Poly Hydroxamic Acid Research Articles

Trace detection of La (III), Ce (III), Ce (IV), Nd (III), and Gd (III) using 2, 8, 14, 20-tetramethyl-5, 7-dinitro calix [4] resorcinarene polyhydroxamic acid by solid-phase extraction and separation

The quantitative trace determination and separation from individual rare earths is a difficult task, with this view a new synthesized and functionalised Calix[4]resorcinarene polyhydroxamic acid is used for sorption, speciation, sequential separation and trace determination of La (II), Ce (III), Ce (IV), Nd (III) and Gd (III). The rare earths are quantitatively separated and trace determination in the range of 2–15 ng with the selectivity order La (III) > Ce (III) > Nd (III) > Gd (III). The column parameters like pH, flow rate and distribution were evaluated. The effect of various electrolytes and diverse metal ions in separation are studied. The present method is applied for estimation of rare earths in monazite and other geological specimens. Suitable eluents were used to effectuate the separations of the binary and ternary combinations.

Polyhydroxamic acid as an efficient metal chelator and flocculant for wastewater treatment

Hydroxamic acid containing organic polymeric flocculants were synthesized from three different commercially available polymeric flocculants, such as WAS590, Zetag 4100, and Zetag 4110. These three polymers are acrylamide and acrylic acid‐based copolymers with different molecular weights and anionic charge density. The conversion of the amide groups to hydroxamic acid groups in the polymers was carried out by the reaction with hydroxylamine at pH 14. The modified polymers were characterized for structure and composition by elemental analysis, FTIR, and NMR. The chelation activity of the modified polymers was determined toward iron (Fe3+) and copper (Cu2+). The flocculation activity of the non‐modified and modified polymers was evaluated toward produced water and scrubber water. The results showed that all the modified flocculants exhibit better chelation with Fe3+ and Cu2+. In addition, the modified polymers display improved flocculation effect on tested wastewater.

Removal of toxic metals using a novel PHA resin-fixed bed column performance study

The performance and efficiency of a fixed bed column loaded with a three-dimensionally crosslinked polyhydroxamic acid resin is studied with glass column. Experiments were carried out with synthetic metal solutions containing Cu(II), Sr(II), Gd(III) individually and with mixed solution containing Cu(II), Sr(II), Gd(III) and U(VI) to establish the efficiency of the fixed bed resin for a mixed solution. The “S” shaped break through curve was generated and percentage saturation of the bed was estimated. The percentage saturation at 10% breakthrough volume was found to be 68.3% for Cu(II) and Sr(II) 71.3% and 65.6% for Gd(III).

Beyond Biological Chelation: Coordination of f‐Block Elements by Polyhydroxamate Ligands

The promise of polyhydroxamic acid ligands for the selective chelation of the f-block elements is becoming increasingly more apparent. The initial studies of polyhydroxamic acid siderophores showed the formation of highly stable complexes with PuIV , but a higher preference for FeIII hindered effective applications. The development of synthetic routes toward highly pure and customizable ligands containing multiple hydroxamic acids allowed for the growth of new classes of compounds. Although the first round of these ligands focused on the incorporation of siderophore-like frameworks, the new synthetic strategies led to small molecules of various frameworks and even resins for applications in the field of f-block element separations and biological desorption. Unfortunately, a lack of consistent stability-constant data makes direct comparisons across this body of work difficult. More studies into the stability constants and separations of the f-block elements in a variety of pH ranges is necessary to truly realize the potential for polyhydroxamic acid ligands.

Preparation of Radioactive Skin Patches Using Polyhydroxamic Acid-Grafted Cellulose Films Toward Applications in Treatment of Superficial Tumors.

The primary objective of this investigation is the development of a strategy for the synthesis of polyhydroxamic acid (PHA)-grafted cellulose film, its characterization, and evaluation of its usefulness for the preparation of 177Lu skin patches for superficial brachytherapy applications. PHA-grafted cellulose films were synthesized and characterized by Fourier transformed infrared spectrometer analysis and visual color test with Fe(III) solution. Uptake of 177Lu on the PHA-grafted cellulose was investigated by varying the experimental conditions such as the pH of feed solution, amount of nonradioactive Lu carrier, time, and temperature of the reaction. Under the optimized conditions, >95% loading of 177Lu on the PHA-cellulose film could be achieved. Autoradiography studies of 177Lu-PHA-cellulose film confirmed the uniform distribution of 177Lu on the surface. Energy dispersive X-ray analysis of nonradioactive Lu-PHA-cellulose film confirmed the loading of Lu on PHA-cellulose film. The utility of PHA-functionalized cellulose films for the fabrication of radioactive sources for superficial brachytherapy applications could be successfully demonstrated.

