Sacide Altinkaya - Academia.edu (original) (raw)

Papers by Sacide Altinkaya

Research paper thumbnail of Preparation and characterization of polyacrylonitrile membranes modified with polyelectrolyte deposition for separating similar sized proteins

Journal of Membrane Science, Oct 1, 2012

Research paper thumbnail of Membrane formation by dry-cast process

J Membrane Sci, 2005

Asymmetric membranes were prepared by dry-cast phase inversion technique from a cellulose acetate... more Asymmetric membranes were prepared by dry-cast phase inversion technique from a cellulose acetate, acetone, water solution in order to assess the validity of the mathematical model recently developed by us. Based on the model predictions, general structural characteristics of the membranes were determined by plotting the composition paths on the ternary phase diagram and polymer concentration profile at the first

Research paper thumbnail of Partial Purification of Hen Egg White Lysozyme by Ethanol Precipitation Method and Determination of the Thermal Stability of Its Lyophilized Form

Turkish Journal of …, 2007

Turkish Journal. of. Agriculture and Forestry. Find Manuscript. agric@tubitak.gov.tr. Scientific ... more Turkish Journal. of. Agriculture and Forestry. Find Manuscript. agric@tubitak.gov.tr. Scientific Journals Home Page. Turkish Journal of Agriculture and Forestry. Partial Purification of Hen Egg White Lysozyme by Ethanol Precipitation ...

Research paper thumbnail of Immobilization of superoxide dismutase/catalase onto polysulfone membranes to suppress hemodialysis-induced oxidative stress: A comparison of two immobilization methods

The objective of this study is to improve the blood compatibility of polysulfone (PSF) based hemo... more The objective of this study is to improve the blood compatibility of polysulfone (PSF) based hemodialysis membranes through generating antioxidative surfaces with superoxide dismutase (SOD)/catalase (CAT) enzyme couple immobilization. Enzymes were attached both covalently and ionically on the plasma treated and polyethyleneimine (PEI) deposited membranes, respectively. The loss of enzymes from PEI modified surface at the end of 4 h was found to be relatively higher during storage in phosphate buffered saline (PBS) at pH 7.4 when compared to the enzymes on the plasma treated surface. The kinetic studies indicated that SOD catalyzed the reaction in the diffusion-limited regime at all substrate concentrations and its inactivation by hydrogen peroxide was prevented in the presence of CAT. SOD/CAT coated PSF membranes were capable of reducing the levels of reactive oxygen species in blood and can significantly prolong activated partial thromboplastin time. In addition, both the adsorption of human plasma proteins and platelet activation on all modified membranes decreased significantly compared to the unmodified PSF membranes. Proposed modification methods did not affect high permeability, high mechanical strength or the non-toxic properties of the PSF membranes.

Research paper thumbnail of Novel low-fouling membrane bioreactor (MBR) for industrial wastewater treatment

Journal of Membrane Science, 2016

Research paper thumbnail of Modeling of Hemodialysis Operation

Annals of Biomedical Engineering, Sep 2, 2010

First and foremost, I would like to thank my advisor Dr. Sacide Alsoy Altınkaya, who has shown a ... more First and foremost, I would like to thank my advisor Dr. Sacide Alsoy Altınkaya, who has shown a large and consistent interest in my project during the times. Beside this work, I have learned so many useful things from her, that will help me to become a part of academia.

Research paper thumbnail of Development of antioxidant food packaging materials with controlled release properties

J Food Eng, 2010

In this study, cellulose acetate (CA) films with different morphological features were prepared i... more In this study, cellulose acetate (CA) films with different morphological features were prepared in order to control the release rates of low molecular weight natural antioxidants, L-ascorbic acid and L-tyrosine. Increasing CA content in the casting solution decreased the average pore size and porosity of the films, thus, reduced the diffusion rates of both antioxidants through the films. Although both antioxidants have similar molecular weights, L-tyrosine released into water much more slowly than L-ascorbic acid. The highest antioxidant activity in release test solutions was observed with highly porous L-tyrosine containing films. However, when the porosity of the films reduced, the antioxidant activity of L-ascorbic acid released into solution was found to be higher due to trapping of significant amount of L-tyrosine in dense films. The use of different antioxidants caused different changes in morphological and mechanical properties of the CA films. Varying the structural features of the films with the preparation conditions or using different surfaces of the films allowed the controlled release of each antioxidant.

