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1
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SURFACE PROPERTIES OF CHITOSAN COMPOSITES WITH POLY(VINYL ALCOHOL) AND HYDROXYAPATITE

100%
Lewandowska K.
Progress on Chemistry and Application of Chitin and its Derivatives
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2015
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vol. 20
177-182
EN
Surface properties of composites containing chitosan (Ch), poly(vinyl alcohol) (PVA) with hydroxyapatite (HAP) were investigated by contact angle measurements and atomic force microscopy (AFM). Thin films of Ch/HAP and Ch/PVA/HAP composites have been formed by casting methods from acetic acid solutions. Measurements of the contact angle for diiodomethane (D), and glycerol (G) on the surface of chitosan films, Ch/HAP and chitosan/PVA/HAP films were made and surface free energy was calculated. It was found that chitosan/HAP or Ch/PVA/HAP blend surface is enriched in high surface energy component i.e. chitosan. The study of composites by AFM showed a completely different morphology when compared with unmodified components. The roughness of composites increase after the addition of hydroxyapatite. This may indicates a strong interaction between the polymeric components and inorganic additive.
2
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VISCOMETRIC STUDIES OF MICROCRYSTALLINE CHITOSAN/POLY(VINYL ALCOHOL) MIXTURES

100%
Lewandowska K.
Progress on Chemistry and Application of Chitin and its Derivatives
|
2011
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vol. 16
43 - 48
EN
In the present paper, the results of viscosity measurements in dilute solutions of microcrystalline chitosan (MCCh) with poly(vinyl alcohol) (PVA) of different degrees of hydrolysis are presented. Microcrystalline chitosan is blended with poly(vinyl alcohol) in aqueous 0.1 MCH3COOH/0.2 M NaCl. Viscosity measurements of dilute polymer solution were carried out in an Ubbelohde capillary viscometer. The final result depends on (I) the thermodynamic goodness of the solvent, on (II) the applied extrapolation method used for determination of the interaction parameters, on (III) the assumed miscibility criteria, on (IV) the degree of hydrolysis of PVA, and on (V) the blend composition.
3
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SURFACE PROPERTIES OF CHITOSAN ACETATE, POLYACRYLAMIDE AND THEIR MIXTURES

100%
Lewandowska K.
Progress on Chemistry and Application of Chitin and its Derivatives
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2013
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vol. 18
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issue 18
29-34
EN
The surface properties of chitosan acetate (ChA), polyacrylamide (PAM) and ChA/PAM mixtures have been investigated by the tapping-mode atomic force microscopy (AFM) and monitored by contact angle measurements. Chitosan is blended with polyacrylamide in acetic acid solution and this solution is cast to prepare the mixture film. Measurements of the contact angle for two different liquids (diiodomethane and glycerol) on the surface of chitosan acetate. The surface free energy (γs) as well as dispersive (gsd) and polar (gsp) components were calculated from contact angle values by Owens-Wendt methods using an appropriate computer program. The values of polar and dispersive components of surface free energy show that PAM films are more polar than chitosan acetate films. In the case of ChA/PAM mixtures, the values of surface free energy and polar component are reduced significantly compared with pure polymers. This behavior indicates rather hydrophobic character of this surface. The changes of topography images were considered by determining the root mean square (RMS) deviation in the image data. The study of blends by AFM showed a completely different morphology when compared with pure components. The roughness of blends increases with the increase of ChA content. This may indicates a strong interaction between the polymeric components.
4
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PHYSICO-CHEMICAL PROPERTIES OF CHITOSAN COMPOSITES WITH SYNTHETIC POLYMERS AND INORGANIC ADDITIVES

