Chitosan-Coating of Cellulosic Materials Using an Aqueous Chitosan-CO2 Solution

Abstract

ABSTRACT:Chitosan was dissolved in water using carbonic acid gas (CO 2 ) via preparation of the gel. The suspension of the gel became transparent and the viscosity increased by the bubbling of CO 2 gas, showing that chitosan was dissolved by CO 2 . Cellulosic materials were easily coated with chitosan using this solution (chitosan-CO 2 solution), because it is unnecessary to remove the acid usually required in the case of the coating using chitosan-acid solutions. Cotton fibers were dipped into chitosan-CO 2 solution, and then dried. The degree of the chitosan coating was examined by adsorbing acidic fluorescent probe on the chitosan-coated cotton and observing it by fluorescence microscope. Chitosan-coating was also performed on paper and the degree of the coating was examined by Fourier transform infraredattenuated total reflection (FT-IR-ATR) spectroscopy. Antimicrobiabil activity of the chitosan coated on cotton gauze to Staphylococcus aureus was examined, and effective activity was ascertained. These results showed that the chitosancoating using chitosan-CO 2 solution was hopeful to coat cellulosic materials with chitosan and render pharmacological activities to them.

Characterization of regenerated cellulose fibers antimicrobial functionalized by chitosan

“…The antimicrobial activity was expressed as a percentage reduction of the organisms after contact with the test specimen (R), compared with the number of bacterial cells surviving after contact with the control. 24 Results and discussion Adsorption of chitosan onto cellulose fibers Chitosan adsorption introduced amino groups onto the fibers. The amounts, accessibilities and activities of these groups depend on the physical-chemical conditions of the substrate and polymer solutions.…”

Antimicrobial and antioxidant functionalization of viscose fabric using chitosan–curcumin formulations

“…The antimicrobial activity was expressed as an R ¼ % reduction of the organism after contact with the test specimen, compared to the number of bacterial cells surviving after contact with the control. 27,28 Antioxidant activity ABTS 2,2 0 -azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical cation decolorization assay. The spectrophotometric analysis of (ABTS + ) cationic radical scavenging activity was determined according to the method of Re et al 29 The ABTS + cation radical was produced by the reaction between 7 mM ABTS in H 2 O and 2.45 mM potassium persulfate, stored in the dark at room temperature for 12 h. Before usage, the ABTS + solution was diluted with a phosphate buffer (0.1 M, pH 7.4) to reach an absorbance of 0.700 AE 0.025 at 734 nm.…”

Adsorption and Antibacterial Activity of Soluble and Precipitated Chitosan on Cellulose Viscose Fibers

“…The average values of the duplicates were converted to CFU/mL in the flasks, by multiplying with the dilution factor. The antimicrobial activity was expressed as R = % reduction of the organism after contact with the test specimen, compared to the number of bacterial cells surviving after contact with the control [14]. Figure 1 contains data from the titration of pure viscose fibers, alkaline washed fibers and viscose fibers that were alkaline washed and further bleached and demineralized.…”

“…When the functionalized fiber (viscose-chitosan) system is examined from an antimicrobial point of view, several other parameters are obviously important besides the amino groups' amount; such as fiber structure (porosity), fiber acidity, its hydrophobicity/hydrophilicity, etc. [14]. Therefore, the microbiological results for chitosan adsorbed onto fibers are often widely conflicting [7], owing to inter-and intra-assay variation when susceptibility testing.…”

“…These methods have been mainly limited to the treatment of cellulose fibers with cross-linking agents [12], the soaking of cotton fibers into chitosan solutions, or impregnation by chitosan solutions, etc. [13][14]. The adsorption of chitosan and its interactions with cellulose material are not only affected by the surface physicochemical characteristics of the cellulosic substrates but may also be strongly influenced by the chitosan aggregate's nature.…”