Graphene nanosheet reinforcement of polyurethane nanocomposite for green and sustainable photoluminescence, superhydrophobic, and anticorrosive paint.

A simple and environmentally friendly method was developed for smart and efficient waterborne polyurethane (PUR) paint. Sugarcane bagasse was recycled into reduced graphene oxide nanosheets (rGONSs). Both lanthanide-doped aluminate nanoparticles (LAN; photoluminescent agent, 7-9 nm) and rGONSs (reinforcement agent) were integrated into a waterborne polyurethane to produce a novel photoluminescent, hydrophobic, and anticorrosive nanocomposite coating. Using ferrocene-based oxidation under masked circumstances, graphene oxide nanosheets were produced from sugarcane bagasse. The oxidized semicarbazide (SCB) nanostructures were integrated into polyurethane coatings as a drying, anticorrosion, and crosslinking agent. Polyurethane coatings with varying amounts of phosphor pigment were prepared and subsequently applied to mild steel. The produced paints (LAN/rGONSs@PUR) were tested for their hydrophobicity, hardness, and scratch resistance. Commission Internationale de l'éclairage (CIE) Laboratory parameters and photoluminescence analysis established the opacity and colourimetric properties of the nanocomposite coatings. When excited at 365 nm, the luminescent transparent paints emitted a strong greenish light at 517 nm. The anticorrosion characteristics of the coated steel were investigated. The phosphor-containing (11% w/w) polyurethane coatings displayed the most pronounced anticorrosion capability and long-persistent luminosity. The prepared waterborne polyurethane paints were very photostable and durable.

Remediation through the coordinated use of local rice husk residues for the selective adsorption of iron and nickel in real landfill leachate.

Herein, we demonstrate the prospects of tackling several environmental problems by transforming a local rice husk residue into an effective adsorbent, which was then applied for the treatment of real landfill leachate (LL). The study focused on establishing (i) the effect of simple washing on morphological aspects, (ii) evaluating target adsorption capacity for total iron (Fe) and nickel (Ni), (iii) determining regeneration and reuse potential of the adsorbent and (iv) complying to the requirements of worldwide legislations for reuse of treated LL wastewater. The adsorbent was prepared by employing a simple yet effective purification process that can be performed in situ. The LL was collected post-membrane treatment, and the characterizations revealed high concentrations of Fe, Ni, and organic matter content. The simple washing affected the crystallinity, resulting in structural alterations of the adsorbents, also increasing the porosity and specific surface. The adsorption process for Ni occurred naturally at pH 6, but adjusting the pH to 3 significantly improved removal efficiency and adsorption capacity for total Fe. The kinetics were accurately described by the pseudo-second-order model, while the Langmuir model provided a better fit for the isotherms. The adsorbent was stable for 5 reuses, and the metals adsorbed were recovered through basic leaching. The removal capacities achieved underscore the remarkable effectiveness of the process, ensuring the treated LL wastewater meets rigorous global environmental legislations for safe use in irrigation. Thus, by employing the compelling methods herein optimized it is possible to refer to the of solving three environmental problems at once.

Fabrication of silver nanoparticles loaded acacia gum/chitosan nanogel to coat the pipe surface for sustainable inhibiting microbial adhesion and biofilm growth in water distribution systems.

Biofilm formation on the inner surfaces of pipes poses significant threats to water distribution systems, increasing maintenance costs and public health risks. To address this immense issue, we synthesized a nanogel formulation comprising acacia gum (AG) and chitosan (Cs), loaded with varying concentrations of silver nanoparticles (AgNPs), for using as an antimicrobial coating material. AgNPs were synthesized using AG as a reducing and stabilizing agent, exhibiting absorbance at 414 nm. The preparation of AgNPs was proved using TEM. Bactericidal efficacy was assessed against E. coli, Klebsiella pneumoniae, Enterococcus faecalis, and Bacillus subtilis. Using the dipping coating method, two pipe materials (polypropylene (PP) and ductile iron (DI)) were successfully coated. Notably, AgNPs2@AGCsNG nanogel exhibited potent antibacterial action against a wide range of pathogenic bacteria. Toxicity tests confirmed nanogel safety, suggesting broad applications. High EC50% values underscored their non-toxic nature. This research proposes an effective strategy for biofilm prevention in water systems, offering excellent antibacterial properties and biocompatibility. AG and Cs nanogels loaded with AgNPs promise to enhance water quality, reduce maintenance prices, and protect human public health in water distribution networks.

