Ionic interactions between sulfuric acid and chitosan membranes

Cui, Zheng; Xiang, Yan; Si, Jiangju; Yang, Meng; Zhang, Qi; Zhang, Tao

doi:10.1016/j.carbpol.2007.11.009

Cited by 126 publications

(78 citation statements)

References 24 publications

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“…Genipine and tripolyphosphate (TPP) have been applied in this sense with a great deal of emphasis [16]. Studies have shown the use of sulfuric acid as a crosslinking agent to be applied as materials for proton exchange and evaporation, as studied by Devi et al [17] and Cui et al [18]. However, its application in the biomedical field, until the present moment, has not been studied yet for biomedical applications.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Chitosan Membranes Crosslinked by Sulfuric Acid

Fideles¹,

Santos²,

Tomás³

et al. 2018

OALib

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Development of novel biomaterials and its practical application have been the subject of much research in the field of scaffolds for tissue engineering, providing the success of producing scaffolds biomaterials that facilitate tissue growth and provide structure support for cells. Due to its biocompatibility and biodegradability, chitosan has been the focus of several researches in recent years to be applied in the biomedical field and chemical modifications of chitosan through crosslinks can produce materials with a wide variety of properties. The objective of this study was to obtain and characterize, chemically and biologically, ionically crosslinked chitosan membranes. Chitosan membranes were prepared by solvent evaporation and the crosslinks were introduced by reaction with sulfuric acid solution. The cross-linked membranes were characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), X-ray Dispersive Energy Spectroscopy (EDX) and contact angle measurements. The biological assays of the membranes were performed with NIH 3T3 cells in two steps: evaluation of cytotoxicity by indirect contact of the cells with the extracts of the chitosan membranes and finally with the direct contact of the cells on the filaments of chitosan to obtain adhesion and cell proliferation information. Non-crosslinked membranes of chitosan were used as controls for all assays. With the physicochemical tests, it was possible to observe an effective crosslinking reaction in chitosan. Biological assays have revealed that the membranes are non-cytotoxic but must still be modified to provide cell adhesion and proliferation.

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Section: Introductionmentioning

confidence: 99%

Characterization of Chitosan Membranes Crosslinked by Sulfuric Acid

Fideles¹,

Santos²,

Tomás³

et al. 2018

OALib

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“…Chitosan (beta-(1,4)-2-amino-2-deoxy-d-glucose) is a low cost N-deacetylated product of chitin. Since CS contains active amino groups and hydroxyl groups that can form hydrogen bonds with water, in the past decades, chitosan has been well recognized as a very promising hydrophilic material for pervaporation membranes and construction of functional films [2,3,7,9,[20][21][22][23][24][25][26]. In this paper, the CS complex membranes were formed under a dynamic filtration process.…”

Section: Introductionmentioning

confidence: 99%

One-step dynamic assembly of polyelectrolyte complex membranes

Zhang¹,

Gao²,

Ji³

et al. 2009

Materials Science and Engineering: C

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a b s t r a c t a r t i c l e i n f oDuring the past decades, layer-by-layer (LbL) assembly technique based on electrostatic adsorption of oppositely charged polyelectrolytes (PEs) has been one of the most frequently utilized processes for assembling ultra-thin film. However, LbL process is also recognized as a time-consuming process, especially for assembly of dense membranes. In this paper, a one-step dynamic assembly based on electrostatic adsorption was developed to prepare the PE complex membranes. The chitosan (CS), used as a model polycation, was dynamically deposited on a hydrolyzed polyacrylonitrile (PAN) support membrane with negative charges under a selected pressure to form a PE complex membrane for pervaporation separation of water-ethanol mixture. Compared with traditional dip-coating method, this new assembly process could offer some advantages such as the formation of selective layer with dilute solution, easily used for different membrane module types and suitable for large scale applications. The assembly conditions such as dynamic pressure, CS molecular weight, and CS concentration were investigated. The appropriate conditions for assembly were: dynamic pressure, 0.2 MPa; CS molecular weight, 82,000; and CS concentration, 0.5 wt.%. In the case of pervaporation of 95 wt.% ethanol/water mixtures, the separation factor and the permeate flux of the CS polyelectrolyte complex membranes were 422 and 230 g/(m 2 h) (60°C), respectively. The cross-linking treatment with glutaraldehyde and sulfuric acid were subsequently performed. It was found that the separation performance was improved by the cross-linking treatment. Finally, inner skin hollow fiber PE complex membranes were also successfully explored using one-step dynamic assembly for pervaporation dehydration. The proposed process will offer a new approach to obtain a relatively integrated PE complex membrane.

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“…The sulfonation of the C 2 amino groups by concentrated H 2 SO 4 solutions occurs in two steps: the amino groups of chitosan are firstly protonated by H 2 SO 4 ; then a SO 4 2-anion interacts with two NH 3 + groups to form ionic bridges between them. 21,22 Therefore, the sulfonation at the C 2 amino groups can also realize the crosslinking of chitosan. The sulfonation reaction of the C 6 hydroxyl groups is illustrated in Fig.…”

Section: Synthesis Mechanism Of Sccrmentioning

confidence: 99%

“…The peak at 1260 cm -1 is attributed to the S=O bond, and that at 802 cm -1 corresponds to the C-O-S bond, indicating the formation of C 6 -O sulfate ester. [21][22][23] Moreover, the characteristic adsorptions of the primary alcoholic C-O bond and glycoside bond in the saccharide ring are overlapped into a broad peak be-…”

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confidence: 99%

A Novel Solid-acid Catalyst Using Sulfonated Crosslinked Chitosan Resin

Tang

et al. 2016

Chem.Biochem.Eng.Q.

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Sulfonated crosslinked chitosan resins (SCCRs) were prepared by firstly crosslinking chitosan to crosslinked chitosan resins (CCRs) using a reverse emulsion crosslinking method, followed by sulfonating CCRs with concentrated H 2 SO 4 as the sulfonation agent. The properties and application of SCCRs as solid acid catalysts were studied. The acidic sites in SCCRs, including C 6 -O and C 2 -N sulfate groups, are all weak acidic sites. SCCRs of higher crosslinking degrees have a higher sulfonation rate of the C 6 primary hydroxyl groups, thus more C 6 -O sulfate groups. High-temperature treatment and TG analysis verified that the crosslinking can improve the thermostability of both SCCR backbone and its acidic groups, and a higher crosslinking degree leads to better thermostability. Catalytic esterification of citric acid with butanol and propionic acid with n-butyl alcohol demonstrated that SCCRs have good catalytic activity and can be repetitively used as efficient solid acid catalysts.

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Ionic interactions between sulfuric acid and chitosan membranes

Cited by 126 publications

References 24 publications

Characterization of Chitosan Membranes Crosslinked by Sulfuric Acid

Characterization of Chitosan Membranes Crosslinked by Sulfuric Acid

One-step dynamic assembly of polyelectrolyte complex membranes

A Novel Solid-acid Catalyst Using Sulfonated Crosslinked Chitosan Resin

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