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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.

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 (ZrO

The reaction of the tridentate ligand bis(2-picolyl)amine (BPA) with the chloride or perchlorate salts of zinc(II) ions yielded two zinc(II) complexes of the types: [(BPA)ZnCl2]·2H2O (1) and [(BPA)2Zn](ClO4)2 (2). The intermediate complex species, namely [(BPA)Zn(OH)(H2O)](ClO4) (3) and [(BPA)Zn-OP(= S)(CH3)2] (4) were successfully isolated separately in good yields and pure forms. Complexes 1–4 were characterized in the solid state by using elemental analyses, thermal analyses, FT-IR, and X-ray single crystal diffraction as well as in solution by using 1H NMR titration and cyclic voltammetry (CV). From X-ray structural and spectral features it can be concluded that the coordination environment around Zn(II) ion in 1 is a distorted square pyramidal geometry with τ5 value of 0.148. Whereas in 2, two picolyl chelates in the equatorial plane and two slightly longer axial pyridines are coordinated in a distorted octahedral trans-facial arrangement. Kinetic studies were performed on these complexes to evaluate their efficiency as functional hydrolase models for the hydrolysis of the toxic organophosphate insecticide, Fenitrothion. The pH-dependence of the catalytic rate gives a bell-shaped curve, which gives a strong proof that the hydroxoaqua complex [(BPA)Zn(H2O)(OH)]− 3 is the catalytically active species in the hydrolysis reactions than that of the octahedral [(BPA)2Zn]2+ with fully saturated coordination sphere.

In this research, the MgO nanoparticles were incorporated into (acrylic acid /polyvinyl alcohol) PAA/PVA hydrogel by using gamma radiation technique at a dose rate of 1.9 kGy/k. The unique properties of MgO nanoparticles as structure, active surface properties, and stability make such nanoparticles have considerable potential as antimicrobial agents in food applications. In spite of known antibacterial activity of MgO NPs, the mechanism of metal oxide nanoparticle action on bacteria is complicated and not fully understood. The PAA/PVA system was mixed with various contents of MgO nanoparticles to prepare its MgO nanocomposite hydrogels. The morphology of the PAA/PVA copolymer hydrogels and their MgO nanocomposites hydrogels was characterized by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to prove the surface, bulk change, size, and the formation of MgO nanoparticles. TEM measurement estimated that the average particle size of prepared MgO NPs was 7.13 nm. The swelling properties of the various AAc hydrogels and its MgO nanocomposites hydrogels were also studied. The prepared acrylic acid copolymers and their MgO nanocomposites were examined for applicability as antibacterial material, and the results revealed that hydrogels and MgO nanocomposites hydrogels prepared in this study have higher antibacterial activity toward Staphylococus Aureus (S.a.) than Escherichia Coli (E. Coli). The discovery of novel and efficient nanocomposites may have a potential therapeutic role.

Silver nanoparticles coated with chitosan (AgNPs) and AAm/HEMA/Ag nanocomposites synthesized by using 60Co gamma radiation cell at a dose rate of 2.8 kGy/h and used for uptake of mercury from wastewater. To study the various properties of the nanocomposites different characterization techniques such as XRD, TEM, FTIR, and SEM were applied. Water uptake for all AAm/HEMA hydrogels studied under the effect of many factors was studied in detailed. Based on the water uptake results the AAm/HEMA (1:0.5 v/v) composition was used as a precursor for preparation AAm/HEMA/Ag nanocomposite hydrogel. By examining, the possibility of using the prepared hydrogels and nanocomposite hydrogel for adsorption of Hg2+ the results showed that the adsorption processes depend on time, initial concentration, dose of adsorbent and pH value. The adsorption capacity increase as pH increased up to pH 5. Then started decreasing at pH values higher than pH 5. The pseudo-first order and pseudo second order used to evaluate the kinetic models and the mechanism of the adsorption. Results showed that the adsorption kinetics best fit the pseudo-second-order model. Thermodynamic data revealed spontaneous exothermic processes and was a physisorption reaction. In addition, results show that the AAm/HEMA/Ag nanocomposite has high efficiency for removing Hg (II) ions from wastewater containing.