Fabrication of Co3O4/Co3S4/CNTs for photocatalytic treatment of wastewater under xenon lamp.

The current study is about the synthesis of nanoparticles (NPs) of cobalt oxide (CO) and cobalt sulfide (CS) followed by their nanocomposites as CO/CS and CO/CS/CNT by ultrasonication approach. The addition of carbon-based materials in the oxides and sulfides enhances their performance by developing physico-chemical interactions. Prepared NPs were utilized for the photodegradation of organic contaminants. The characteristics, as well as the efficiency of the prepared samples, have been systematically examined by X-ray diffraction (XRD) technique, Fourier transform infrared spectroscopy (FTIR), and UV-vis spectroscopy. Photocatalytic activities of bare samples and synthesized nanocomposites were tested for the degradation of methyl orange (MO) using a xenon lamp. The percentage degradation of dye was 24.14%, 57.94%, 71.66%, and 85.04% in the presence of CO, CS, CO/CS, and CO/CS/CNT, respectively. Crystal violet (CV), Rhodamine B (rho-B), and industrial wastewater were also degraded by the ternary composite. The comparative studies showed the best performance of CO/CS/CNT, which enhanced the generation of electron-hole pairs by absorption of photons of incoming radiations, increased charge separation, and maximum surface area for adsorption.

Improving the Durability of Chitosan Films through Incorporation of Magnesium, Tungsten, and Graphene Oxides for Biomedical Applications.

Bacterial infections that cause chronic wounds provide a challenge to healthcare worldwide because they frequently impede healing and cause a variety of problems. In this study, loaded with tungsten oxide (WO3 ), Magnesium oxide (MgO), and graphene oxide (GO) on chitosan (CS) membrane, an inexpensive polymer casting method was successfully prepared for wound healing applications. All fabricated composites were characterized by X-ray powder diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). A scanning electron microscope (SEM) was used to study the synthesized film samples' morphology as well as their microstructure. The formed WO3/MgO@CS shows a great enhancement in the UV/VIS analysis with a highly intense peak at 401 nm and a narrow band gap (3.69 eV) compared to pure CS. The enhanced electron-hole pair separation rate is responsible for the WO3/MgO/GO@CS scaffold's antibacterial activity. Additionally, human lung cells were used to determine the average cell viability of nanocomposite scaffolds and reached 121 % of WO3 /MgO/GO@CS nanocomposite, and the IC50 value was found to be 1654 µg/mL. The ability of the scaffold to inhibit the bacteria has been tested against both E. coli and S. aureus. The 4th sample showed an inhibition zone of 11.5±0.5 mm and 13.5±0.5 mm, respectively. These findings demonstrate the enormous potential for WO3 /MgO/GO@CS membrane as wound dressings in the clinical management of bacterially infected wounds.

Magnesium Ortho-Vanadate/Magnesium Oxide/Graphene Oxide Embedded through Cellulose Acetate-Based Films for Wound Healing Applications.

