Solution Of Chitosan In Acetic Acid Research Articles

The Study of Chitosan Solution Coating on Water Barrier Property of Seedling Paper Bag Made from Water Hyacinth

Seedling bags are low cost and light weight containers used by farmers to germinate and sprout seeds into seedlings before transplanting into the ground. However, cutting and removing seedling bags before the transplantation can damage the plant roots and cause losses in their productivity. In addition, plastics used in conventional seedling bags contribute to more plastic waste during this process. This study offers a solution to these problems with alternative biodegradable materials; i.e. modified papers made from an invasive alien aquatic plant species—water hyacinth—and enhanced with Chitosan solution coating. Papers were made from water hyacinth and dipped or sprayed with Chitosan solution in acetic acid at concentrations of 1% wt., 1.5% wt., and 2% wt. The dipping method showed better water barrier properties than the spraying method in every concentration, with 2% wt. concentration having the best barrier properties. The 2% wt. concentration of Chitosan coating by dipping method changed the water contact angle of the water hyacinth paper from a hydrophilic to a hydrophobic surface. This enhancement in water resistance was confirmed by water absorption time, which reached over 1.5 hours—3 times longer than the spraying method.

Characterization of Cellulose-Chitosan-Based Materials from Different Lignocellulosic Residues Prepared by the Ethanosolv Process and Bleaching Treatment with Hydrogen Peroxide.

Cellulose-based composites are promising biomaterials with potent applications in absorbents, cosmetics, and healthcare industries. In this study, the cellulose fractions from various agricultural residues, including bagasse (BG), rice straw (RS), corncob (CC), and palm fiber (PF), were prepared by the organosolv process using 70% v/v ethanol, followed by bleaching and forming with chitosan powder. Organosolv treatment at 180 °C of BG, RS, and PF and at 190 °C of CC for 60 min using H2SO4 as the catalyst was optimal for high cellulose recovery (87.9–98.9%) with efficient removals of the hemicellulose (59.3–86.0%) and lignin (61.1–73.7%). High cellulose purity in the solids (76.9–86.8%) was obtained after bleaching with 4% v/v H2O2 compared with that of 84.9% for commercial cellulose. The isolated celluloses were incubated with 2% w/v chitosan solution in acetic acid for the formation of the hydrogen-bonding interaction between the cellulose fiber and chitosan. The pieces of evidence of the obtained sheet materials were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction analysis, and thermogravimetric analysis. All cellulose–chitosan materials absorbed water fraction in the range of 54.3–94.2 g/m2. Efficient oil absorption was observed for cellulose–chitosan sheets prepared from PF (96.3 g/m2) and CC (81.1 g/m2). This work demonstrated the preparation of potent biobased absorbents with a promising application in waste treatment and healthcare industries.

Influence of ethanol–alkali mixture on the structure of chitosan fibers and film coatings

Structural features of films and fibers obtained from mixtures of a chitosan solution in acetic acid with an ethanol and NaOH solution were investigated. Phase separation in the system that included chitosan, acetic acid, ethanol, NaOH and water was studied using scanning electron microscopy and time dependence of optical density. Optical densities of the mixtures were measured at λ = 330 nm. Structural studies involved two types of films: (a) the samples obtained from the mixtures of the chitosan solutions and various precipitants by lyophilization; and (b) the samples obtained by drying at room temperature. It was demonstrated that the most stable structure is formed upon the mixing of the chitosan solution with the ethanol–alkali mixture. Chitosan fibers prepared by wet spinning had the following characteristics: tensile strength σ = 188 ± 9.1 МPа; Young’s modulus E = 11.5 ± 0.6 GPа; tensile strain ε = 4.8 ± 0.6%.

Formulasi dan Evaluasi Sediaan Tablet Nanopartikel Ekstrak Daun Salam (Syzygium Polyanthum) dengan Variasi Konsentrasi Na Alginat dan Avicel PH 102

The use of traditional medicines is an alternative treatment which is considered safer in terms of side effects and toxicity. One of the herbal plants that have properties that can reduce blood pressure is bay leaf (Syzigium polyanthum) because it contains essential oils (citral, eugenol), tannin, and flavonoids. Ethanol extract of bay leaves (Syzigium polyanthum) with antihypertensive potential needs to be made into dosage forms. This study aimed to determine the optimal formula of the preparation of bay leaf (Syzigium polyanthum) nanoparticles tablet with variations in the concentration of Na alginate and Avicel PH 102. Salam leaf extract was made using maceration method using ethanol 96%, followed by evaporation until thick extract was formed. Colloidal nanoparticles were prepared by mixing bay leaf extract into technical ethanol 96% and aquadest, chitosan solution in acetic acid and NaTTP solution. Further, it was measured using PSA (Particle Size Analyzer) to determine the particle size. Tablets were prepared using 4 formulas with variations in the concentration of sodium alginate and avicel PH 102 using the direct pressing method. The results of this study indicate that variations in the concentration of Na alginate and Avicel PH 102 affect the physical properties of tablets. The addition of Avicel PH 102 can increase the hardness and disintegration time of the tablet. While the addition of Na alginate can increase the fragility of tablets. Based on the evaluation results, the optimum formulation of tablet formulas is formula 4.

