focused on the modeling of the coalescence phenomenon based on the well-known Bellehumeur model. The latter has been commonly used to describe the coalescence phenomenon between identical grains. The novelty of the present work consists in the extension of the coalescence model to wider describe the coalescence phenomenon between grains of different polymers. In addition, probabilistic analysis was performed in order to investigate the effect of the parameters governing the coalescence model, namely the viscosity, the surface tension and the relaxation time. The results have shown a good compromise between the experimental results and the predictive generalized Bellehumeur model. http://hdl.handle.net/10985/26067 Investigation of a constitutive law for the prediction of the mechanical behavior of WEEE recycled polymer blends EDDHAHAK, Anissa; GAUDY, Alain This research focuses on a mechanical study of an acrylonitrile–butadiene–styrene (ABS)/ polycarbonate (PC) blend totally derived from Waste Electrical and Electronic Equipment (WEEE) recycling. First, an experimental work was developed in laboratory for the preparation of different mixtures of ABS/PC blend. Then, mechanical tensile tests were performed on the injected specimens and the stress/strain experimental data were gathered to be used in the modelling part. In order to enable the prediction of the mechanical response of the blend, G’Sell and Jonas constitutive law was considered for this purpose. An optimization method based on the Generalized Reduced Gradient (GRG) nonlinear algorithm was developed to identify the input parameters governing the mechanical model. In addition, an uncertainty parametric study was assessed to qualitatively and quantitatively evaluate the constitutive law sensitivity versus the parameter uncertainty. Monte Carlo simulations were performed and the convergence of the numerical model was proved in terms of means and standard deviation statistical data. The results showed an excellent agreement between the numerical approach and the experiments. Besides, it was highlighted the crucial role of coupling uncertainty parametric study with modelling for accurately describing the mechanical behavior of the blend. Wed, 29 Jan 2025 00:00:00 GMT http://hdl.handle.net/10985/26067 2025-01-29T00:00:00Z EDDHAHAK, Anissa GAUDY, Alain This research focuses on a mechanical study of an acrylonitrile–butadiene–styrene (ABS)/ polycarbonate (PC) blend totally derived from Waste Electrical and Electronic Equipment (WEEE) recycling. First, an experimental work was developed in laboratory for the preparation of different mixtures of ABS/PC blend. Then, mechanical tensile tests were performed on the injected specimens and the stress/strain experimental data were gathered to be used in the modelling part. In order to enable the prediction of the mechanical response of the blend, G’Sell and Jonas constitutive law was considered for this purpose. An optimization method based on the Generalized Reduced Gradient (GRG) nonlinear algorithm was developed to identify the input parameters governing the mechanical model. In addition, an uncertainty parametric study was assessed to qualitatively and quantitatively evaluate the constitutive law sensitivity versus the parameter uncertainty. Monte Carlo simulations were performed and the convergence of the numerical model was proved in terms of means and standard deviation statistical data. The results showed an excellent agreement between the numerical approach and the experiments. Besides, it was highlighted the crucial role of coupling uncertainty parametric study with modelling for accurately describing the mechanical behavior of the blend. http://hdl.handle.net/10985/18475 Étude expérimentale et numérique pour la caractérisation thermique des bétons à changement de phase (BCP) ESSID, NESRINE; EDDHAHAK, Anissa; NEJI, Jamel In order to satisfy the technological challenges required by the new building concepts in the aim of improved performances in terms of durability, thermal comfort and respect for the environment, many research ideas have been considered by researchers and building professionals. Among these ideas, the reinforcement of construction materials by innovative and eco-efficient materials known as phase change materials (PCM) has attractive and promising advantages. Known for their high latent heat storage capacities, PCMs combined with cementitious materials such as concrete, are presented in the construction market as potential and intelligent actors for “clean” and sustainable construction. However, when PCMs are incorporated into the concrete paste, the estimation of the thermal conductivity and the specific heat capacity of the latter is not trivial and thus requires solving the optimization problems known as “inverse heat transfer problems”. In this context, this work proposes an iterative parametric optimization procedure, using a numerical model developed in order to estimate the thermal conductivity and the specific heat of the material containing the PCMs, such as phase change concrete, for example. To achieve this, we will use thermograms obtained from experimental tests carried out with an experimental DEsProTherm, developed at the I2M laboratory