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A new kind of Camellia sinensis-loaded nanocomposite hydrogel based on modified gelatin/iron-metal-organic framework was developed as an antibacterial wound dressing. Gelatin as a biocompatible natural polymer was modified with methacrylate anhydride to produce gelatin methacrylate. Thereafter, acrylic acid and acrylamide were grafted on gelatin methacrylate during an aqueous polymerization process. To enhance the porosity, mechanical strength, and drug loading capability of the hydrogel and reduce its toxicity, iron- based metal-organic framework was incorporated within the hydrogel. To add more functionality to the final wound dressing, Camellia sinensis, an antibacterial herbal drug was loaded on the hydrogel. The structural and chemical properties of prepared nanocomposite hydrogel were investigated by FTIR, XRD, SEM, and TGA techniques. The incorporation of iron-based metal-organic framework within the hydrogel matrix led to an increase in its water absorption value from 400.10 to 547.96 (g/g). The release study of Camellia sinensis (CS) extract from the prepared nanocomposite hydrogel exhibited a sustained release manner. The antibacterial test revealed the nanocomposite hydrogel contain extract has an effective antibacterial function against "Bacillus serous", "Staphylococcus aureus", "Streptococcus mutans"," Escherichia coli", "Klebsiella pneumoniae", and "Pseudomonas aeruginosa" bacteria. Therefore, the synthesized nanocomposite is a good candidate as an antibacterial hydrogel wound dressing. .

In this study, graphene oxide (GO) was functionalized with polyethylene glycol (PEG) to understand the effect of PEGlayted GO on properties of chitosan-based nanocomposite scaffold. GO was synthesized according to modified Hummer's method and covalently linked to polymeric chains of PEG to produce polyethylene glycolated GO (PGO). Successful preparation of GO and PGO was confirmed by FT-IR and Raman techniques, where the chemical bonding of PEG and GO nanosheets were concluded based on PGOs' lower zeta potential compared to GO. Nanocomposite scaffolds were prepared by adding equal amounts of GO and PGO into 2% (w/v) chitosan (Cs) solutions. The highly porous scaffolds were developed by lyophilization of solutions. Incorporation of GO and PGO into chitosan scaffold network resulted in uniform and spherical pores. Modified samples offered higher porosity and density, indicating adequate scaffold structure. Improvements in the physical properties of prepared chitosan scaffolds were concluded through higher water absorption and retention values. Compressive strength measurement showed 6.33 and 5.5 times improvement respectively for Cs-GO and Cs-PGO samples compared to Cs scaffold. The Cs-GO scaffolds showed minimum susceptibility toward enzymatic degradation and higher degrees of protein adsorption (26% and 23% improvement in value of adsorbed protein respectively for Cs-GO and Cs-PGO compared to Cs scaffold) and biomineral formation on scaffold surface. Also, Cs-PGO sample showed the highest degree of cell viability and lower hemolysis than both Cs and Cs-GO scaffolds. Investigations showed that cell infiltration into scaffold porous structure was more prominent in Cs-PGO scaffolds than in Cs and Cs-GO scaffolds.

In this study, a system was investigated for controlled delivery of gemcitabine (GEM), an anti-cancer drug with short biological half-life time (8–17 min), using graphene oxide (GO)/montmorillonite (MMT)/chitosan (CS) nanocomposite. The structure, morphology, zeta potential, and thermal stability of the nanocomposite were evaluated by FT-IR, XRD, zeta potential analyzer, FESEM, and TGA. The results revealed that the GO interacted with positively charged GEM and CS surface. Also, the drug was intercalated between the silicate layers of MMT, and this phenomenon is responsible for more protection of the drug from burst release. The positive zeta potential of GO/GEM/CS/MMT nanocomposite (+ 16.5 mV) promotes physical stability and interaction with the negative domains of the cell membrane. A significant synergistic effect of GO and MMT on the controlled release of GEM from the drug delivery system-based chitosan matrix has been obtained. The nanocomposite with 17 wt% MMT in the release media with pH of 7.4 provided the optimal combination of drug release rate and drug release content, whereas the time for GEM 50% release (T50%) was obtained about 2 h. The non-Fickian diffusion mechanism and Korsmeyer–Peppas kinetic model were confirmed for release of GEM from drug-loaded nanocomposites. Finally, to investigate the efficiency of nanocomposite as an anti-cancer drug delivery system, an in vitro cytotoxicity assay was also carried out using breast cancer cell line MDA-MB-231. Results confirmed that the prepared nanocomposite could be used as a potential breast cancer therapy system for the controlled delivery of GEM.