The objective of study is preparing multi-responsive, nontoxic, and highly stable nanocomposite hydrogels for effective reduction and decolonization of broad spectrum of toxic dyes. The nanocomposite hydrogels are composed of N-isopropy acrylamide, acrylic acid, and silver/chitosan nano-dispersion and prepared by the effect of Gamma radiation at a dose rate of 2.6 kGy/h. The physical and chemical properties of the various prepared nanocomposites hydrogels were studied by various techniques as SEM, TEM, XRD, and FTIR. The swelling properties of the nanocomposites hydrogels were studied under various conditions as pH and temperature. Given the physical properties of multifunctional thermo-responsive N-isopropy acrylamide, acrylic acid hydrogel, and its Ag nanocomposite, they hold the strong potential for toxic dyes degradation as Erioglaucine as a model dye. In this paper, we review various silver and thermo-responsive poly (N- isopropylacrylamide/Acrylicacid /silver), (PNIPAM/AA/Ag) nanocomposites and highlight their high activity as a catalyst for degradation of various types of dyes.

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.

A new mixed ligand complex, viz., [Ni(Tren)(Barb)(H2O)](Barb)(Barb-H)•2H2O (NiC) {Tren = tris(2-aminoethyl)amine and Barb = 5,5-diethlybarbiturate} has been synthesized and characterized. The nickel(II) complex was grafted to g-C3N4, forming NiC@g-C3N4. The obtained NiC complex and its hybrid material NiC@g-C3N4 were characterized by means of FT-IR, TGA-DSC, UV-vis., SEM-EDX, and XRD. Single crystal X-ray crystallography suggests that NiC exhibits NiN5O octahedral geometry. The results also show that the complex molecules are connected via N–H××××O hydrogen bonds. The complex NiC and its NiC@g-C3N4 composite showed cytotoxic effects on in vivo experiments. They also showed an increase in tissue damage markers that are represented by the increase in tissue levels of malondialdehyde (MDA) in brain, liver, kidney and heart. In parallel, both materials showed inhibitory activity for examined antioxidants such as glutathione-S-transferase (GST), superozide dismutase (SOD), glutathione (GSH), glutathione reductase (GSH-R). The destructive effects were clearer for the NiC@g-C3N4 composite compared to in liver, brain and kidney, respectively. The grafting of NiC complex in g-C3N4 is responsible for improving the catalytic activity, which is due to the synergistic effect of both components and facile recovery, as well recycling of the catalyst.

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.

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.

ERRATUM available: The authors regret that an incorrect version of Scheme 1 was given in the original article. See here for more information: 10.1039/D1RA08530A; International audience; Three transition metal complexes (MC) namely, [Tp(MeMe)CuCl(H2O)] (CuC), [Tp(MeMe)NiCl] (NiC), and [Tp(MeMe)FeCl(2)(H2O)] (FeC) {Tp(MeMe) = tris(3,5-dimethylpyrazolypborate) 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 H-2 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 H-2 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.

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.

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.

Silver nanoparticles (Ag NPs) are widely used as engineered nanomaterials in many advanced nanotechnologies, due to their versatile, easy and cheap preparations combined with peculiar chemical-physical properties. Their increased production and integration in environmental applications including water treatment raise concerns for their impact on humans and the environment. In this study, gamma radiation dose of 20 kGy was utilized to induce the synthesis silver nanoparticles (Ag NPs) in the alginate micro beads to prepare calcium Alginate/Ag (Ca-ALG/Ag) nanocomposite beads. These beads were then used to degrade toxic basic dyes in waste water. Initially, Ca-ALG /Ag nanocomposite beads were synthesized and characterized using Ultra Violet-visible spectrum (UV-Vis), Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD) and Transmission Electron Microscope (TEM) for confirming the formation of Ag NPs and morphological study. The catalytic efficiency of the resulting Ca-ALG/Ag nanocomposite beads is evaluated for the degradation of dyes such sandocryl blue dye in the presence of NaBH4. The catalytic degradation of sandocryl blue dye was very fast in the present conditions: 0.1 g of catalyst 5 ml NaBH4 and the optimum time for complete reduction was 30 min. The pseudo-first order, pseudo second order and intra particle diffusion model used to evaluate the kinetic models and the mechanism of the degradation. Results showed that the degradation kinetics best fit the pseudo-second-order model and Langmuir isotherm model. The Biopolymer-based nanocomposite beads of calcium alginate, and Ag NPs can be applied to reduce dyestuff, where it is economically viable and environmentally friendly.

