Sulfamic Acid Research Articles

UTILIZATION OF WASTE ALKALINE SOLUTIONS FOR PROCESSING THE ELECTRODE MASS OF NICKEL-CADMIUM BATTERIES

The possibility of electrochemical purification of the filtrate after the stage of cadmium precipitation in the technology of processing nickel-cadmium battery masses using sulfamic acid in the galvanostatic mode is considered. The optimal conditions for carrying out the process of purification from nickel and cadmium, such as current density and time, are determined. It is shown that an increase in current density over 0.7 A/cm2 has practically no effect on the degree of extraction of cadmium and nickel, which is 98.8-99.3% and 97.6-97.8%, respectively. It was found that intensive mixing of the electrolyte during electrolysis has a positive effect on the degree of extraction of cadmium and nickel, however, it does not allow reaching the residual concentrations of these metals below the level of their maximum allowable concentrations in the waters of water bodies of fishery importance. It has been established that in order to reduce the metal content below the maximum permissible concentrations, it is necessary to carry out the electrolysis process with a titanium cathode for 14 h. The use of graphite materials with a developed surface or three-dimensional electrodes, such as graphite felt "GFA - 10" and carbon cloth brand "THP - 50R", reduces the time of cleaning from nickel and cadmium by 2 times to concentrations, with a residual content of cadmium and nickel in solution after electrolysis below the MPC level of 0.003 mg/l and 0.008-0.009 mg/l, respectively. The resulting cathodic and anode deposits were characterized by X-ray phase analysis. Cathodic deposits are a mechanical mixture of individual metals cadmium and nickel. Anode deposits are represented by NiO and Ni(OH)2 phases. According to the results of chemical analysis, the cathode product contains 91.5 - 95.8% cadmium and 4.2 - 8.5% nickel. For citation: Chernyshova O.V., Tsygankova M.V., Uvarov B.V. Utilization of waste alkaline solutions for processing the electrode mass of nickel-cadmium batteries. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2023. V. 66. N 2. P. 78-84. DOI: 10.6060/ivkkt.20236602.6701.

Sulfamic acid grafted to cross-linked chitosan by dendritic units: a bio-based, highly efficient and heterogeneous organocatalyst for green synthesis of 2,3-dihydroquinazoline derivatives.

In this work, novel cross-linked chitosan by the G1 dendrimer from condensation of melamine and toluene-2,4-diisocyante terminated by sulfamic acid groups (CS-TDI-Me-TDI-NHSO3H), as a bio-based and heterogeneous acidic organocatalyst, was designed and prepared. Also, the structure of the prepared organocatalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and thermogravimetric analysis/derivative thermogravimetry (TGA/DTA). Subsequently, the catalytic performance of the biobased and dendritic CS-TDI-Me-TDI-NHSO3H, as a multifunctional solid acid, was evaluated for the preparation of 2,3-dihydroquinazoline derivatives through a three-component reaction by following green chemistry principles. Some of the advantages of this new protocol include high to excellent yields and short reaction times as well as easy preparation and remarkable catalyst stability of the introduced acidic organocatalyst. The CS-TDI-Me-TDI-SO3H catalyst can be used for up to five cycles for the preparation of quinazoline derivatives with a slight decrease in its catalytic activity.

Synthesis of new class of indole acetic acid sulfonate derivatives as ectonucleotidases inhibitors.