A multifunctional nano-films of cellulose acetate (CA)/magnesium ortho-vanadate (MOV)/magnesium oxide/graphene oxide wound coverage was fabricated. Through fabrication, different weights of the previously mentioned ingredients were selected to receive a certain morphological appearance. The composition was confirmed by XRD, FTIR, and EDX techniques. SEM micrograph of Mg3(VO4)2/MgO/GO@CA film depicted that there was a porous surface with flattened rounded MgO grains with an average size of 0.31 µm was observed. Regarding wettability, the binary composition of Mg3(VO4)2@CA occupied the lowest contact angle of 30.15 ± 0.8o, while pure CA represents the highest one at 47.35 ± 0.4°. The cell viability % amongst the usage of 4.9 µg/mL of Mg3(VO4)2/MgO/GO@CA is 95.77 ± 3.2%, while 2.4 µg/mL showed 101.54 ± 2.9%. The higher concentration of 5000 µg/mL exhibited a viability of 19.23%. According to optical results, the refractive index jumped from 1.73 for CA to 1.81 for Mg3(VO4)2/MgO/GO@CA film. The thermogravimetric analysis showed three main stages of degradation. The initial temperature started from room temperature to 289 °C with a weight loss of 13%. On the other hand, the second stage started from the final temperature of the first stage and end at 375 °C with a weight loss of 52%. Finally, the last stage was from 375 to 472 °C with 19% weight loss. The obtained results, such as high hydrophilic behavior, high cell viability, surface roughness, and porosity due to the addition of nanoparticles to the CA membrane, all played a significant role in enhancing the biocompatibility and biological activity of the CA membrane. The enhancements in the CA membrane suggest that it can be utilized in drug delivery and wound healing applications.

Titanium Dioxide/Chromium Oxide/Graphene Oxide Doped into Cellulose Acetate for Medical Applications.

Wound dressings have been designed based on cellulose acetate encapsulated with different concentrations of chromium oxide (Cr2O3) and titanium oxide (TiO2) with/without graphene oxide (GO). This study comprises the structural, morphological, optical, thermal, and biological behavior of chromium oxide/titanium dioxide/graphene oxide-integrated cellulose acetate (CA) films. The CA-based film bond formation was introduced by functional group analysis via Fourier transform infrared (FTIR) spectroscopy. The fabricated Cr2O3/TiO2/GO@CA film SEM micrographs demonstrate transition metal oxides Cr2O3 and TiO2 on a nano-scale. The TiO2@CA shows the lowest contact angle with 30°. Optically, the refractive index increases from 1.76 for CA to 2.14 for the TiO2@CA film. Moreover, normal lung cells (A138) growth examination in a function of Cr2O3/TiO2/GO@CA film concentration is conducted, introducing 93.46% with the usage of 4.9 µg/mL. The resulting data showed a promising wound-healing behavior of the CA-based films.

Cellulose-Acetate-Based Films Modified with Ag2O and ZnS as Nanocomposites for Highly Controlling Biological Behavior for Wound Healing Applications.

For wound healing, functional films with certain physicochemical and biological properties are needed. Thus, the current work aimed to fabricate multifunctional materials comprising metal oxide nanoparticles loaded with an efficient polymer to be used as dressing material. A composite containing polymeric phases of cellulose acetate (CA) blended with zinc sulfide (ZnS), silver oxide (Ag2O), and graphene oxide (GO) was successfully synthesized. The prepared composite crystallinity was studied using the X-ray diffraction technique (XRD). Further, the functional groups and the elemental analysis were investigated using Fourier-transform infrared spectroscopy (FTIR) and energy-dispersive X-ray spectroscopy (EDX). Furthermore, the surface morphology was studied using scanning electron microscopy (SEM) to obtain the shape and size of particles. SEM showed that the particles were formed in wide distribution in the range of 18-915 nm with an average size of 235 nm for Ag2O/ZnS/GO/CA. The particle size of Ag2O in the CA film was in the range between 19 and 648 nm with an average size of 216 nm, while the particle size of ZnS in CA was in the range of 12-991 nm with an average age particle size of 158 mm. In addition, EDX, based on SEM investigation, detected high carbon and oxygen quantities at around 94.21% of the composite. The contact angle decreased and reached 26.28° ± 2.12° in Ag2O/ZnS/CA. Furthermore, thermogravimetric analysis (TGA) was used to investigate the thermal stability, and the composition was thermally stable until 300 °C. Moreover, the cell viability of "normal lung cells" reached 102.66% in vitro at a concentration of 1250 µg/mL. The antibacterial activity of Ag2O/ZnS/GO/CA was also detected against E. coli with a zone of inhibition reaching 17.7 ± 0.5 mm. Therefore, the composite can be used in biomedical applications due to its biocompatibility and antibacterial activity.