Correction for ‘Electrocatalytic hydrogen generation using tripod containing pyrazolylborate-based copper(ii), nickel(ii), and iron(iii) complexes loaded on a glassy carbon electrode’ by Mohamed M. Ibrahim et al., RSC Adv., 2022, 12, 8030–8042, https://doi.org/10.1039/D1RA08530A.

Copolymers of polyvinyl butyral (PVB)/polyethylene glycol diacrylate (PEGDA) were prepared by free radical polymerization using gamma irradiation. The physical properties such as gelation, swelling and the thermal behavior of the prepared PVB/PEGDA copolymer were investigated as a function of molecular weight of PEGDA. The thermal behavior of blank PVB (PVB/PEGDA)-575 and (PVB/PEGDA)-750 copolymers as a function of absorbed dose up to 100 kGy was determined using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The thermal stability of the prepared copolymers was improved by gamma irradiation, PEGDA and the increasing of PEGDA molecular weight. Two textile dyes, Diamine Fast Scarlet GG and Direct Pink 3B, were used as model anionic dyes. The adsorption of PVB/PEGDA hydrogels of different molecular weights was investigated towards the two anionic dyes by the batch equilibrium method. The adsorption capacity of the copolymers was evaluated as a function of initial dye concentration, different molecular weight, and time. The equilibrium data obtained in batch experiments were correlated to Langmuir and Freundlich isotherm equations. Results showed that the adsorption of Direct Pink 3B fitted well to the Langmuir model, while the adsorption pattern of Diamine Fast Scarlet GG followed the Freundlich isotherm, which suggests heterogeneity of the adsorption sites on the copolymer. Thermodynamic data revealed spontaneous exothermic processes and was a physisorption reaction. Our results demonstrate that the PVB/PEGDA copolymer is very promising for removing organic dyes from waste water.

The development of safe and cost-effective methods for the treatment of dye polluted wastewater has been a great concern among researchers. Herein, N-vinylpyrrolidon/chitosan/Fe3O4 (NVP/CS/Fe3O4) nanocomposite as a magnetic nano-adsorbent has been prepared by the in situ co-precipitation of iron salts in the CS/NVP hydrogel matrix. To study the various physical morphological and structural properties of the magnetic nanocomposites different characterization techniques such as IR, SEM, TEM, and XRD were applied. IR spectra confirmed the formation of magnetic nanoparticles through the appearance of the specific band at the wave number range of 400–500 cm−1. VSM study showed that in spite of embedding of magnetic nanoparticles with in the NVP/CS hydrogel network they are still super paramagnetic compared with the pare Fe3O4 nanoparticles. The NVP/CS/Fe3O4 nanocomposite was used as sorbent for the removal of methyl orange (MO) as a model dye. Kinetic isotherm and diffusional behavior of the prepared NVP/CS hydrogels and their magnetic nanocomposites were also, studied. By examining the possibility of using the prepared hydrogels and magnetic nanocomposite for adsorption of MO the results showed that the adsorption processes depend on time, initial concentration, and dose of adsorbent. The pseudo-first order, pseudo second order and intra particle diffusion model used to evaluate the kinetics and the mechanism of the adsorption process where it is found that the second order kinetics describing well the adsorption process of MO dye using NVP/CS/Fe3O4 nanocomposite and the adsorption rate was controlled by various diffusion models not only intra particle diffusion.