Ectonucleotidases inhibitors (ENPPs, e5'NT (CD73) and h-TNAP) are potential therapeutic candidates for the treatment of cancer. Adenosine, the cancer-developing, and growth moiety is the resultant product of these enzymes. The synthesis of small molecules that can increase the acidic and ionizable structure of adenosine 5-monophosphate (AMP) has been used in traditional attempts to inhibit ENPPs, ecto-5'-nucleotidase and h-TNAP. In this article, we present a short and interesting method for developing substituted indole acetic acid sulfonate derivatives (5a-5o), which are non-nucleotide based small molecules, and investigated their inhibitory potential against recombinant h-ENPP1, h-ENPP3, h-TNAP, h-e5'NT and r-e5'NT. Their overexpression in the tumor environment leads to high adenosine level that results in tumor development as well as immune evasion. Therefore, selective, and potent inhibitors of these enzymes would be expected to decrease adenosine levels and manage tumor development and progression. Our intended outcome led to the discovery of new potent inhibitors like' 5e (IC50 against h-ENPP1 = 0.32 ± 0.01 μM, 58 folds increased with respect to suramin), 5j (IC50 against h-ENPP3 = 0.62 ± 0.003 μM, 21 folds increase with respect to suramin), 5c (IC50 against h-e5'NT = 0.37 ± 0.03 μM, 115 folds increase with respect to sulfamic acid), 5i (IC50 against r-e5'NT = 0.81 ± 0.05 μM, 95 folds increase with respect to sulfamic acid), and 5g (IC50 against h-TNAP = 0.59 ± 0.08 μM, 36 folds increase with respect to Levamisole). Molecular docking studies revealed that inhibitors of these selected target enzymes induced favorable interactions with the key amino acids of the active site, including Lys255, Lys278, Asn277, Gly533, Lys528, Tyr451, Phe257, Tyr340, Gln465, Gln434, Lys437, Glu830, Cys818, Asn499, Arg40, Phe417, Phe500, Asn503, Asn599, Tyr281, Arg397, Asp526, Phe419 and Tyr502. Enzyme kinetic studies revealed that potent compounds such as 5j and 5e blocked these ectonucleotidases competitively while compounds 5e and 5c presented an un-competitive binding mode. 5g revealed a non-competitive mode of inhibition.

Thrombin and Factor Xa Hydrolysis of Chromogenic Substrates in the Presence of Sulfated Derivatives of Galactomannan and Galactoglucomannan Natural Gels.

Polysaccharides are important structural components of all plant species. Gel-like polysaccharides have found wide application in various fields, including medicine, construction, and the food industry. In the present work, galactomannan and galactoglucomannan gel-like polysaccharides were modified with sulfate groups and their anticoagulant activity was studied. Sulfation with chlorosulfonic acid in pyridine and with sulfamic acid in pyridine and a sulfamic acid-urea deep eutectic solvent were used as synthesis routes. The resulting gel-like polysaccharide sulfates were studied by elemental analysis, Fourier-transform infrared spectroscopy, and gel permeation chromatography. It was established that the anticoagulant effect of sulfated galactoglucomannan (SGGM) and galactomannan (SGM-1 and SGM-2) is related to an independent antithrombin-independent decrease in the amidolytic activity of thrombin and factor Xa. It is shown that the inhibitory activity of SGGM and SGM-2 against the collagen-induced platelet aggregation can be an additional factor in selecting compounds that are most promising for modifying polymer surfaces to ensure resistance to blood clotting.

Characterization of PVVH/PEMA blend polymer with gold nanoparticles as corrosion inhibitors for N80 carbon steel in a 5% sulfamic acid solutions

Characterization of PVVH/PEMA blend polymer with gold nanoparticles as corrosion inhibitors for N80 carbon steel in a 5% sulfamic acid solutions

Investigating the structure and optical characteristics of two new organic-inorganic hybrid crystals

Using the solvent evaporation approach at room temperature (RT), we produced transparent single crystals of two new organic-inorganic hybrid materials: (C5H6NO)SO3NH2 (crystal 1: reaction by sulfamate and 4-hydroxypyridine) and (C3H5N2)SO3NH2 (crystal 2: reaction by sulfamate and imidazole). Both crystals have the same space structure and belong to the P21/c space group of the monoclinic crystal system, according to the results of X-ray single crystal diffraction. In crystals 1 and 2, sulfamic acid and organics (4-hydroxypyridine, imidazole) are alternatively positioned by hydrogen bonds to create a layered structure. Hydrogen bonds and electrostatic Coulomb forces connect the layers to one another. Powder XRD demonstrates the remarkable phase purity of both crystals. Furthermore, the optical properties of both crystals, including IR, UV absorption, and fluorescence spectra, have been investigated in detail. The presence of functional groups such as NH2 and CC in the grown crystals was confirmed by Fourier transform infrared analysis. The optical band gaps for crystals 1 and 2 are about 4.33 and 4.31 eV, respectively, and the UV absorption findings show a low light absorption. According to the photoluminescence spectra, the two crystals have distinct fluorescence characteristics, with emission peaks of approximately 433 nm and 442 nm, apiece.