Polyhydroxamic acid functionalized sorbent for effective removal of chromium from ground water and chromic acid cleaning bath

Polyhydroxamic acid sorbent was synthesized by polymerization of acrylamide using N, N′-methylene-bis-acrylamide as crosslinker and ammonium per sulphate as a thermal initiator. The sorbent was characterized for composition, thermal stability, functional group and morphology by elemental analysis, thermal analysis, infrared spectroscopy and secondary electron microscopy respectively. The synthesized sorbent was evaluated for the removal of trivalent and hexavalent chromium ion from aqueous solution. Experimental parameters such as pH, equilibration time, solute concentration and temperature were optimized. It showed a sorption capacity of 322mgg−1 for Cr (III) and 176mgg−1 for Cr (VI) at pH 4. The sorbent reduces the more toxic Cr (VI) to relatively less toxic Cr (III) during the sorption process as confirmed by X-ray photoelectron spectroscopy. The sorption phenomena followed Langmuir model and the sorption reaction was found to be pseudo–second order confirming chemisorption.

Transition metal complexes of polyhydroxamic acid grafted on chitosan

Graft copolymerisation of acrylamide onto chitosan using ammonium ceric nitrate as an initiator was studied. Then –CONH2 functional groups converted to the –CONHOH moieties by addition of NH2OH·HCl solution for 36 h in base media. Evidence for graft-copolymerisation was obtained by infrared spectroscopy, 1H and 13C-NMR data. Polyhydroxamic acid grafted on chitosan (Chit-g-PHA) was prepared and studied as specific binders for the transition M2+ and M3+ ions. Their architecture is based on aliphatic backbones, as many functional groups in hydroxamate chelating units. One of the most usages of Chit-g-PHA is transition metal complexes. Polyhydroxamic acid grafted on chitosan in pH = 5 coordinated to Cu2+ and Fe3+, in pH = 6, 8 coordinated to Cr2+ and Ni2+ respectively.

Poly-hydroxamic acid (PHA) matrix for gadolinium pre-concentration and removal

A novel hydrophilic, three dimensionally cross-linked, aliphatic backbones with pendant hydroxamic acid (HA) group as functional moiety has been synthesized and utilized targeting removal of gadolinium [Gd(III)] from laboratory waste aqueous effluent. To understand the nature of sorption, gadolinium solution of various concentrations viz., 20, 10, 5.0, 1.0, 0.5 and 0.1 ppm has been contacted with a dose rate of 1 g/100 mL for 2 h. In this study, ICP-AES has been used for determination of concentration (ppm) of gadolinium in feed, filtrate and elute. EDXRF study also ensures the presence of gadolinium in the respective medium. Loaded gadolinium matrix was eluted with 1 N HCl for determining the elution factor (0.98).

Preparation of poly (acro-yellow hydroxamic acid) from the polymer (methyl acrylate) and study use it in the water purification from heavy metal elements.

The aim of this research is the preparation of Poly (Methylacrylate) by a free radical initiating process for polymerization methyacrylate using benzoyl peroxide as an intiator at (70°C ) and(10%) ratio of conversion. Conversion of the ester group of the Poly (Methylacrylate) in to Hydroxamicacid was carried out by treatment of (PMA) with hydroxylaminehydrochloride in alkaline medium at (pH=13) using Sodium Hydroxide. The poly hydroxamic acid was identified by (FT-IR) spectroscopy. Sorption Capacity (qe) of the metal ions (Fe3+ ) , (Cu2+ ),( Ni2+) ,( Co2+) ,( Cr3+),( V3+),( Zn2+),(Al3+)and) Pb2+) by using (PHA) was determined . Also the study showed that there was an effect of initial (pH) and temperature on the sorption capacity of the metal ions , by poly Hydroxamic acid.

