Chitosan dissolution with sulfopropyl imidazolium Brönsted acidic ionic liquids

Sun, Yu; Qing, Mengyi; Chen, Luxin; Li, Jun; Zhong, Fei; Jiang, Ping; Wang, Guowei; Zhuang, Linghua

doi:10.1016/j.molliq.2019.111533

Cited by 13 publications

(9 citation statements)

References 52 publications

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“…The depolymerization of chitosan carried out by hydrochloric acid in the presence of ionic liquids shows a higher yield of total reducing sugars when compared to an aqueous system using only hydrochloric acid [26]. Additionally, chitosan is highly dissolved in ionic liquids, which facilitates the hydrolysis process [38,39].…”

Section: Effect Of Acid Concentrationmentioning

confidence: 99%

Production of Low Molecular Weight Chitosan and Chitooligosaccharides (COS): A Review

2021

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Chitosan is a biopolymer with high added value, and its properties are related to its molecular weight. Thus, high molecular weight values provide low solubility of chitosan, presenting limitations in its use. Based on this, several studies have developed different hydrolysis methods to reduce the molecular weight of chitosan. Acid hydrolysis is still the most used method to obtain low molecular weight chitosan and chitooligosaccharides. However, the use of acids can generate environmental impacts. When different methods are combined, gamma radiation and microwave power intensity are the variables that most influence acid hydrolysis. Otherwise, in oxidative hydrolysis with hydrogen peroxide, a long time is the limiting factor. Thus, it was observed that the most efficient method is the association between the different hydrolysis methods mentioned. However, this alternative can increase the cost of the process. Enzymatic hydrolysis is the most studied method due to its environmental advantages and high specificity. However, hydrolysis time and process cost are factors that still limit industrial application. In addition, the enzymatic method has a limited association with other hydrolysis methods due to the sensitivity of the enzymes. Therefore, this article seeks to extensively review the variables that influence the main methods of hydrolysis: acid concentration, radiation intensity, potency, time, temperature, pH, and enzyme/substrate ratio, observing their influence on molecular weight, yield, and characteristic of the product.

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Section: Effect Of Acid Concentrationmentioning

confidence: 99%

Production of Low Molecular Weight Chitosan and Chitooligosaccharides (COS): A Review

2021

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“…Due to ILs' unique properties and the wide variety of intermolecular interactions afforded, these solvents have proven to be also adequate solvents for biopolymers dissolution, allowing the substitution of the use of organic solvents in this field. In this sense, the dissolution of proteins [76,77], and more extensively polysaccharides (e.g., cellulose [78], chitosan [79,80], chitin [81], or guar gum [82]), has been reported using mostly imidazolium-based ILs, as summarized in Table 3. Despite the promising results reported, biopolymers' dissolution is usually performed at moderately high temperatures; thus, to prevent the biopolymers' decomposition or incomplete dissolution, the dissolution conditions should be carefully evaluated and the IL properly designed for this purpose.…”

Section: Ils As Novel Solvents Of (Bio)polymersmentioning

confidence: 99%

Ionic Liquids in Drug Delivery

et al. 2021

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Ionic liquids (ILs) are molten salts composed of a large organic cation and an organic/inorganic anion. Due to their ionic character, most ILs present advantageous properties over conventional solvents, such as negligible volatility at atmospheric conditions and high thermal and chemical stabilities. The wide variety of IL anion–cation combinations allows these solvents to be designed to display a strong solvation ability for a myriad of active pharmaceutical ingredients (APIs) and (bio)polymers. Given these properties, ILs have been used as solvents and as formulation components in different areas of drug delivery, as well as novel liquid forms of APIs (API-ILs) applied in different stages of development of novel drug delivery systems. Furthermore, their combination with polymers and biopolymers has enabled the design of drug delivery systems for new therapeutic routes of administration.

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“…The alkaline titration method was used to determine the degree of deacetylation (DD) of the chitosan samples [19]. Dried chitosan (0.25 g) was dissolved in 20 mL of 0.1 mol/L hydrochloric acid (HCl) with magnetic stirring.…”

Section: J O U R N a L P R E -P R O O Fmentioning

confidence: 99%