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It has become crucial to develop new adsorbents to remove toxic dye wastes from wastewater to protect our existing aquatic ecosystem. Here, to remove methyl orange azo dye from aqueous solutions, a new p(HEMA-co-AETAC)/VMt nanocomposite hydrogel was prepared by using 2-hydroxyethyl methacrylate and [2-(acryloyloxy)ethyl]trimethylammonium chloride monomers using vinyl-based montmorillonite crosslinker. Obtained new types of crosslinker and nanocomposite hydrogels have been characterized by various analysis methods. In addition, the effects of crosslinker amount, monomer amount and pH on the swelling behavior of nanocomposite hydrogel were investigated. The effects of essential parameters such as contact time, initial dye concentration, pH effect of the solution, adsorbent amount, and temperature on adsorption were evaluated. It was determined that there was no significant change in the adsorption ability of the nanocomposite hydrogel in the pH range of 3–10. Experimental results showed that the Langmuir isotherm model fit better, and the calculated maximum adsorption capacity was 961.54 mg/g. In addition, it was determined that vinyl-based montmorillonite used as a crosslinker supported MO adsorption. p(HEMA-co-AETAC)/VMt nanocomposite hydrogel may be a new type of adsorbent to remove toxic synthetic dye residues from aqueous media. A new adsorbent for the removal of toxic synthetic dye residues from aqueous media in a wide range of pH. Hydrogels containing AETAC and HEMA are easily obtained with modified montmorillonite. The adsorption properties of the nanocomposite hydrogel were evaluated with methyl orange dye molecules. According to Langmuir isotherm, the maximum adsorption capacity was determined to be 961.54 mg/g.

Recycling industrial wastes is necessary for the economy and the environment. Additionally, it is important to develop high-efficiency adsorbents to prevent severe water pollution caused by wastewater containing dye agents. Here, poly(2-acrylamido-2-methylpropane sulfonic acid)-fly ash composite hydrogel was synthesized with a variety of fly ash proportions with the radical polymerization method. The synthesized composite hydrogel was used for adsorption of methylene blue and methyl orange dyes from water containing dye agents. A variety of parameters such as initial dye concentration, solution pH, anion effects, temperature, contact time and adsorbent amount were investigated for optimization of the adsorption process. The poly(2-acrylamido-2-methylpropane sulfonic acid)-fly ash composite hydrogel was determined to be an effective adsorbent to remove both the cationic dye methylene blue (1438.68 mg g−1) and the anionic dye methyl orange (646.54 mg g−1). Experimental adsorption data were assessed with a variety of isotherm and kinetic models. It was determined that the adsorption of both dye molecules abided by the pseudo-second-order kinetic model. The thermodynamic parameters were determined as ΔH° = − 15.77 ± 5.22 kJ mol−1, ΔS = − 45.05 ± 16.42 J mol−1 K−1 and ΔG° 0 for MO. In conclusion, a material was synthesized that can be used as a single adsorbent composite material for both anionic and cationic dyes. In addition to the perfect adsorption capacity of this material, it offers reusability and a broad area of application for a variety of dye agents.

In this study, the cationic monomer [2-(acryloyloxy)ethyl]trimethylammonium chloride solution (AETAC) and vinyl imidazole (VI) were used with the free radical polymerization technique, which is a simple and rapid synthesis method, to synthesize p(AETAC-co-VI) hydrogels. To increase the density of cationic charge on the hydrogel, it underwent the protonation process with HCl. The obtained p(AETAC-co-VI)/Q hydrogel was modified with Au nanoparticles to increase bactericidal effect to obtain the AuNPs/p(AETAC-co-VI)/Q nanocomposite hydrogel. The morphology and chemical structure of the hydrogels were characterized with SEM and FTIR. Additionally, the swelling capabilities were tested in different pH media. XRD and TEM confirmed the formation of the nanocomposite hydrogel. The antibacterial activity of the hydrogels was tested against E. coli and S. aureus, and controlled release implementations were completed with sodium diclofenac (NaDc) drug. The NaDc drug release profiles of the hydrogels were researched using the Korsmeyer-Peppas model at 37 degrees C in different simulated buffer (pH 6.0, 7.2, and 8.0) solutions. It was found that both the hydrogel and nanocomposite hydrogel followed non-Fickian diffusion mechanisms as free release mechanism. Here, the maximum drug release efficacy was found to be 97%, and drug release was more rapid in basic media when release media were compared. The AuNPs/p(AETAC-co-VI)/Q nanocomposite hydrogels produced in this study with advanced antibacterial features were suitable for recommendation as good carriers for in vitro release of NaDc drugs in areas like the biomedical and pharmaceutical industries.

In this study we synthesized Pd(0) nanoparticles with nearly 20 nm size using p(3-Sulfopropyl acrylate) (p(SPA)) hydrogel as support material. Pd@p(SPA) containing Pd (0) nanoparticles with nearly homogeneous distribution was characterized structurally with TEM, XRD, XPS and elemental mapping. The Pd@p(SPA) was used for the catalytic hydrolysis reaction of ethylenediamine bisborane (EDAB). A series of reactions were completed by changing parameters like the catalyst amount, EDAB concentration and temperature. The Pd@p(SPA) was determined to have turnover frequency (TOF) value of 354 mol H2.molPd(0)−1.h−1 at 30 °C for the hydrolysis reaction of EDAB. The activation parameters for the reaction were Ea = 67.79 kJmol-1, ΔH# = 65.15 kJmol-1 and ΔS# = -103.26 Jmol−1K−1. Pd@p(SPA) also had excellent reusability for the hydrolysis of EDAB. Even after ten reaction cycles, Pd@p(SPA) had 87% catalytic activity. At the same time after four months of storage in an aqueous medium, Pd@p(SPA) still had 100% catalytic activity.

