Physical Properties of Chitosan Films Obtained after Neutralization of Polycation by Slow Drip Method

Abstract

The development of new materials from biodegradable constituents is enticing for applications in bioelectronics and biomedicine, due to their considerable durability, versatility and biodegradability. The present work aims to determine the chemical and physical properties of chitosan membranes after neutralization of the polycation solution. This work was divided into two stages: solubilization and neutralization. In the first stage, the chitosan was solubilized with three different concentrations of acetic acid (1%, 0.8% and 0.5%) in order to evaluate whether the acid affected the physical-chemical properties of the films. In the second stage, the chitosan polycation was neutralized with two strong bases (NaOH and KOH) using three different molar concentrations, by the slow drip method for obtaining films with pH values close to neutrality. The characterization of the membranes obtained from casting method showed that the different concentrations of acetic acid did not affect the physical-chemical properties of the films. In contrast, the neutralization process did affect their properties, and in particular, different behaviors were observed depending on the type of base used for neutralization. More ductile and plasticity were obtained in the films when the polycation was neutralized with KOH, whereas the films neutralized with NaOH exhibited a more fragile behavior.

Microscopic Image Segmentation and Morphological Characterization of Novel Chitosan/Silica Nanoparticle/Nisin Films Using Antimicrobial Technique for Blueberry Preservation

“…Elongation-at-break of Chitosan films alone and after the addition of Silica Nanoparticle and nisin exhibited greater resistance to the strain. Llanos et al [ 13 ] reported high values among Chitosan films in stress tests due to the porosity of the membranes. Chitosan/Silica Nanoparticle films showed a higher strain of 12.49% compared with Chitosan/Silica Nanoparticle/N films at 5.25%.…”

“…The solubility of the films in water was evaluated according to the method by Lianos et al [ 13 ]. The film samples were cut into (2 × 6 cm) and were stored in a desiccator with P2O5 (0% RH) for 72 h. Dry films were weighed to the nearest 0.01 g, immersed in phosphate buffer solutions with respective (pH = 5.9), and stirred for 1 h at the ambient temperature.…”

“…Chitosan films are commonly used in food packaging and coating materials prepared by the solvent casting with dilute aqueous acid solutions. Chitosan films achieved high mechanical properties in stress tests due to the porosity of the membranes [13]. Chitosan improves the gas barrier and the mechanical properties by the interaction between chitosan chains and the chemical components such as oil, fatty acids, and polysaccharides [14][15][16][17].…”

Chitosan–Glycerol Gel as Barrier Formulation for Metal Allergy

“…However, the amine group in chitosan has a p K a of 6.3; hence, Cs remains soluble at weakly acidic solutions. 24 In the present case, the metal chelation testing was done in the artificial sweat solution (EN 1811:2011) at pH 6.5 considering that the applied gel will encounter only sweat on practical application.…”

Chitosan and Aloe vera gel formulations as wound healing agents in episiotomy

“…The incorporation of Aloe vera was performed manually with a glass stick. All formulations were neutralized by slow drip of neutralizing solution (NaOH, 2M) at the rate of one drop of solution per minute (1 drop/minute) until reaching a pH of ≈ 7.0 under constant agitation (50 rpm), a methodology adapted from Llanos et al (2015). The organoleptic analysis of the gels was performed to evaluate the characteristics detectable by sight and smell.…”