Reaction Of Β-cyclodextrin Research Articles

Synthesis and characterization of novel β-CD-Xanthate and its application in the treatment of heavy metal containing wastewater and lignin enriched paper industry wastewater

ABSTRACT Three grades of β-cyclodextrin xanthates (β-CDXs) have been synthesized by the reaction of β-cyclodextrin (β-CD) with CS2 in alkaline medium (NaOH), through xanthation process. The synthesized β-CDXs has been characterized by UV-visible (UV-Vis) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, Proton Nuclear Magnetic Resonance (1HNMR) spectroscopy, Thermogravimetric (TG) analysis, Differential Scanning Calorimetry (DSC) analysis, scanning electron microscopy (SEM) analysis and point of zero charge (ΔpHPZC) analysis. Further, β-CDXs and raw β-CD has been used for the heavy metals removal (Cu2+ and Ni2+) and also used for the treatment of lignin enriched paper industry wastewater (LEPIW). The maximum % removal by β-CDX3 for Cu2+ ion at optimum dosage of 2 g/L, optimum pH of 6.5, temperature of 45°C, initial concentration of 1000 mg/L and at contact time of 80 min was 95.8%. For Ni2+ ion the maximum % removal by β-CDX3 at optimum dosage of 2.5 g/L, optimum pH of 5.8, initial concentration of 1000 mg/L, temperature of 55°C and contact time of 100 min was 94.1%. While LEPIW treatment efficacy of 86% has been observed with β-CDX3. The calculated data fitted well in Langmuir isotherm model confirming that the adsorption of Cu2+ & Ni2+ ions onto the β-CDXs adsorbent is monolayer. The rate of adsorption of heavy metals (Cu2+ and Ni2+) on the β-CDXs adsorbent has been controlled by Pseudo second order kinetic model indicating the chemisorption process. The optimal adsorption capacity of β-CDX3 has been found to be 534.75 mg/g for Cu2+ and 423.72 mg/g for Ni2+ ions, respectively.

Enhancement in the therapeutic potential of lapatinib ditosylate against breast cancer by the use of β-cyclodextrin based ternary nanosponge system

The present investigation was performed to demonstrate the therapeutic potential of lapatinib ditosylate (LD) loaded nanosponge for the treatment of breast cancer. The study reports the fabrication of nanosponge by reaction of β-cyclodextrin with a cross-linking agent, diphenyl carbonate, at several molar ratios using the ultrasound-assisted synthesis method. The drug was loaded into the rightest nanosponge by lyophilization with and without 0.25% w/w polyvinylpyrrolidone. The significantly reduced crystallinity of developed formulations was established by differential scanning calorimetry (DSC), and powder X-ray diffractometry (PXRD). Morphological changes of LD, and formulations were compared by scanning electron microscopic (SEM) technique. Fourier transform infrared (FT-IR), and nuclear magnetic resonance (NMR) spectroscopic analysis were performed to establish the interacting groups of the host and guest molecules. It revealed interaction of the quinazoline ring, furan ring, and chlorobenzene functionality of LD with the hydroxyl group of β-cyclodextrin based nanosponge. Similar predictions were also obtained during their in-silico analysis. Saturation solubility and in vitro drug release studies revealed a 4.03-fold, and 2.43-fold rise in aqueous solubility, and dissolution of LD in the optimized formula (F2). The MCF-7 cell line study, too, revealed the higher efficiency of nanosponge formulations. The in vivo pharmacokinetic studies of optimized formulation illustrated 2.76-times, and 3.34-times enhancements in Cmax and oral bioavailability, respectively. Concomitant results were obtained during the in vivo studies performed using DMBA-induced breast cancer models in female Sprague Dawley rats. The tumor burden was found to be reduced to approximately 60% by the use of F2. The hematological parameters of animals treated with F2 were also improved. Histopathology of breast tissue excised from an F2-treated rat showed a reduced size of ductal epithelial cells associated with shrunken cribriform structures and cross-bridges. The in vivo toxicity studies also showcased reduced hepatotoxicity of the formulation. Altogether, it can be concluded that encapsulation of lapatinib ditosylate in β-cyclodextrin nanosponge has improved aqueous solubility, bioavailability and, in turn, therapeutic efficacy.