Herein, new microspheres were successfully fabricated from pentaerythritol tetrakis(3-mercaptopropionate) as model monomer and hexachlorocyclotriphosphazene as crosslinker using a single-step via p...

In this study, p(AAm-co-TACYC) hydrogels were synthesized using TACYC crosslinker. The p(AAm-co-TACYC) hydrogel was used for preparation of Cu(0) nanoparticles as support material. The p(AAm-co-TACYC)@Cu was prepared by chemical reduction of Cu2+ ions in the p(AAm-co-TACYC) networks and was structurally characterized in detail. Later the catalytic activity of p(AAm-co-TACYC)@Cu was investigated for hydrogen production from AB and EDAB hydrolysis. Detailed kinetic studies were performed for both hydrogen storage materials. The p(AAm-co-TACYC)@Cu was a more active catalyst for the EDAB hydrolysis reaction. The Ea values of p(AAm-co-TACYC)@Cu for the AB and EDAB hydrolysis reactions were determined as 68.36 kJ mol−1 and 39.07 kJ mol−1, respectively. In addition to the perfect catalytic activity of p(AAm-co-TACYC)@Cu, it had good reusability. After ten consecutive uses for AB and EDAB hydrolysis, the p(AAm-co-TACYC)@Cu still had 88% and 85% of initial activity, respectively.

Efficient, low-cost and safe new systems are still needed for the storage and usage of hydrogen energy, which is considered the most important energy source of the future. For this reason, the aim of this study was to prepare Co0, Ni0, and Cu0 composite catalysts with fly ash (FA) formed by combustion of coal in thermal power plants to be used for the dehydrogenation of ethylenediamine bisborane (EDAB) as a hydrogen source. In the hydrolysis reactions of EDAB, parameters such as metal type, catalyst concentration, temperature, and EDAB concentration were investigated. The FA-Cu0 composite catalyst was determined to be an effective catalyst system for hydrogen production by hydrolysis of EDAB from among the FA-M0 composite catalysts. Besides, FA can be used as an effective support material in order to prevent agglomeration of metal particles.

In this study, Ru(0) nanoparticles supported in 2-hydroxyethyl starch-p-(2-Acrylamido-2-methyl-1-propanesulfonic acid) interpenetrating polymeric network (HES-p(AMPS) IPN) were synthesized as hydrogel networks containing hydroxyethyl starch, which is a natural polymer with oxygen donor atoms. The structure and morphology of the prepared HES-p(AMPS) IPN hydrogel and Ru@HES-p(AMPS) IPN catalyst were characterized using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), X-ray diffraction (XRD), and transmission electron microscope (TEM). Ru@HES-p(AMPS) IPN was used as catalyst for hydrogen production from the hydrolysis of ethylenediamine bisborane (EDAB). The activation parameters for the hydrolysis reaction of EDAB catalyzed by Ru@HES-p(AMPS) IPN were calculated as Ea = 38.92 kJ mol−1, ΔH# = 36.28 kJ mol−1, and ΔS# = −111.85 J mol−1 K−1, respectively. The TOF for the Ru@HES-p(AMPS) IPN catalyst was 2.253 mol H2 (mol Ru(0) min)−1. It was determined that Ru@HES-p(AMPS) IPN, a reusable catalyst, still had 81.5% catalytic activity after the 5th use.

In this study, hydroxyethyl starch (HES)-based hydrogels, hydroxyethyl starch/p(sodium acrylate) (HES/p(NaAAc)), hydroxyethyl starch/p(3-(acrylamidopropyl) trimethyl ammonium chloride) (HES/p(APTMACl)) and hydroxyethyl starch/p(acrylamide) (HES/p(AAm)) were synthesized with redox polymerization. The structural, morphological, and water absorption characterization of the synthesized hydrogels was investigated. HES-based hydrogels, containing anionic, cationic and neutral functional groups, were used for adsorption of methyl violet (MV) as a model cationic dye and methyl orange (MO) as a model anionic dye from aqueous media. HES/p(APTMACl) and HES/p(NaAAc) hydrogels had maximum adsorption values for MO and MV dyes of 238.1 mg/g and 185.2 mg/g. The isotherm and kinetic parameters for both dye adsorptions were determined. The adsorption isotherm and kinetic data were compatible with the Langmuir isotherm and pseudo-first-order kinetic models.

In this study, monodispersed silica nanoparticles were synthesized using the Stöber method. The synthesized nanoparticles underwent a range of surface modifications and were converted to nanoparticles with drug release and antibacterial features. For modification, firstly –NH2 groups were created on the silica nanoparticle surface using (3-Aminopropyl)triethoxysilane (APTES). In the second stage, hexachlorocyclotriphosphazene (Phz) molecules were bound to the silica nanoparticle surfaces due to these amino groups. In the final stage of modification, the chloride groups in the hexachlorocyclotriphosphazene structure were modified with trimethoprim (TMP) and nanoparticles with antibacterial properties were obtained. The modified silica nanoparticles were characterized with scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), and Thermogravimetric analysis (TGA). The silica-based nanoparticles were used for release of rhodamine 6G, chosen as a model drug. As a result of the drug release studies, the modified silica nanoparticles were found to abide by the Korsmeyer–Peppas low power model and non-Fickian release mechanism as release model. Additionally, nanoparticles both loaded and not loaded with the model drug were determined to have antibacterial properties against Escherichia coli, Bacillus subtilis, and Staphylococcus aureus bacteria.