Sodium alginate/chitosan/hydroxyapatite (SA/CS/HAP) nanocomposite hydrogel containing different amounts, 0.6, 2.0, 3.5 and 5.0 % wt/v, of HAP was synthesized using gamma radiation as cross-linker to be utilized for oral delivery drug. The nanocomposites were characterized using Fourier transform infrared, X- ray diffraction, scanning electron microscope and transmission electron microscope (TEM). The efficiency of nanocomposite hydrogel samples as a drug delivery system was examined where doxorubicin (DOX)—an anticancer drug for liver cancer—was chosen as a model drug. The in vitro drug release behavior of DOX from the nanocomposite was studied at pH 7.4 and pH 5 within 24 h at 37 °C. Based on the diffusion as well as the drug release behavior, the mechanism of the drug release from the nanocomposite has been described. The effect of initial feed concentration of drug as well as the % of HAP on drug release was also studied. The results showed that, drug release is pH sensitive and samples showed higher release at pH 5.

Photocatalytic degradation of 2-chlorophenol (2-CP) was studied using the photocatalyst chitosane/CoFe2O4 nanocomposite (CS/CF) under visible light. CS/CF nanocomposites were synthesized via gamma irradiation cross-linking method with the aid of sonication. Physical characteristics of CS/CF were studied using infrared spectrophotometer (IR), scanning electron microscopy (SEM), transmission electron microscope (TEM) and ultraviolet–visible (UV–vis) spectroscopy. Their photocatalytic activity was tested for the degradation of 2-CP in aqueous medium using sunlight. The effect of different parameters such as catalyst concentration, 2-CP concentration and reaction pH on degradation was also examined. It was verified that the 2-CP degradation rate fits a pseudo-first-order kinetics for initial 2-CP concentrations between 25 and 100 mg/l, at 30 °C. The degradation kinetics fit well Langmuir–Hinshelwood rate law. The degradation of (2-CP) follows pseudo-first-order kinetics. Results showed that after the catalyst had been used 5 times repeatedly, the degradation rate was still above 80%.

Organophilic montmorillonite (OMMT) was synthesized by cationic exchange reaction of Na+-MMT and vinyl benzyl triethyl ammonium chloride (VBTAC) as a reactive organic modifier in an aqueous solution. A series of styrene (St)/acrylic acid (AA)/OMMT nanocomposite hydrogel containing different wt% of OMMT was synthesized through in situ polymerization using γ-ray. The samples were characterized using Fourier transform infrared (FTIR), X-ray powder diffraction (XRD), and transmission electron microscope (TEM), whereas thermal stability was examined by thermogravimetric analysis (TGA). The adsorption capacity and rate for both Acid Green B (anionic) and Maxilon C.I. Basic (cationic) dye including adsorption kinetics and isotherm were investigated at 30°C. TEM measurements showed spherical nanosized particles of average diameter 30–40 nm and XRD suggested the formation of exfoliated nanocomposite. TGA measurements showed that the addition of OMMT did not enhance the thermal stability where the onset temperature of the degradation for all samples was around 125°C. The effect of some important parameters on dye adsorption such as solution pH, initial dye concentration, and contact time was investigated. The equilibrium data obtained in batch experiments were correlated to Langmuir and Freundlich isotherm equations. Results showed that the adsorption of Acid Green B fitted well to the Langmuir model while the adsorption pattern of Maxilon C.I. Basic followed the Freundlich isotherm, which suggests heterogeneity of the adsorption sites on the nanocomposite. POLYM. COMPOS., 35:2353–2364, 2014. © 2014 Society of Plastics Engineers

The goal of this research is to develop a composite hydrogel system for sustained release of therapeutic agents. The hybrid hydrogels were prepared by radiation crosslinking on aqueous solution of Chitosan (CS)/N-vinyl-2-pyrrolidone (NVP) with different loads of CaCO3 in the presence of hydrocortisone acetate (HCA), an anti-inflammatory drugs. Physical characteristics of CS/NVP/CaCO3 were studied using X-ray diffraction (XRD) and infrared spectrophotometery (IR). The porous structure of resulted hydrogel was confirmed by SEM micrographs. The effect of doses and calcium carbonate amount on the swelling of the hydrogels was investigated. The ability of the prepared CS/NVP/CaCO3-based hybrid hydrogels to be used as drug carriers for anti-inflammatory-specific drug delivery system was estimated using HCA as a model drug. POLYM. COMPOS., 35:1176–1183, 2014. © 2013 Society of Plastics Engineers