AFM Studies of Chitosan, Gold‐Chitosan, and Silver‐Chitosan Films Morphology

AbstractAtomic force microscopy is used in this work as a primary tool for investigating chitosan‐based films morphology. Chitosan films casted from chitosan solutions in acetic acid of various concentrations, as well as gold‐ and silver‐containing chitosan films, are studied. Chitosan films are revealed to be composed of globular‐like structures with 20–80 nm lateral sizes. At a higher chitosan concentration, a tendency is observed for these globular‐like structures to be organized in fibril‐like “strands.” The presence of metal does not seem to affect the general structure of chitosan‐based films.

Synthesis and characterization of chitosan-pectin as adsorbent of dyes

Environmental pollution due to the disposal of colored substances can endanger both the environment and humans. For this reason, the presence of dyes pollutants needs to be reduced, where adsorption method has become one of the alternative. Research on synthesis of modified chitosan to pectin polyelectrolyte complex (PEC) Chi-Pec has been carried out in order to improve the characteristic of chitosan as adsorbent. The research was done by mixing chitosan solution in acetic acid with pectin solution in water for 3 hours stirring. The solution was then printed out into a polypropylene container and dried. The formed membrane was characterized using FTIR to identify functional groups, XRD and SEM to analyze their physical characteristic. The results showed that the Chi-Pec adsorbent had stability and resistance to the acidic environment. Characterization results using FTIR showed that the adsorbent has functional group of amine, carboxyl and hydrogen. The results of XRD show that the adsorbent was not crystalline. Furthermore, SEM data shows a solid structure of the adsorbent.

Preparation and characterization of chitosan aqueous dispersion as a pharmaceutical film forming material

Chitosan film, when prepared from chitosan solution in acetic acid, possesses some unpleasant properties, such as its remaining acid content and poor mechanical properties. This study aimed to develop a new chitosan aqueous dispersion as a film-forming material with a lower acid content and improved mechanical properties. Chitosan aqueous dispersions were prepared by solvent displacement method. The system consisted of chitosan/cetyl alcohol particles stabilized with polyvinyl alcohol. Compared to the film from chitosan solution, the film from the chitosan aqueous dispersion had 4.9 times lower acid content, a higher tensile strength, a higher elongation at break, lower water uptake and weight loss, and lower drug permeability. These results indicated the improved mechanical properties and the decreased drug diffusion rate resulting from the chitosan dispersion-based film. Moreover, the addition of a plasticizer, in particular glycerol, could improve the mechanical properties of the chitosan dispersion-based film. The optimum formulation consisted of 1 %w/v chitosan, 0.1 %w/v cetyl alcohol, 0.1 %w/v polyvinyl alcohol and glycerol (20 %w/w based on polymer weight). In conclusion, the results demonstrated that chitosan aqueous dispersion could be used as a pharmaceutical film-forming material.

Physicochemical properties of white button mushrooms ( Agaricus bisporus) as affected by coating

The aim of this study was to determinate the influence of chemical coating treatments for quality maintenance of whole button mushrooms (Agaricus bisporus) during storage at 2 °C. Six different treatments [distilled water (C), E1: 0.3% CaCl2, E2: 2% CaCl2, E3: 0.1% chitosan in 1% citric acid, E4: 0.5% chitosan in 1% citric acid, E5: 0.1% chitosan in 0.5% acetic acid] were used. Physicochemical properties such as color, weight loss, texture, total antioxidant activity, and total phenolic content were monitored during 14 days. The results showed that the mushrooms treated with CaCl2 and chitosan solution in citric acid could be storage up to 14 days at 2 °C without significant deterioration in their quality. In contrast, coating with chitosan solution in acetic acid allows the mushroom to be stored for up to 4 days. Coatings do not protect mushrooms against excessive loss of phenolic compounds and their ability to reduce free radicals. Practical applications Physiological processes associated with maturation of mushrooms do not end after harvest. Shelf life of mushrooms is 3–4 days at room temperature (20–25 °C). In recent years, the method to extend the durability and quality of these products has become edible coatings. According to the presented results, it is possible to maintain the good quality of product up to 14 days for mushrooms washed with CaCl2 solutions.