Synthesis, Characterization and Antibacterial Activity of Novel β-cyclodextrin Polyurethane Materials

The advanced water treatment taken by organic micro-pollution or microbiological pollution water resource has been a hot issue of public concern. In this article, novel quaternary ammonium salt functionalized β-cyclodextrin polyurethane (QAS-β-CDPU) microparticles were successfully constructed for above-mentioned pollutants removal. By adjusting the proportion of the chlorine-containing monomers, we studied the effect of different quaternization degree (0%, 20%, 40%, 60%) on solvent resistance and thermal stability. Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) are recognized as significant human bacterial pathogens, which were used as model bacteria to investigate the antibacterial activity by contact-killing tests. Methylene blue (MB) served as a toxic organic model to quantify the dye wastewater remediation efficiency. Research shows that the reaction of β-cyclodextrin and diisocyanate can form a cyclodextrin-based carbamate network structure. Since both the cyclodextrin cavity and the carbamate network may remove the dye, the obtained polymer has a double advantage. Besides, the presence of quaternary ammonium groups enables QAS-β-CDPU microparticles to possess good bactericidal properties. When the quaternization degree is 60%, sterilization rates of QAS-β-CDPU microparticles are over 96% for S. aureus and E. coli. On basis of this simple, green and economical synthetic route, QAS-β-CDPU microparticles have the potential to become an ideal multifunctional material in water purification. Novel quaternary ammonium salt functionalized β-cyclodextrin polyurethane (QAS-β-CDPU) microparticles were successfully constructed for removing bacteria and dyes from wastewater.

Study on pharmacokinetics of nimodipine nano-controlled release agent modified by host-guest reaction of β-cyclodextrin in rats

Nimodipine (NIMO) has been identified as a second-generation dihydropyridine calcium channel antagonist. NIMO’s specificity for the cerebrovascular smooth muscle contributes to its broad usage in treating ischemic cerebrovascular diseases in the elderly. Therefore, enhancing NIMO’s therapeutic effect and reducing its adverse reactions caused by short-term repeated use have become a focus of research. As a result, a new controlled-release preparation of NIMO, the carboxymethyl chitosan/nimodipine-hydroxypropyl-β-cyclodextrin nanoparticle (Nano-NIMO), was constructed based on hydroxypropyl-β-cyclodextrin. The novel composite Nano-NIMO preparation could significantly improve the stability of NIMO in rat plasma, achieving an absolute bioavailability as high as 62.3%, which is three times that of the traditional NIMO oral preparation. Therefore, Nano-NIMO is expected to provide a new direction for the preparation of modified controlled-release Nano- NIMO agents.

Hyper-cross-linked β-cyclodextrin nanosponge: a three-dimensional, porous and biodegradable catalyst in the one-pot synthesis of kojic acid-based heterocyclic compounds

In the present study, β-cyclodextrin-based nanosponges were prepared by reaction of β-cyclodextrin with dicarbonyl imidazole as a crosslinker agent. The synthesized polycarbonate nanosponge was characterized by FT-IR spectroscopy, thermogravimetric analysis, scanning electron microscopy and Brunauer–Emmett–Teller. The catalytic activity of β-cyclodextrin-based nanosponges was successfully tested in the one-pot three-component condensation of kojic acid, aromatic aldehydes and various aromatic amines. The superiority of this new strategy is short reaction times, high yields and utilizing of biodegradable and nontoxic nanocatalyst.

A complete description on effect of β-cyclodextrin-ester as a bio-based additive for preparation of safe PVC: From synthesis to computational study

Due to existing additive in the PVC product in some crucial fields for example, toys and biomedical devices, migration of Di-2-ethylhexyl phthalate (DEHP) can be hazardous to human health. Therfore migration of DEHP has caused a wide concern and this problem must be solved. In the present study, a water-insoluble β-cyclodextrin-ester (β -CDPN) was synthesized by reaction of β-cyclodextrin with terephthaloyl chloride as a cross-linker using micro-emulsion method. The β -CDPN loading DEHP was introduced to Polyvinyl chloride (PVC) as an active inhibitor to reduce DEHP migration. DEHP migration was determined using the UV–vis spectroscopy. It was found that the addition of β -CDPN can decrease the levels of DEHP migration from the tree component sample containing β -CDPN by almost 57 % as compare with PVC-DEHP sample. Also the anti-migration efficiency results showed improvement about 57.19 %. Mechanical properties of β -CDPN and DEHP including the tensile strength (TS), Young’s modulus (YM) and elongation at break (EB) were investigated. The results of mechanical properties indicated that all the mechanical data in this samples were slightly improved in the presence of β -CDPN by loading DEHP as compare to the PVC/DEHP system. The PVC films containing 2.4 mass% of β –CDPN showed the increasing in tensile strength (13 %), Young’s modulus (6 %) and elongation at break (7.2 %) values as compare to the PVC/DEHP. Also, computational method was used to investigate the inclusion complex of DEHP and β -CDPN and also inclusion shape and orientation. Based on the obtained results, it can be suggested that the most energetically favorable structure is in the form that aromatic group of DEHP enters into the cavity of β -CDPN through its wide rim. Altogether the results showed that the synthesized β -CDPN has large potential as green inhibitor to reduce DEHP migration. This could be a promising option to overcome the environmental problems caused by DEHP plasticizer.