In this study, methacrylic acid-based containing both anionic and cationic groups in its structure p(Methacrylic acid-co-(3-acrylamidopropyl)trimethylammonium chloride) (p(MAA-co-APTMACl)) and p(Methacrylic acid-co-(2-(acryloyloxy)ethyl)trimethylammonium chloride) (p(MAA-AETAC)) hydrogels were synthesized by redox polymerization technique. The morphology, chemical structure and thermal properties of the synthesized hydrogels were characterized by SEM, FT-IR, and TGA. The swelling characterizations of the synthesized MAA-based hydrogels were carried out in various biological environments. Usability of amphoteric hydrogels containing anionic and cationic groups in their structures as a drug carrier cargo material were investigated for the treatment of two different diseases. For this, two of the selected model drugs were loaded simultaneously on hydrogels and their release properties were examined. The drug release mechanisms were investigated according to the Korsmeyer–Peppas model. Rhodamin 6G and ceftriaxone sodium were loaded to p(MAA-co-APTMACl) hydrogel for dual drug release. In addition, Rhodamin 6G and sulfadiazine were loaded simultaneously on the p(MAA-co-AETAC) hydrogel. According to the release mechanism results obtained for p(MAA-co-AETAC) hydrogels, it was determined that it showed a super-state diffusion mechanism. In addition, antibacterial activities of p(MAA-co-APTMACl) and p(MAA-co-AETAC) hydrogels against gram-negative bacteria (Escherichia coli and Pseudomonas Aeruginosa) and gram-positive bacteria (Staphylococcus Aureus and Bacillus Subtilis) were investigated.

Poly((methacryloylamino)propyl trimethylammonium chloride-co-vinylimidazole) (p(MAPTAC-co-VI)) hydrogels were synthesized through free radical polymerization of 3-(methacryloylamino)propyl trimethylammonium chloride (MAPTAC) and 1-vinylimidazole (VI) in aqueous solutions with ammonium persulfate (APS) used as initiator and N,N′-methylenebis(acrylamide) (MBA) as the crosslinking agent. By modifying with HCl, the positive charge density on the hydrogel network structure was increased and quaternized hydrogels (p(MAPTAC-co-VI)-q) were obtained. Traditional swelling and spectrophotometric characterization techniques were used to gain a better understanding of the performance of cationic hydrogels for the removal of anionic dyes. FTIR, SEM, and EDX confirmed the structure of the hydrogel before and after the adsorption process. Later, dye adsorption performance of these p(MAPTAC-co-VI)-q hydrogels was investigated under different adsorption conditions, including initial concentration, temperature, pH values of dye solutions, and adsorption contact time, adsorbent dosage and in real water samples. Various isotherm and kinetic models of dye adsorption by the hydrogel were also studied and the experimental adsorption followed a pseudo-second order model and fitted the Langmuir isotherm well. Thanks to the effective use of existing adsorption sites, high adsorption capacity was achieved for eriochrome black T (EBT) and methyl orange (MO) dyes. The values of qmax are as follows: 1818.2 mg/g and 1449.3 mg/g, respectively. Thermodynamic parameters indicate that the process was spontaneous and endothermic. P(MAPTAC-co-VI)-q hydrogels can be used as a potential adsorbent for removal of anionic dye molecules, one of the industrial pollutants, from wastewater.

In this study, chitosan, an aminopolysaccharide, was reacted with phosphazene-derived crosslinker by Schiff-base reaction to yield crosslinked-chitosan hydrogel. Here, hexakis(4-formylphenoxy)cyclo...

This study used biocompatible and biodegradable hydroxyethyl starch (HES), 2-hydroxyethyl methacrylate (HEMA) and N-vinyle-2-pyrrolidone (NVP) monomers for hydrogel synthesis with the aim of use as a drug carrier system. As a result of the synthesis reactions using the redox polymerization technique, hydrogels were produced in both film and cylindrical form. The morphological characterization and structural characterization of hydrogels were performed using scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR), respectively. In addition, swelling characterizations of hydrogels to be used for drug release in various media were examined. The release properties of sodium diclofenac (NaDc) and trimethoprim (TMP) loaded into hydrogels produced in order to use as drug carrier material for controlled drug release were examined in media with pH = 1.2 and 7. It was determined that the hydrogels performed controlled release according to the type of drug and the pH values of the medium. Drug release mechanisms deviated from Fickian mode according to determined drug release rate constants, diffusion exponent (n) and regression values at different pH values. In addition, antibacterial properties of drug-loaded hydrogels against B. subtilus, S. aureus and E. coli were investigated.

This study is the first report of the preparation of hydroxyethyl starch (HES) hydrogels rapidly crosslinked with divinyl sulfone in a single step and single pot. To develop the physical and chemical features of hydrogels, Graphene oxide (GO) nanoparticles were combined with the crosslinked HES. In addition to swelling studies, structural characterization of the samples was conducted with a scanning electron microscope (SEM) and transmission electron microscope (TEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), Brunauer–Emmett–Teller (BET) analysis and thermogravimetric analysis (TGA). For the removal of malachite green model dye by GO-HES, the effects of GO content, solution concentration, temperature, contact duration, dosage and pH on varying adsorption features were researched. Additionally, adsorption isotherms, kinetic and thermodynamic systematics were analyzed. The maximum adsorption capacity of GO-HES composite hydrogel was found to be 89.3 mg/g for Langmuir isotherm. The possible adsorption mechanism of the composite hydrogels for malachite green dye involved electrostatic, hydrogen bonding, and π–π interactions. In addition to reasonable cost and simple synthesis method, the prepared composite materials have potential use in wastewater treatment as adsorbents for the removal of dye from aqueous solutions due to efficient adsorption capacity.