SINTESIS DAN KARAKTERISASI NANOPARTIKEL KITOSAN – EKSTRAK KULIT BUAH MANGGIS (Garcinia Mangostana)

The chitosan – Garcinia Mangostana extract nanoparticles has been prepared by ionic gelation reaction by mixture 0.2 % chitosan solution in acetic acid with Garcinia Mangostana extract and it’s continued by reaction process with 0.1 % sodium tripolyphosphate. The particle size of material was determined by Particle Size Analyzer (PSA) that it showed in the range of 200 – 500 nm. The color, pH, water, α- mangostin, mercury, arsenic, cadmium, lead, totally microbe aerobic, totally mold and yeast, and solvent residue contents of nanoparticles were also examined by many methods that these resulted are yellow, 4.50 – 5.50, 89 – 90 %, 1.05 %, < 0.005 ppm, < 0.01 ppm, < 0.01 ppm, < 0.05 ppm, < 10 CFU/g, < 10 CFU/g and not detected, respectively. The other characterization was also observed that it’sincluded stability andTLC chromatogram. A mixture of nanoparticles with cosmetics bases was showed that it’s increased stability, homogeneity and easy to formed.

Immobilization of Keratinolytic Metalloprotease from Chryseobacterium sp. Strain kr6 on Glutaraldehyde-Activated Chitosan

Keratinases are exciting keratin-degrading enzymes; however, there have been relatively few studies on their immobilization. A keratinolytic protease from Chryseobacterium sp. kr6 was purified and its partial sequence determined using mass spectrometry. No significant homology to other microbial peptides in the NCBI database was observed. Certain parameters for immobilization of the purified keratinase on chitosan beads were investigated. The production of the chitosan beads was optimized using factorial design and surface response techniques. The optimum chitosan bead production for protease immobilization was a 20 g/l chitosan solution in acetic acid [1.5% (v/v)], glutaraldehyde ranging from 34 g to 56 g/l, and an activation time between 6 and 10 h. Under these conditions, above 80% of the enzyme was immobilized on the support. The behavior of the keratinase loading on the chitosan beads surface was well described using the Langmuir model. The maximum capacity of the support (qm) and dissociation constant (Kd) were estimated as 58.8 U/g and 0.245 U/ml, respectively. The thermal stability of the immobilized enzyme was also improved around 2-fold, when compared with that of the free enzyme, after 30 min at 65 degrees C. In addition, the activity of the immobilized enzyme remained at 63.4% after it was reused five times. Thus, the immobilized enzyme exhibited an improved thermal stability and remained active after several uses.

ОСОБЕННОСТИ ФИЗИКО-ХИМИЧЕСКИХ СВОЙСТВ РАСТВОРОВ ХИТОЗАНА

The rheological, electrochemical and surface properties of chitosan solutions in acetic acid were studied for several molecular masses, polymer and acid concentrations. Changes in the viscosity, structurization degree, and in the character of flow curves were observed when the solutions were kept in time. The stability of the viscous properties is essentially influenced by the concentration and molecular mass of the polymer, and the ionic strength of the solution. The surface tension and conductivity of the solutions did not change in time. The kinetic instability of the rheological properties of chitosan being independent of any destructive processes is hypothesized.

Rheological properties of microcrystalline chitosan gels

The procedure of thermocatalic processing of chitosan developed allows one to decrease its degree of polymerization to the so-called leveling-off degree and, after the precipitation from a solution and washing, to obtain hydrogels of microcrystalline chitosan (MCC.) The flow curves of the MCC gels showed that a spatial structure was formed in the gels even at low their concentrations. The measurements of vicoelastic properties of the dispersions verified the existence of such a structure. It is shown that, at MCC concentrations above 3%, a transition from the isotropic phase to a liquid-crystalline one occurs. For comparison, the flow properties of chitosan solutions in acetic acid were studied too. The measurements showed that, at the solution concentrations considered, they did not exhibit liquid-crystalline rheological properties.

Reasons for unstable viscous properties of chitosan solutions in acetic acid

A decrease in the molecular mass of chitosan as a result of polymer degradation during storage of its acetic acid solutions has been simulated by means of mixing of chitosan fractions with different molecular masses. It has been shown that a decline in the polymer molecular mass is responsible for a reduction in the dynamic viscosity of chitosan solutions in acetic acid during their storage.

New chitosan–calcium pectinate pellets and their adsorption capacity

A new simple procedure to prepare chitosan–calcium pectinate pellets from a chitosan solution in acetic acid was developed. Porous beads were prepared by mixing a chitosan solution in acetic acid and a pectinate solution in water. The obtained suspension was dropped into a CaCl2 solution. These pellets were studied as adsorbents for Pb(II) and Cd(II) in acidic aqueous solutions because chitosan is a biopolymer with the capacity of adsorbing heavy and transition metal ions. Kinetics data were reported for conditions under which these contaminants were adsorbed in low concentrations.