of ENSAMBordeaux and based on the method of the hot plan. The tests were carried out on different types of concrete samples incorporating different amounts of PCM. Sun, 01 Jan 2017 00:00:00 GMT http://hdl.handle.net/10985/18475 2017-01-01T00:00:00Z ESSID, NESRINE EDDHAHAK, Anissa NEJI, Jamel In order to satisfy the technological challenges required by the new building concepts in the aim of improved performances in terms of durability, thermal comfort and respect for the environment, many research ideas have been considered by researchers and building professionals. Among these ideas, the reinforcement of construction materials by innovative and eco-efficient materials known as phase change materials (PCM) has attractive and promising advantages. Known for their high latent heat storage capacities, PCMs combined with cementitious materials such as concrete, are presented in the construction market as potential and intelligent actors for “clean” and sustainable construction. However, when PCMs are incorporated into the concrete paste, the estimation of the thermal conductivity and the specific heat capacity of the latter is not trivial and thus requires solving the optimization problems known as “inverse heat transfer problems”. In this context, this work proposes an iterative parametric optimization procedure, using a numerical model developed in order to estimate the thermal conductivity and the specific heat of the material containing the PCMs, such as phase change concrete, for example. To achieve this, we will use thermograms obtained from experimental tests carried out with an experimental DEsProTherm, developed at the I2M laboratory of ENSAMBordeaux and based on the method of the hot plan. The tests were carried out on different types of concrete samples incorporating different amounts of PCM. http://hdl.handle.net/10985/21222 Experimental and numerical analysis of the energy efficiency of PCM concrete wallboards under different thermal scenarios ESSID, Nessrine; EDDHAHAK, Anissa; NEJI, Jamel This paper aims to investigate the energy efficiency of PCM-concrete wallboards using experimental and numerical approaches. First, a laboratory experimental work was performed to manufacture PCM-concrete mixtures with different proportions of PCMs. Then, an innovative bench test based on the transient plane source theory was used for the thermal analysis of the mixtures. Besides, numerical simulation by finite element method was carried and the confrontation of the numerical results with the experience has showed an excellent agreement. Accordingly, the numerical approach was validated and generalized for the study of PCM-concrete at macro scale under different thermal scenarios and PCM distributions (homogeneous/Bilayer/Matrix-inclusions). The numerical simulations highlighted clearly the role of PCMs in decreasing the indoor temperature of the different PCM-wallboards as well as the thermal fluctuations. Moreover, the time delay in the temperature peaks emphasized the enhancement of the energy efficiency of PCM-wallboards in comparison with a traditional concrete, especially for the case of the bilayer wallboard. Sat, 01 Jan 2022 00:00:00 GMT http://hdl.handle.net/10985/21222 2022-01-01T00:00:00Z ESSID, Nessrine EDDHAHAK, Anissa NEJI, Jamel This paper aims to investigate the energy efficiency of PCM-concrete wallboards using experimental and numerical approaches. First, a laboratory experimental work was performed to manufacture PCM-concrete mixtures with different proportions of PCMs. Then, an innovative bench test based on the transient plane source theory was used for the thermal analysis of the mixtures. Besides, numerical simulation by finite element method was carried and the confrontation of the numerical results with the experience has showed an excellent agreement. Accordingly, the numerical approach was validated and generalized for the study of PCM-concrete at macro scale under different thermal scenarios and PCM distributions (homogeneous/Bilayer/Matrix-inclusions). The numerical simulations highlighted clearly the role of PCMs in decreasing the indoor temperature of the different PCM-wallboards as well as the thermal fluctuations. Moreover, the time delay in the temperature peaks emphasized the enhancement of the energy efficiency of PCM-wallboards in comparison with a traditional concrete, especially for the case of the bilayer wallboard. http://hdl.handle.net/10985/18476 Effect of the processing conditions on the viscoelastic properties of a high-RAP recycled asphalt mixture: micromechanical and experimental approaches CHERIF, Rabeb; EDDHAHAK, Anissa; GABET, Thomas; HAMMOUM, Ferhat; NEJI, Jamel With the depletion of the virgin aggregates, many efforts have been oriented towards the recycling of the reclaimed asphalt pavement (RAP). However, quality control of the recycled product is required during the manufacture process. This research deals with the use of high-content RAP recycled asphalt mixture composed of 70% RAP based on experimental and micromechanical approaches. For the experimental part, a "Good" and a "Bad" blended mixture were manufactured in laboratory. Then, rheological measurements of the complex modulus of the different binders and