In this study, new pH-sensitive nanogels containing rivastigmine as a model drug were synthesized by graft polymerization of Acrylamid/Sodium Acrylate monomers onto chitosan (CS) and kappa-carrageenan (CG or κ-carrageenan) backbone in the presence of N, N'-Methylenebisacrylamide (MBA) as cross-linker, nitrogen-doped carbon dots (N-CDs) and ammonium persulfate as an initiator. The prepared nanogels were characterized by FE-SEM, XRD, FTIR, EDX and TGA techniques. The swelling behavior of the nanogels was affected by MBA content, monomer content, amount of CG or CS, and pH in the synthesis. The nanogels exhibited well pH-sensitivity during drug release investigation under simulated gastric (

The effect of glutaraldehyde and calcium cations as covalent and ionic crosslinkers was investigated on the main characteristics of scaffolds based on chitosan and cellulose nanocrystals. Therefore, four different scaffolds based on chitosan/cellulose nanocrystals with different crosslinking methods were fabricated using the freeze-drying method for potential use in bone tissue engineering. The structural and chemical features of prepared scaffolds were studied by the FTIR technique. FESEM images revealed that all scaffold samples are porous three-dimensional networks in which the pores are connected. TGA analysis showed that the thermal stability of scaffolds based on chitosan/cellulose nanocrystals has not been changed significantly by using different crosslinking methods. The chitosan/cellulose nanocrystals scaffold crosslinked by glutaraldehyde represented the highest compressive strength and the uncrosslinked scaffold showed the highest swelling ratio in comparison to the other scaffolds. The fastest degradation rate belonged to the scaffold crosslinked by calcium cations. FESEM images and EDX analysis confirmed that fabricated scaffolds have good biomineralization ability. The cell viability and cell attachment results indicated that all four scaffolds support cell proliferation and cell adhesion. However, the viability of NIH3T3 fibroblast cells in the presence of glutaraldehyde-containing scaffolds was lower than that of other scaffolds.

In this study, the synergistic effect of graphene oxide (GO) and Montmorillonite (MMT) additives on the chemical, physical, mechanical, and biological properties of chitosan-gelatin (CS-Gel) scaffolds samples were investigated. FT-IR, XRD, Raman spectroscopy, and zeta potential analysis were used to investigate the accuracy of GO synthesis. Morphological studies of scaffold samples showed highly porous structure of all scaffold samples. The water absorption values of CS-Gel/GO and CS-Gel/GO/MMT samples were almost the same, but the highest value of water retention was observed for CS-Gel/GO scaffold. All scaffold samples showed the ability to form biomineral on the surface when exposed to SBF, although CS-Gel/GO/MMT scaffold had the best biomineralization ability. Considerable improvement in mechanical properties of scaffold samples were observed for CS-Gel/GO/MMT in comparison to CS-Gel scaffold, from 17.56 to 22.73 MPa for Young's modulus and from 0.14 to 0.2265 MPa for compressive strength. Protein adsorption of the scaffold was almost doubled in CS-Gel/GO/MMT samples compared to CS-Gel scaffold. Cell viability results indicated that none of the samples were cytotoxic and 30% of improvement in cell viability was observed for CS-Gel/GO/MMT scaffold in comparison to CS-Gel samples after 72 h of incubation.

In this work, starch–montmorillonite/polyaniline (St–Mt/PANI) nanocomposite was prepared by in situ polymerization of aniline on the surface of starch–montmorillonite (St–Mt) nanocomposite and was applied for adsorption and removal of Cr(VI) ions from aqueous solution in batch mode. Various characterization techniques such as Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy were utilized to characterize and evaluate the prepared nanocomposite. In order to verify the optimum conditions for adsorption of Cr(VI) ions by St–Mt nanocomposite, as powder, different parameters affecting the adsorption efficiency including pH of the solution, the initial concentration of Cr(VI) ions, contact time and adsorbent dosage were investigated. According to the results, the best conditions for Cr(VI) removal was obtained as pH 2, C0 = 10 mg L−1, time = 15 min and M = 0.05 g. The adsorption process was well fitted by Langmuir isotherm model and the maximum adsorption capacity was calculated as 208.33 mg g−1. Also, the kinetic adsorption process was well described by the pseudo-second-order kinetic model. The study of thermodynamic parameters confirmed the spontaneous and exothermic nature of adsorption and removal process. Desorption tests revealed the reusability of St–Mt/PANI nanocomposite for three adsorption cycles and so the method is almost cost efficient.

In this work, the effect of graphene-based materials on the physicochemical, mechanical, and biological properties of chitosan-gelatin scaffolds was investigated. Graphene oxide (GO) and amine-modified graphene oxide (GNH2) were synthesized and covalently linked to the polymeric chains of chitosan and gelatin, using glutaraldehyde as a crosslinking agent. The accuracy of synthesis of graphene-based materials was verified using FT-IR, XRD, Raman, and Zeta potential techniques. The negatively and positively charged surfaces of respectively GO and GNH2 nanosheets were of great importance affecting the physicochemical properties of scaffolds; higher pore size, interconnectivity, better water absorption and retention capability, shape retention, porosity, and density compared to those of chitosan-gelatin scaffold as a control sample. All scaffolds showed biomineralization ability in vitro. Also, less biodegradation was observed for modified scaffolds. Improved mechanical properties of GO and GNH2 incorporated scaffolds were observed. Cell viability of modified scaffolds was improved by 10 and 4% respectively for GO and GNH2, compared to chitosan-gelatin scaffold.