Research paper thumbnail of Multi-Zone Drying Schemes for Lowering the Residual Solvent Content during Multi-Component Drying of Semicrystalline Polymers

Http Dx Doi Org 10 1080 07373930701396741, Jun 16, 2010

Research paper thumbnail of Characterization of waterborne acrylic based paint films and measurement of their water vapor permeabilities

Progress in Organic Coatings, Aug 1, 2006

Recently, production of waterborne coatings has increased significantly as a consequence of stric... more Recently, production of waterborne coatings has increased significantly as a consequence of strict pollution regulations. Waterborne coatings are sensitive to humidity, thus, their barrier properties with respect to permeation of moisture needs to be determined. Among various coating constituents, binder represents the matrix structure and its amount relative to the amounts of pigments and fillers can significantly affect the structure, hence the barrier property of the coating. In this study, waterborne acrylic based paints applied as protective coating on interior and exterior wall of the buildings are studied. The paint samples formulated with four different binder contents by a commercial paint company are used in the experiments. We first determine unknown ingredients of the paint samples using different characterization tools and then investigate the effect of the binder content on the structure of the paint films. In addition, water vapor permeability of the paint films is measured using a permeation cell. Results show that the barrier property of the waterborne acrylic based paint films against humidity decreases with decreased binder content due to uneven distribution of the pigments, consequently, porous structure formation in the films.

Research paper thumbnail of Effect of enzyme location on activity and stability of trypsin and urease immobilized on porous membranes by using layer-by-layer self-assembly of polyelectrolyte

Journal of Membrane Science, Dec 1, 2010

The layer-by-layer (LbL) self-assembly of polyelectrolyte is one of the simplest ways to immobili... more The layer-by-layer (LbL) self-assembly of polyelectrolyte is one of the simplest ways to immobilize enzyme on membrane. In this paper, the immobilization of trypsin (TRY) and urease (URE) on polyacrylonitrile based membranes using the LbL assembly technique was presented. The studied systems consisted in bilayered assemblies with the enzyme layer as the outer layer and trilayered assemblies with the enzyme layer as the inner sandwiched layer. The membrane pore size was chosen so that the smaller enzyme TRY was mainly immobilized within the membrane and confined in the porous membrane structure while URE immobilization mainly took place at the membrane surface. No dramatic difference on reactivity was evidenced between these two enzyme locations. The catalytic activity of immobilized enzymes was found to be lower than the free ones in solution but their stability was dramatically enhanced. The higher activity was observed when the enzyme is deposited as the outer layer of the LbL assembly. On the other hand, the more stable catalytic membranes were obtained when the outer layer consists of a polyelectrolyte covering the enzyme layer.

Research paper thumbnail of Modeling of Diffusion in Closed Cell Polymeric Foams

Journal of Cellular Plastics

ABSTRACT

Research paper thumbnail of Communication par Affiche : "Enzymes modified membranes. Preparation, characterization and modelling

Research paper thumbnail of Communication Orale : "Enzymes modified membranes. Preparation and reactivity

Research paper thumbnail of Communication par Affiche : "Elaboration of reactive membrane by immobilization of trypsin with polyelectrolyte layer

Research paper thumbnail of Layer-by-layer surface modification of poly(ether sulfone) membranes using polyelectrolytes and AgCl/TiO2 xerogels