100%
Lewandowska K.
Progress on Chemistry and Application of Chitin and its Derivatives
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2015
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vol. 20
162-169
EN
In the present study the results of rheological measurements and atomic force microscopy (AFM) of polymer composites with montmorillonite (MMT) are presented. Chitosan is blended with synthetic polymers and inorganic additives in acetic acid solution and this solution is cast to prepare the mixture film. Flow measurements were made on a Bohlin Visco 88 rotary viscometer in the temperature range 25ºC-40ºC. The apparent shear viscosity and rheological parameters of the unmodified components and their composites were determined and discussed. Polymer films were examined using a Scanning Probe Microscopy SPM production Veeco. The obtained results suggest that the modification of several properties of polymer composites is a consequence of the interaction between the polymeric components and inorganic additives.
5
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MISCIBILITY AND INTERACTIONS IN CHITOSAN AND POLYACRYLAMIDE MIXTURES

100%
Lewandowska K.
Progress on Chemistry and Application of Chitin and its Derivatives
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2014
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vol. 19
65-71
EN
In the present work, the results of Fourier transform infrared (FTIR) and atomic force microscopy (AFM) studies of films of chitosan acetate (ChA), polyacrylamide (PAM), and their mixtures are presented. The morphology of the ChA and PAM films and their mixtures was studied by tappingmode atomic force microscopy (AFM). The topography images were considered by determining the root mean square (RMS) deviation in the image data. The study of mixtures by AFM showed a completely different morphology when compared with pure components. The roughness of mixtures increases with the increase of ChA content but is significantly reduced after UV exposure. This may indicate a strong interaction between the polymeric components. The FTIR spectroscopy also supports the obtained results. The miscibility of polymer mixtures is related to interactions between the functional groups of the polymeric components.
6
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THERMAL AND ATOMIC FORCE MICROSCOPY (AFM) STUDIES OF MICROCRYSTALLINE CHITOSAN/POLY(VINYL ALCOHOL) MIXTURES

100%
Lewandowska K.
Progress on Chemistry and Application of Chitin and its Derivatives
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2010
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vol. 15
11 - 16
EN
In the present paper, the results of thermal analysis (DSC and TGA) and atomic force microscopy studies of microcrystalline chitosan (MCCh) with poly(vinyl alcohol) (PVA) are presented. Microcrystalline chitosan is blended with poly(vinyl alcohol) in acetic acid solution and this solution is cast to prepare the blend film. From thermal curves the thermal transitions: Tg, Tm and characteristic temperatures of decomposition: Tdi, Tmax have been determined and compared. The influence of the degree of PVA hydrolysis on the thermal properties of blend systems has been discussed. The surface properties of the MCCh and PVA films and their blends have been studied by tapping-mode atomic force microscopy (AFM). The changes of topography images were considered by determining the root mean square (RMS) deviation in the image data. The obtained results suggested that in solid MCCh/PVA mixtures the components are poorly miscible.
7
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RHEOLOGICAL PROPERTIES OF CHITOSAN BLENDS WITH PARTIALLY HYDROLYZED POLYACRYLAMIDE IN DIFFERENT SOLVENTS

100%
Lewandowska K.
Progress on Chemistry and Application of Chitin and its Derivatives
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2012
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vol. 17
53 - 62
EN
In the present paper, the results of rheological measurements in solutions of chitosan (Ch) with partially hydrolyzed polyacrylamide (HPAM) are presented. Aqueous acetic acid, lactic acid and aqueous acetic acid/NaCl were used as solvents for chitosan, HPAM and Ch/HPAM solution blends. The criterion of miscibility of solution blends, based on the additivity rule of apparent shear viscosity (ηa) has been discussed. The rheological parameters from power law (Ostwald de Waele model) and activation energy of viscous flow (Ea) have been calculated from the flow curves and Arrhenius plots, respectively. It was found that studied polymer solutions exhibited the non-Newtonian behaviour with shear-thinning and/or shear-thickening areas. The final result depends on the thermodynamic goodness of the solvent and on the blend composition.
8
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CHARACTERISATION OF THIN CHITOSAN FILMS FOR GUIDED TISSUE REGENERATION PURPOSES