The present study reports the electrical characteristics of a low voltage ZnO/Polypyrrole nanocomposite varistor which was fabricated as a thin disk based on zinc oxide with different weight percentages of polypyrrole as additive using a cold pressing method. Current-voltage characteristics and nonlinear coefficients of the ZnO/Polypyrrole nanocomposite thin disks were studied in direct current mode. Results showed good varistor behavior of prepared ZnO/Polypyrrole nanocomposite. According to the results, ZnO/Polypyrrole nanocomposite thin disk varistors can be utilized to preserve circuits from 35 V up to 350 V over voltages. I-V characteristics of nanocomposite samples showed that by increasing zinc oxide content from 98.52% to 99.01%, the breakdown voltage of ZnO/Polypyrrole nanocomposite varistor increased whereas its nonlinear coefficient decreased. However, more increase in ZnO content of nanocomposite caused to the reduction of its breakdown voltage and increase of nonlinear coefficient. The results obtained from SEM micrographs indicated that by increasing ZnO content, both the grain numbers and their morphologies are changed which is caused the different effects in the grain boundaries, I-V characteristics, and varistor properties of nanocomposites. As a very important result, in this experimental work, an ideal varistor with sufficient low breakdown voltage and acceptable high nonlinear coefficient was obtained.

A simple, cheap, and environmentally friendly bio-conducting interpenetrated polymer blend network was prepared and introduced as a highly efcient system with suitable physical and mechanical properties for industrial removal of toxic Cr(VI) ionsfrom aqueous solution. Carboxymethyl cellulose/polyaniline (CMC/PANI) interpenetrated network (IPN) blend was preparedby simple simultaneous ion-cross-linking of CMC and PANI chains using Al³+ cations. The CMC/PANI bio-conductingnanocomposite was characterized using X-ray difraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and scanning electron microscopy equipped with an "energy dispersive X-ray spectroscopy"(SEM–EDX) technique. The CMC/PANI blend, ion-cross-linked by Al³+ cations, showed good stability and high surfacearea, proper for the removal of toxic Cr(VI) ions of the aqueous solution. Batch removal experiments were accomplished andthe impression of efective variables including solution pH, initial concentration of Cr(VI) ions, contact time, and adsorbentdosage were checked and optimized. The outcome of our fndings revealed that the removal of Cr(VI) ions by CMC/PANInanocomposite IPN strongly depends on solution pH. The removal information was matched with the Langmuir adsorptionisotherm model and the utmost monolayer adsorption capacity at pH 2 was 136.98 mg/g at 25 °C. The pseudo-second-orderkinetics were operated and the thermodynamic parameters suggested spontaneous and exothermic nature of the adsorptionprocess. Consequences indicated that CMC/PANI nanocomposite IPN could be an afective eco/environmentally friendlyadsorbent for the removal of Cr(VI) ions from aqueous solutions. Refereed/Peer-reviewed

In this study, a facile method for the production of Antibacterial and Antistatic polyurethane coatings was investigated using copper modified ZnO nanoparticles–polyaniline nanofibers (PANI–CuZnO) ternary nanocomposite. PANI–CuZnO ternary nanocomposite was synthesized through two steps. First, copper-modified ZnO nanoparticles were produced through the hydrolysis method using acetate precursors, and then they were mixed with polyaniline nanofibers, which were synthesized by seeding method. The obtained nanocomposite was characterized by FTIR, XRD, and FESEM techniques. Results of evaluating the antibacterial action of the polyurethane coatings with the content of ternary nanocomposite showed that the obtained coatings have a proper antibacterial action against Gram-positive and Gram-negative bacteria. In addition, measuring the coatings’ surface electrical resistance revealed that addition of the ternary nanocomposite to the polyurethane coatings’ matrix causes the surface electrical resistance of the coatings significantly decreases and reaches 8 × 107 Ω/sq. Thereby, they could be categorized as an antistatic coating. Moreover, the addition of PANI–CuZnO enhanced adhesion strength and scratch resistance of the final polyurethane coatings. Graphical abstract

Semi-interpenetrating polymer network (semi-IPN) of starch-graft-poly(acrylic acid-co-acrylamide)/polyvinyl alcohol/clinoptilolite (starch-g-p(AA-co-AAm)/PVA/clino) superabsorbent nanocomposite was synthesized by free-radical graft co-polymerization technique in an aqueous solution. Taguchi method was used to optimize the synthesis reaction condition based on the equilibrium swelling capacity of the hydrogels. FTIR, XRD, and SEM analyses were used to study the chemical and structural properties of the hydrogel samples. The equilibrium swelling capacity of the semi-IPN superabsorbent nanocomposite (364.82 g/g) was higher than that of neat hydrogel (286.21 g/g) and in both of them water penetration into hydrogel network occurred through non-Fickian diffusion mechanism. Incorporation of clino into the polymeric matrix not only increased the equilibrium swelling capacity of the hydrogel, but also induced a substantial enhancement in its mechanical strength. Semi-IPN superabsorbent nanocomposite showed reasonable water absorbency under different loads, good salt and pH-sensitive swelling behavior, and better water retention capability, which make it potentially useful for hygiene products.

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.