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.

pH-Sensitive hydrogel was synthesized by gamma radiation crosslinking for sodium alginate extracted from the marine brown alga Turbinaria decurrens and acrylic acid. Preparation of the hydrogels involved free radical polymerization of a combination of acrylic acid (w = 0.2) and different contents of sodium alginate (w = 0.05, 0.10, and 0.15) in aqueous solution using gamma rays of a 60Co source at an irradiation dose rate of 1.2 kGy/h. The swelling behavior of the prepared hydrogel was determined by investigating the swelling time, pH of medium, and alginate content in the hydrogel. The results showed that the hydrogel reached the equilibrium swelling state in water after 6 h. The hydrogel was found to be pH responsive. The drug loading and in vitro release properties of the hydrogel were also evaluated using chlortetracycline hydrochloride as the model drug. The adsorption isotherm studies by batching techniques under the effect of different initial feed concentrations of drug, different pH values, and different sodium alginate content of the adsorbent hydrogel were investigated. The diffusion of chlortetracycline hydrochloride within the hydrogel was found to be of non-Fickian character. The kinetic parameters such as the diffusion exponent, diffusion constant, and diffusion coefficient were also evaluated. .

In this paper, the preparation, characterization and dye adsorption properties of nanocomposite (calcium alginate/organophilic montmorillonite) (CA/OMMT) were investigated. A new nanocomposite consisting of alginate and OMMT was prepared by polymerization using γ-rays irradiation as initiator. Physical characteristics of CA/OMMT were studied using X-ray diffraction (XRD), infrared spectrophotometery (IR), thermal gravimetric analysis (TGA), transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED). Two textile dyes, acid green B and direct pink 3B, were used as model anionic dye. Factors affecting dye sorption, such as pH, sorbent concentration and temperature of each dye solution were extensively investigated. It was found from the study that the sorption of dyes by the nanocomposite is pH-dependent and maximum sorption was obtained at pH 2. The thermodynamic data showed that dye adsorption onto alginate was spontaneous, exothermic, and a physisorption reaction. On the basis of the data of the present investigation, one could conclude that the as-prepared adsorbents exhibited excellent affinity for the dye, and can be applied to treat wastewater containing anionic dyes.

The present work reports the effect of radiation cross-linking on aqueous solution of 4-acryloyl morpholine (ACMO)/acrylic acid (AA) in the presence of flutamide (FLT), an anticancer drug. Use of a γ-irradiation process within 5 kGy provided an insoluble hydrogel. Ultraviolet-visible absorption, fluorescence spectroscopy, and Fourier transform infrared spectroscopy were employed to study the complex formation of FLT with ACMO and AA. The ability of the prepared ACMO/AA-based hydrogels to be used as drug carriers for anticancer-specific drug delivery system was estimated using FLT as a model drug. In vitro drug release studies in a pH 7 buffer solution show that 20%–30% of the FLT was continuously released from the FLT-incorporated ACMO/AA hydrogel within 1 day, followed by a gradual release upon 7 days under in vitro non-degradation hydrogel conditions. The recognition affinity of the ACMO/AA/FLT hydrogel is increased when synthesized in a high-concentration template solution. Open image in new window

Protein conjugates consisting of hydroxyethyl methacrylate and acrylic acid monomers in the presence of bovine serum albumin (BSA) were prepared by gamma irradiation to examine the potential use of these hydrogels in the controlled drug release systems. The study parameter was the BSA content in the as-prepared conjugates. Polymers were characterized with FTIR, scanning electron microscopy (SEM), and swelling studies. The polymerization reaction caused the rearrangement of the BSA carbonyl hydrogen bonding and finally led to the modification of the BSA secondary structure as proved by FTIR. SEM proved that the prepared conjugates matrices are porous, with a three-dimensional interconnected microstructure. The swelling kinetics of the hydrogels and the release dynamics of an anticancer model drug (flutamide) have been studied. High equilibrium swelling values, up to 1550%, could be observed and were correlated with the increase in pH, temperature, and BSA content. The mechanism of swelling changed from Fickian to non-Fickian by reducing the acidity of the medium. This study proved that there is a direct relationship between the protein content in the conjugates and both the loaded and the released drug. These pH responsive conjugates may be exploited for the delivery of flutamide. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