Preparation and characterization of superparamagnetic chitosan microspheres: Application as a support for the immobilization of tyrosinase

AbstractSuperparamagnetic chitosan microspheres were prepared by a water‐in‐oil suspension‐crosslinking technique. To this end, magnetite particles were dispersed in a chitosan solution in acetic acid. The dispersion was added to toluene containing Span 20 as a surfactant with stirring. Chitosan solution droplets were hardened with glutaraldehyde. The magnetic chitosan microspheres obtained were characterized with scanning electron microscopy, differential thermal analysis, and vibrational magnetometry. The microspheres had a wide size distribution, ranging from 43 ± 25 to 255 ± 55 μm, that depended on the reaction conditions. The mean particle size decreased with an increase in the concentration of Span 20 or the amount of glutaraldehyde and with the addition of NaCl. However, a major size reduction was achieved by an increase in the stirring rate. Tyrosinase was immobilized on the microspheres. The immobilized enzyme retained 70% of its activity, as determined by the capacity to degrade phenolic compounds. The immobilized tyrosinase resulted in greater stability than the free enzyme. In addition, the enzyme maintained 65% of its phenol oxidation activity after 10 cycles of reuse. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 651–657, 2005

WATER VAPOR PERMEABILITY AND MECHANICAL PROPERTIES OF CHITOSAN COMPOSITE FILMS

Chitosan films or membranes can be obtained by casting chitosan solutions in acetic acid at 1 % w/v concentration at room temperature. The films set were elaborated from 2% chitosan solutions mixed with three plasticizers (polyethylene glycol 200 (PEG), sorbitol and glycerol) and two surfactants (Tween 60 and Tween 80) at two concentrations. The goal was to decrease the water vapor permeability and to improve the mechanical properties of chitosan films. The effects of plasticizers (PEG, sorbitol and glycerol) and emulsifiers (Tween 60 and Tween 80) at two concentrations from chitosan solution on water vapor permeability and mechanical properties of cast films were evaluated. Water vapor permeability ranged from 3.64 to 6.56 g mm / h m2 KPa., tension force from 7.23 to 48.3 MPa and elongation percentage from 22.9 to 167.02 were obtained. Chitosan two percent with 0.3 % Tween 80 produces films that showed the lowest permeability value. Chitosan with 0.6 % glycerol has the highest percentaje of elongation, being 4.5 times higher than chitosan films. Chitosan with 0.6% Tween 80 improved the hydrophobicity of the chitosan film in 1.14 times. The highest value for tension force was found for chitosan with 0.6 % of Tween 60. These values are similar to some polymers based on mineral oil

Electrospinning of chitosan solutions in acetic acid with poly(ethylene oxide)

Electrospinning of chitosan solutions with poly(ethylene oxide) (PEO) in an aqueous solution of 2 wt% acetic acid was studied. The properties of the chitosan/PEO solutions, including conductivity, surface tension and viscosity, were measured. Morphology of the electrospun chitosan/PEO was observed by using scanning electron micrographs. Results showed that the ultrafine fibers could be generated after addition of PEO in 2:1 or 1:1 mass ratios of chitosan to PEO from 4-6 wt% chitosan/PEO solutions at 15 kV voltage, 20 cm capillary-collector distance and flow rate 0.1 ml/h. During electrospinning of the chitosan/PEO solutions, ultrafine fibers with diameters from 80 nm to 180 nm were obtained, while microfibers with visually thicker diameters could be formed as well. Results of X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and differential scanning calorimeter exhibited the larger electrospun microfibers were almost entirely made from PEO, while the electrospun ultrafine fibers mainly contained chitosan.

Chitosan hollow fiber membranes.

Chitosan hollow fibers were produced by wet spinning, taking advantage of the unique rheological properties of highly viscous chitosan solutions in acetic acid. The mechanical and separation properties of hollow fibers were tested. The mechanical properties were determined by measuring tensile force, tensile stress, elongation, and initial elasticity module. The separation properties were specified by determining retention coefficients of particular blood components and determining cut-off of the membrane by the analysis of dextran molecular weight distribution in the feed and permeate using a technique of gel chromatography (GPC)-Shimadzu gel chromatograph.

Flow birefringence and viscosity of chitosan solutions in acetic acid of various ionic strengths

Chitosan solutions of different ionic strength I were studied, using viscometry and double flow birefringence. The MWs of the samples used were in the range 1 × 10 4–5 × 10 5. A linear dependence of intrinsic viscosity on chitosan concentration in a 100 fold range of I was observed in iso-ionic solutions. The characteristic viscosity is a linear function of I −0.5. Folding of the molecular chain during polyelectrolyte swelling causes 2–3 fold increase in the optical anisotropy of the segment, which is explained by an increase in the length of the Kuhn segment. In the solutions studied, the chitosan macromolecules have a swollen coil conformation, the dimensions and rigidity of which are determined by the magnitude of I.