mixtures were carried out. The micromechanical work is based on the generalised self-consistent scheme (GSCS) which was used to predict the mechanical properties of the recycled mixture. This approach aims to homogenize the heterogeneous material by taking into account both the intergranular porosity and the possible interactions between phases. The confrontation of the micromechanical model with the experimental results showed good agreements between measured data and predicted values of the complex modulus of the recycled asphalt. Moreover, it was highlighted from the experimental results that the blending process of the recycled mixture has a great influence on the viscoelastic properties of the recycled mixture. This result was also validated by the GSCS-based approach. Tue, 01 Jan 2019 00:00:00 GMT http://hdl.handle.net/10985/18476 2019-01-01T00:00:00Z CHERIF, Rabeb EDDHAHAK, Anissa GABET, Thomas HAMMOUM, Ferhat NEJI, Jamel With the depletion of the virgin aggregates, many efforts have been oriented towards the recycling of the reclaimed asphalt pavement (RAP). However, quality control of the recycled product is required during the manufacture process. This research deals with the use of high-content RAP recycled asphalt mixture composed of 70% RAP based on experimental and micromechanical approaches. For the experimental part, a "Good" and a "Bad" blended mixture were manufactured in laboratory. Then, rheological measurements of the complex modulus of the different binders and mixtures were carried out. The micromechanical work is based on the generalised self-consistent scheme (GSCS) which was used to predict the mechanical properties of the recycled mixture. This approach aims to homogenize the heterogeneous material by taking into account both the intergranular porosity and the possible interactions between phases. The confrontation of the micromechanical model with the experimental results showed good agreements between measured data and predicted values of the complex modulus of the recycled asphalt. Moreover, it was highlighted from the experimental results that the blending process of the recycled mixture has a great influence on the viscoelastic properties of the recycled mixture. This result was also validated by the GSCS-based approach. http://hdl.handle.net/10985/18477 Prediction of the viscoelastic properties of an asphalt mixture: Micromechanical and experimental approaches(Article) [Prédiction des propriétés viscoélastiques des enrobés bitumineux Approches micromécaniques et expérimentales] CHERIF, Rabeb; EDDHAHAK, Anissa; GABET, Thomas; HAMMOUM, Ferhat; NÉJI, Jamel The asphalt mixtures are composed of aggregates and asphalt used in the construction of the majority of roads. In order to ensure the sustainability of the infrastructures, the evaluation of the quality and the performances of these materials are essential. In this context, several researches have been focused on the development of predictive models, often empirical ones, in order to deduce the viscoelastic properties of an asphalt mixture based on the properties of its constituents (binder and/or aggregate). In this context, we suggest a homogenization model based on the generalized self-consistent scheme (GSC) to predict the complex module of the asphalt concrete from the properties of its components. In the aim of the approach validation, different types of mixtures (hot and warm) made in the laboratory were tested. The results showed that one can predict the complex modulus of the different types of asphalt concretes for temperatures less than 20 °C. However, beyond this temperature, the precision of the model decreases. Besides, the comparison of the micromechanical model with the rheologic models in literature showed that the suggested model can be also relevant in terms of predictions as the considered models. Sun, 01 Jan 2017 00:00:00 GMT http://hdl.handle.net/10985/18477 2017-01-01T00:00:00Z CHERIF, Rabeb EDDHAHAK, Anissa GABET, Thomas HAMMOUM, Ferhat NÉJI, Jamel The asphalt mixtures are composed of aggregates and asphalt used in the construction of the majority of roads. In order to ensure the sustainability of the infrastructures, the evaluation of the quality and the performances of these materials are essential. In this context, several researches have been focused on the development of predictive models, often empirical ones, in order to deduce the viscoelastic properties of an asphalt mixture based on the properties of its constituents (binder and/or aggregate). In this context, we suggest a homogenization model based on the generalized self-consistent scheme (GSC) to predict the complex module of the asphalt concrete from the properties of its components. In the aim of the approach validation, different types of mixtures (hot and warm) made in the laboratory were tested. The results showed that one can predict the complex modulus of the different types of asphalt concretes for temperatures less than 20 °C. However, beyond this temperature, the precision of the model decreases. Besides, the comparison of the micromechanical model with the rheologic models in literature showed that the suggested model can be also relevant in terms of predictions as the considered models.