Construction and characterization of nitrite optical sensing nanoplatform based on spectral response

In this paper, two recyclable nitrite sensing platforms were constructed through a core-shell structure, using Fe3O4 nanoparticles as core, a silica molecular sieve MCM-41 as shell and rhodamine molecules as chemosensor, respectively. This hybrid structure was analyzed using electron microscopy images, porous measurement, magnetic analysis, IR spectra and thermal stability. It was found that emission of these two composite samples was quenchable by nitrite through a static sensing mechanism. Low LOD values were obtained for these two composite samples (1.4 µM). In addition, this static sensing reaction could be reversed by sulphamic acid. These two composite samples could be recycled, showing their recyclability.

Attenuation of Mild Steel-Acid Corrosion Using Exfoliated Graphite Oxide-Polymer Composite: Synthesis, Characterization, Electrochemical, and Response Surface Method Approach

This work deals with the study of the anticorrosion behavior of a biopolymer, namely Guar Gum (GG) and its composite on mild steel (MS) in sulfamic acid (SA) solution using electrochemical techniques. GG was found to be a potential inhibitor relatively at its higher concentration and showed maximum inhibition efficiency (IE) of 74% at 3 g/L (3000 ppm). To improve its IE, exfoliated graphite oxide (xGO)/GG polymer composite was prepared, and its inhibition property was assessed in 1 M SA solution at different temperatures by weight loss method (WL). The chemical structure of xGO/GG polymer composite was examined by FT-IR, and the morphology was inspected by optical microscopy, scanning electron microscopy study, and energy dispersive spectroscopy technique. xGO/GG polymer composite emerged as an efficient corrosion inhibitor for MS as marked from the outcomes of the electrochemical investigations and showed improved IE of 93% at 0.6 g/L (600 ppm) when compared to GG. Experimental results found by WL measurements are used to evaluate the thermodynamic parameters at various temperatures. Further, a Box-Behnken composite design with three factors and three levels has been used to minimize the experimental conditions. The IE was enhanced with the increase in the inhibitor concentration as observed from the main effect plot. The maximum IE of 84.21% was projected by the response surface method (RSM) with temperature (A = 30 °C), inhibitor concentration (B = 600 ppm), and time (C = 1 h).

Prothrombotic Transformation of the Endothelium Is Markedly Augmented By Cytokine Priming and Inhibited By Tie2 Activation

