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Different compositions of hydrogels composed of mathacrylamide homopolymer (60 and 90% of PMAM) were prepared using the free radical polymerization technique, with and without methylene bisacrylamide as crosslinker (0 and 3%). Several parameters and properties were studied to evaluate their performance as oil/water separators. Many parameters are used, such as residual oil in water, water recovery, separation time, hydrogels coated percentages, swelling parameters, mechanical properties, microscopic and photographic images, and scanning electron microscopy. The results showed that water recovery (87-97), Separation efficiency (96.2-99.6 %), separation time (6-9.5 min.), hydrogels coated percentages (18-23 %), water content (70-97 %), and tensile test (63-90 MPa). The effect of polymer crosslinking density, mesh pore size, and polymer composition on the parameters and properties mentioned above were also studied. The results showed that the separation efficiency of 1000 micron mesh composite is better than 500-micron mesh composites.

Carbon dioxide (CO2) can be considered as a hazardous gas due to its impacts to our environment and public health. Adsorption is an easy and simple technique to reduce CO2 level in the environment. Various waste materials have been applied as CO2 adsorbents, thus alum sludge which is a waste generated from a drinking water treatment plant was reused as CO2 sorbent in this study. The sorption kinetics, equilibrium, and thermodynamics of 1000 – 3000 mg/L of CO2 were investigated using the sludge in a fixed bed column at 303 K. The results revealed that the maximum uptake of CO2 was 0.524 mmol.g-1 at 303 K. The isotherm of CO2 sorption was well-fitted with the Freundlich model due to closeness of the R2 to unity, whereas the sorption kinetics of CO2 on the sorbent was best described by pseudo-second-order kinetic model which is in good agreement with the experimental data. The sorption of CO2 using alum sludge is a spontaneous process as the value of Gibbs free energy change is negative. The results suggested that alum sludge could be a good candidate for CO2 sorption

In the agricultural industry, biomass waste generated along with the production of food, is transformed into value-added products. Also, the demand for the slow or control release fertilizer is increasing to reduce the cost of maintaining the agricultural land. These issues are tackled by converting biomass waste to a slow fertilizer release vehicle and biodegradable water retention material that could reduce the cost for fertilizer application and simultaneously preserved the soil from dryness. A series of carboxymethyl sago pulp (CMSP) hydrogels were prepared by electron beam irradiation. Slow release systems were evaluated by loading potassium nitrate (KNO3) and ammonium nitrate (NH4NO3) into the CMSP hydrogels. These CMSP hydrogels endow slow release property, biodegradability and a soil moisture preservation property that could find greener application in agricultural industries. The results indicate that CMSP hydrogels have a great potential as an agent for slow release of fertilizers.

In the present work, a simple and green co-precipitation method was used to prepare copper oxide-zeolite nanocomposites (CuO-zeolite NCs). The weight ratio (1, 3, 5, 8 and 10 wt%) of CuO nanoparticles (NPs) loaded into zeolite was investigated to obtain the optimum CuO distribution for antibacterial activities. The prepared CuO-zeolite NCs were characterized by ultraviolet-visible (UV–vis) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (XRD), and energy dispersive X-ray fluorescence spectrometry (EDXRF). The transmission electron microscopy (TEM) and field emission scanning electron microscopy (FE-SEM) revealed a uniform surface morphology of the CuO-zeolite NCs. The UV–vis spectrum of NCs showed absorption peaks between 230 and 280 nm for nano-CuO in the XRD patterns, and new peaks appeared between (36.56°–38.83°) related to the CuO. At weight ratio less than 10 wt%, the CuO nanoparticles loaded to the zeolite exhibited spherical shapes with average particle diameter of 6.5 nm measured by TEM and XRD. Antibacterial activities were tested against Gram-negative and Gram-positive bacteria. The obtained results showed that, CuO-zeolite NCs with 8 wt% CuO nanoparticles had the highest antibacterial activities against Bacillus Subtilis B29 and Salmonella Choleraesuis ATCC 10708, which can be attributed to the good dispersion of CuO NPs on the zeolite surface.