Journal of Membrane Science, 2015

ABSTRACT In this study, the layer-by-layer (LBL) assembly method was employed to modify a commerc... more ABSTRACT In this study, the layer-by-layer (LBL) assembly method was employed to modify a commercial poly(ether sulfone) (PES) membrane by successive adsorption of chitosan and alginate as cationic and anionic polyelectrolytes. To enhance anti-biofouling property, pure, PEG mixed and PEGylated AgCl/TiO2 xerogels were incorporated solely in the top layer of the LBL modified membranes. Organic and biological fouling was addressed separately using alginate and E.coli bacteria suspensions as the organic and biological model foulants, respectively. LbL-modifying the commercial PES membrane successively with chitosan and alginate polyelectrolyte multilayers prevented organic fouling extensively. In addition, we found that AgCl/TiO2-incorporated membranes showed higher water permeability and improved resistance to biological fouling as compared to the PES membrane. Silver amounts in consecutively collected permeate samples was quantified by ICP-MS analysis to assess the stability of AgCl/TiO2-incorporated layers. Silver loss per filtration cycle followed an increasing trend initially, up to a filtration volume totaling 3000 L/m2, leading to 4.2% reduction in the immobilized silver amount. After that, silver loss per filtration cycle stabilized at ~7.44 μg/L, which extrapolates to ~265 days time-span for the remaining silver to be released at a filtration rate of ~1000 L/m2.h. Antibacterial activity tests showed that AgCl/TiO2-incorporated layers do not permit bacterial growth on the membrane surface.

Research paper thumbnail of Responsive Pentablock Copolymers for siRNA Delivery

RSC Adv., 2015

ABSTRACT In this study, temperature and pH responsive cationic and amphiphilic pentablock copolym... more ABSTRACT In this study, temperature and pH responsive cationic and amphiphilic pentablock copolymers, which consist of the temperature responsive triblock Pluronic F127 sandwiched between the pH responsive PDEAEM (poly(2-diethylaminoethyl methacrylate)) end blocks, were used for the first time in the development of polyplex and gold nanoparticle (AuNP) based multicomponent siRNA delivery systems (MCSs). Copolymers in both systems protected siRNA from external effects, provided cell entry and endosomal escape. The thermoreversible micellization of hydrophobic PPO block facilitated the cellular entry while the PDEAEM blocks enhanced endosomal escape through protonated tertiary amine groups by pH buffering. The synergistic advantages of the different blocks showed an enhanced effect in the MCSs due to attachment and surface configuration reasons. The siRNA transfection efficiency of MCSs against luciferase expressing SKOV3 cells was 15% higher than both the polyplexes alone and commercial siRNA transfection agent Lipofectamine RNAiMax at the same applied dose, without any toxicity. The results indicated that the multicomponent systems based on the responsive cationic pentablock copolymers and gold nanoparticles have promising potential as efficient siRNA delivery vector for future applications.

Research paper thumbnail of A step forward to a more efficient wastewater treatment by membrane surface modification via polymerizable bicontinuous microemulsion

Journal of Membrane Science, 2015

ABSTRACT An innovative hydrophilic and anti-fouling coating material for application in membrane ... more ABSTRACT An innovative hydrophilic and anti-fouling coating material for application in membrane technology for wastewater treatment has been developed by polymerization of a polymerizable bicontinuous microemulsion (PBM) and used for surface modification of a commercial flat polyethersulfone (PES) membrane. The novel nanostructured coating has been produced using acryloyloxyundecyltriethylammonium bromide (AUTEAB) as a co-polymerizable surfactant, obtained through a synthetic method characterized by a lower cost and a higher reproducibility compared to other known polymerizable surfactants. The novel composite membranes have been characterized and compared with the uncoated PES membranes. Coated membranes resulted in a smoother surface and a higher hydrophilicity with respect to the uncoated ones, and showed a particular nano-size channel-like morphology making them highly resistant to the fouling phenomenon. The covalent anchorage of the surfactant on the membrane surface ensured the embedment of the molecule in the polymeric matrix avoiding its leaching and also leading the coated membranes to have significant antimicrobial activity, which is very important for reducing the biofouling phenomenon.