64%
Lewandowska K., Furtos G. F.
Progress on Chemistry and Application of Chitin and its Derivatives
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2017
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vol. 22
118-124
EN
The morphology and structure of thin films containing chitosan (Ch) with montmorillonite (MMT) were characterised by scanning electron microscopy (SEM), atomic force microscopy (AFM) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). Thin films of two chitosan samples and a composition of chitosan with montmorillonite were formed by casting methods from acetic acid solutions and were soaked in a simulated body fluid (SBF) solution at 37C for 14 days. The samples were compared before and after soaking. The obtained results showed growth of new phases containing calcium in all prepared films.
9
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Conciliating the nonadditive entropy approach and the fractional model formulation when describing subdiffusion

64%
Kosztołowicz T., Lewandowska K.
Open Physics
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2012
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vol. 10
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issue 3
645-651
EN
We consider here two different models describing subdiffusion. One of them is derived from Continuous Time Random Walk formalism and utilizes a subdiffusion equation with a fractional time derivative. The second model is based on Sharma-Mittal nonadditive entropy formalism where the subdiffusive process is described by a nonlinear equation with ordinary derivatives. Using these two models we describe the process of a substance released from a thick membrane and we find functions which determine the time evolution of the amount of substance remaining inside this membrane. We then find ‘the agreement conditions’ under which these two models provide the same relation defining subdiffusion and give the same function characterizing the process of the released substance. These agreement conditions enable us to determine the relation between the parameters occuring in both models.
10
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RHEOLOGICAL AND MECHANICAL STUDIES OF CHITOSAN BLENDS WITH THE ADDITION OF AN IONIC LIQUID

64%
Lewandowska K., Szulc M.
Progress on Chemistry and Application of Chitin and its Derivatives
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2019
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vol. 24
119 - 126
EN
In the present paper, results from rheological measurements and tensile tests of polymer blends containing chitosan and poly(vinyl alcohol) with different additions of an ionic liquid are presented. Flow measurements were carried out using solutions of pure polymers and their blends with and without the addition of an ionic liquid. It has been observed that the polymer solutions and their blends exhibited non-Newtonian behaviour. Rheological parameters from the power law and activation energy of viscous flow were determined and discussed. Mechanical properties, such as the tensile strength and ultimate percentage of elongation of films, have been determined and compared. This study thus shows that the addition of an ionic liquid is an effective method for improving the flexibility of chitosan blends.
11
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VISCOMETRIC STUDIES OF CHITOSAN/POLYACRYLAMIDE MIXTURES

51%
Lewandowska K., Sionkowska A., Krasińska K.
Progress on Chemistry and Application of Chitin and its Derivatives
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2014
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vol. 19
73-78
EN
Polymer-polymer interactions and miscibility for chitosan (Ch) and partially hydrolysed polyacrylamide (HPAM) have been investigated using dilute solution viscosity. The intrinsic viscosity, [η], and the viscosity interaction parameters, bm, have been determined for the binary (solvent/polymer) and ternary (solvent/polymer A/polymer B) systems. Degree of miscibility of these polymer mixtures was estimated on the basis of two criteria. The final result depends on (i) the applied extrapolation method used for determination of the interaction parameters, (ii) the assumed miscibility criteria, and (iii) the blend composition.
12
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CHARACTERISATION OF CHITOSAN/HYALURONIC ACID BLEND FILMS MODIFIED BY COLLAGEN

51%
Lewandowska K., Alina S., Grabska S., Michalska M.
Progress on Chemistry and Application of Chitin and its Derivatives
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2017
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vol. 22
125-134
EN
In the present study, thin films based on the blends of chitosan (Ch) and hyaluronic acid (HA) with and without collagen (Coll) were characterised using tensile tests, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and thermogravimetric analysis (TGA). Ch/HA and Ch/HA/Coll polymer blends were prepared using the solvent evaporation technique. The interactions between polymer components in the binary and ternary blends were studied by FTIR analysis. Mechanical properties were studied and compared with those of simple polymer films. These results show that the addition of collagen into Ch/HA blends led to the increase of tensile strength and Young modulus. Moreover, it was found that the thermal stability of the Ch/HA binary blend significantly increased upon the addition of collagen.
13
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INFLUENCE OF THE INTERMOLECULAR INTERACTION ON PHYSICO-CHEMICAL PROPERTIES OF CHITOSAN/HYALURONIC ACID BLENDS