The present research offers an innovative cyclic approach to cleaning colored water of toxic dyes due to the increased need for pure and safe water. Novel anionic hydrogels were fabricated via free radical copolymerization method in the presence of acrylamide or 2-hydroxyethyl methacrylate as neutral comonomer and N-tert-butylmaleimic acid as anionic monomer with the addition of N , N ′-methylenebisacrylamide as cross-linker. Hydrogels were examined for morphology and chemical structure using SEM and FTIR analyses. The swelling and adsorption behavior of the hydrogels with different molar ratios were examined. The parameters affecting the adsorption of the model dyes of CV and MB onto the hydrogel were investigated such as initial concentration of dye, various comonomer ratios, dose of hydrogel, and temperature. The adsorption behavior was consistent with the Langmuir isotherm model. Also, the thermodynamic analysis and Dubinin-Radushkevich isotherm model revealed that the adsorption of the dyes onto hydrogels was applicable in a wide temperature range as well as with physical and weak chemical interactions. TBMAC-based hydrogels were found to be a cost-effective prospective candidate with great regeneration efficiency and selectivity to be used as an adsorbent to effectively remove hazardous dyes from industrial waste.

In this study, N-tert-butylmaleimic acid was designed for the first time and synthesized by reaction of maleic anhydride with tert-butylamine and evaluated as a new functional monomer for preparation of new pH-responsive hydrogels. Its structure was verified with FTIR, 1H and 13C NMR. A new pH- and temperature-responsive hydrogel p(TBMAC-co-NIPAM), based on TBMAC and NIPAM, was successfully prepared via free-radical copolymerization technique in an aqueous solution. The chemical and structural properties of the hydrogels were identified by FTIR and SEM. The swelling properties of these hydrogels were systematically investigated according to various parameters such as time, temperature, pH and salt effects, and the results show that they are strongly influenced by the content of TBMAC and exhibit strong pH, temperature and salinity sensitivity. In addition, swelling kinetics and water diffusion mechanisms in hydrogels were discussed. In addition, in vitro drug release studies were performed in simulated gastric, isotonic serum and intestinal fluid at two different temperatures (23 and 37 °C) by taking R6G as a model drug. Drug loading results were investigated with various isotherm models such as Langmuir, Freundlich, Temkin and Dubinin-Radushkevich. Various kinetic models such as zero-order, first-order, Higuchi model and Korsmeyer-Peppas models were applied to determine the drug release mechanism. The results indicated that drug release involves non-Fickian transport mechanism. These results suggest that this new pH- and thermo-responsive hydrogel may be used to improve sustained release of drugs.

In this study, firstly N-metacrylamido thiomorpholine containing thioether group was synthesized as monomer. Then, p(AAm-co-MTM) hydrogels were prepared from the redox polymerization of acrylamide and N-metacrylamido thiomorpholine as a selective support material. p(AAm-co-MTM) hydrogel-gold nanoparticles were obtained as a result of the reduction of the selectively absorbed gold(III) ions by the hydrogel network using NaBH4 as reducing agent. All materials were characterized using techniques such as SEM, EDX, TEM and XRD analysis. It was determined that p(AAm-co-MTM)-Au composite material has high catalytic activity for the reduction of 4-nitrophenol. The activation parameters of the reduction reaction of 4-nitrophenol using NaBH4 in the presence of p(AAm-co-MTM)-Au catalyst were calculated as Ea = 38.80 kJ/mol, ΔH# = 36.16 kJ/mol and ΔS#= −161.37 J/mol K.

As pharmaceutical carrier materials having antibacterial and pH-sensitive properties, hydrogels have great potential for clinical applications. Alginate based hydrogels were designed as an oral drug carrier and investigated for the drug release study in biomedical fields especially the colon-targeted system. Structural changes of synthesized hydrogel have been characterized using Fourier transform-infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) devices. Hydrogels have been studied for their water absorption behavior under the influence of various monomer compositions and changing ambient conditions such as salt, pH and temperature. In this study, diclofenac sodium was used as a model drug to investigate the in vitro release behavior at simulated intestinal (pH 7.0) and gastric fluid (pH 1.2). Lastly, the antibacterial effect of hydrogels and drug-loaded hydrogels was characterized using a disc diffusion method against Gram-positive and Gram-negative bacteria. The suitability of controlled drug release for the use of these new hydrogels in the pharmaceutical and biomedical field has been investigated and our results have shown that the produced hydrogels are promising materials for developing pH-controlled drug delivery devices like capsules for oral use.

In this study, for the first time in the literature, synthesis of Au(0) nanoparticles supported by a crosslinked gel structure was performed via enzyme-mediated reduction of Au(III) ions without using any chemical reductant. in our newly-developed method, glucose oxidase enzymes immobilized in the crosslinked gelatine structure ensured simultaneous reduction of the Au(III) ions diffused within the gel to Au(0). the Au@Gel obtained was structurally characterised with TEM (Transmission electron microscopy), EDX (Energy dispersive X-ray analysis) elemental mapping, XPS (X-Ray photoelectron spectroscopy) and XRD (X-Ray Diffraction) analyses. the catalytic activity of Au(0) particles with nearly 8 nm size in the Au@Gel was investigated for the reduction of 4-nitrophenol (4-NP) as a model compound in the presence of NaBH(4)as reducing agent. the activation parameters for the reduction reaction of 4-nitrophenol in the presence of Au@Gel catalyst were determined as E-a= 30.16 kJmol(-), Delta H= 27.52 kJmol(-)and Delta S= -197.45 Jmol(-)K(-). the Au@Gel catalyst system, with good catalytic activity, simultaneously has nearly perfect reusability., Canakkale Onsekiz Mart University Scientific Research Coordination UnitCanakkale Onsekiz Mart University [FBA-2018-2508], The authors thank Canakkale Onsekiz Mart University Scientific Research Coordination Unit (Project number: FBA-2018-2508) for financial support.