Research paper thumbnail of Development of mono and multilayer antimicrobial food packaging materials for controlled release of potassium sorbate

LWT - Food Science and Technology, 2011

ABSTRACT In this study, cellulose acetate (CA) based mono and multilayer films including potassiu... more ABSTRACT In this study, cellulose acetate (CA) based mono and multilayer films including potassium sorbate (Psb) as an antimicrobial agent were prepared using dry phase inversion technique. To achieve appropriate controlled release of Psb, the structure of the films was changed by manipulating the film preparation conditions. In particular, the initial casting composition, wet casting thickness and drying temperature were varied. Results indicate that Psb release rate decreased as the CA content in the casting solution, the wet casting thickness and the drying temperature for both mono and multilayer films were increased. Compared to the results for the monolayer films, a significant decrease of Psb release rate through the multilayer films was recorded. Drying-induced crystallization was observed in the monolayer films. As a consequence of this, a fast initial release of Psb, controlled by Fickian diffusion, was followed by a slower release controlled by dissolution of Psb crystals. In multilayer films, no crystals were detected in the structure and the release rate was regulated only by diffusion of Psb through the film. The results suggest that the films prepared in this study can be used as food packaging materials for achieving controlled and extended release of Psb.

Research paper thumbnail of REMOVED: Preparation and Characterization of Polysulfone based Hemodialysis Membranes with Improved Biocompatibility Through Alpha–lipoic Acid Immobilization

Procedia Engineering, 2012

Research paper thumbnail of The influence of binder content on the water transport properties of waterborne acrylic paints

Progress in Organic Coatings, 2010

... a w activity of water vapour D diffusion coefficient (cm 2 /s) D o diffusion coefficient at i... more ... a w activity of water vapour D diffusion coefficient (cm 2 /s) D o diffusion coefficient at initial concentration (cm 2 /s) G ww cluster integral View the MathML source mass diffusion flux of penetrant relative to velocity of polymer (g/cm 2 s) k p polymer–penetrant interaction ...

Research paper thumbnail of Preparation and characterization of polyacrylonitrile membranes modified with polyelectrolyte deposition for separating similar sized proteins

Journal of Membrane Science, Oct 1, 2012

Research paper thumbnail of Membrane formation by dry-cast process

J Membrane Sci, 2005

Asymmetric membranes were prepared by dry-cast phase inversion technique from a cellulose acetate... more Asymmetric membranes were prepared by dry-cast phase inversion technique from a cellulose acetate, acetone, water solution in order to assess the validity of the mathematical model recently developed by us. Based on the model predictions, general structural characteristics of the membranes were determined by plotting the composition paths on the ternary phase diagram and polymer concentration profile at the first

Research paper thumbnail of Partial Purification of Hen Egg White Lysozyme by Ethanol Precipitation Method and Determination of the Thermal Stability of Its Lyophilized Form

Turkish Journal of …, 2007

Turkish Journal. of. Agriculture and Forestry. Find Manuscript. agric@tubitak.gov.tr. Scientific ... more Turkish Journal. of. Agriculture and Forestry. Find Manuscript. agric@tubitak.gov.tr. Scientific Journals Home Page. Turkish Journal of Agriculture and Forestry. Partial Purification of Hen Egg White Lysozyme by Ethanol Precipitation ...

Research paper thumbnail of Immobilization of superoxide dismutase/catalase onto polysulfone membranes to suppress hemodialysis-induced oxidative stress: A comparison of two immobilization methods