Preparation and Properties of Polyhydroxamic Acid and Poly(Vinyl Acetonyl Ketone) and Their Chelated Compounds

Polyacrylonitrile was prepared. Polyhydroxamic acid was obtained from this polymer by its reaction with hydroxyl amine hydrochloride. Poly(vinyl acetonyl ketone) was prepared from vinyl methyl ketone using BF3-methanol complex in the presence of acetic anhydride and sodium acetate. The β-diketone and polyhydroxamic acid were reacted with cobalt acetate and nickel chloride, respectively, to produce chelated compounds. The thermal stabilities and the electrical properties of these prepared polymers and their chelated compounds were determined. It was found that the prepared polymers have the properties of a semiconductor that were enhanced upon reacting them with some metals.

Preparation of bifunctional isocyanate hydroxamate linkers: synthesis of carbamate and urea tethered polyhydroxamic acid chelators

Two novel bifunctional N-methylhydroxamate–isocyanate linkers 20 and 21 were prepared in good yield and high purity from the corresponding amine salts using a biphasic reaction with phosgene. The facile ring opening reaction of N-Boc lactams using the anion of O-benzylhydroxylamine gave the protected amino hydroxamates 6a and 6c in good yields. The selective methylation of the hydroxamate nitrogen in the presence of the N-Boc group in these intermediates could be readily accomplished. The utility of the linkers was clearly demonstrated by the synthesis of the carbamate-tethered trishydroxamic acid 27 and the urea-tethered 29.

Treatment of Copper-Containing Acid Mine Drainage by Neutralization-Adsorption Process Using Calcite as Neutralizer and Polyhydroxamic Acid Resin as Adsorbent

Acid solution and copper-containing acid mine drainage (AMD) was treated by neutralization-adsorption process. The results showed that pH can be adjusted to 4.0 by adding 10g·L-1calcite in acid solution with pH=1.0. Adsorption and desorption performance of poly(hydroxamic acid) (PHA) resin for Cu2+and Fe3+ions were investigated by column tests. The results showed that adsorption capacities of PHA for Cu2+and Fe3+ions were satisfying, and the metals adsorbed on PHA can be eluted by sulfuric acid solution effectively. AMD of Dexing copper mine of Jiangxi was treated as a sample. The results showed that 1.5g·L-1calcite can remove almost all of the Fe3+ion, and Cu2+ion can be removed by PHA and then be eluted by sulfuric acid solution with adsorption ratio of 98.95% and elution ratio of 98.50%, separately.

PREPARATION OF POLY (HYDROXAMIC ACID )FROM POLY (METHYLMETHACRYLATE – CO-METHYLACRYLATE ) AND STUDING OF ADSORPTION CAPACITY FOR( FE3+ ) AND (CU2+ ).

The aim of this research is the preparation of Poly (Methyl methacrylate –co- Methylacrylate) by a free radical initiating process for co-polymerization between methylmethacrylate and methyacrylate with amixing ratio (1:1), using benzoyl peroxide as an intiator at (70°C ) and(10%) ratio of conversion. Conversion of the ester group of the (CPMMA-MA) in to Hydroxamicacid was carried out by treatment of (CPMMA-MA) with hydroxylaminehydrochloride in alkaline medium at (pH=13) using Sodium Hydroxide. The poly hydroxamic acid was identified by (FT-IR) spectroscopy. Adsorption Capacity (qe) of the metal ions (Fe3+ ) and (Cu2+ ) using (PHA) was determined . Also the study showed that there was an effect of initial (pH ) and temperature on the adsorption capacity of (Fe3+ ) and (Cu2+ ) . Langmuir and Freundlich equation models were used to describe the equilibrium Sorption Isotherms , using different concentrations solution of (Fe3+ ) and (Cu2+ ) at pH=4 and 25°c by poly hydroxamic acid.

Matrix separation and preconcentration of rare earth elements from seawater by poly hydroxamic acid cartridge followed by determination using ICP-MS

The determination of rare earth elements in seawater is a challenge due to high salt content of seawater and extremely low concentrations of rare earth elements. Therefore separation of matrix and preconcentration of rare earth elements is necessary for their detection by inductively coupled plasma mass spectrometer. Polyhydroxamic acid is a potential chelating resin for separation and preconcentration of many elements. In the present work polyhydroxamic acid synthesized from acryl amide as monomer and N, N′- methylene bis acryl amide as cross linker was used in a self fabricated glass cartridge for the preconcentration of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu simultaneously from seawater. Polyhydroxamic acid was found to have good selectivity for rare earth elements with respect to alkali and alkaline earth metals. Therefore major matrix elements such as Na, K and Mg were separated in a single stage with the achievement of a preconcentration factor of 100 for rare earth elements. The uptake of rare earth elements by PHA was >95% in a wide pH range of 3–7. The limit of detection as calculated by taking synthetic seawater was between 0.08 to 0.44ngL−1.

