Prepared Hydrogel Nanocomposite Research Articles

Synthesis of poly(2-acrylamido-2-methylpropane sulphonic acid/ 2-hydroxyethyl methacrylate)/TiO2/ZnO hydrogel nanocomposite by γ-irradiation for remediation of dyes in wastewater

ABSTRACT This study aimed to synthesise a novel adsorbent of poly(AMPS/HEMA)/TiO2/ZnO hydrogel nanocomposite by γ-irradiation polymerisation of 2-acrylamido-2-methylpropane sulphonic acid (AMPS) solution and 2-hydroxyethyl methacrylate (HEMA) monomer incorporated with TiO2/ZnO nanoparticles for potential use in the uptake of methylene blue (MB) and crystal violet (CV) dyes from wastewater. The effect of irradiation dose and AMPS/HEMA composition ratio on gel content (%) and swelling (%) were studied. From the results of the gel content (%) and swelling (%), the composition ratio AMPS/HEMA (80/20) and the dose of 15 kGy were selected for the preparation of the hydrogel nanocomposite. The properties of prepared materials were characterised by different analytical techniques. FTIR results proved the successful interaction of TiO2/ZnO nanoparticles within AMPS and HEMA chains. The SEM/EDS results proved the peaks corresponding to C, O, S, Zn, and Ti. XRD of nanocomposite indicated the peaks of TiO2 and ZnO nanoparticles. The factors affecting the uptake of MB and CV dyes were evaluated according to the impact of reaction time, pH, dye concentration, dosage, and temperature. The adsorption amount of MB and CV onto poly(AMPS/HEMA)/TiO2/ZnO hydrogel nanocomposite was fast time and effective for highly concentrated dye-bearing effluents. The uptake characteristics of the two dyes were similar. The ideal adsorption capacity of nanocomposite towards MB and CV dyes were 257.6 and 215.9 (mg/g) with a removal rate of 89.7% and 81.8%, respectively. The optimal conditions were pH 9 and 7, a reaction time of 70 min, dye concentration of 300 mg/L, and 0.3 g nanocomposite dosage. The adsorption process was chemisorption, endothermic and spontaneous. It is fitted with Langmuir isotherm and Pseudo-second-order models. Furthermore, the poly(AMPS/HEMA)/TiO2/ZnO nanocomposite supports the high capability for adsorption of binary MB/CV dyes mixture. The prepared hydrogel nanocomposite is a novel adsorbent for the uptake of dyes from wastewater with good recyclability.

Nanofibrous Wound Healing Nanocomposite Based on Alginate Scaffold: In Vitro and In Vivo Study

The combination of nanofibers with 3D scaffolds has shown promising results as the wound healing/dressing/care biomaterials. The present study aimed to fabricate and optimized alginate hydrogel composited by Lignin-derived carbon nanofibers (CNFs). The nanofibers were obtained from electrospun Lignin nanofibers as the precursor through two steps heat treatments. The synthesized nanofibers blended with an alginate polymer solution with different concentrations (1, 5, and 10 wt.%) and cross-linked using CaCl2 through the physical cross-linking. The findings illustrated that the prepared Lignin and CNFs have acceptable diameter. The composited Alginate hydrogels possessed a porous internal-structure with interconnected architecture. The fabricated hydrogel exhibited proper porosity and swelling behavior beneficial for wound healing application. The In Vitro experiments revealed that the hydrogel were red blood cell (RBC)-compatible, cytocompatible, and induced proliferative effects on cells. The animal experiments indicated that the application of the hydrogel promoted the process of wound healing. These observations implied that the prepared hydrogel nanocomposites exhibited promising properties and can be considered as wound healing nanobiomaterials.

Development of a ghatti gum/poly (acrylic acid)/TiO2 hydrogel nanocomposite for malachite green adsorption from aqueous media: Statistical optimization using response surface methodology

The primary goal of this study is to prepare and characterize a ghatti gum/poly(acrylic acid)/TiO2 (GG/poly(AA)/TiO2) hydrogel nanocomposite for adsorption of the dye malachite green (MG) from the aqueous phase in a discontinuous system. A variety of approaches were used to investigate the structure, morphology, and thermomechanical characteristics of the synthesized hydrogel nanocomposite. Response surface methodology (RSM) was performed to analyze the impact of three processing parameters, namely adsorbent dosage, dye concentration, contact duration, and their interactions on MG dye adsorption capacity. Analysis of variance was used to assess the experimental findings, which revealed that the quadratic regression model was statistically acceptable. The integration of TiO2 nanoparticles into the hydrogel matrix improved its thermal stability, mechanical strength, and performance in adsorbing MG dye from water. The kinetics and isotherm were evaluated, and the adsorption process was well fitted with pseudo-second order and Temkin isotherm models, respectively. Using the Langmuir equation, the maximum adsorption capacity at 45 °C within 50 min was calculated to be 2145 mg/g. Thermodynamic analysis at 25-45 °C revealed that the MG dye was spontaneously absorbed by the hydrogel nanocomposite. The prepared hydrogel nanocomposite demonstrated excellent reusability without a noticeable loss in MG dye adsorption capability for 6 cycles.