An increase in the electromagnetic wave pollution generated from wireless telecommunication devices has devoted to a great request for exploiting microwave absorbing materials for themselves. The combination of inherently conducting polymers such as polypyrrole (PPy) with metal oxides has led to design ideal microwave absorbing materials which benefit both advantage effects of ICPs and metal oxide nanoparticles. Herein, the quaternary nanocomposite of Epoxy-PPy/Fe3O4-ZnO was prepared and tested for the absorption of X-band microwaves. Simultaneous application of metal oxides and conducting polypyrrole in the epoxy matrix was evaluated in order to increase the absorption intensity and broadness of microwaves in X-band region. The morphology, microstructure, and phase structure of Fe3O4, ZnO, and PPy, as well as quaternary nanocomposite were characterized and studied using FTIR, XRD, FESEM and TEM techniques. The presence of nanoparticles in the quaternary nanocomposite was confirmed by EDS. The magnetization of iron oxide was studied by VSM. The synergetic effect of iron oxide and zinc oxide nanoparticles in different weight ratios (Fe3O4/ZnO) on the electromagnetic wave absorption was evaluated. The electromagnetic parameters have been evaluated by the vector network analyzer in the frequency range of 8.2–12.4 GHz which is named as X-band region and is adequate for radar applications. The electromagnetic wave absorbing outcomes indicated that Epoxy-PPy/Fe3O4-ZnO quaternary nanocomposite has wide absorption area and high attenuation, which is believed to be due to dielectric loss properties related to the polypyrrole, magnetic loss factor of Fe3O4, and synergetic effects of components. The maximum reflection loss reached to −32.53 dB at 9.96 GHz with a nanocomposite thickness of 2 mm which is dedicated to the Epoxy-PPy/Fe3O4-ZnO with iron oxide to zinc oxide ratio of 2:1. The absorption bandwidth with the reflection loss lower than −10 dB (90% attenuation) was up to 4.2 GHz that covering a frequency range of 8.2–12.4 GHz. Results showed that absorber having %15 (w/w) polypyrrole/epoxy resin in Epoxy-PPy/Fe3O4-ZnO nanocomposite with iron oxide to zinc oxide ratio of 2:1 displays the best reflection loss properties. The loss curves illustrated the values of dielectric loss tangent and magnetic loss tangent of prepared nanocomposites which are in the range of 0.25–0.7 and −0.08 to 0.09 respectively. Therefore, microwave absorption mechanism is probably attributed to dielectric loss.

Nowadays, self-cleaning technology is used in various industries to decreasing the time, energy consumption and costs of surface servicing as well as the increasing of surface durability. Self-cleaning and anti-bacterial coatings can be made by the addition of suitable additives to a polymer matrix with good properties. In the present research, TiO 2 /polypyrrole nanocomposites were prepared in different TiO 2 to polypyrrole weight ratios and used in various percent as an additive in waterborne commercial grade polyacrylic latex. Characterization and evaluation of structural and morphological features of nanocomposites and coatings were performed by FTIR, XRD, UV–Vis and FESEM techniques. By the addition of prepared nanocomposites as an additive to the polyacrylic matrix, the hydrophilic, water resistant, anti-bacterial, and photocatalytic coatings were prepared. The TiO 2 to polypyrrole weight ratio of TiO 2 /polypyrrole nanocomposites and the percent of nanocomposite additive in the polymeric matrix were optimized. According to the results, the coating containing 2% and 3% of TiO 2 /polypyrrole nanocomposite with TiO 2 to polypyrrole weight ratio of 100:10 are proposed as the best coating formulations in the formulations examined in this work, due to their good properties in the most of experiments.

Semi-interpenetrating polymer network (semi-IPN) superabsorbent nanocomposite based on montmorillonite (MMT) and sodium alginate (NaAlg)-g-poly(acrylic acid(AA))/polyvinylpyrrolidone (PVP) was synthesized. Chemical structure and surface morphology of the hydrogels were characterized by FTIR, XRD, thermogravimetric analysis (TGA), SEM, and TEM techniques. FTIR results revealed that graft polymerization, PVP interpenetration through hydrogel network, and nanocomposite formation have occurred. The coarse surface of the hydrogels was changed into interlinked porous structures in the presence of MMT. The effect of polymerization variables on water absorbency of the hydrogels was assessed and optimized. Semi-IPN superabsorbent nanocomposite presented higher equilibrium swelling capacity (618.92 g/g) compared with neat hydrogel (521.17 g/g). Swelling behavior of the hydrogels strongly depended on pH values of the solution as well as the type and concentration of saline solution. Semi-IPN superabsorbent nanocomposite possessed good reswelling capability, making it as an efficient water reservoir to supply required water to plants in agricultural applications.

Graphite/TiO2 nanocomposite additive was used to make a photocatalytic, hydrophilic, and antibacterial polyacrylic based coating. Various amounts of nanocomposite additive with different weight ratios of graphite to TiO2 were used in a commercial grade polyacrylic matrix and the properties of the related coating were investigated and compared with the polyacrylic coating not containing a nanocomposite additive. FTIR, XRD, FESEM, and UV–Vis spectroscopy were applied to characterize the nanocomposite additive and coating. The water contact angle of additive contained polyacrylic coating reached less than 10° after 24 h illumination of LED lamp light. Photodecolorization efficiency of methylene blue dye aqueous solution in the presence of modified coatings reached 47% during 5 h LED lamp irradiation. The nanocomposite additive formulated coatings exhibited good stability in water environment and antibacterial property against Bacillus anthracis and Staphylococcus aureus Gram positive species. Surfactant presence in the coating formulation and electron–hole pairs produced in graphite/TiO2 nanocomposite additive under LED lamp light prevented the growth of bacterial species. Graphite also adsorbed the bacteria species and kept them in vicinity of antibacterial agents. According to the results, polyacrylic coating containing 3% of graphite/TiO2 nanocomposite additive with graphite to TiO2 weight ratio of 20:100 is proposed as the best coating formulation with the considerable properties between the all of formulations examined in this paper.