The endothelium is an intrinsically anticoagulant surface that upon viral or bacterial infection promotes thrombosis via the upregulation of pro-coagulatory mechanisms and loss of anticoagulant properties. The COVID-19 pandemic has underscored the association between respiratory infection and thrombosis by highlighting the importance of host cytokine responses in mediating systemic vasculopathy. Immune activation within the alveolar-capillary unit precedes systemic pathogen spread and induces marked increases in plasma cytokine levels prior to pathogen circulation. We therefore tested the hypothesis that cytokine exposure primes ECs toward a pro-coagulatory state that is subsequently activated by pathogen-associated molecular patterns (PAMPs). In initial studies, human ECs were exposed to cytokines elevated in the setting of pneumonia including TNFα, IFNα, IFNβ, IFNγ, IL-1β, IL-6, IL-10, and MCP for 24 hours prior to induction with poly(I:C), a viral PAMP mimetic and TLR3 agonist, and subsequently evaluated for thrombin generation in a plasma-based assay. Pre-incubation of ECs with several candidate cytokines enhanced responses to poly(I:C) by 10-20-fold. Focusing on the antiviral type-II interferon cytokine IFNγ, we found that its pre-incubation with ECs enhanced thrombin generation induced by poly(I:C) in a dose-dependent manner. IFNγ followed by poly(I:C) also enhanced factor VIIa-dependent factor Xa (FXa) generation, implicating upregulation of TF activity. SARS-CoV-2 nucleocapsid and spike proteins showed little prothrombotic effects in ECs by themselves. However, following incubation of ECs with IFNγ, both proteins stimulated FXa generation. These observations were not limited to viral PAMPs, as pre-incubation with IFNγ enhanced thrombin and FXa generation in response to lipopolysaccharide (LPS), a bacterial PAMP. Exposure of ECs to IFNγ also resulted in a reduction in total thrombomodulin, even prior to PAMP exposure. To better replicate the alveolar-capillary functional unit, we used an alveolus-on-chip model. The chip includes primary pulmonary microvascular ECs cultured under flow conditions in a vascular channel and small airway epithelial cells in an alveolus channel. The two channels are separated by a collagen matrix and the chip is subject to cyclic stretch to mimic breathing. Exposure of pneumocytes in the pulmonary channel to IFNγ and either poly(I:C) or LPS resulted in decreased production of thrombomodulin in the vascular channel, validating the monoculture results. One strategy for preventing the prothrombotic transformation of ECs is to stimulate cytoprotective endothelial pathways. Tie2 is a cytoprotective receptor found primarily on ECs. Incubation of ECs with the Tie2 ligand angiopoietin-1 (Angpt-1) significantly reversed the marked thrombin generation observed with IFNγ-priming followed by poly(I:C) exposure. Angpt-1 did not directly inhibit thrombin or FXa generation, as measured in standard thrombin time and aPTT assays. However, exposure to Angpt-1 did reverse depletion of protein C generation induced by poly(I:C) or LPS. Angpt-1 also reversed thrombomodulin reduction, providing an explanation for the ability of Angpt-1 to suppress cytokine/PAMP-induced prothrombotic changes on the ECs. To test the effect of Tie2 activation on thrombus formation in vivo, we used an LPS model since LPS was the most thrombotic of the PAMPs that we tested in mice. We used the small molecule [4-[(2S)-2-[[(2S)-2-(methoxycarbonylamino)-3-phenylpropanoyl]amino]-2-(2-thiophen-2-yl-1,3-thiazol-4-yl)ethyl]phenyl]sulfamic acid to promote Tie2 activation. Infusion of this Tie2 activating compound reduced LPS-induced accumulation of fibrin in both lung and liver. Taken together, these studies show that cytokines prime ECs for prothrombotic changes in response to PAMP exposure. Decreased thrombomodulin expression upon cytokine priming with resultant reduction in activated protein C production is essential to these prothrombotic changes. Tie2 activation inhibits the prothrombotic transformation and represents a potential strategy for reversing thrombosis associated with respiratory infection.

Additive Engineering with Triple Cations and Bifunctional Sulfamic Acid for Tin Perovskite Solar Cells Attaining a PCE Value of 12.5% without Hysteresis

Additive Engineering with Triple Cations and Bifunctional Sulfamic Acid for Tin Perovskite Solar Cells Attaining a PCE Value of 12.5% without Hysteresis

Mitigation of corrosion of zinc with amylopectin: Electrochemical, adsorption, and surface studies

AbstractCarbohydrate polymers are proven to be potential green corrosion inhibitors because of their outstanding structural features and eco‐friendliness. Work undertaken reflects the effectiveness of biopolymer amylopectin (AMP) as an eco‐friendly green inhibitor to mitigate the deterioration of zinc in 0.1 M sulphamic acid (NH2SO3H). Electrochemical studies like potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) were applied for corrosion rate measurement in the absence and presence of AMP. Thermodynamic and kinetic parameters were calculated and described in detail. The results were fitted into a suitable adsorption isotherm model, and an appropriate mechanism was proposed for the corrosion inhibition process. A detailed surface morphology study was done using scanning electron microscopy (SEM), electron‐dispersive X‐ray (EDX), and atomic force microscopy (AFM) techniques. The inhibition efficacy of AMP increased with an increase in its concentration and temperature. Upon the addition of the inhibitor, corrosion potential shifted more towards the positive side, indicating more control of the anodic process. The adsorption of AMP over zinc conformed to the Freundlich adsorption isotherm. For the concentration of 0.1 gL−1, maximum corrosion inhibition efficiency of 74% could be accomplished. Surface studies reaffirmed the adsorption of AMP on the surface of the metal. Thus, AMP turned out to be an effective green inhibitor with economic benefits.