The objective of this study is to improve the blood compatibility of polysulfone (PSF) based hemo... more The objective of this study is to improve the blood compatibility of polysulfone (PSF) based hemodialysis membranes through generating antioxidative surfaces with superoxide dismutase (SOD)/catalase (CAT) enzyme couple immobilization. Enzymes were attached both covalently and ionically on the plasma treated and polyethyleneimine (PEI) deposited membranes, respectively. The loss of enzymes from PEI modified surface at the end of 4 h was found to be relatively higher during storage in phosphate buffered saline (PBS) at pH 7.4 when compared to the enzymes on the plasma treated surface. The kinetic studies indicated that SOD catalyzed the reaction in the diffusion-limited regime at all substrate concentrations and its inactivation by hydrogen peroxide was prevented in the presence of CAT. SOD/CAT coated PSF membranes were capable of reducing the levels of reactive oxygen species in blood and can significantly prolong activated partial thromboplastin time. In addition, both the adsorption of human plasma proteins and platelet activation on all modified membranes decreased significantly compared to the unmodified PSF membranes. Proposed modification methods did not affect high permeability, high mechanical strength or the non-toxic properties of the PSF membranes.

Research paper thumbnail of Novel low-fouling membrane bioreactor (MBR) for industrial wastewater treatment

Journal of Membrane Science, 2016

Research paper thumbnail of Modeling of Hemodialysis Operation

Annals of Biomedical Engineering, Sep 2, 2010

First and foremost, I would like to thank my advisor Dr. Sacide Alsoy Altınkaya, who has shown a ... more First and foremost, I would like to thank my advisor Dr. Sacide Alsoy Altınkaya, who has shown a large and consistent interest in my project during the times. Beside this work, I have learned so many useful things from her, that will help me to become a part of academia.

Research paper thumbnail of Development of antioxidant food packaging materials with controlled release properties

J Food Eng, 2010

In this study, cellulose acetate (CA) films with different morphological features were prepared i... more In this study, cellulose acetate (CA) films with different morphological features were prepared in order to control the release rates of low molecular weight natural antioxidants, L-ascorbic acid and L-tyrosine. Increasing CA content in the casting solution decreased the average pore size and porosity of the films, thus, reduced the diffusion rates of both antioxidants through the films. Although both antioxidants have similar molecular weights, L-tyrosine released into water much more slowly than L-ascorbic acid. The highest antioxidant activity in release test solutions was observed with highly porous L-tyrosine containing films. However, when the porosity of the films reduced, the antioxidant activity of L-ascorbic acid released into solution was found to be higher due to trapping of significant amount of L-tyrosine in dense films. The use of different antioxidants caused different changes in morphological and mechanical properties of the CA films. Varying the structural features of the films with the preparation conditions or using different surfaces of the films allowed the controlled release of each antioxidant.

Research paper thumbnail of Multi-Zone Drying Schemes for Lowering the Residual Solvent Content during Multi-Component Drying of Semicrystalline Polymers

Http Dx Doi Org 10 1080 07373930701396741, Jun 16, 2010

Research paper thumbnail of Characterization of waterborne acrylic based paint films and measurement of their water vapor permeabilities

Progress in Organic Coatings, Aug 1, 2006

Recently, production of waterborne coatings has increased significantly as a consequence of stric... more Recently, production of waterborne coatings has increased significantly as a consequence of strict pollution regulations. Waterborne coatings are sensitive to humidity, thus, their barrier properties with respect to permeation of moisture needs to be determined. Among various coating constituents, binder represents the matrix structure and its amount relative to the amounts of pigments and fillers can significantly affect the structure, hence the barrier property of the coating. In this study, waterborne acrylic based paints applied as protective coating on interior and exterior wall of the buildings are studied. The paint samples formulated with four different binder contents by a commercial paint company are used in the experiments. We first determine unknown ingredients of the paint samples using different characterization tools and then investigate the effect of the binder content on the structure of the paint films. In addition, water vapor permeability of the paint films is measured using a permeation cell. Results show that the barrier property of the waterborne acrylic based paint films against humidity decreases with decreased binder content due to uneven distribution of the pigments, consequently, porous structure formation in the films.