ZnO nanosheets were synthesized using a cost effective and simple precipitation method. Polyaniline/zinc oxide nanocomposites in various weight ratios were produced by the synthesis of polyaniline as a conducting polymer followed by adsorption of polymer chains on the ZnO nanosheets. UV–Vis spectroscopy, X-ray diffraction patterns, and SEM technique were utilized to characterize the nanocomposite structure. The polyaniline/ZnO nanocomposites prepared in various weight percent of polyaniline and ZnO nanosheets were pressed as thin disks at a pressure of 60 MPa and their usage electrical varistors were studied. The current–voltage characteristics of thin polyaniline/ZnO nanocomposites disk varistors were investigated. The results demonstrated good varistor behavior of polyaniline/ZnO nanocomposite disks so that they can be used to protect the electrical circuits from over voltages in the range of 250–550 V. The efficiency of ZnO percent on the varistors properties of polyaniline/ZnO nanocomposites disks was experimented. According to the results, the nanocomposites sample containing 99.01 wt% of ZnO showed minimum breakdown voltage (250 V) and highest nonlinear coefficient (4.28) and also the lifetime of this sample is high. From the UV–Vis spectra recorded for polyaniline/ZnO nanocomposites samples with various ZnO percent, it was found that absorption and light absorption band gap decreased by reducing ZnO content in nanocomposites samples. The band gap in the best sample is 3 eV.

A slow release NPK fertilizer formulation was prepared via insitu free radical graft polymerization of salep with an acrylic acid (AA) monomer in the presence of montmorillonite (MMT) and fertilizer. Evidence of component interactions, morphology, thermal properties, and fertilizer incorporation into hydrogel nanocomposite fertilizer formulation was obtained using FTIR, XRD, TGA, and SEM techniques. The swelling behavior of hydrogels in various pH and saline solutions was investigated. In addition, the water retention capability of loamy sand soil having the prepared fertilizer formulation was evaluated. The results showed that the synthesized hydrogels have pH and salt sensitive swelling behaviors as well as good water retention properties. Fertilizer release studies also showed that the presence of MMT caused the formulation system to liberate the nutrient in a more controlled manner. Finally, these good characteristics showed that these formulations are potentially applicable for agricultural and horticultural purposes.

In the present study, the electro-Fenton (EF) process has been used to remove ceftazidime (CAZ) from an aqueous solution. In the first part of this study, the iron(II) doped carbonaceous aerogel (denote as FCA) as a three-dimensional cathode was synthesized as a cathode electrode. For this purpose, resorcinol–formaldehyde polymers containing iron(II) salt were prepared by sol–gel method and after drying by ambient drying method, the resulting polymer was finally carbonized in a furnace with inert nitrogen medium at 800 °C and the resulting composite properties examined by Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray, Brunaur-Emmett-Teller, X-ray Diffraction, Fourier Transform Infrared Spectroscopy, and cyclic voltammetry analyses. In the last part of this study, the prepared carbonaceous aerogel was employed as a cathode electrode in the EF system to remove CAZ from an aqueous medium. The influence of key factors such as applied current (mA), initial pH of the solution, initial CAZ concentration (mg/L), and process time (min) on the CAZ removal efficiency (RE (%)) under the EF process was assessed. The mineralization current efficiency (MCE) was found as 60.66% in 200 min. Response surface methodology (RSM) was used to optimize the process. The results showed that the optimal values for the variables of applied current intensity, pH, initial CAZ concentration, and process time were 400 mA, 4, 40 mg/L, and 110 min, respectively. The intermediates of CAZ removal were identified by gas chromatography-mass spectrometry analysis. Moreover, the possible removal mechanism of CAZ was proposed. The reusability and stability of the FCA cathode was assessed and revealed an approximately 4% decline in CAZ removal efficiency after eight consecutive cycles. The amount of organic carbon degraded by this process was investigated by chemical oxygen demand test and it was 99% after 200 min of reaction time.

New superabsorbent nanocomposite was synthesized by free-radical graft polymerization of sulfonated-carboxymethyl cellulose (SCMC) with acrylic acid (AA) in the presence of polyvinylpyrrolidone (PVP) and silica nanoparticles. Carboxymethyl cellulose (CMC) was first sulfonated using chlorosulfonic acid, and then AA monomers were grafted onto SCMC. FTIR results confirmed that sulfonation of CMC as well as grafting of AA monomers onto SCMC has been performed successfully. Moreover, the presence of silica nanoparticles into superabsorbent nanocomposite was evaluated with EDX analysis. The element mappings show a homogenous distribution of silica nanoparticles throughout the hydrogel nanocomposite. SEM images exhibited porous morphology for hydrogel nanocomposite, which was due to the incorporation of PVP in its network. The experimental findings from TGA analysis indicated that incorporation of PVP and silica nanoparticles into the hydrogel network improved thermal stability of superabsorbent nanocomposite. Swelling kinetic studies revealed that superabsorbent nanocomposite hydrogel had higher equilibrium swelling capacity and swelling rate compared with the neat hydrogel sample. Besides that, superabsorbent nanocomposite depicted excellent salt and pH-sensitive behavior in different saline and pH solutions. As a consequence, this hydrogel nanocomposite acts as useful water reservoir, which might be most profitable in agricultural applications.