The clay minerals montmorillonite (MMT) was combined with ZnO to form efficient nanocomposite which was used as an adsorbent. Zinc oxide nanoparticles (ZnO-NP) were successfully incorporated into the layers of montmorillonite by green simple heat method using zinc nitrate and sodium alginate as zinc oxide precursor and stabilizer respectively. The XRD and FESEM measurements revealed the presence of ZnO nanoparticles with hexagonal wurtzite structure in the ZnO/MMT nanocomposites. The role of the ZnO in enhancing the adsorption efficiency of the ZnO/MMT nanocomposite for the removal of copper and lead ions from aqueous solutions was investigated. The effects of different parameters such as contact time, dosage, initial concentration, and pH were investigated. Kinetics of adsorption were studied using pseudo-first-order and pseudo-second order. The efficiency of the nanocomposites was studied by Langmuir and Freundlich isotherms. The material showed high efficiency in a wide pH range, for the adsorption of Pb and Cu ions. Kinetic studies showed that the adsorption followed the pseudo-second-order and equilibrium best described by Langmuir isotherm. The regeneration results show that the nanocomposites can be utilized for at least three times because of its stability and durability. Thus, it can serve as a promising adsorbent for the removal of copper and lead ions from aqueous solutions.

Rice straw is available in abundance as an agricultural waste and has been used in various applications.

A Zeolite\Zinc Oxide-Copper oxide Nanocomposite (Zeolite\ZnO-CuO) was prepared via the facile chemical method and characterized by using Fourier transform infrared spectroscopy, X-ray diffraction (XRD), BET Nitrogen adsorption-desorption analyzer, Field emission scanning electron microscope (FESEM) and energy dispersive X-ray spectrometry. The FTIR spectrum showed the characteristic bands for metal oxide bonds. The average particles' diameters, measured by FESEM, were in agreement with those calculated from XRD by the Scherrer equation, which was 25.9 and 56.2 nm for ZnO and CuO respectively. The prepared NC was evaluated for the antibacterial activity tested against Gram-positive ( Bacillus subtilis B29) and Gram-negative bacteria ( Escherichia coli E266). After sufficient bacterial growth (24 h), the NC showed remarkable antibacterial activity with 18.9 and 23.8 mm inhibition zones, against Bacillus subtilis B29 and Escherichia coli E266 respectively, under normal light and conditions.

This research work has proposed preparation of Zeolite/Zinc Oxide Nanocomposite (Zeolite/ZnO NCs) by using a co-precipitation method. Then, the prepared Nanocomposite has been tested for adsorption of Lead Pb (II) and Arsenic As (V) from aqueous solution under the room pressure and temperature. After that, the prepared adsorbent has been studied by several techniques. For adsorption process; the effect of the adsorbent masses, contact time, PH and initial metals concentration as well as, the kinetics and isotherm for adsorption process have been investigated. The results revealed that; ZnO nanoparticles (NPs) with average diameter 4.5 nm have successfully been loaded into Zeolite. The optimum parameters for the removal of the toxic metals 93% and 89% of Pb (II) and As (V), respectively, in 100 mg/L aqua solutions were pH4, 0.15 g and 30 min. According to the obtained results; pseudo second-order kinetic and Langmuir isotherm model have higher correlation coefficients and provided a better agreement with the experimental data. The prepared sorbent showed an economical and effective way to remove the heavy toxic metals due to its ambient operation conditions, low- consumption energy and facile regeneration method. Keywords: Zeolite, ZnO, Nanocomposites, Adsorbent, Kinetic, Isotherm

Carboxymethyl sago starch (CMSS) hydrogel was prepared by dissolving CMSS in HCl solution under vigorous stirring to form gel. The parameter studied were the effect of the percentage of CMSS, concentration of the acid solution, reaction time and reaction temperature to identify the optimum condition of preparation of CMSS hydrogel. 60% of CMSS in 2.0M acid solution for 12 hours reaction time at room temperature were the optimum conditions for CMSS hydrogel. The hydrogel was characterized by using Fourier Transform Infrared (FT-IR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). FTIR spectrum of CMSS shows an additional absorption band at 1597 cm-1 indicating the substitution of CH2COO-Na+ group on the starch molecular chain during carboxymethylation, while the spectrum of CMSS hydrogel shows an additional sharp absorption band at 1723 cm-1 indicating that the Na in CMSS being exchanged to H from hydrochloric acid solution. SEM image of CMSS hydrogel shows pores in structure and connected to each other to form networks. TGA curve shows that the maximum rate of thermal decomposition of CMSS hydrogel is higher than CMSS at 330.22 ºC with 60.22% major weight loss. This could be due to the presence of the cross-linkages in the CMSS hydrogel. CMSS hydrogel gives high swelling degree in PBS solution at pH 7 and low swelling degree in acidic medium.