Ethylene diamine bisborane (EDB) was synthesized in a single step as the hydrogen storage material. The synthesized compound was firstly used in the literature for the production of hydrogen gas by catalytic hydrolysis reaction. Cu, Co and Ni nanoparticles with average sizes of 75–150 nm formed in p(acrylicacid-co-vinylimidazole) hydrogel network structures were used as catalysts for the hydrolysis reaction. The effect of the parameters such as catalyst type, EDB concentration, catalyst concentration, temperature and solvent environment on the catalytic hydrolysis reaction of EDB was investigated. In the activity tests for the catalyst, it was determined that the catalyst had a loss of only 15% in activity even at the end of 5 cycles. The activation energies of hydrolysis reaction were calculated as 39.42 kJmol–1, 44.77 kJmol–1 and 47.48 kJmol–1 for Cu, Co and Ni hydrogel composite catalyst, respectively.

Three novel fully substituted urea derivative cyclotriphosphazene compounds 5-7 were synthesized by alkyne-azide 1,3-dipolar cycloaddition reaction of propargyl substituted ureas 2-4 with hexaazide substituted cyclotriphosphazene 1 in the presence of Cu(I) catalyst. All compounds were characterized with spectroscopic techniques such as FT-IR, H-1, C-13, and P-31 nuclear magnetic resonance and mass spectroscopy. Also, the usefulness of compounds 5-7 as anion carriers was investigated by H-1 NMR spectroscopy. For this purpose, H-1 NMR spectra of compounds 5-7 were recorded in the presence of tetrabutylammonium fluoride in DMSO-d(6). It was determined, that the urea protons in the compounds interact with fluoride.

In this study, we synthesized a novel phosphazene compound hexakis[4-(acrylamido)phenoxy]cyclotriphosphazene (HAAP) as crosslinker. The structure of compound was identified using spectroscopic techniques. Then, HAAP was used as crosslinker for the synthesis of thermo and pH responsive p(NIPAM-co-VI) hydrogels. The structure and swelling behavior of hydrogel was investigated. Then, HAAP-crosslinked p(NIPAM-co-VI) hydrogels were used for in vitro release of Rhodamine 6G as drug release matrix. Additionally, HAAP-crosslinked p(NIPAM-co-VI) hydrogels were used as support material for the preparation of cobalt metal catalysts. The prepared HAAP-crosslinked p(NIPAM-co-VI)-Co composite catalyst was used as catalyst for the reduction reaction of 4-nitrophenol.

Within the scope of this study, p(2-hydroxyethyl methacrylate-co-tetraacrylic cyclen) (p(HEMA-co-TACYC)) hydrogels were synthesized for the first time in the literature using a tetraacrylic cyclen (TACYC) as both functional monomer and crosslinker. The hydrogels designed especially for Cu2+ ions showed colorimetric sensor behavior selective for Cu2+ ions in all aqueous media (deionized, tap, river and sea water) and in metal ion mixtures. The p(HEMA-co-TACYC) hydrogels forming a stable complex with Cu2+ ions simultaneously showed properties of being a good adsorbent material. The hydrogels have reuse capacity as both sensor and adsorbent material. Changing the amount of TACYC in the hydrogel structure changes the maximum adsorption capacity for Cu2+ ions. The Langmuir and Freundlich adsorption constants for Cu2+ ion adsorption of the hydrogels, acting as selective adsorbent in all aqueous media and metal ion mixtures, were determined.

In this study firstly, phosphazene crosslinked cyclen microspheres were synthesized. Then, supported copper nanoparticles were prepared on these phosphazene crosslinked cyclen microspheres for use as a metal catalyst. The prepared microparticles and microparticle-supported metal catalyst were characterized using FT-IR, SEM-EDX, TEM and XPS analysis. Also, the prepared metal composite was used as a catalyst for the reduction reaction of 4-nitrophenol in the presence of NaBH4 in aqueous media. The catalytic activity of the Cu-cyclen composite catalyst was investigated using UV–Vis spectroscopy. The reduction studies were completed at four different temperatures (30–60 °C). The activation parameters were calculated from the obtained rate constants at the four different temperatures (30–60 °C). The activation energy, activation enthalpy and activation entropy for the reduction reaction of 4-NP in the presence of Cu-cyclen composite catalyst were calculated as 39.88, 36.56 and −143.30 kJmol−1, respectively. The total turnover frequency (TOF) for Cu-cyclen composite catalyst was 0.794 mol 4-NP (mol Cu)−1 (min)−1.

A novel sensor with a hexacenter containing nitrophenylurea groups on a cyclotriphosphazene core was synthesized by click reaction of N-propargyl-substituted urea with a hexaazide-substituted cyclotriphosphazene compound. It was characterized by spectroscopic techniques such as Fourier transform infrared spectroscopy, nuclear magnetic resonance, and mass spectroscopy. This compound was used for naked-eye and spectrophotometric detection of F- anions. The optical sensor properties of compound were investigated using ultraviolet-visible spectroscopy.

In this study, p([2-(acryloyloxy)ethyl]trimethylammonium chloride-co-1-vinyl-2-pyrrolidinone) (p(AETAC-co-NVP) hydrogels containing positive charge in the structure were synthesized for the removal of anionic dyes from the aqueous media. The swelling behaviors affecting the adsorption properties of hydrogels structurally characterized by FTIR, SEM and EDX/mapping analysis were investigated. The effects of pH, dye concentration, adsorbent amount, dissolved anions and temperature on the adsorption of methyl orange (MO) and alizarin red S (AR) from aqueous media using p(AETAC-co-NVP) hydrogels were investigated. Using data obtained in adsorption studies, the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms and pseudo-first order (PFO), pseudo-second order (PSO), intra-particular diffusion, and Elovich kinetic model analyses were performed. The results showed that the p(AETAC-co-NVP) hydrogel was a good adsorbent for MO and AR anionic dyes and the adsorption process for both dyes complied with the Freundlich isotherm and PSO kinetic model. This situation indicates that the dominant mechanism for the adsorption of MO and AR dyes by the p(AETAC-co-NVP) hydrogel is strong electrostatic interactions and occurs as multilayered adsorption, not only on a planar region. Additionally, to the maximum adsorption values using p(AETAC-co-NVP) hydrogel for MO and AR dyes were reached at pH values of 7.0 and 5.0, respectively. According to all these findings, it can be said that the p(AETAC-co-NVP) hydrogel containing positivelly charged groups is a super adsorbent for adsorption of anionic dyes.