In order to reach an antibacterial, photocatalytic, and hydrophilic coating, commercial grade polyurethane (CPU) resin was modified with silver ion exchanged montmorillonite/TiO2 nanocomposite in various montmorillonite to TiO2 nanoparticle ratios. To characterize the prepared nanocomposites and coatings, X-ray diffraction patterns, FTIR and UV–Vis spectroscopy and SEM images were used. The modified commercial grade polyurethane coatings containing nanocomposites show better properties, including hydrophilicity, degradation of organic pollutants, antibacterial activity and water resistivity, compared to unmodified commercial grade polyurethane coatings. The water droplet contact angle of unmodified CPU coating was 70°, however it decreased to lower than 10° in modified CPU coatings after 24 h LED lamp irradiation. Decolorization efficiency of malachite green dye solution by the use of modified CPU coatings achieved up to 70% after 5 h LED lamp illumination, compared to less than 5% for unmodified CPU coatings. Modified CPU coatings also showed significant water resistivity and antibacterial properties.

In recent years more attentions have been paid for preparation of coatings with self-cleaning and antibacterial properties. These properties allow the surface to maintain clean and health over long times without any need to cleaning or disinfection. Acrylic coatings are widely used on various surfaces such as automotive, structural and furniture which their self-cleaning and antibacterial ability is very important. The aim of this work is the preparation of a polyacrylic based self-cleaning and antibacterial coating by the modification of TiO2 as a coating additive. TiO2 nanoparticles were sensitized to the visible light irradiation using graphene oxide through the preparation of TiO2/graphene oxide nanocomposite. Graphene oxide was prepared via a modified Hummers method. TiO2/graphene oxide nanocomposite was used as additive in a polyacrylic coating formulation. Hydrophilicity, photocatalytic and antibacterial activities as well as coating stability were evaluated for TiO2/graphene oxide modified polyacrylic coating and compared with that of pristine TiO2 modified and unmodified polyacrylic coatings. TiO2/graphene oxide nanocomposite and polyacrylic coating modified by TiO2/graphene oxide additive were characterized using FT-IR, UV–Vis, XRD, and FESEM techniques. The effect of TiO2/graphene oxide composition and its percent in the coating formulation was evaluated on the polyacrylic coating properties. Results showed that polyacrylic coating having 3% W TiO2/graphene oxide nanocomposite additive with TiO2 to graphene oxide ratio of 100:20 is the best coating considering most of beneficial features such as high photodecolorization efficiency of organic dye contaminants, high hydrophilicity, and stability in water. According to the results, TiO2 is effectively sensitized by graphene oxide and the polyacrylic coating modified by TiO2/graphene oxide nanocomposite shows good photocatalytic activity under visible light irradiation.

Copper nanoparticles were synthesized by a convenient and rapid chemical reduction method in ambient condition using $$\hbox {Cu}(\hbox {NO}_{3})_{2}{\cdot } 3\hbox {H}_{2}\hbox {O}$$ as a precursor, hydrazine hydrate as reducing agent and deionized water as solvent. The product was characterized by X-ray diffraction (XRD) patterns, field emission scanning electron microscopy, Fourier transform infrared spectroscopy and UV–Vis spectroscopy. However, agglomerated copper nanoparticles were obtained by this chemical reduction method. Hence, the effects of three polymers of polyvinyl pyrrolidone, polyethylene glycol (PEG) and starch as stabilizers on the size and size distribution of Cu nanoparticles were investigated. According to the results, smallest copper nanoparticles (30–50 nm) with a narrow size distribution were obtained using PEG as the stabilizing polymer. Zero-valent copper nanoparticles with high purity were obtained by this method and there was no peak related to the oxidized impurities such as CuO and $$\hbox {Cu}_{2}\hbox {O}$$ in the XRD and UV–Vis studies, both in the presence and in the absence of stabilizer. On the other hand, by this method, zero-valent copper nanoparticles were obtained in the absence of any anti-oxidant agent and any inert gas flow. The effects of synthesis parameters including initial concentration of precursor, polymer concentration and the reaction temperature on the size and size distribution of copper nanoparticles were investigated using the UV–Vis analysis to determine the optimum synthesis conditions.

A novel fertilizer-integrated superabsorbent nanocomposite based on maize bran (MB), acrylic acid (AA), and acrylamide (AAm) was synthesized in an aqueous solution containing montmorillonite (MMT) and NPK fertilizer compound. FTIR spectra indicated that hydroxyl group of the starch molecules in MB composition has participated in grafting reaction with acrylate-based monomers. The swelling behavior of the synthesized hydrogels in different salt and pH solutions was evaluated. Also, the N,N′-methylenebisacrylamide (MBA) and MMT contents were systematically optimized to obtain a highest swelling capacity. Fertilizer release assessments on the NPK-loaded superabsorbent nanocomposite confirmed the effective role of MMT nanolayers in slow-release property of the prepared formulation. Also, the prepared fertilizer formulation exhibited good water retention capacity in soil. As a result, this eco-friendly and economical product can effectively reduce fertilizer loss, improve water utilization efficiency, and prolong irrigation cycles which are benefit for agricultural applications, especially in drought-prone environments.

