Study of the supramolecularly ordered layered structure of chitosan gel films

Konduktorova, A A; Kurochkina, V A; Babicheva, Tatiana S.; Shmakov, S. L.; Shipovskaya, A. B.

doi:10.1088/1742-6596/2086/1/012112

Cited by 2 publications

(2 citation statements)

References 7 publications

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“…We chose TEA for this purpose, since it is highly soluble in water, approved for use in medicine, and its pKa (7.74 [19]) significantly exceeds this value for chitosan amino groups (6.0-6.3, according to various sources), which is the condition of effective deprotonation of these groups. In recent years, it has been increasingly used for deprotonation of the salt form of chitosan [20][21][22]. It should be noted that whereas a strong inorganic alkali directly dissociates into OHions and a cation, TEA first interacts with a water molecule and is protonated, releasing a hydroxide ion into the solution.…”

Section: Introductionmentioning

confidence: 99%

Structural and Morphological Features of Anisotropic Chitosan Hydrogels Obtained by Ion-Induced Neutralization in a Triethanolamine Medium

Shmakov,

Babicheva,

Kurochkina

et al. 2023

Gels

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For the first time, anisotropic hydrogel material with a highly oriented structure was obtained by the chemical reaction of polymer-analogous transformation of chitosan glycolate—chitosan base using triethanolamine (TEA) as a neutralizing reagent. Tangential bands or concentric rings, depending on the reaction conditions, represent the structural anisotropy of the hydrogel. The formation kinetics and the ratio of the positions of these periodic structures are described by the Liesegang regularities. Detailed information about the bands is given (formation time, coordinate, width, height, and formation rate). The supramolecular ordering anisotropy of the resulting material was evaluated both by the number of Liesegang bands (up to 16) and by the average values of the TEA diffusion coefficient ((15–153) × 10−10 and (4–33) × 10−10 m2/s), corresponding to the initial and final phase of the experiment, respectively. The minimum chitosan concentration required to form a spatial gel network and, accordingly, a layered anisotropic structure was estimated as 1.5 g/dL. Morphological features of the structural anisotropic ordering of chitosan Liesegang structures are visualized by scanning electron microscopy. The hemocompatibility of the material obtained was tested, and its high sorption–desorption properties were evaluated using the example of loading–release of cholecalciferol (loading degree ~35–45%, 100% desorption within 25–28 h), which was observed for a hydrophobic substance inside a chitosan-based material for the first time.

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Section: Introductionmentioning

confidence: 99%

Structural and Morphological Features of Anisotropic Chitosan Hydrogels Obtained by Ion-Induced Neutralization in a Triethanolamine Medium

Shmakov,

Babicheva,

Kurochkina

et al. 2023

Gels

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“…Periodic precipitation (also known as the Liesegang phenomenon) is one of the oldest pattern formation phenomena executed in the laboratory. − The formed pattern structure consists of a spatially periodic appearance of the precipitate, which can be manifested in the formation of parallel bands (test tube) or concentric rings (radial spreading in thin gel layers) depending on the experimental setup. In these chemical systems, the coupling of the precipitation reaction to the diffusion of the reagents creates a pattern with the continuously increasing wavelength ranging between a few tens of micrometers to a few centimeters. , Recently, it has been presented that these systems offer a new route in material science to engineer and design layered hierarchical materials. − In a classical setup, the solutions of two water-soluble salts are spatially separated. One salt (called the inner electrolyte) is homogeneously dispersed in a hydrogel matrix (e.g., gelatin, agarose, polyacrylamide), and the other one diffuses in the gel (called the outer electrolyte).…”

Section: Introductionmentioning

confidence: 99%

Periodic Precipitation of Zeolitic Imidazolate Frameworks in a Gelled Medium

et al. 2022

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Formation of spatially periodic patterns is a ubiquitous process in nature and man-made systems. Periodic precipitation is the oldest type of pattern formation, in which the formed colloid particles are self-assembled into a sequence of spatially separated precipitation zones in solid hydrogels. Chemical systems exhibiting periodic precipitation mostly comprise oppositely charged inorganic ions. Here, we present a new sub-group of this phenomenon driven by the diffusion and reaction of several transition metal cations (Zn 2+ , Co 2+ , Cd 2+ , Cu 2+ , Fe 2+ , Mn 2+ , and Ni 2+ ) with an organic linker (2-methylimidazole) producing periodic precipitation of zeolitic imidazolate frameworks. In some cases, the formed crystals reached the size of ∼50 μm showing that a gel matrix can provide optimal conditions for nucleation and crystal growth. We investigated the effect of the gel concentration and solvent composition on the morphology of the pattern. To support the experimental observations, we developed a reaction−diffusion model, which qualitatively describes the spatially periodic pattern formation.

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Study of the supramolecularly ordered layered structure of chitosan gel films

Cited by 2 publications

References 7 publications

Structural and Morphological Features of Anisotropic Chitosan Hydrogels Obtained by Ion-Induced Neutralization in a Triethanolamine Medium

Structural and Morphological Features of Anisotropic Chitosan Hydrogels Obtained by Ion-Induced Neutralization in a Triethanolamine Medium

Periodic Precipitation of Zeolitic Imidazolate Frameworks in a Gelled Medium

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