The use of hydrogels as carriers for anticancer delivery has been a subject of significant recent research. In our recent work, we have shown that diffusion-controlled delivery of flutamide from hydrogels containing poly (dimethylaminoethyl methacrylate (DMAEMA)/ethyleneglycol dimethacrylate (EGDMA)) can be possible and controlled by the three-dimensional structure. Hydrogels based essentially on dimethylaminoethyl methacrylate and different ratios of ethyleneglycol dimethacrylate monomers were synthesized using gamma radiation copolymerization. The influence of copolymer composition and pH value of the surrounding medium on swelling behavior into the glassy polymer were discussed. The results showed that the ratio of EGDMA in the comonomer feeding solution has a great effect on the gel fraction and water content in the final hydrogel. In this regard, it was observed that the increase of EGDMA ratio decreased these properties. The ability of the prepared copolymer to be used as drug carrier for anticancer drug-delivery system was estimated using flutamide as a model drug. In vitro drug-release studies in different buffer solutions show that the basic parameters affecting the drug release behavior of hydrogel are the pH of the solution and DMAEMA content of hydrogel.

This paper describes the use of gamma radiation Co60 source as crosslinker for the preparation of gelatin based pharmaceutical hydrogels. Glutaraldehyde (GLU) (0.5% v/v) was incorporated after irradiation to crosslink the gelatin chains. Several samples of hydrogels P(PVA/MAA) were prepared by varying the ratio of PVA and MAA monomer. The swelling behavior of these hydrogels was investigated as a function of doses, concentration, copolymer composition (PVA:MAA ratio) and pH of the immersion medium. It was found that the swelling of test hydrogels was larger (8) in the alkaline medium than in the acid medium (3) and at pH 5.3 was the smallest (3). The characterizations of the hydrogels were performed by FTIR, SEM to evaluate the relationship of the structure and morphology of the hydrogels. The adsorption isotherm studies by batching techniques under the effect of different initial feed concentrations of drugs and MAA content of the adsorbent hydrogels will be investigated. Furthermore, for the evaluation ...

Organophilic montmorillonite (OMMT) was synthesized by cationic exchange between Na-MMT and Vinyl benzyl triphenyl phosphonium chloride in an aqueous solution. A new nanocomposite consisting of 4-acryloyl morpholine-chitosan and OMMT was prepared by γ -ray irradiation polymerization. The intercalation spacing of these nanocomposites was investigated with X-ray diffraction and its thermal stabilities by adding nanocomposites were characterized by thermal gravimetric analysis. The nanocomposites showed improved resistance to water absorption. The most interesting application of the nanocomposite is its ability for adsorption purification of waste water containing acid dyes. One of the objectives in this study was to develop new and active prepared copolymers which can be examined for their antimicrobial activities. It was found that the copolymer nanocomposite based on phosphonium group and some heavy metal ions in its structure having broad spectrum against pathogenic bacteria such as Staphylococcus aurius...

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.

In the present study, the copolymeric hydrogels based on 2-hydroxyethyl methacrylate (HEMA) and itaconic acid (IA) were synthesized by gamma radiation induced radical polymerization, in order to examine the potential use of these hydrogels in immobilization of Citrullus vulgaris urease. Gelation and Swelling properties of PHEMA and copolymeric P (HEMA/IA) hydrogels with different IA contents (96.5/3.5, 94.4/5.6 and 92.5/7.5 mol) were studied in a wide pH range. Initial studies of so-prepared hydrogels show interesting pH sensitivity in swelling and immobilization. C. vulgaris urease was immobilized on HEMA/IA (92.5/7.5) at 6 kGy with 41.3% retention of activity. The properties of free and immobilized urease were compared. Immobilized urease maintained a higher relative activity than free urease at both lower and higher pH levels, indicating that the immobilized urease was less sensitive to pH changes than the free urease. The Km value of the immobilized urease was approximately 2 times higher than that of...