Synthesis of 6I-O-(4-Methylbenzenesulfonyl)-β-cyclodextrin

An improved procedure has been proposed for the synthesis of 6I-O-(4-methylbenzenesulfonyl)-β-cyclodextrin by reaction of β-cyclodextrin with p-toluenesulfonyl chloride in aqueous alkali. Repeated use of unreacted p-toluenesulfonyl chloride and reduction of the volume of water by half in combination with optimized conditions make it possible to obtain the target product in up to 58% yield without loss of purity.

Interaction of β-cyclodextrin with tosyl chloride in an aqueous alkaline medium

The regioselective functionalisation of the cyclodextrin matrix provides the possibility of purposefully altering the ability of cyclodextrins to form inclusion compounds, as well as to ensure their solubility, thus expanding the scope of their practical application [1, 2]. The most significant and promising trend in the selective modification of β-cyclodextrins consists in the preparation of tosyl derivatives, given that the substitution of such nucleophilic reagents as iodide, azide, thioacetate, hydroxylamine, alkylamide or polyalkylamide for the tosyl group results in the corresponding monosubstituted derivatives. In this study, we impl emented a method for the synthesis of mono-6-O-(p-toluenesulphonyl)-β-cyclodextrin, which was improved by β-cyclodextrin reacting with tosyl chloride in an aqueous medium in the presence of a base. The reaction of β-cyclodextrin with tosyl chloride in an aqueous alkaline medium produced a 58% yield of mono -6- O-(p-toluenesulphonyl)-β-cyclodextrin not requiring additional purification. The optimal concentrations of β-cyclodextrin and tosyl chloride were found to be 0.0032 mol/l and 0.0015 mol/l, respectively. It was shown that a decrease in the rate of filtering the unreacted tosyl chloride out of the reaction mixture is acc ompanied by an increase in the proportion of ditosyl derivatives and mono(3,6-anhydro)-β-cyclodextrin resulting from the intramolecular cyclisation of mono-6-O-(p-toluenesulphonyl)-β-cyclodextrin at room temperature under alkaline conditions. The structure of the obtained mono-6-O-(p-toluenesulphonyl)-β-cyclodextrin was confirmed using Proton NMR Spectroscopy. The proton NMR spectrum of the product resulting from the reaction of β-cyclodextrin with tosyl chloride contains signals corresponding to a tosyl radical: a singlet (2.42 ppm) and two doublets (7.41–7.43 ppm) produced by hydrogens of the benzene ring having radicals in the para position. Monosubstitution was confirmed by comparing the integrated intensities of signals produced by the protons of the cyclodextrin skeleton and the protons from the aromatic part of the reaction product. Their ratio indicated that only one of the seven primary hydroxyl groups of β-cyclodextrin was substituted.

Enhanced photocatalytic New Coccine degradation and Pb(II) reduction over graphene oxide-TiO2 composite in the presence of aspartic acid-β-cyclodextrin

In this work, aspartic acid-β-cyclodextrin (ACD) was synthesized by the reaction of β-cyclodextrin with aspartic acid and epichlorohydrin, and graphene oxide-TiO2 (GO-TiO2) composite catalyst was prepared by a hydrothermal method. The complexation of ACD with New Coccine (NC) and Pb2+ was characterized with FT-IR and XPS, respectively, the results show that ACD can simultaneously complex NC and Pb2+. XRD analysis and SEM images of GO-TiO2 show that TiO2 platelets are well distributed on both sides of the graphene oxide sheets, and display a similar XRD pattern to the pure TiO2 nanoparticles with the typical diffraction peak of anatase phase. The effects of ACD on the photocatalytic degradation of NC and photocatalytic reduction of Pb2+ were investigated in the single pollution system, and the synergistic effects on the simultaneous photocatalytic NC degradation and Pb2+ reduction in the presence of ACD were also evaluated. The results showed that the presence of ACD was favorable to the acceleration of photocatalytic oxidation of NC and photocatalytic reduction of Pb2+ in the single pollution system, and the photocatalytic reaction rate constants of NC and Pb2+ in the presence of ACD increased 58% and 42%, respectively. For the combined pollution system, the synergistic effects on the simultaneous conversion of NC and Pb2+ in aqueous solutions were also further enhanced. ACD enhanced photocatalytic activity was attributed to the improvement of the electron transfer and mass transfer at the GO-TiO2 interface.