A novel compound hexa-rhodamine substituted phosphazene (HRP) with six active centers on a cyclotriphosphazene ring was synthesized using the alkyne-azide “click” reaction. The structure of HRP was characterized using spectroscopic techniques. The optical sensor properties of HRP for metal ions were investigated using UV-Vis and Fluorescence spectroscopy. It was determined that HRP is a selective sensor with colorimetric and fluorescent properties for Fe3+ ions. Limit of detection (LOD) of HRP was determined as 6.94 × 10−9 M using fluorescence intensities in the presence of different concentrations of Fe3+ ions. It was determined that HRP-Fe3+ complex has high quantum yield and excellent photostability.

In this study, a new cationic monomer 2-(3-indol-yl)ethylmethacrylamide (IEMA) derived from tryptamine was synthesized in a single step and characterized by Fourier transform infrared (FTIR), H-1-NMR, and C-13-NMR. Then, one-step preparation of novel poly[2-hydroxyethylmethacrylate-c-2-(3-indol-yl)ethylmethacrylamide], or p(HEMA-c-IEMA), copolymeric hydrogels has been performed successfully with IEMA and 2-hydroxyethylmethacrylate (HEMA) as monomers using free radical aqueous polymerization. The hydrogels were characterized with scanning electron microscopy, FTIR, elemental analysis, thermogravimetric analysis, and texture profile analysis instruments. p(HEMA-c-IEMA) hydrogels were used for swelling, diffusion, drug release, and antibacterial activity studies. The drug-release behavior of the hydrogels was determined as a function of time at 37 degrees C in pH1.2 and 7.2. The swelling and drug-release studies showed that an increased IEMA amount caused a higher increase in swelling and drug-release values. Additionally, zero-order, first-order, and Higuchi equation kinetic models were applied to the drug-release data, and the data fit well in the Higuchi model, and the Peppas power-law model was applied to the release mechanism. Finally, the antibacterial activities of the hydrogels were screened against Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli and Salmonella typhimurium). (c) 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45550.

In this work, a new phosphazene/carbazole hybride dendron (PC) was synthesized and then directly coated onto ITO glass surface to provide a dendritic polymer network, poly-(PC), by using potentiodynamic electrochemical process. Structure of dendron was identified by FT-IR, 1H and 31P NMR, and also TOF-MS analyses. The optical and electrochemical properties of PC and its electrochemical crosslinked product were investigated by using UV–vis absorption, fluorescence and CV techniques. A neutral, colorless electrochromic device was constructed in the sandwich configuration [indium tin oxide (ITO)-coated glass/anodically coloring material (poly-(PC))//gel electrolyte//cathodically coloring material (PEDOT)/ITO-coated glass] and revealed a short response time (about 0.5 s), high coloration efficiency (981 cm2 C−1) and high redox stability.

In this study, microspheres of trimethoprime (TMP), which is an antibiotic drug, were synthesized in a single step. To synthesize microspheres in various sizes, the amount of TMP was kept constant while mole number of the phosphazene used as crosslinker was reduced. TMP microspheres were synthesized through the precipitation polymerization technique with different mole ratios of crosslinker (1:1, 1:2, 1:3, and 1:6) and characterized by FT-IR, TG, XPS, particle size analysis and SEM-EDX analyses. An in vitro biodegradation test conducted on TMP microspheres in acidic media showed that they degraded at a ratio of 92% in 50 days. In addition, TMP microspheres were used in controlled release of Vitamin B12 and Rhodamine 6G, which had been chosen as model drugs.

In this study, Fe3+ ion selective N-(Rhodamine-6G)lactam-N'-acryloyl-ethylenediamine (RH6GAC) monomer was synthesized. Then, p(Acrylamide-co-N-(Rhodamine-6G)lactam-N'-acryloyl-ethylenediamine) (p(AAm-co-RH6GAC)) and p(2-hydroxyethyl- methacrylate-co- N-(Rhodamine-6G)lactam-N'-acryloyl-ethylenediamine) (p(HEMA-co-RH6GAC)) colorimetric hydrogels were synthesized by using acrylamide (AAm) and 2-hydroxyethylmethacrylate (HEMA) as primary monomers. FT-IR, SEM, polymerization yield and swelling characterizations were conducted for the resulting hydrogels. Then, these hydrogels were used in selective absorption of Fe3+ ions from aqueous media. The hydrogels, which could absorb Fe3+ ions selectively from a mixture of metal ions, were used as column packing material. The solutions containing Fe2+ and Fe3+ ions at different concentrations were separated at a rate of 97.7 ± 0.7%.

A novel on/off fluorescent rhodamine-based hexapodal Fe(3+) probe (L) containing a cyclotriphosphazene core was synthesized by an azide-alkyne "click-reaction". The synthesized compounds (1-5 and L) were characterized by FT-IR; (1)H, (13)C, and (31)P NMR; and MALDI MS spectrometry. The optical sensor features for the Fe(3+) complex of L were investigated by UV-vis and fluorescence spectroscopy. The stoichiometry of L-Fe(3+) complex was found to be 1:3 (ligand/metal ion), and the detection limit of L was determined as 4.8 μM (0.27 mg L(-1)) for Fe(3+) ions. The reusability of the sensor was tested by the addition of ethylenediamine to L-Fe(3+) complex solutions followed by the addition of Fe(3+) solution.