Synthesis and Characterization of Chitosan-Containing ZnS/ZrO2/Graphene Oxide Nanocomposites and Their Application in Wound Dressing.

The development of scaffold-based nanofilms for the acceleration of wound healing and for maintaining the high level of the healthcare system is still a challenge. The use of naturally sourced polymers as binders to deliver nanoparticles to sites of injury has been highly suggested. To this end, chitosan (CS) was embedded with different nanoparticles and examined for its potential usage in wound dressing. In detail, chitosan (CS)-containing zinc sulfide (ZnS)/zirconium dioxide (ZrO2)/graphene oxide (GO) nanocomposite films were successfully fabricated with the aim of achieving promising biological behavior in the wound healing process. Morphological examination by SEM showed the formation of porous films with a good scattering of ZnS and ZrO2 nanograins, especially amongst ZnS/ZrO2/GO@CS film. In addition, ZnS/ZrO2/GO@CS displayed the lowest contact angle of 67.1 ± 0.9°. Optically, the absorption edge records 2.35 eV for pure chitosan, while it declines to 1.8:1.9 scope with the addition of ZnS, ZrO2, and GO. Normal lung cell (WI-38) proliferation inspection demonstrated that the usage of 2.4 µg/mL ZnS/ZrO2/GO@CS led to a cell viability % of 142.79%, while the usage of 5000 µg/ mL led to a viability of 113.82%. However, the fibroblast malignant cell line exposed to 2.4 µg/mL ZnS/ZrO2/GO@CS showed a viability % of 92.81%, while this percentage showed a steep decline with the usage of 5000 µg/ mL and 2500 µg/mL, reaching 23.28% and 27.81%, respectively. Further biological assessment should be executed with a three-dimensional film scaffold by choosing surrounding media characteristics (normal/malignant) that enhance the selectivity potential. The fabricated scaffolds show promising selective performance, biologically.

Colour-switchable and photoluminescent polyvinyl chloride for multifunctional smart applications.

Recycled polyvinyl chloride (PVC) waste was used to prepare transparent materials with long-lasting phosphorescence, photochromic activity, hydrophobicity, strong optical transmission, ultraviolet (UV) light protection, and stiffness. Lanthanide-activated aluminate (LaA) microparticles were prepared using a high temperature solid-state procedure, and were subjected to top-down grinding technology to produce lanthanide-aluminate nanoparticles (LaAN). Laminated PVC bottles were shredded into a transparent plastic matrix, which was combined with LaAN and drop casted to produce smart materials for various applications. Smart windows and photochromic film for smart packaging can be made from recycled PVC waste by immobilizing it with various ratios of LaAN. Long-lasting phosphorescent translucent PVC smart windows and films need LaAN to be evenly dispersed in PVC without clumping. Different analytical methods were used to assess the material's morphological structure and chemical composition. Photoluminescence and decay spectra were all used to investigate the luminescence characteristics. In addition, the mechanical performance was studied. According to Commission Internationale de l'Éclairage laboratory colour measurements, this transparent PVC smart material becomes bright green under UV rays and turns a greenish-yellow in the dark. The PVC luminescence was observed to exhibit apparent emission bands at 429 and 513 nm when excited at 367 nm. Improvements were monitored in UV shielding and hydrophobicity when increasing the phosphor concentration. LaAN-immobilized PVC exhibited reversible photochromism. The present approach can be applied to various applications such as anticounterfeiting films for smart packaging, smart windows, and warning light marks.