51%
Lewandowska K., Alina S., Grabska S.
Progress on Chemistry and Application of Chitin and its Derivatives
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2015
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vol. 20
170-176
EN
In the present study, the results of viscosity measurements in dilute solutions of chitosan (Ch) with hyaluronic acid (HA) are presented. Chitosan is blended with hyaluronic acid in aqueous 0.1M CH3COOH/0.2M NaCl and 0.3M NaCl respectively, or with the addition of HEPES. Viscosity measurements of dilute polymer solution were carried out in an Ubbelohde capillary viscometer. The intrinsic viscosity, [], and the viscosity interaction parameters, bm, have been determined for the binary (solvent/polymer) and ternary (solvent/polymer A/polymer B) systems. The homogeneity and morphology of chitosan blends were ascertained from the tapping-mode atomic force microscopy. The surface roughness of chitosan, hyaluronic acid and Ch/HA blended films was altered by mixing. The obtained results suggested that there was existence of the strong interactions between chitosan and hyaluronic acid.
14
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THE INFLUENCE OF THE TYPE SOLVENT ON THE STRUCTURE OF CHITOSAN BLENDS WITH HYALURONIC ACID

51%
Lewandowska K., Sionkowska A., Grabska S.
Progress on Chemistry and Application of Chitin and its Derivatives
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2016
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vol. 21
147-153
EN
The influence of the type solvent on the structure of chitosan, hyaluronic acid and their blend films was investigated. Aqueous acetic acid, hydrochloric acid, sodium chloride and aqueous acetic acid/NaCl were used as solvents for chitosan, hyaluronic acid and Ch/HA solution blends. Ch, HA and their blend films were prepared by casting technique. The homogeneity and morphology of chitosan blends were ascertained from the tapping-mode atomic force microscopy (AFM) and scanning electron microscopy (SEM). The changes of topography images are considered by determining the root mean square (RMS, Rq) deviation in the image data. The surface roughness of chitosan, hyaluronic acid and Ch/HA blended films was altered by mixing. The structure of chitosan blends with hyaluronic acid depends on the blend composition and on the solvent used for preparing the blend.
15
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CHARACTERISATION OF CHITOSAN AFTER CROSS-LINKING BY TANNIC ACID

51%
Sionkowska A., Kaczmarek B., Lewandowska K.
Progress on Chemistry and Application of Chitin and its Derivatives
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2014
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vol. 19
135-138
EN
Chitosan is widely applied in biomedical and cosmetic fields. For this reason, there is a need to modify this biopolymer to achieve new properties of chitosan-based materials. The properties of chitosan can be modified by several cross-linking methods. In this work, we used the chemical cross-linking of chitosan with tannic acid, after which cross-linked chitosan was shaped into a 3D structure by the lyophilisation process. For the material obtained, FTIR-ATR analysis was performed to characterise the structure of cross-linked chitosan. Moreover, mechanical properties and swelling properties were measured for chitosan before and after cross-linking. The results show that several properties of chitosan can be changed after cross-linking by tannic acid. The positions of bands in the FTIR spectra of chitosan were shifted after cross-linking. Mechanical properties were altered for cross-linked chitosan. However, the highest compressive modulus was observed for pure chitosan. The lowest compressive modulus was observed for chitosan cross-linked with 20 wt% of tannic acid. Swelling behaviour also depends on the cross-linking of chitosan. It decreases for chitosan after cross-linking by tannic acid. Overall, the properties of cross-linked chitosan depend on the amount of tannic acid used for modification. This method of cross-linking can be useful for obtaining materials with specific properties.
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