In this study, N-Allylsuccinamic acid was synthesized and characterized by FT-IR, 1H and 13C NMR analyses. Then, copolymeric hydrogels were synthesized by using N-Allylsuccinamic acid and acrylamide as monomers by using free radical polymerization. Once FT-IR, SEM and swelling characterizations of the obtained p(Acrylamide-co-N-Allylsuccinamic acid) hydrogels had been carried out, usability of the hydrogels in environmental applications as an effective absorbent material was shown. For this purpose, the absorption values were determined as 0.545 mmol g−1, 0.179 mmol g−1 and 0.051 mmol g−1 for the used hydrogels in the absorption of Cr3+, 4-Nitrophenol and basic fuchsin from aqueous media respectively.

Cu(0) metal nanoparticles were prepared inside p(2-acrylamido-2-methyl-1-propansulfonic acid) hydrogel networks. The p(2-acrylamido-2-methyl-1-propansulfonic acid)-Cu composites were used in the reduction of 4-nitrophenol and 2-nitrophenol, as model reactions in the presence of excess NaBH4, and showed excellent catalytic activity. The reduction rate of 4-nitrophenol with p(2-acrylamido-2-methyl-1-propansulfonic acid)-Cu composites, even in the presence of a very low amount of catalyst (1.1 mg Cu(0)) at close to room temperature (30 degrees C), resulted in a very high value (0.1032 min(-1)) in comparison to Co(0) and Ni(0) catalysts prepared under very similar conditions. The kinetic parameters were determined at different reaction temperatures and the activation energies for 4-nitrophenol and 2-nitrophenol were found to be 28.2 and 39.2 kJmol(-1), respectively.

Poly(acrylonitrile) (p(AN))-based materials such poly(acrylonitrile-co-(3-acrylamidopropyl)-trimethylammonium chloride (p(AN-co-APTMACl)), poly(acrylonitrile-co-4-viniyl pyridine) (p(AN-co-4-VP)) and poly(acrylonitrile-co-N-isopropylacrylamide) (p(AN-co-NIPAM)) core-shell nanoparticles were prepared. The core materials, AN, in p(AN-co-4-VP) nanoparticles, were amidoximated and the shell materials, 4-VP, were quaternized to generate p(AN-co-4-VP)(+) and p(AN-co-4-VP)(++), single and double positively charged core-shell nanoparticles, respectively. Furthermore, interpenetrating microgels-hydrogel (IPN) polymeric networks were prepared by mixing double quaternized p(AN-co-4-VP)(++) core-shell particles with acrylamide (AAm) and 2-hydroxyethylmethacrylate (HEMA) before polymerization. A model drug, fluorescein sodium salt (FSS) was used in absorption/release studies from these IPNs. Moreover, the prepared and chemically modified particles were tested against Staphylococcus aureus ATCC6538, Pseduomonas aeruginosa ATCC9027, Bacillus subtilis ATCC6633, and Escherichia coli ATCC8739, and found that some of these particles had antibacterial properties against tested bacteria.

4-vinyl pyridine (4-VP) based hydrogels with 2-hydroxyethylmetacrylate (HEMA) and magnetic composites were prepared and tested for use in the removal of UO 2 2 + and Th4+ ions from aqueous environments. It was found that the absorption of these metal ions from aqueous environments decreased with an increase in the amount of HEMA contained within p(4-VP-co-HEMA) hydrogels between 0.498 mmol for pure p(4-VP) and 0.027 mmol for pure p(HEMA). The characterization of the hydrogels was determined by swelling experiments, FT-IR and thermal analysis. The effects of initial metal ion concentration, hydrogel amount and the temperature of the medium on absorption of the ions were investigated. Langmuir and Freundlich isotherms were constructed for the absorption of UO 2 2 + and Th4+. Both isotherms demonstrated that these metal ions complied with monolayer absorption kinetics.

We report the preparation of metal nanoparticles in various formulations inside p(2-acrylamido-2-methyl-1-propansulfonic acid; p(AMPS)) hydrogels and their utilization as a catalyst in hydrolysis of NaBH4. The swollen, flexible p(AMPS) network was used for metal ion loading and reduction in situ for the preparation of Co:Ni nanoparticles as bimetallic clusters in various formulation, and Co and Ni bimetallic catalysts as Co + Co, Co + Ni, Ni + Co and Ni + Ni. In addition to utilization of hydrogels as support materials, the p(AMPS)-metal nanoparticle system was used as catalyst to generate hydrogen in the hydrolysis of NaBH4 with very high yield. Various parameters for the hydrolysis reaction were determined and the activation parameters were calculated. For the first time, inclusion of ferrite magnetic particles to control hydrogen generation on demand by using an externally applied magnetic field to remove the hydrogel-catalyst system from the hydrolysis medium is reported. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

This work reports a facile method for preparation of CdS quantum dots (Q-dots), using a crosslinked hydrophilic p(AMPS) hydrogel network by absorption of Cd(II) ions and sequential precipitation with aqueous Na2S within the network at room temperature. The TEM images revealed that prepared CdS Q-dots were distributed throughout the p(AMPS) hydrogel network and their sizes were about 5 nm. The amount of inorganic material inside p(AMPS) hydrogel was determined by TGA measurements to be 16.9% by weight. Additionally, the Cd and S amounts inside the p(AMPS) network were determined by dissolution of particles with HCl (three treatments with 3 M HCl) and by using ICP-AES (for Cd) and an elemental analyzer (for S). From UV–visible absorbance measurements, optical energy gap values of 5.1 ± 0.1 eV for p(AMPS) and 2.4 ± 0.05 eV for p(AMPS)–CdS were determined. From the fluorescence spectrum of the p(AMPS)–CdS hydrogel, the peak energy was observed at 2.30 eV. The in situ prepared Q-dots were recovered from hydrogel matrices by placing the p(AMPS)–CdS composite in purified water.