Antidiabetic Wound Dressing Materials Based on Cellulosic Fabrics Loaded with Zinc Oxide Nanoparticles Synthesized by Solid-State Method.

The current study aims for the use of the solid-state technique as an efficient way for the preparation of zinc oxide nanoparticles (ZnONPs) as an antimicrobial agent with high concentration using sodium alginate as stabilizing agent. ZnONPs were prepared with three different concentrations: ZnONPs-1, ZnONPs-2, and ZnONPs-3 (attributed to the utilized different concentrations of zinc acetate, 1.5, 3 and 4.5 g, respectively). The as-fabricated ZnONPs (ZnONPs-1, ZnONPs-2, and ZnONPs-3) were used for the treatment of cellulosic fabrics as dressing materials for the diabetic wounds. DLS findings illustrated that the as-prepared ZnONPs exhibited average particle size equal to 78, 117, and 144 nm, respectively. The data also showed that all the formulated ZnONPs were formed with good stability (above -30 mv). The topographical images of cellulosic fabrics loaded with ZnONPs that were obtained by SEM confirmed the deposition of nanoparticles onto the surface of cellulosic fabrics with no noticeable agglomeration. The findings also outlined that the treated cellulosic fabrics dressings were proven to have enhanced bactericidal characteristics against the pathogenic microorganisms. The finding of wound contraction for the diabetic rats was measured after 21 days and reached 93.5% after treating the diabetic wound with cotton fabrics containing ZnONPs-2. Ultimately, the generated wound dressing (cellulosic fabrics loaded with ZnONPs) offers considerable promise for treating the wound infections and might be examined as a viable alternative to antibiotics and topical wound treatments.

Correction: Electrocatalytic hydrogen generation using tripod containing pyrazolylborate-based copper(ii), nickel(ii), and iron(iii) complexes loaded on a glassy carbon electrode.

[This corrects the article DOI: 10.1039/D1RA08530A.].

Electrocatalytic hydrogen generation using tripod containing pyrazolylborate-based copper(ii), nickel(ii), and iron(iii) complexes loaded on a glassy carbon electrode.

Three transition metal complexes (MC) namely, [TpMeMeCuCl(H2O)] (CuC), [TpMeMeNiCl] (NiC), and [TpMeMeFeCl2(H2O)] (FeC) {TpMeMe = tris(3,5-dimethylpyrazolyl)borate} were synthesized and structurally characterized. The three complexes CuC, NiC, and FeC-modified glassy carbon (GC) were examined as molecular electrocatalysts for the hydrogen evolution reaction (HER) in alkaline solution (0.1 M KOH). Various GC-MC electrodes were prepared by loading different amounts (ca. 0.2-0.8 mg cm-2) of each metal complex on GC electrodes. These electrodes were used as cathodes in aqueous alkaline solutions (0.1 M KOH) to efficiently generate H2 employing various electrochemical techniques. The three metal complexes' HER catalytic activity was assessed using cathodic polarization studies. The charge-transfer kinetics of the HER at the (GC-MC)/OH- interface at a given overpotential were also studied using the electrochemical impedance spectroscopy (EIS) technique. The electrocatalyst's stability and long-term durability tests were performed employing cyclic voltammetry (repetitive cycling up to 5000 cycles) and 48 h of chronoamperometry measurements. The catalytic evolution of hydrogen on the three studied MC surfaces was further assessed using density functional theory (DFT) simulations. The GC-CuC catalysts revealed the highest HER electrocatalytic activity, which increased with the catalyst loading density. With a low HER onset potential (E HER) of -25 mV vs. RHE and a high exchange current density of 0.7 mA cm-2, the best performing electrocatalyst, GC-CuC (0.8 mg cm-2), showed significant HER catalytic performance. Furthermore, the best performing electrocatalyst required an overpotential value of 120 mV to generate a current density of 10 mA cm-2 and featured a Tafel slope value of -112 mV dec-1. These HER electrochemical kinetic parameters were comparable to those measured here for the commercial Pt/C under the same operating conditions (-10 mV vs. RHE, 0.88 mA cm-2, 108 mV dec-1, and 110 mV to yield a current density of 10 mA cm-2), as well as the most active molecular electrocatalysts for H2 generation from aqueous alkaline electrolytes. Density functional theory (DFT) simulations were used to investigate the nature of metal complex activities in relation to hydrogen adsorption. The molecular electrostatic surface potential (MESP) of the metal complexes was determined to assess the putative binding sites of the H atoms to the metal complex.