A transparent, industrial, and cost effective coating with self-cleaning property for indoor and outdoor applications based on commercial grade water-based polyacrylic emulsion was prepared using TiO2/polyaniline nanocomposite. TiO2/polyaniline nanocomposites was produced in various TiO2 to polyaniline ratios and used to modify polyacrylic coatings. The TiO2/polyaniline nanocomposites and additive contained polyacrylic coatings were specified by the use of FT-IR, UV–Vis, SEM, and XRD methods. The additive contained polyacrylic coatings showed better hydrophilicity, water resistivity, Vis and UV lights absorption, surface photodecolorization of contaminants and antibacterial property in compare to the pristine polyacrylic coating. The coatings modified with TiO2/PANI nanocomposites showed more hydrophilic surface with the water contact angle of < 10° compared to the unmodified coating with the water contact angle of 68°. Also according to the results, polyacrylic coating containing 3 wt% of TiO2/polyaniline nanocomposite with 100:1 ratio of TiO2 to polyaniline is the best coating formulation because of its high UV and visible light absorption, stability in aqueous environment, and so high efficiency in the surface photodecolorization of organic contaminant and hydrophilicity under visible light illumination.

Delivery of chemotherapy drugs, such as cisplatin, with controlled manner is a significant area of research in cancer treatment. The main purpose of this study was to investigate the in-vitro release of cisplatin from pH sensitive and controlled release hydrogels based on cellulose nanofibers (CNFs) and poly(vinyl alcohol) (PVA). Various hydrogels with different amounts of CNFs were prepared. This novel drug delivery system was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) analyses. By in-vitro experiments the influence of CNFs contents and pH of the release media on the release rate of the drug were investigated. According to the results, the hydrogel containing 1 wt% CNFs in the release media with the pH of 7.4, efficiently sustained the drug release and so can cause to the reduction of side effects of drug. By fitting the experimental data with various kinetic models it was concluded that the release mechanism is best fitted by Korsmeyer-Peppas kinetic model suggesting the diffusion controlled release mechanism. The prepared hydrogel system is suitable for delivery of cisplatin in the small intestine with a controlled manner.

New slow release nitrogen (N), phosphorous (P), and potassium (K) (NPK) fertilizer formulation was synthesized by in situ free-radical graft copolymerization of sodium alginate (NaAlg), acrylic acid (AA), and acrylamide (AAm) in the presence of rice husk ash (RHA) and fertilizer compound solution. FTIR results confirmed that NaAlg chains have been grafted onto acrylate monomers successfully. The water absorbency of hydrogel sample was affected greatly by different salt and pH solutions. The swelling ratio of the hydrogel sample was increased from 830 to 1070 g/g by the addition of RHA up to 15 wt%. The experimental findings indicated that incorporation of RHA into the hydrogel network not only improved its water retention capability, but also caused the system to liberate fertilizer in a more controlled manner compared with the neat hydrogel. Consequently, this new environment-friendly product with good slow release property and high water retention capacity can be useful in agricultural and horticultural applications.

In this work, with the aim of improving the water uptake behavior and mechanical properties, a novel nano-composite hydrogel system was synthesized using clinoptilolite as a semi-layered zeolite. Accordingly, the gelatin/SCMC-g-poly (AA-co-AAm)/clinoptilolite semi-IPN nano-composite hydrogel samples were synthesized and studied. The FTIR, XRD, SEM and EDX analysis were accomplished to confirm the successful synthesis of the nano-composite hydrogel samples. Additionally, to investigate the effect of clinoptilolite content on water uptake properties and gel characteristics of the synthesized nano-composite hydrogel samples, water absorption kinetics studies and rheological evaluations were carried out. It is obtained that, there is an optimum amount for additive content which can improve the hydrogel properties. Results showed that nano-composite hydrogel sample with 5% W/W of clinoptilolite with respect to the gelatin amount has the best efficiency from the point of view of the water absorption properties and gel characteristics. This phenomenon is related to the creation of physical cross linking in the hydrogels’ structure which leads to the creation of porous hydrogels.

Humidity and pollution deposition on the surface of porcelain insulators affect the electrical field distribution and their performance which may lead to partial discharge and decreasing flashover voltage. Thereby one essential aspect of insulator designing is their surface science and surface wettability. To address these challenges, in this study robust omniphobic coatings were designed which can repel water and oil droplets as well as other contaminant particles from the porcelain insulators surface. In this regard, slippery liquid infused porous surface (SLIPS) coatings were applied on the porcelain substrate by infusing perfluorinated liquid lubricants into 200 %-stretched Teflon tape cover or fluoro-silanized porcelain. The surface of the designed transparent coatings repelled water, olive oil, kaolin, sodium chloride microparticles, and ice. The applied coatings exhibited low contact angle hysteresis (Δθ ≤ 5°) and a low sliding angle (α ≤ 7°) for water and olive oil droplets. SLIPS coatings showed good stability to extreme environments like immersion into acid, base, brine solutions, UV radiation and withstood at 4.5 kV inclined plane test without failure after 6 h. So, the modified SLIPS can be used as effective coatings in the porcelain insulators surface engineering.