The pH responsive poly(4-vinylpyridine-co-1-vinylimidazole) p(4-VP-co-VI) and magnetic p(4-VP-co-VI) were prepared by microemulsion polymerization and modified with various bromoalkanes to tune the charge and size of the soft particles. The prepared p(4-VP-co-VI) particles were treated with quaternization agents containing various numbers of carbon atoms including HCl, bromoethane (BE), 1-bromobutane (BB), 1-bromohexane (BH), and 2-bromoethylamine (BEA) to generate charges on the nitrogen atom of the polymeric moieties. The versatile usage of the prepared and modified hydrogel particles were demonstrated in various fields: (1) as drug delivery devices using a model drug, naproxene sodium salt (NS), (2) in environmental applications i.e., toxic species removal of an organic species, 4-nitrophenol (4-NP), and a toxic metal, arsenic, and (3) in catalysis by using the prepared p(4-VP-co-VI) hydrogel particle as a template to prepare a Cu (0) metal nanocatalyst in situ for use in the reduction of 4-NP.

Stimuli-responsive (pH, temperature and magnetic field) 4-vinylpyridine (4-VP)-based nanoparticles in copolymeric formulation with core-shell morphology were synthesized using N-isopropylacrylamide (NIPAM), 2-hydroxyethyl methacrylate (HEMA), acrylic acid (AAc), and methacrylic acid (MAc) as shell-forming monomers. Keeping the 4-VP ratio constant and varying the comonomer amounts produced particles with variant shell thickness. Multi-responsive p(4-VP)-based nanoparticles were further modified by reacting with different functional groups containing bromoalkanes by quaternization. These p(4-VP)-based particles were also utilized to include composite materials by encapsulating separately prepared magnetic ferrites. To demonstrate the potential usage of the synthesized particles and their modified forms as drug delivery devices, naproxene sodium salt as an antibacterial drug was used for in vitro release studies in PBS.

Tunable poly(4-vinylpyridine) (p(4-VP)) nanoparticles were synthesized in an oil-in-water emulsion using ethylene glycol dimethacrylate (EGDMA) as the cross-linker and ammonium persulfate (APS) as the initiator. The modification of p(4-VP) particles with N-alkyl quaternization was carried out through reacting with various quaternization agents containing carbon chains of various lengths, such as HCl, bromoethane, 1-bromobutane and 1-bromohexane. The obtained nanostructures were demonstrated to be resourceful materials as they are adaptable in terms of charge, size, hydrophilic/hydrophobic nature and magnetic responsive ability, rendered by encasing magnetic ferrites in the particles, for guidable use. Furthermore, the p(4-VP) particles have been shown to be inventive materials for biomedical applications, such as drug release systems using a model drug release of Naproxene Sodium, and as environmental materials to remove organic toxic phenols.

In this study, hydrogels were synthesized from 2-acrylamido-2-methyl-1-propansulfonic acid (AMPS) via a photo polymerization technique. Approximately 100 nm Ni metal nanoparticles were generated in situ inside these p(AMPS) hydrogel networks and used as a catalyst in hydrogen production by hydrolysis of sodium boron hydride in a basic medium. The effects of several parameters on the hydrolysis reaction such as the amount of catalyst, the initial concentration of NaBH4, and the temperature were investigated. The activation energy, activation enthalpy and activation of entropy for the reaction were calculated as 42.28 kJ mol(-1), 39.59 kJ mol(-1) and -171.67 J mol(-1) K-1, respectively. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.

Bulk poly(2-acrylamido-2-methyl-1-propansulfonic acid) (p(AMPS)) hydrogels were prepared by irradiation of an aqueous solution of AMPS in the presence of crosslinker and photoinitiator. These p(AMPS) hydrogel networks were utilized for in situ cobalt nanoparticle synthesis by reduction of metal ions absorbed into the hydrogel network with a reducing agent, i.e., NaBH(4). TEM images confirmed that Co particles are about 100 nm in size. The hydrogel network with embedded Co nanoparticles was utilized as a catalyst in the reduction of 4-nitrophenol (4-NP) and 2-nitrophenol (2-NP) in aqueous media in the presence of an excess amount of NaBH4. The kinetics of the reduction reaction under different reaction conditions was investigated to determine the activation parameters. Activation energies are 27.8 kJ mol(-1) and 39.3 kJ mol(-1) for 4-NP and 2-NP, respectively. It was found that hydrogel-Co composites were 99% active after 5 days storage. (C) 2010 Elsevier B.V. All rights reserved.

Lignite powered electric generation plants result in increasing environmental problems associated with gaseous emissions and the disposal of ash residues. Especially, low quality coals with high ash content cause enormous quantities of both gaseous and solid fly ash emissions. The main problem is related to the disposal of fly ash, which, in many cases, contains heavy metals. It is known that toxic trace metals may leach when fly ash is in contact with water. In this study, fly ash samples obtained from the thermal power plant in the town of Can in Turkey were investigated for leachability of metals under different acidic and temperature conditions. The experimental results show that a decrease in pH of the leachant favors the extraction of metal ions from fly ash. A significant increase in the extraction of arsenic, cadmium, chromium, zinc, lead, mercury, and selenium ions from the ash is attributed to the instability of the mineral phases. These heavy metals concentrations increase with respect to increasing acidic conditions and temperature. Peak concentrations, in general, were found at around 30 degrees C.