Electrochemical dissolution behavior of Narloy-Z in sulfuric acid and sulfamic acid solutions

Electrochemical dissolution behavior of Narloy-Z in sulfuric acid and sulfamic acid solutions

A novel ion exchange resin as an alternative for conventional chelates for separation and removal of toxic metal ions from industrial wastewater

Tamarind Kernel-Power (TKP), a naturally occurring polysaccharide, has been used for the synthesis of a novel ion exchange resin, namely Tamarind triazine methyl sulphamic acid (TTMSA). The resin acts as a scavenger for toxic metal ions from the effluents of various industries. Characterization of resin has been done by FTIR, TGA and elemental analysis. Various physico- chemical properties of resin were analyzed including ion-exchange capacity, % nitrogen content, bulk density, bulk volume and moisture content. The resin was found to be stable with good reproducibility, good ion exchange capacity and selectivity for toxic metal ions. The partition coefficient values and percentage adsorption of various metal ions on the newly synthesized resins were determined by batch method with the help of Atomic Absorption spectrophotometer. The efficiency of resin was studied for up to 10 cycles. Analysis has shown that the adsorption of different metal ions on TTMSA resin followed the order Fe+2 >Cu+2> Zn+2>Pb+2>Cd+2. A suitable and cost-effective method was employed to reach the result of this experiment.

Sulfamic acid–modified zeolitic imidazolate framework (ZIF-90) with synergetic Lewis and Brønsted acid sites for microalgal biodiesel production

In order to enhance acidic sites in catalysts to improve conversion efficiency of microalgal lipids into biodiesel, an efficient bifunctional catalyst with synergetic Lewis and Brønsted acid sites was synthesized by modifying zeolitic imidazolate framework (ZIF-90) with sulfamic acid (SA). The sulfamic acid that combined with ZIF-90 through imine bond (CN) provided protons and destroyed coordinated Zn-N bonds in ZIF-90, thereby enhancing the number of Brønsted and Lewis acid sites. The total acidity of optimal catalyst increased from 0.478 to 0.848 mmol/g, while ratio of Brønsted acid to Lewis acid increased from 0.32 to 0.49. The Lewis acid sites in bifunctional catalysts exhibited higher activity towards transesterification reactions of triglycerides in microalgal lipids, while Brønsted acid sites exhibited higher activity towards esterification reactions of free fatty acids. Therefore, the optimal catalyst (weight ratio of SA to ZIF-90 was 0.05) promoted conversion efficiency of microalgal lipids into biodiesel from 80.6 % to 98.3 % at 200 °C, while conversion efficiency remained 91.7 % after 6 reusability cycles.

Bright green emitting Terbium-MOF with high quantum yield achieved through post synthetic modifications

A luminescent material with high brightness and good quantum yield is the need of our multifunctional applications in the area of light emitting diodes (LEDs), bioimaging and anticounterfeiting. But most of the work in this area focuses on lanthanide ion doped inorganic materials which have issues with lattice strain, doping related issues of/and charge compensating defect, and lack of tunability. Here in this work we have utilized the potential of metal organic framework (MOF) for inducing terbium luminescence in Tb-BDC-NH2 (BDC = 1, 4-benzenedicarboxylate) MOF and probe the effect of different organic linker's viz. 2-pyridine carboxaldehyde (PC), maleic anhydride (MA), sulfamic acid (SA), diphenylphosphoryl chloride (DPC), etc. All the samples revealed green luminescence of terbium via ligand sensitization through BDC. The highest emission intensity with many fold increases in green emission with absolute quantum yield (QY) ∼ 33% was observed in Tb-BDC-DPC. The same has been ascribed to highest host sensitized energy transfer and unique rod shaped morphology of Tb-BDC-DPC. Luminescence lifetime measurements suggested non-homogenous distribution of terbium ions in the MOF with majority having non-asymmetric environment. High QY, longer excited state lifetime coupled with rod shaped morphology and higher thermal stability makes Tb-BDC-DPC an excellent candidate for green phosphor for phosphor converted light emitting diodes (pc-LEDs).

Investigation of Solupred as a pharmaceutical drug as a corrosion inhibitor for copper corrosion in 1.0 M sulfamic acid solution

Investigation of Solupred as a pharmaceutical drug as a corrosion inhibitor for copper corrosion in 1.0 M sulfamic acid solution

Titanate nanotubes covalently bonded sulfamic acid as a heterogeneous catalyst for highly efficient conversion of levulinic acid into n-butyl levulinate biofuels

Titanate nanotubes covalently bonded sulfamic acid as a heterogeneous catalyst for highly efficient conversion of levulinic acid into n-butyl levulinate biofuels

Sulfation of Wheat Straw Soda Lignin with Sulfamic Acid over Solid Catalysts.