Detection of arsenic agents by polyhydroxamic acid

AbstractArsenic agents are among the most destructive and fatal factors that exist in the environment, chemical agents, medicines, toxics, pesticides, etc., and working with these compounds is too limited and difficult due to their high toxicity. These deadly, dangerous, and weakening toxins are consumed for a large variety of purposes in the military industries. So measurement and identification of them are of great necessity. In this research work, acryl carbohydroxamic acid monomer was first prepared from acrylamide and then polymerized under radical conditions in the presence of azobisisobutyronitrile as an initiator. The produced polyhydroxamic acid (PHA) has antibacterial and anticancer properties as well as high complex‐forming properties with transition elements. By using the chelating properties of PHA, we took steps to identify arsenic agents such as trichloroarsine, dichloroethylarsine, and lewisites (I, II, III). This polymer, possessing unique properties, measures well the arsenic of low concentrations, lower than 10 ppm, existing in the samples within a very short time (a few seconds). We will also be able to perform qualitative assessments on it through instrumental methods or titration, if required. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

ChemInform Abstract: Convenient Method for the Preparation of Some Polyhydroxamic Acids: Michael Addition of Amines to Acrylohydroxamic Acid Derivatives.

Abstract Reagents 1, 2, and 3 are readily prepared by the reaction of the appropriate hydroxylamine derivatives with acryloyl chloride. They undergo Michael addition with a variety of amines to give the corresponding O-protected hydroxamate derivatives in moderate to good yields. Subsequent removal of the protecting group provides a convenient method for the preparation of a number of mono, di, tri and tetrahydroxamic acids.

ChemInform Abstract: Reactions of N‐Benzyloxycarbamate Derivatives with Stabilized Carbon Nucleophiles: A New Synthetic Approach to Polyhydroxamic Acids and Other Hydroxamate‐Containing Mixed Ligand Systems.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Reactions of N-benzyloxycarbamate derivatives with stabilized carbon nucleophiles: a new synthetic approach to polyhydroxamic acids and other hydroxamate-containing mixed ligand systems.

Hydroxamic acids are an important class of chelators of hard metal ions such as Fe(III), which have found applications in therapeutic, diagnostic, and separation chemistry. Hence, methods for their preparation and incorporation into various matrices are important. A new strategy for the preparation of hydroxamic acids that uses readily available N-benzyloxy carbamic acid ethyl ester, 1, has been developed. N-Alkylation of 1 occurs readily to give N-alkyl-N-benzyloxy carbamates, 2, which react with a variety of stabilized carbon nucleophiles to give functionalized protected hydroxamic acids, 3, in good to excellent yields. The O-protected hydroxamate intermediates 3 can be further alkylated with halides to access a variety of potential metal binding hosts. The usefulness of this methodology has been demonstrated by the synthesis of a novel trihydroxamic acid 6, mixed ligand systems 9 and 12, and the macrocyclic dihydroxamic acid 16.

Polyhydroxamic Acid Sorbents for Uranium Recovery

Crosslinked polyacrylamides were synthesized by solution polymerization using benzoyl peroxide as the radical initiator. The water–insoluble polymer obtained was functionalized by reacting with hydroxylamine to convert the amide group into hydroxamic acid group. The resultant functionalized polymer was characterized in terms of moisture uptake, elemental composition, IR spectra, thermal stability, exchange capacity and heavy metal sorption. The sorbent, obtained in particulate form, was investigated for its sorption properties with respect to uranium from uranyl nitrate solutions under unstirred batch conditions. This paper will concentrate on preparation, characterization and performance evaluation with respect to uranium sorption as a function of concentration, time, solution pH and temperature. The potential of this sorbent for uranium and other heavy metal ion recovery from sea water is ascertained.

The use of positron annihilation lifetime technique to study the effect of doping metal salts on polyhydroxamic acid polymers

The use of positron annihilation lifetime technique to study the effect of doping metal salts on polyhydroxamic acid polymers