Green metallochromic cellulose dipstick for Fe(III) using chitosan nanoparticles and cyanidin-based natural anthocyanins red-cabbage extract.

Environmentally-friendly, cyanidin(Cy)-based anthocyanin isolated from red-cabbage served as a spectroscopic probe imprinted onto chitosan nanoparticles (CsNPs), which were in turn integrated onto cellulose paper strip (CPS) as a host matrix to develop a metallochromic solid state sensor for real-time selective determination of ferric ions in an aqueous medium. The ferric transition metal ions in aqueous environments were detected using a novel, simple, portable, fast responsive, low-cost, real-time, environmentally safe, reversible and colorimetric sensor based on chitosan nanoparticles as a hosting biopolymer and cyanidin phenol chromophore as a biomolecular probe. In order to use the cyanidin biomolecule as a pH indicator and chelating agent, it was purified from red-cabbage and added into the CsNPs biosensor film. The colorimetric shift increased in direct proportion to the ferric ion concentration. As a result, the current research that was both qualitative and quantitative was carried out. While the Cy-CsNPs-CPS sensor showed high selectivity for ferric ions, no color change was detected for other metal cations. It was discovered that the detection process occurred as a result of a coordination complex formed between the active sites of phenolic cyanidin and Fe(III) ions.

Fabrication of Bio-Based Film Comprising Metal Oxide Nanoparticles Loaded Chitosan for Wound Dressing Applications.

In the current work, chitosan (CS)-metal oxide nanohybrid (MONH) composites are prepared via combining CS with MONH made of vanadium oxide (V2O5), ytterbium trioxide (Yb2O3), and graphene oxide (GO) to generate promising wound dressing materials using the film-casting method. The developed nanohybrid@CS was examined using techniques such as Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDX), and thermogravimetric analysis (TGA). For Yb2O3@CS, the surface morphology was shown to be a rough and porous surface with pores that ranged in size from 3.0 to 5.0 µm. For CS with Yb2O3, Yb2O3/V2O5@CS, and Yb2O3/V2O5/GO@CS, the contact angles were 72.5°, 68.2°, and 46.5°, respectively. When the nanohybrid@CS was in its hydrophilic phase, which is good for absorbing moisture and drugs, there was a notable decrease in angles that tended to rise. Additionally, the inclusion of MONH allowed the cell viability to be confirmed with an IC50 of 1997.2 g/mL and the cell growth to reach 111.3% at a concentration of 7.9 g/mL.

Photocatalytic degradation of Maxilon C.I. basic dye using CS/CoFe2O4/GONCs as a heterogeneous photo-Fenton catalyst prepared by gamma irradiation.

CS/CF/GONCs were synthesized via gamma irradiation cross-linking method with the aid of sonication. The nanocomposites exhibited a photo-Fenton catalytic feature for the degradation of Maxilon C.I. basic dye in aqueous medium using sunlight. The effects of pH, H2O2 concentration, and dosage of the catalyst, on the degradation rates of the dyes were examined. The optimal degradation rate was reached with 10mM H2O2 at pH 9.5. It was verified that the Maxilon C.I. basic dye degradation rate fits a pseudo-first-order kinetics for different initial concentrations of Maxilon C.I. dye. Fourth cyclic tests for Maxilon C.I. degradation showed that the magnetic catalyst was very stable, recoverable, highly active, and easy to separate using an external magnet. Hence, this magnetic catalyst has potential use in organic pollutant removal.