Soda lignin is a by-product of the soda process for producing cellulose from grassy raw materials. Since a method for the industrial processing of lignin of this type is still lacking, several research teams have been working on solving this problem. We first propose a modification of soda lignin with sulfamic acid over solid catalysts. As solid catalysts for lignin sulfation, modified carbon catalysts (with acid sites) and titanium and aluminum oxides have been used. In the elemental analysis, it is shown that the maximum sulfur content (16.5 wt%) was obtained with the Sibunit-4® catalyst oxidized at 400 °C. The incorporation of a sulfate group has been proven by the elemental analysis and Fourier-transform infrared spectroscopy. The molecular weight distribution has been examined by gel permeation chromatography. It has been demonstrated that the solid catalysts used in the sulfation process causes hydrolysis reactions and reduces the molecular weight and polydispersity index. It has been established by the thermal analysis that sulfated lignin is thermally stabile at temperatures of up to 200 °C. According to the atomic force microscopy data, the surface of the investigated film consists of particles with an average size of 50 nm. The characteristics of the initial and sulfated β-O-4 lignin model compounds have been calculated and recorded using the density functional theory.

Experimental and theoretical study of the sulfamic acid-urea deep eutectic solvent

A sulfamic acid-urea mixture deep eutectic solvent has been intensively investigated in the last few years as an agent for sulfating natural substances alternative to toxic complexes of sulfur trioxide with organic bases. We first report on the examination of the sulfamic acid-urea deep eutectic solvents with different ratios of active components. This complex has been studied by Fourier-transform infrared spectroscopy, X-ray diffraction, and thermal analysis. The melting points of the synthesized deep eutectic solvents have been determined and, using the data obtained, the thermodynamic characteristics, including the enthalpy, entropy, chemical potential, and effective interaction parameter, have been calculated. The calculations have been made by the density functional theory, quantum theory of atoms in molecules, reduced density gradient, electron localization function, highest occupied molecular orbital-lowest unoccupied molecular orbital, and molecular electrostatic potential methods. The structure of the sulfamic acid-urea complex has been optimized within the density functional theory. The Laplacian and interaction energy of the complexes have been calculated using the quantum theory of atoms in molecules. The reduced density gradient and electron localization function have been used to explore the intermolecular interaction of sulfamic acid with urea taken in different ratios. It has been found using the reduced density gradient that, with an increase in the number of urea molecules mixed with sulfamic acid in a deep eutectic solvent, the blue and green regions of the reduced density gradient functions significantly increase, which is indicative of an increase in the number of hydrogen bonds and van der Waals interaction regions. It has been demonstrated by the molecular electrostatic potential mapping that the nucleophilic and electrophilic attack areas increase with the urea content in the mixture with sulfamic acid. It has been determined by analyzing the thermodynamic characteristics of the mixtures with different urea contents that an increase in the number of urea molecules leads to the almost linear growth in the heat capacity, entropy, and E (thermal). According to the obtained linear dependences, the R2 value is high (0.9996–1.0000), which is indicative of the maximum heat capacity and E (thermal).

Surface sulfation of crab chitin for anisotropic swelling and nanodispersion

Crab chitin was sulfated under heterogeneous conditions using sulfamic acid in N’N-dimethylformamide to selectively sulfate the microfibril surface. The degree of sulfation followed a first order kinetics assuming a limited available reaction sites on the surface, and leveled off at a bulk degree-of-substitution of 0.4, corresponding to 2 mol/kg of sulfate groups. The reaction rate was proportional to the square of sulfamic acid concentration, suggesting involvement of two sulfamic acid molecules in a reaction. When washed with water after sulfation, the crab shell chitin fragments swelled anisotropically in the helicoidal axis direction, revealing regular alternating birefringence under optical microscope. Further mechanical treatment with high-pressure homogenizer led to slender nanofibrils, whose diameters were of the order of 6 nm according to turbidimetric analysis, in agreement with the Scherrer size estimated from X-ray diffraction line broadening. Both atomic force microscopy and transmission electron microscopy measurement showed presence of further smaller fragments with diameter of 3–4 nm and contour length of 0.5–1 \(\upmu \hbox {m}\) with a few kinks. The current approach presents a rapid and efficient modification to chitin, and a strategy for the preparation of stable nanochitin suspension.