Interaction of Carboxylic Acids with Chitosan: Effect of pK and Hydrocarbon Chain Length

Shamov, M.V; Bratskaya, Svetlana; Avramenko, V. A.

doi:10.1006/jcis.2002.8248

Cited by 54 publications

(34 citation statements)

References 8 publications

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“…Chitosan is a basic polymer of helix structure with reactive amine groups, which gives a lot of possibilities for modification and ionic interactions (4). It is a hydrophilic biopolymer usually obtained from chitin through chemical deacetylation.…”

Section: Introductionmentioning

confidence: 99%

Effects of Spray Drying on Physicochemical Properties of Chitosan Acid Salts

et al. 2011

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Abstract. The effects of spray-drying process and acidic solvent system on physicochemical properties of chitosan salts were investigated. Chitosan used in spray dryings was obtained by deacetylation of chitin from lobster (Panulirus argus) origin. The chitosan acid salts were prepared in a laboratory-scale spray drier, and organic acetic acid, lactic acid, and citric acid were used as solvents in the process. The physicochemical properties of chitosan salts were investigated by means of solid-state CP-MAS 13 C nuclear magnetic resonance (NMR), X-ray powder diffraction (XRPD), differential scanning calorimetry, and Fourier transform infrared spectrometry (FTIR) and near-infrared spectroscopy. The morphology of spray-dried chitosan acid salts showed tendency toward higher sphericity when higher temperatures in a spray-drying process were applied. Analysis by XRPD indicated that all chitosan acid salts studied were amorphous solids. Solid-state 13 C NMR spectra revealed the evidence of the partial conversion of chitosan acetate to chitin and also conversion to acetyl amide form which appears to be dependent on the spray-drying process. The FTIR spectra suggested that the organic acids applied in spray drying may interact with chitosan at the position of amino groups to form chitosan salts. With all three chitosan acid salts, the FTIR bands at 1,597 and 1,615 cm −1 were diminished suggesting that -NH groups are protonated. The FTIR spectra of all chitosan acid salts exhibited ammonium and carboxylate bands at 1,630 and 1,556 cm −1 , respectively. In conclusion, spray drying is a potential method of preparing acid salts from chitosan obtained by deacetylation of chitin from lobster (P. argus) origin.

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Section: Introductionmentioning

confidence: 99%

Effects of Spray Drying on Physicochemical Properties of Chitosan Acid Salts

et al. 2011

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“…The higher stability of complexes with polyelectrolyte ligands can be explained considering that the stability of complex species could be dependent not only on the ionic interactions between amino groups of chitosan and carboxylic groups of ligands, but even on interactions between hydrophobic skeleton of chitosan and polyelectrolytes (Shamov et al, 2002). Formation constants are increasing regularly for each type of complex species as a function of the charge z.…”

Section: Formation Constants Of Chitosan -Carboxylate Complex Speciesmentioning

confidence: 99%

Speciation of chitosan with low and high molecular weight carboxylates in aqueous solution

Cataldo

Stefano

Gianguzza

et al. 2009

Chemical Speciation & Bioavailability

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Quantitative data on the speciation of chitosan (310 kDa) with low and high molecular weight \ud carboxylates in aqueous solution are reported. The following carboxylic ligands were considered: \ud monocarboxylate (butyrate); dicarboxylates (malonate, succinate, azelate); tricarboxylate (1,2,3-propa- \ud netricarboxylate); tetracarboxylate (1,2,3,4-butanetetracarboxylate); polyacrylates (2.0 and 20 kDa); \ud polymethacrylate (5.4 kDa). The investigation was performed by potentiometry at t 1/4 25 C, at low \ud ionic strength (without addition of supporting electrolyte) and at I 1/4 0:15 mol L \ud 1 (NaCl). For all the \ud systems the formation of (chitosan)LHi species was found (L 1/4 carboxylic ligand; i 1/4 1 to 4 depending on \ud the carboxylic ligand considered). The stability of proton – chitosan – carboxylate species depends on the \ud number of carboxylic groups involved in the complexation, and it was possible to calculate a rough free \ud energy value per bond DGn 1/4 15 2 kJ mol \ud 1. By using the stability data, the quantitative seques- \ud tering capacity of chitosan towards the carboxylates here considered [expressed as the – log(total \ud chitosan concentration) necessary to bind 50% of carboxylate, i.e., pL50] was calculated for different \ud pH values, at low ionic strength and at I 1/4 0:15 mol L \ud 1. The pL50 values, ranging from 3 to 7, show that \ud chitosan is quite a strong sequestering agent towards carboxylates. Evidences were also obtained for \ud the different behaviour between low and high molecular weight carboxylates

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“…The effect of pK a on the solubility of CS has been studied. [15][16][17] Four carboxylic acids used in this study are weak acids that have similar pK a values of around 4-4.8. Their pK a value follow the order: acetic acid (4.76) > adipic acid (4.43) > succinic acid (4.16) > malic acid (3.4).…”

Section: Experimental Partmentioning

confidence: 99%

“…The chain length of the carboxylic acid determines its sorption on CS. [17] Not only the chain length but also the chemical steric structure of each acid reduces the solubility of CS, and the dispersion in the solution is also limited. In this study, the pH of the CS solution was adjusted to 3.…”

Section: Experimental Partmentioning

confidence: 99%

Polyion Complex Nanofibrous Structure Formed by Self‐Assembly of Chitosan and Poly(acrylic acid)

Chen

Wang

Hon

2006

Macro Materials & Eng

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Summary: An ideal scaffold design has a nanofibrous structure that can replace the natural extracellular matrix (ECM) until host cells can repopulate and resynthesize a new natural matrix. In this study, chitosan (CS)‐poly(acrylic acid) (PAA) nanofibers with diameters that range from 50 to 150 nm are synthesized successfully by a modified dropping method. Exactly how various carboxylic acid solvents affect the formation of CS‐PAA nanofibrous complex is also discussed. The results show that using adipic acid as a solvent to dissolve CS, adjusting the final pH value of the CS solution to 3, and then dropping the CS solution into the PAA solution at a ratio of 3:1, cause a significant reaction of CS with PAA and the nanofibers are dispersed uniformly. After freeze‐drying, a 3‐D interconnected CS‐PAA nanofibrous scaffold with a fiber diameter that ranges from 50 to 200 nm can be obtained. The CS‐PAA nanofibrous matrix is of particular interest in tissue engineering for controlled drug release and tissue remodeling.Nanofibrous structure via polyion complex formation between chitosan and poly(acrylic acid).imageNanofibrous structure via polyion complex formation between chitosan and poly(acrylic acid).

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Interaction of Carboxylic Acids with Chitosan: Effect of pK and Hydrocarbon Chain Length

Cited by 54 publications

References 8 publications

Effects of Spray Drying on Physicochemical Properties of Chitosan Acid Salts

Effects of Spray Drying on Physicochemical Properties of Chitosan Acid Salts

Speciation of chitosan with low and high molecular weight carboxylates in aqueous solution

Polyion Complex Nanofibrous Structure Formed by Self‐Assembly of Chitosan and Poly(acrylic acid)

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