There are different methods for soil phosphorus (P) availability assessment. Researchers have recently introduced a new method called diffusive gradients in thin films (DGT) to evaluate P availability in soils. The aim of this study was manufacturing DGT gel using copolymerization of acrylamide and allylic double bonds agarose to replace the patented agarose as a cross-linker. We evaluated the efficacy of the prepared gel and used the assembled DGT with that gel in 10 calcareous soils. We compared the available P measured with the assembled DGT in those soils to Olsen’s P measured in the same soils. Corn plant (Zea mays L.) was also grown in those soils in a greenhouse for two months. Results showed that the diffusion coefficient of P ions in the gel with 0.3% of allylagarose at 25 °C was 6.9 * 10–6 cm2.s−1, implying that P ions were allowed to diffuse freely through the prepared diffusive gel. Measured P by the assembled DGT showed a close linear correlation (r2 = 0.98) with the P concentrations ...

In order to prepare a self cleaning and antibacterial coating, nanostructured TiO2/Ag+-exchanged-montmorillonite composite material was prepared and used as additive in a commercial grade polyacrylic latex coating. FT-IR and UV–visible spectroscopy, X-ray diffraction patterns and FESEM were used to characterize the composition and structure of the nanocomposites and coatings. The polyacrylic coatings, prepared by the using of TiO2/Ag+-exchanged-montmorillonite additive, showed better UV and visible light absorption, hydrophilic property, photodegradation of organic pollutants, stability in water and antibacterial properties than pristine commercial grade polyacrylic latex coating. According to the results, the modified polyacrylic coating containing 3% w of nanostructured TiO2/Ag+-exchanged-montmorillonite composite material as additive, with TiO2 to Ag+-exchanged-montmorillonite ratio of 2:1, was the best coating considering most of the useful properties such as low water contact angle, high photodegradation efficiency, and high water resistivity. The water contact angle for unmodified polyacrylic latex coating was 68° while it was decreased to about 10° or less for modified coating after 24 h LED lamp illumination.

A semi-interpenetrating polymer network (semi-IPN) superabsorbent hydrogel composite based on starch (St)-graft-poly(acrylic acid (AA)-co-acrylamide (AM))/polyvinyl alcohol (PVA) and cellulose nanocrystals (CNC) was synthesized using free radical aqueous polymerization method. Cellulose nanocrystals were extracted from potato peel waste using alkali treatment followed by acid hydrolysis. FTIR analysis affirmed the grafting reaction of acrylate-based monomers onto starch backbone as well as composite formation. The structural and morphological features of the hydrogels were examined by XRD, SEM, and TEM techniques. The hydrogel composite exhibited higher equilibrium swelling ratio (921.8 g/g) compared with the neat hydrogel (772.4 g/g). The swelling kinetics of the prepared hydrogels had high compliance with the first order swelling kinetic model. The diffusion coefficient value of the hydrogel composite was higher than that of the neat hydrogel, revealing that the incorporation of cellulose nanocrystals into the hydrogel matrix had resulted in faster penetration of water molecules into the polymeric network. The examination of the viscoelastic behavior of hydrogel samples by rheological tests revealed that the elastic behavior of the samples prevails over their viscous behavior. Moreover, the storage modulus of hydrogel composite was higher than that of the neat hydrogel over the entire frequency range which shows the stiffer network of the hydrogel composite. The hydrogel composite exhibited high saline absorbency under load, good deswelling kinetics in different saline solutions, desirable swelling/drying capability, and acceptable pH-dependent swelling reversibility which make it a potential candidate for agricultural and horticultural applications.

As a model herbicide, paraquat (PQ) was intercalated into montmorillonite (MMT) and clinoptilolite (CL) clays at different concentrations. FT-IR, XRD, and SEM techniques were used to characterize the structures of the prepared formulations. The prepared PQ/clay samples were further encapsulated with alginate (Alg) polymer. After characterization, the potential application was verified through release of PQ from PQ/clay and PQ/clay/Alg formulations. According to the results, the release of PQ from PQ/MMT was slower than the release from the PQ/CL system. The presence of the alginate polymer in PQ/clay/Alg capsule beads caused the system to liberate PQ in a more controlled release manner than PQ/clay samples. Furthermore, the release data were fitted to empirical equations to estimate the kinetic parameters. The results suggested the feasibility of the use of clay/Alg formulations for controlled release of herbicides in agricultural applications.

The commercial grade polyacrylic latex was modified in order to prepare a self-cleaning coating. TiO2/Ag-exchanged-zeolite-A nanocomposite was prepared and used as additive in the matrix of polyacrylic latex to achieve a hydrophilic and photocatalytic coating. FTIR and UV–visible spectroscopy, X-ray diffraction patterns and FESEM were used to characterize the composition and structure of the nanocomposites and coatings. The acrylic coatings, were prepared by using of TiO2/Ag-exchanged-zeolite-A additive, had better UV and visible light absorption, hydrophilic, degradation of organic pollutants, stability in water and antimicrobial properties than pristine commercial grade polyacrylic latex coating. According to the results, the modified polyacrylic based coating containing 0.5 wt% of TiO2/Ag-exchanged-zeolite-A nanocomposite additive with TiO2 to Ag-exchanged-zeolite-A ratio of 1:2 was the best coating considering most of useful properties such as small band gap and low water contact angle. The water contact angle for unmodified polyacrylic latex coating was 68° which was decreased to less than 10° in modified coating after 24 h LED lamp illumination.