Hydrophilic hydrogels based on poly(acrylic acid) as synthetic polymer and sodium alginates as natural polymer (AG) were prepared by gamma irradiation. The AAc/AG hydrogels were characterized by X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The effect of temperature and pH on the degree of swelling in water was studied. In addition, the metal sorption affinity of the prepared hydrogels for Cu +2 , Co +2 and Ni +2 was investigated. The XRD spectroscopic analysis indicates the formation of interpenetrating polymer networks. The TGA study showed that the hydrogels based on AAc/AG hydrogels at different ratios displayed lower thermal stability than PAAc hydrogel. The kinetic study of swelling in water showed that PAAc and AAc/AG hydrogels reached the equilibrium swelling state after five hours. However, AAc/AG hydrogels showed degree of swelling in water greater than PAAc hydrogel. The degree of swelling of AAc/AG hydrogels was affected by temperature, it increases within the temperature range 25–40 °C and displayed pH sensitivity within the range 5.5–9 depending on composition. The metal sorption study showed that PAAc hydrogel possessed higher affinity for Cu +2 ions than AAc/AG hydrogels, whereas AAc/AG hydrogels showed higher affinity for Co +2 and Ni +2 ions than PAAc hydrogel.

Graft copolymerization of acrylic acid (AA) and acrylamide (AAm) onto chitosan (CS) was carried out using gamma irradiation. Their swelling behavior was investigated. The hydrogels before and after alkaline hydrolysis were confirmed by FTIR spectroscopic studies. The hydrogels show ampholytic and reversible pH-responsiveness characteristics. The swelling variations were explained according to swelling theory based on the hydrogel chemical structure. The ability of the prepared copolymer to be used as gastric antibiotic delivery system was estimated using amoxicillin trihydrate as a model drug. Release of amoxicillin trihydrate from these investigated hydrogels was studied. For non-ionized drugs, such as amoxicilin trihydrate, the electrostatic polymer/ polymer interactions take place between the cationic groups from CS and the anionic ones from PAA resulting in entrapping the drug into the mesh space of the hydrogel. The non-ionized amoxicillin release was controlled by the swelling/eroding ratio.

Hydrophilic copolymers of 2-acrylamidopyridine (AP) and 2-hydroxyethylmethacrylate (HEMA) with different molar ratios were prepared by gamma irradiation-induced copolymerization using 60Co gamma rays of 20 wt.% aqueous solutions of monomer mixtures. The prepared polymers were characterized by FTIR, NMR and TGA analysis. The capacities for the adsorption of phenolic compounds onto the copolymers were found to be 26.7, 12.5 and 8.5 mg/g polymer for phenol, 2,6-dimethylphenol (DMP) and 2,6-di-t-butylphenol (DBP), respectively, using 20% AP copolymer. When the ratio of AP increased to 50% in the copolymer composition the amount of the above mention phenols retained increased significantly to be 35.1, 30.1 and 17.2 mg/g polymer for phenol, 2,6-dimethylphenol (DMP) and 2,6-di-t-butylphenol (DBP), respectively. Increasing the pH of the medium resulted in increasing of the amount of adsorbed phenols by the polymers. The kinetics of the adsorption at different concentration was also investigated.

Graft copolymer networks of poly(methacrylic acid-g-polyamidoamine dendrimer) with different loads of nickel salt were synthesized by gamma radiation-induced copolymerization of polyamidoamine dendrimer and methacrylic acid (MAA). Nickel release and metal adsorption from the polymeric systems, and their thermal stability were analyzed. A high percentage of the nickel loaded was released, although strong interactions between the polymeric matrices and the nickel ion was established since a total nickel release did not take place. The higher the concentration of the loading Ni 2 + , the higher were the adsorption capacities obtained. The metal release and uptake by such prepared hydrogels was determined by using atomic absorption technique. On the other hand, the presence of nickel salt induced an evident thermal instability in the polymeric matrices, although all the polymeric systems can be considered thermally stable.