Designed biocompatible nano-inhibitor based on poly(β-cyclodextrin-ester) for reduction of the DEHP migration from plasticized PVC.

The easy migration of di(2-ethylhexyl) phthalate (DEHP) from the plasticized PVC (P-PVC) poses a serious threat to human health and the ecosystems. Thus, its control migration from the P-PVC products is very important. In this work, a poly(β-cyclodextrin-ester) network (β-CDP) was synthesized via reaction of β-cyclodextrin with 3,3',4,4'-benzophenone tetracarboxylic dianhydride. As a potential inhibitor for reduction of the DEHP migration, the β-CDP was grafted to Fe3O4 nanoparticles. Poly(β-cyclodextrin-ester) functionalized Fe3O4 nanoparticles (MNP-CDP) has been used in PVC/DEHP system as a reactive nano-inhibitor to reduce DEHP migration. Thermal stability and mechanical properties of obtained films were investigated. DEHP migration tests of the P-PVC films were also carried out by using Gas chromatography. It was found that by incorporating the small amounts of nano-inhibitor in PVC/DEHP system, the migration of DEHP effectively reduced from the P-PVC samples about 65% without any serious changes in mechanical and thermal properties of the P-PVC films.

Preparation of β-cyclodextrin-ester network and new organo-modified LDH as dual additives of PVA: Thermal, dynamic-mechanical and migration study

Abstract A new ternary nanocomposite based on poly(vinyl alcohol) (PVA) by using a β −cyclodextrin-ester network and organo-modified layered double hydroxides (MLDH) was prepared by water solution casting method. β-cyclodextrin-ester network (β-CDE) was synthesized by using the reaction of β-cyclodextrin with 3,3′,4,4′-benzophenone tetracarboxylic dianhydride in the basic media. The interlayer basal spacing of LDH was modified by using a bio based modifier containing three carboxylic groups (TA) through the regeneration method (MLDH). As a potential adjuvant, the MLDH, combined with and without β-CDE, was used in a PVA system. The morphology, thermal and thermo-mechanical properties of all the PVA systems as well as migration of modifier from PVA/MLDH and ternary PVA/CDE-MLDH nanocomposites were investigated. In the presence of the β-CDE, the MLDH showed a synergistic effect on improving all of the investigated properties of PVA. Based on TGA results, it can be concluded that adding both of the β-CDE network and MLDH into PVA matrix increased the char yields from 3.1 (in the neat PVA) to 6.1 (in the PVA/CDE-MLDH nanocomposite) in inert atmospheres. The temperature at 5 mass% loss (T5) increased from 188.1 °C to 197.7 °C in PVA/CDE-MLDH nanocomposite containing 4 mass% of each the β-CDE and MLDH in comparison to the neat PVA. Dynamic mechanical analysis revealed that the storage modulus and thermal stability were improved by incorporation of both MLDH and β-CDE into PVA. Migration results indicate that migration of TA from PVA matrix for PVA/CDE-MLDH is much lower than that for PVA/MLDH.

Selective monoallylation of β-cyclodextrin

Reaction of β-cyclodextrin with allyl bromide in dimethyl sulfoxide affords 2-О-allyl-β-cyclodextrin, while in dimethylformamide 6-О-allyl-β-cyclodextrin is formed. Optimal conditions of the reaction were found allowing to obtain the target products in quantitative yield.