Ultrasonic-assisted synthesis of xanthan gum/ZnO hydrogel nanocomposite for the removal of methylene blue from aqueous solution

Herein, xanthan gum grafted poly(acrylic acid-co-itaconic acid)/zinc oxide (XG-cl-p(AA-co-IC)/ZnO) hydrogel nanocomposite was prepared ultrasonically and employed for the removal of methylene blue (MB) dye from water through batch experiments. The structure and morphology of the synthesized material were confirmed by FTIR, XRD, and SEM. The mechanical properties were studied by DMA and the swelling ability was measured gravimetrically in aqueous solution. The adsorption processes were consistent with the Freundlich isothermal model. The maximum adsorption capacity for the prepared hydrogel nanocomposite was found to be 212.8 mg/g. Compared with hydrogel, the synthesized hydrogel nanocomposite had a 14.6% improvement for MB dye uptake with remarkable enhanced swelling capacity. These findings demonstrated that ZnO nanoparticles influenced the hydrogel polymer matrix.

Efficient remediation of chlorpyrifos pesticide from contaminated water by superparamagnetic adsorbent based on Arabic gum-grafted-polyamidoxime

A novel organic/inorganic biosorbent hydrogel nanocomposite based on Arabic Gum-grafted-polyamidoxime and CuFe2O4 magnetic nanoparticles (AG-g-PAO/CuFe2O4) was prepared in three steps. The prepared hydrogel nanocomposite was well characterized using Fourier transform infrared (FT-IR), energy-dispersive X-ray analysis (EDX), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), CHN, zeta potential, and Brunauer-Emmett-Teller (BET) analyses. The adsorption efficiency of the AG-g-PAO/CuFe2O4 for removing an organophosphorus pesticide (OPP) (chlorpyrifos) from aqueous solutions was studied. Effect of different experimental conditions such as the pH of the solution, adsorbent dosage, contact time, initial concentration on adsorption efficiency was evaluated. The experimental adsorption data described well by the Langmuir isotherm model and the maximum adsorption capacity (Qmax) of the prepared biosorbent for chlorpyrifos was found 769.23 mg/g. The adsorption kinetic data were well fitted by the pseudo-second-order model. It was suggested that the chlorpyrifos was adsorbed onto AG-g-PAO/CuFe2O4 hydrogel biosorbent mainly through electrostatic interaction and hydrogen bonding. The result of adsorption-desorption experiments revealed that the AG-g-PAO/CuFe2O4 can be excellently regenerated and reused after three sequential runs without a considerable decline in its adsorption performance.

In Situ Preparation of Novel Porous Nanocomposite Hydrogel as Effective Adsorbent for the Removal of Cationic Dyes from Polluted Water.

The use of some hydrogels as adsorbents for pollutants removal from wastewater is limited due to their high swelling properties and the difficulty in recovering them after the adsorption process. To overcome these problems, a new hydrogel nanocomposite based on chitosan-grafted-polyacrylic acid/oxidized electrospun carbon nanofibers (CT-g-PAA/O-ECNFs) was prepared by an in situ grafting polymerization process. The prepared hydrogel nanocomposite was used as a novel effective and highly reusable adsorbent for the removal of methylene blue (MB) from polluted water with low cost. The morphology and the structure of CT-g-PAA/O-ECNFs were investigated by numerous techniques. The effect of incorporating O-ECNFs on the swelling capability of the prepared hydrogel was explored in distillated water and MB solution at normal pH. The effect of parameters including ratio of O-ECNFs, contact time, pH, initial concentration, and temperature on adsorption process were explored. The adsorption isotherm and kinetic were studied by numerous non-linear models. The obtained results confirmed that the incorporation of O-ECNFs into the hydrogel network decreased the swelling capacity and improved its ability towards MB dye removal. The adsorption process depended on the pH value of the dye solution. Additionally, the adsorption and kinetic results were fitted using the Freundlich isotherm model and pseudo second order model (PSO), respectively. Moreover, the new adsorbents can be recycled for at least five cycles keeping its adsorption capacity and can be easily recovered without loss in its initial weight.