Radiation synthesis of multifunctional polymeric hydrogels for oral delivery of insulin.

Polyelectrolyte crosslinked hydrogel was synthesized using gamma radiation-induced copolymerization of methacrylic acid (MAA), N,N-dimethyl aminoethyl methacrylate (DMAEMA) in aqueous solution to utilize for oral delivery of insulin. The influence of copolymer composition and pH value of the surrounding medium on the type of water diffusion in the glassy polymer was discussed. In addition, the swelling kinetics tests on MAA/DMAEMA (90/10) reveal that the swelling kinetics of the proposed hydrogel follows a Fickian diffusion process in media of pH 5, and an anomalous diffusion process in media of pH 1.5 and 7.2. The cross-linked three-dimensional polymers were characterized by scanning electron microscopy and FT-IR. In the matrices with increase in the content of MAA had shown increased bioadhesivity. Insulin was entrapped in these gels and the in vitro release profiles were established separately in both (SGF, pH 1.5) and (SIF, pH 7.2). The release profile of insulin showed negligible release in acidic media (SGF, pH 1.5) and sustained release in simulated intestinal fluid (SIF, pH 7.2). Drug release studies showed that the increasing content of MAA in the copolymer enhances release in SIF to design and improve insulin release behavior from these carriers.

Radiation preparation of PVA/CMC copolymers and their application in removal of dyes.

Copolymer hydrogels composed of poly(vinyl alcohol) (PVA) and carboxymethyl cellulose (CMC) was prepared by using electron beam irradiation as crosslinking agent. The copolymers were characterized by FTIR and the physical properties such as gelation. The thermal behavior and swelling properties of the prepared hydrogels were investigated as a function of PVA/CMC composition. The factors effecting adsorption capacity of acid, reactive and direct dyes onto PVA/CMC hydrogel, such as CMC content, pH value of the dye solution, initial concentration and adsorption temperature for dyes were investigated. Thermodynamic study indicated that the values the negative values of DeltaH suggested that the adsorption process is exothermic. The value of DeltaH (38.81 kJ/mol) suggested that the electrostatic interaction is the dominant mechanism for the adsorption of dyes on hydrogel.

Adsorption and desorption of phosphate and nitrate ions using quaternary (polypropylene-g-N,N-dimethylamino ethylmethacrylate) graft copolymer.

Study has been made on the preparation of functionalized copolymer by grafting N,N-(dimethylaminoethyl) methacrylate (DMAEMA) onto polypropylene (PP) films using gamma-irradiation technique. The effect of monomer concentration and irradiation dose on the grafting yield was studied. It was found that grafting yield increases with increasing the monomer concentration and irradiation dose. Subsequent quaternization of the amine group of PDMAEMA graft chain using different reagents, 1-bromo octadecane, methyl iodide and benzyl chloride, to improve their ionic character was carried out. The grafted PP films were characterized by IR spectroscopy, and mechanical and thermal properties. During the adsorption of phosphate (PO(4)(3-)) and nitrate (NO(3)(-)) ions, the rate of adsorption, pH effect, desorbability and initial feed concentration effect were investigated. It was found that the adsorption of PO(4)(3-) and NO(3)(-) ions increases with increasing the adsorption time up to 10h and decreases with increasing the pH of medium. The desorbability is ranging from 18 to 30%, and it is relatively difficult to desorb PO(4)(3-) and NO(3)(-) ions from the functionalized grafted copolymers. Results showed good possibility for the use of such functionalized grafted film in the field of removal of some anions such as PO(4)(3-) and NO(3)(-) from their media.