Research paper thumbnail of Effect of enzyme location on activity and stability of trypsin and urease immobilized on porous membranes by using layer-by-layer self-assembly of polyelectrolyte

Journal of Membrane Science, Dec 1, 2010

The layer-by-layer (LbL) self-assembly of polyelectrolyte is one of the simplest ways to immobili... more The layer-by-layer (LbL) self-assembly of polyelectrolyte is one of the simplest ways to immobilize enzyme on membrane. In this paper, the immobilization of trypsin (TRY) and urease (URE) on polyacrylonitrile based membranes using the LbL assembly technique was presented. The studied systems consisted in bilayered assemblies with the enzyme layer as the outer layer and trilayered assemblies with the enzyme layer as the inner sandwiched layer. The membrane pore size was chosen so that the smaller enzyme TRY was mainly immobilized within the membrane and confined in the porous membrane structure while URE immobilization mainly took place at the membrane surface. No dramatic difference on reactivity was evidenced between these two enzyme locations. The catalytic activity of immobilized enzymes was found to be lower than the free ones in solution but their stability was dramatically enhanced. The higher activity was observed when the enzyme is deposited as the outer layer of the LbL assembly. On the other hand, the more stable catalytic membranes were obtained when the outer layer consists of a polyelectrolyte covering the enzyme layer.

Research paper thumbnail of Modeling of Diffusion in Closed Cell Polymeric Foams

Journal of Cellular Plastics

ABSTRACT

Research paper thumbnail of Communication par Affiche : "Enzymes modified membranes. Preparation, characterization and modelling

Research paper thumbnail of Communication Orale : "Enzymes modified membranes. Preparation and reactivity

Research paper thumbnail of Communication par Affiche : "Elaboration of reactive membrane by immobilization of trypsin with polyelectrolyte layer

Research paper thumbnail of Layer-by-layer surface modification of poly(ether sulfone) membranes using polyelectrolytes and AgCl/TiO2 xerogels

Journal of Membrane Science, 2015

ABSTRACT In this study, the layer-by-layer (LBL) assembly method was employed to modify a commerc... more ABSTRACT In this study, the layer-by-layer (LBL) assembly method was employed to modify a commercial poly(ether sulfone) (PES) membrane by successive adsorption of chitosan and alginate as cationic and anionic polyelectrolytes. To enhance anti-biofouling property, pure, PEG mixed and PEGylated AgCl/TiO2 xerogels were incorporated solely in the top layer of the LBL modified membranes. Organic and biological fouling was addressed separately using alginate and E.coli bacteria suspensions as the organic and biological model foulants, respectively. LbL-modifying the commercial PES membrane successively with chitosan and alginate polyelectrolyte multilayers prevented organic fouling extensively. In addition, we found that AgCl/TiO2-incorporated membranes showed higher water permeability and improved resistance to biological fouling as compared to the PES membrane. Silver amounts in consecutively collected permeate samples was quantified by ICP-MS analysis to assess the stability of AgCl/TiO2-incorporated layers. Silver loss per filtration cycle followed an increasing trend initially, up to a filtration volume totaling 3000 L/m2, leading to 4.2% reduction in the immobilized silver amount. After that, silver loss per filtration cycle stabilized at ~7.44 μg/L, which extrapolates to ~265 days time-span for the remaining silver to be released at a filtration rate of ~1000 L/m2.h. Antibacterial activity tests showed that AgCl/TiO2-incorporated layers do not permit bacterial growth on the membrane surface.