Development of bacterial resistant acrylamide-polyvinylpyrrolidone-metal oxide hydrogel nanocomposites

Fabrication of polymer-based nanocomposites for numerous biomedical applications represents a predominant form of therapeutics for combating microbial and bacterial infections. Herein, we firstly synthesized metal oxide nanoparticles (MONPs) by previously reported precipitation methods. Hydrogel nanocomposites were then prepared by free radical polymerization of a combination of the synthesized MONPs, polyvinylpyrrolidone (PVP) and acrylamide. The hydrogel nanocomposites were characterized by FTIR, XRD and investigated for potential antibacterial protection. FTIR spectra of the prepared hydrogel nanocomposites revealed significant characteristic peaks of the distinctive MONPs within the polymer matrix. XRD micrographs revealed slight shifting of peak positions in nanocomposites; the change in peak intensity, coupled with the observed slight shift in the diffraction peaks of both CuO and ZnO nanoparticles confirmed the successful incorporation of the MONPs into the polymer matrix. The presence of the MONPs, in combination with PVP, displayed a synergistic antibacterial activity, with increasing concentration of the MONPs. The treatment against S.pneumoniae, revealed a zone of inhibition phenomenon which showed zones of PVP-5 > PVP-8 > PVP-6 > PVP-9 > PVP-7. PVP-1, PVP-2, PVP-3, PVP-4 did not show any significant zone of inhibition on treatment due to the quantity of MONPs present. The findings show that the hydrogel nanocomposites are potential topical wound dressing materials for the management of bacterial infections.

Carbon dots-incorporated pH-responsive agarose-PVA hydrogel nanocomposites for the controlled release of norfloxacin drug

Several hydrogels-based delivery systems are designed and studied in order to meet the requirements in biomedical fields. Herein, the possibility of carbon dots (CDs)-incorporated hydrogel nanocomposites was investigated for the drug release study. Highly fluorescent CDs synthesized from groundnuts using hydrothermal method were characterized with TEM, FTIR, UV–visible and fluorescence spectroscopy. pH-responsive biodegradable hydrogel nanocomposites were synthesized using agarose polymer and agarose–poly(vinyl alcohol) copolymer with the successful integration of CDs. CDs improved the swelling as well as the biodegradation properties of the prepared hydrogel nanocomposites. Structural changes of prepared hydrogel nanocomposites have been characterized using FTIR, SEM and TGA analysis. Hydrogel nanocomposites showed highly porous surface as shown by SEM analysis. In this study, norfloxacin (NFX) was used as a model drug to investigate the in vitro release behavior at two different pH (pH 1.2 and pH 7.4). NFX release from hydrogel nanocomposites followed zero-order kinetics, and Korsemeyer–Peppas model confirmed the release of NFX through erosion of hydrogel nanocomposites. Degradation of hydrogel nanocomposites films was checked using hen egg lysozyme enzyme which confirmed the biodegradable nature of prepared hydrogel nanocomposites films. MTT assay confirmed the nontoxic nature of hydrogel nanocomposites films when treated with blood cells (PBMC).

Slow-release NPK fertilizer encapsulated by carboxymethyl cellulose-based nanocomposite with the function of water retention in soil

In this study, new slow release fertilizer encapsulated by superabsorbent nanocomposite was prepared by in-situ graft polymerization of sulfonated-carboxymethyl cellulose (SCMC) with acrylic acid (AA) in the presence of polyvinylpyrrolidone (PVP), silica nanoparticles and nitrogen (N), phosphorous (P), and potassium (K) (NPK) fertilizer compound. The prepared materials were characterized by FT-IR, XRD and scanning electron microscopy (SEM) techniques. The incorporation of NPK fertilizer into hydrogel nanocomposite network was verified by results of these analyses. Also, the swelling behavior in various pH and saline solutions as well as water retention capability of the prepared hydrogel nanocomposite was evaluated. The fertilizer release behavior of the NPK loaded hydrogel nanocomposite was in good agreement with the standard of Committee of European Normalization (CEN), indicating its excellent slow release property. These good characteristics revealed that the hydrogel nanocomposite fertilizer formulation can be practically used in agricultural and horticultural applications.