β-cyclodextrin grafted on lignin as inverse phase transfer catalyst for the oxidation of benzyl alcohol in H2O

β-cyclodextrin grafted on lignin (l-β-CD) was prepared by the reaction of β-cyclodextrin (β-CD) and lignin with epichlorohydrin (EPI) as a cross-linking agent. The polymer was characterized by Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), Scanning electron microscopy (SEM), and solid-state nuclear magnetic resonance spectroscopy (CP-MAS-NMR). It was used as an inverse phase transfer catalyst for selective oxidation of benzyl alcohol (BzOH) to benzaldehyde (BzH) with hydrogen peroxide as the oxidant. The effects of various reaction variables, e.g., catalyst, the amount of catalyst, stirring speed, reaction temperature, oxidant, and cocatalyst on the catalytic performances were investigated. Under optimal conditions, high selectivity (>99%) was observed for the oxidation of BzOH under rather mild conditions. A plausible mechanism for the liquid-solid phase oxidation of BzOH has been proposed. Synergistic effects based on weak interactions between catalyst and support played an important role for the effective oxidation of BzOH under solution condition. The catalyst can be easily recycled and reused without a significant loss in reaction activity and selectivity, which would lead to its potential application foreground for environmental friendly synthesis of BzH.

Cysteine-β-cyclodextrin enhanced phytoremediation of soil co-contaminated with phenanthrene and lead.

It is necessary to find an effective soil remediation technology for the simultaneous removal of hydrophobic organic contaminants and heavy metals from contaminated soils. In this work, a novel cysteine-β-cyclodextrin (CCD) was synthesized by the reaction of β-cyclodextrin with cysteine, and the structure of CCD was confirmed by (1)H-NMR, (13)C-NMR, FT-IR spectroscopy and elemental analysis. Pot-culture experiments were conducted to investigate the effects of CCD on the phytoremediation of soil co-contaminated with phenanthrene and lead. The results showed that CCD can enhance the phytoremediation of soil co-contaminated with phenanthrene and lead. When CCD was added to the co-contaminated soil, the concentrations of phenanthrene and Pb in roots and shoots of ryegrass (Lolium perenne L.) significantly increased, the presence of CCD is beneficial to the accumulation of phenanthrene and Pb in ryegrass, and the residual concentrations of phenanthrene and Pb in soils significantly decreased. Under the co-contamination of 500 mg Pb kg(-1) and 50 mg PHE kg(-1), the bioconcentration factor of phenanthrene and Pb in the presence of CCD was increased by 1.43-fold and 4.47-fold, respectively. After CCD was added to the contaminated soils, the residual concentration of phenanthrene and Pb in unplanted soil was decreased by 18 and 25%, respectively. However, for the planted soil, the residual concentration of phenanthrene and Pb was decreased by 48 and 56%, respectively. CCD may improve the bioavailability of phenanthrene and Pb in co-contaminated soil; CCD enhanced phytoremediation technology may be a good alternative for the removal of hydrophobic organic contaminants and heavy metals from contaminated soils.

Solubilization of Hydroxypropyl-β-Cyclodextrin on Cholesterol in Aqueous Solution

Hydroxypropyl-β-Cyclodextrin (HP-β-CD), prepared via reaction of β-Cyclodextrin (β-CD) and propylene oxide (PO), is utilized to research solubilization of HP-β-CD on cholesterol in aqueous solution. HP-β-CD is characterized by Fourier Transform Infrared Spectrometry (FT-IR), and concentrations of cholesterol solution are measured by ultraviolet and visible (UV VIS) spectrophotometer. The research on optimal synthesis conditions of HP-β-CD indicates that sodium hydroxide amounts have the most effect on yields of product. The maximum solubilization multiples of HP-β-CD reaches 15, below which molecular rate of HP-β-CD and cholesterol in inclusion complex is 1:1.

Simultaneous removal of phenanthrene and lead from artificially contaminated soils with glycine-β-cyclodextrin

Preparation of glycine-β-cyclodextrin (GCD) was carried out by the reaction of β-cyclodextrin with glycine in the presence of KOH and epichlorohydrin. The enhanced solubilization behavior of phenanthrene and lead carbonate by GCD was studied, and the desorption behavior of phenanthrene and lead from co-contaminated soil was also investigated. The results showed that GCD has obvious solubilization for phenanthrene and lead carbonate. The solubility of phenanthrene in 30g/L of GCD was enhanced about 30-fold. And the apparent aqueous solubilities of lead carbonate are also obviously increased with increasing GCD concentration, when the concentration of GCD reached 20g/L, the aqueous lead concentration was 2945mg/L. GCD could simultaneously increase the apparent aqueous solubility of phenanthrene and complex with lead. The desorption process of GCD for phenanthrene and lead from co-contaminated soil followed the pseudo-second-order kinetic model. The removal efficiencies of phenanthrene and lead in soil increased dramatically with increasing GCD concentrations. At concentration of 40g/L, GCD has a removal efficiency of 85.8% and 78.8% for lead and phenanthrene, respectively, from the combined contaminated soil. The use of GCD as an extractant to enhance the removal of heavy and hydrophobic organic contaminants (HOCs) from co-contaminated soils appears as a promising remediation method.