Research paper thumbnail of Responsive Pentablock Copolymers for siRNA Delivery

RSC Adv., 2015

ABSTRACT In this study, temperature and pH responsive cationic and amphiphilic pentablock copolym... more ABSTRACT In this study, temperature and pH responsive cationic and amphiphilic pentablock copolymers, which consist of the temperature responsive triblock Pluronic F127 sandwiched between the pH responsive PDEAEM (poly(2-diethylaminoethyl methacrylate)) end blocks, were used for the first time in the development of polyplex and gold nanoparticle (AuNP) based multicomponent siRNA delivery systems (MCSs). Copolymers in both systems protected siRNA from external effects, provided cell entry and endosomal escape. The thermoreversible micellization of hydrophobic PPO block facilitated the cellular entry while the PDEAEM blocks enhanced endosomal escape through protonated tertiary amine groups by pH buffering. The synergistic advantages of the different blocks showed an enhanced effect in the MCSs due to attachment and surface configuration reasons. The siRNA transfection efficiency of MCSs against luciferase expressing SKOV3 cells was 15% higher than both the polyplexes alone and commercial siRNA transfection agent Lipofectamine RNAiMax at the same applied dose, without any toxicity. The results indicated that the multicomponent systems based on the responsive cationic pentablock copolymers and gold nanoparticles have promising potential as efficient siRNA delivery vector for future applications.

Research paper thumbnail of A step forward to a more efficient wastewater treatment by membrane surface modification via polymerizable bicontinuous microemulsion

Journal of Membrane Science, 2015

ABSTRACT An innovative hydrophilic and anti-fouling coating material for application in membrane ... more ABSTRACT An innovative hydrophilic and anti-fouling coating material for application in membrane technology for wastewater treatment has been developed by polymerization of a polymerizable bicontinuous microemulsion (PBM) and used for surface modification of a commercial flat polyethersulfone (PES) membrane. The novel nanostructured coating has been produced using acryloyloxyundecyltriethylammonium bromide (AUTEAB) as a co-polymerizable surfactant, obtained through a synthetic method characterized by a lower cost and a higher reproducibility compared to other known polymerizable surfactants. The novel composite membranes have been characterized and compared with the uncoated PES membranes. Coated membranes resulted in a smoother surface and a higher hydrophilicity with respect to the uncoated ones, and showed a particular nano-size channel-like morphology making them highly resistant to the fouling phenomenon. The covalent anchorage of the surfactant on the membrane surface ensured the embedment of the molecule in the polymeric matrix avoiding its leaching and also leading the coated membranes to have significant antimicrobial activity, which is very important for reducing the biofouling phenomenon.

Research paper thumbnail of Development of mono and multilayer antimicrobial food packaging materials for controlled release of potassium sorbate

LWT - Food Science and Technology, 2011

ABSTRACT In this study, cellulose acetate (CA) based mono and multilayer films including potassiu... more ABSTRACT In this study, cellulose acetate (CA) based mono and multilayer films including potassium sorbate (Psb) as an antimicrobial agent were prepared using dry phase inversion technique. To achieve appropriate controlled release of Psb, the structure of the films was changed by manipulating the film preparation conditions. In particular, the initial casting composition, wet casting thickness and drying temperature were varied. Results indicate that Psb release rate decreased as the CA content in the casting solution, the wet casting thickness and the drying temperature for both mono and multilayer films were increased. Compared to the results for the monolayer films, a significant decrease of Psb release rate through the multilayer films was recorded. Drying-induced crystallization was observed in the monolayer films. As a consequence of this, a fast initial release of Psb, controlled by Fickian diffusion, was followed by a slower release controlled by dissolution of Psb crystals. In multilayer films, no crystals were detected in the structure and the release rate was regulated only by diffusion of Psb through the film. The results suggest that the films prepared in this study can be used as food packaging materials for achieving controlled and extended release of Psb.

Research paper thumbnail of REMOVED: Preparation and Characterization of Polysulfone based Hemodialysis Membranes with Improved Biocompatibility Through Alpha–lipoic Acid Immobilization

Procedia Engineering, 2012

Research paper thumbnail of The influence of binder content on the water transport properties of waterborne acrylic paints

Progress in Organic Coatings, 2010

... a w activity of water vapour D diffusion coefficient (cm 2 /s) D o diffusion coefficient at i... more ... a w activity of water vapour D diffusion coefficient (cm 2 /s) D o diffusion coefficient at initial concentration (cm 2 /s) G ww cluster integral View the MathML source mass diffusion flux of penetrant relative to velocity of polymer (g/cm 2 s) k p polymer–penetrant interaction ...