Synthesis of superabsorbent hydrogel nanocomposites for use as hemostatic agent

ABSTRACTUncontrolled hemorrhage continues to be the major cause of death in trauma. In this study, the authors prepared hydrogel nanocomposites (HNCs) using three different nanoparticles, SiO2, natural clinoptilolite (nC), and Ca2+-modified clinoptilolite (mC). Fast-swelling superabsorbent hydrogel was used as a matrix of NCs. The hydrogel and HNCs were characterized by FTIR, XRD, FE-SEM, and TGA. The hemocompatibility of HNCs was evaluated by hemolysis test and blood cells function. HNC formed a physical barrier by dehydrating the injury site and concentrating clotting factors. Additionally, highly charged nanoparticles, promoted local hemostasis by activating the intrinsic pathway of the blood coagulation cascade.

Synthesis and Characterization of a Chitosan/PVA Antimicrobial Hydrogel Nanocomposite for Responsive Wound Management Materials

The development of novel wound management materials must address several challenges to be most efficacious. Successful wound management should include the ability to adhere to wound surfaces, absorb wound exudates, and enhance bactericidal effectiveness. Few current biomaterials address all of these characteristics and in addition often have poor structural rigidity leading to a lack of protection and support to ensure proper cell growth. The focus of this study was to develop a multifunctional biomimetic nanocomposite system that will improve mechanical stability, effectively eliminate E. coli and S.aureus biofilm propagation, and serve as a scaffold for effective adult human dermal fibroblast (HDFa) growth. Synthetic parameters, such as the ratio of chitosan to PVA concentration and deposition method for the incorporation of Ag+-functionalized nanoparticles into the final nanocomposite, were optimized. It was determined the deposition reaction pH and Ag+ concentration played a key role in the control of post reaction particle size and zeta potential. It was also determined that the concentration of Ag+ functionalized nanoparticle incorporated into the nanocomposite must be greater than 5 mM to achieve optimal control of biofilm formation. The prepared hydrogel nanocomposites demonstrated effective bacterial inhibition when exposed to cultures of E. coli, S. aureus, and MRSA. Lastly, human dermal fibroblast test results revealed that when PVA concentration increased in the system, there was no appreciable cell growth. On the other hand, when the ratio of biomimetic chitosan and PVA is optimized to reduce the overall amount of synthetic polymer (PVA), there was healthy cell growth. These results directly speak to a key finding that reveals the importance of the correct balance or the removal of synthetic polymer from the system.

Nanocomposite hydrogels composed of cloisite 30B-graft-poly(acrylic acid)/poly(acrylic acid): Synthesis and characterization

The hydrophilicity of Cloisite 30B is enhanced by surface grafting of polyacrylic acid (PAA). The radical polymerization of acrylic acid with the vinylsilylated Cloisite 30B leads to chemical grafting of PAA onto the organoclay surface. Chemical grafting of the PAA onto the surface of Cloisite 30B is shown by FTIR spectroscopy. Hydrogel nanocomposites are successfully prepared by using acrylic acid, vinylsilylated Cloisite 30B, and N,Nmethylene bisacrylamide as a crosslinker. Thermogravimetric analysis (TGA) and differential thermal mechanical analysis (DMTA) revealed that prepared hydrogel nanocomposites show enhanced ther� mal and mechanical properties than those of pure hydrogel (hydrogel without nanoparticles). Swelling degree and equilibrium swelling capacity of hydrogel nanocomposites 1-7 wt % (loaded with 1-7 wt % of vinylsily� lated Cloisite 30B, with respect to monomer) are also increased regarding to pure hydrogel. The interlayer and surface changes of the clay in the prepared nanocomposite materials and the grafted nanoparticles are studied by Xray diffraction and scanning electron microscopy.

Preparation and Characterization of Hydrogel Nanocomposites Based on Oxidized Starch and Incompletely Condensed Polyhedral Oligomeric Silsesquioxanes

Incompletely condensed polyhedral oligomeric silsesquioxanes (POSS) are nanosized particles (1-3 nanometer) that can be used as reinforcing fillers in hydrogel nanocomposites based on oxidized starch with polymeric cross linkers containing amine groups like chitosan.In this work we have prepared hydrogel nanocomposites based on oxidized starch and incompletely condensed POSS nanomaterials for the first time. POSS nanomaterials synthesized by hydrolysis and condensation method. Different percentages of POSS nanomaterials were composited to different ratios of oxidized starch and chitosan. The mechanical and thermal properties increased for composites containing POSS nanomaterials. The swelling percentage varies in different ratios of oxidized starch/chitosan and maximum of swelling percentage was 970%. In many cases the swelling percentage and solubility decreased for samples containing POSS nanomaterials.Also these hydrogel nanocomposites were characterized with various methods like FT-IR, SEM, XRD, TGA and DSC.