Modified β-cyclodextrins as prospective agents for improving water solubility of organic pesticides

The drawback of some organic pesticides is their low water solubility. Cyclodextrins are used as agents for improving pesticides water solubility. However, the stabilization of the crystalline lattice can reduces to a large extent the solubility of cyclodextrins, especially β-cyclodextrin. Here, searching for the water soluble β-cyclodextrin derivatives, a set of new “host” compounds were prepared by the reaction of β-cyclodextrin with methyl epoxycinnamate. The reactants ratio was varied in to study the substitution degree of the obtained derivatives. The structure was determined by the 1H-NMR and FT IR spectra. The average degree of substitution was determined by integration of the corresponding NMR signals and by elemental analysis. The solubility of four selected pesticides: dimethoate, simazine, linuron and thiram, in water with and without addition of the new modified β-cyclodextrin was measured by ultraviolet spectrophotometry. Our results showed that the modified β-cyclodextrins significantly improve solubility of pesticides.

Radiation synthesis of pH-sensitive hydrogels from β-cyclodextrin-grafted PEG and acrylic acid for drug delivery

A water-soluble macromonomer (PEG-β-CD) was synthesised by reaction of β-cyclodextrin with poly(ethylene glycol) diglycidyl ether. Then, a novel hydrogel with pH-sensitivity was prepared by irradiating the mixture of acrylic acid and PEG-β-CD with electron beam. Compared with the normal PAAc hydrogel, this novel hydrogel had a higher swelling ratio at pH 3–8. 5-Fluorouracil (5-FU) was chosen as a model drug, and the kinetics of 5-FU releasing behavior was studied. Compared with the PAAc hydrogel, the results showed the release time of 5-FU from the cyclodextrin containing hydrogel was prolonged. It may be ascribed to the formation of inclusion complexes between the drug molecules and cyclodextrin groups.

β-Cyclodextrin-Cross-Linked Polymer as Solid Phase Extraction Material Coupled Graphite Furnace Atomic Absorption Spectrometry for Separation/Analysis of Trace Copper

The β-cyclodextrin cross-linked polymer (β-CDCP) was synthesized by the reaction of β-cyclodextrin with epichlorohydrin in NaOH and characterized by fourier transform infrared spectroscopy and thermoanalysis. The β-CDCP as a solid phase extraction (SPE) material was used to preconcentrate/separate trace copper using l-(2-pyridylazo)-2-naphthol (PAN) as a complexing agent for Cu-(II)-PAN coupled with a graphite furnace atomic absorption spectrometry (GFAAS) for analysis. The optimized experiment conditions and adsorption capacity were investigated. The detection limit (DL) was 1.11 µg.L−1 with RSD 4.27% (n = 5, c = 25.0 µg L−1). The linear range is 6.25–31.25 µg L−1. Moreover, the β-CDCP could be used repeatedly and offered better a recovery and estimation of trace copper. In order to verify the accuracy of the method, a certified reference water sample was analyzed and the results obtained were in agreement with the certified values. The recovery for copper was 103.6%. The proposed method was applied to the analysis of copper in lake water samples.

Synthesis of new ionic β-cyclodextrin polymers and characterization of their heavy metals retention

In this study, a new aqueous insoluble ionic β-cyclodextrin polymer (PYR), synthesized by reaction of β-cyclodextrin with pyromellitic anhydride [1], is characterized by IR spectroscopy, showing typical cyclodextrin and carboxylic absorptions. pH-metric titrations of the acidic functions with standard NaOH solutions followed by a refinement of protonation constants, with specific software for equilibrium in solution, have been performed. Through this approach, the pK a values of the functional groups have been calculated. The complexation capabilities of PYR towards metal ions [Al(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pd(II), Cd(II), Pt(IV), Tl(I), and U(IV)] have been evaluated in aqueous solution (pH 3–5). The retention is mainly pH dependent and higher than 70% for Al(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pd(II), Cd(II) and U(IV). For Tl(I) and Pt(IV) the retention is about 60% and 40% respectively.