Synthesis of copper nanoparticles was carried out with nanocrystalline cellulose (NCC) as a support by reducing CuSO4·5H2O ions using hydrazine. Ascorbic acid and aqueous NaOH were also used as an antioxidant and pH controller, respectively. The synthesized copper nanoparticles supported on NCC (CuNPs@NCC) were characterized by UV–vis, XRD, TEM, XRF, TGA, DSC, N2 adsorption-desorption method at 77 K and FTIR. The UV–vis confirmed the formation and stability of the CuNPs, which indicated that the maximum absorbance of CuNPs@NCC was at 590 nm due to the surface plasmon absorption of CuNPs. Morphological characterization clearly showed the formation of a spherical structure of the CuNPs with the mean diameter and standard deviation of 2.71 ± 1.12 nm. Similarly, XRD showed that the synthesized CuNPs@NCC was of high purity. The thermal analysis showed that the CuNPs@NCC exhibited better thermal behaviors than NCC. BET surface area revealed that the N2 adsorption–desorption isotherms of CuNPs@NCC featured a type IV isotherm with an H3 hysterisis loop. This chemical method is simple, cost effective, and environmentally friendly. Compared to NCC-supported CuNPs and unsupported CuNPs, the as-prepared CuNPs@NCC exhibit a superior catalytic activity and high sustainability for the reduction of methylene blue with NaBH4 in aqueous solution at room temperature. The CuNPs@NCC achieved complete reduction of MB with completion time, rate constant and correlation coefficient (R 2) of 12 min, 0.7421 min−1 and 0.9922, respectively.

How to completely remove toxic metals from water is still a serious challenge, and is the mission that faces researchers and scientists today. In this work, zeolite/copper oxide (CuO) and zeolite/iron oxide (Fe3O4) nanocomposites (NCs) were prepared via a co-precipitation method. Several techniques were used for characterization of the prepared NCs including UV-visible, powder X-ray diffraction, N2 adsorption for determining the specific surface areas (Brunauer–Emmett–Teller (BET)) and pore volumes. The morphology was investigated by field emission scanning electron microscopy. The batch adsorption experiment process was used to study the applicability of the prepared NCs to removing lead (Pb) and arsenic (As) from aqueous solutions. The effects of the adsorbent dosage, pH, initial metal concentration and contact time on the adsorption process were investigated. The obtained results revealed that in 40 minutes 0.15 g of prepared zeolite/Fe3O4 (NCs) was able to remove 97.2% of Pb and 96.8% of As from 100 mg/L aqua solutions at a pH of between 4 and 6. The Langmuir isotherm model showed higher correlation coefficients and provided better agreement with the experimental data. The adsorption kinetic is a chemi-physisorption process that follows the pseudo second-order kinetic model.

The artificial neural network (ANN) modeling of adsorption of Pb(II) and Cu(II) was carried out for determination of the optimum values of the variables to get the maximum removal efficiency. The input variables were initial ion concentration, adsorbent dosage, and removal time, while the removal efficiency was considered as output. The performed experiments were designed into two data sets including training, and testing sets. To acquire the optimum topologies, ANN was trained by quick propagation (QP), Batch Back Propagation (BBP), Incremental Back Propagation (IBP), genetic algorithm (GA) and Levenberg-Marquardt (LM) algorithms for testing data set. The topologies were defined by the indicator of minimized root mean squared error (RMSE) for each algorithm. According to the indicator, the IBP-3-9-2 was selected as the optimized topologies for heavy metal removal, due to the minimum RMSE and maximum R-squared.

An eco-friendly photochemical method for preparing silver nanoparticles (Ag-NPs) in a natural polymer (κ-carrageenan) was successfully developed and is reported in this study. The Ag-NPs have been synthesized via a photochemical method by using UV-irradiation, silver nitrate and κ-carrageenan as a reducing agent, a silver precursor and a stabilizer at room temperature, at different irradiation time. The formation of Ag-NPs was improved by UV–vis spectroscopy where surface plasmon absorption maxima was observed at 420–430 nm. Transmission electron microscopy (TEM) data and the size distribution were in an agreement with the finding from the UV–vis spectra. Scanning electron microscope data illuminated the changes in the surface of κ-carrageenan. Fourier transform infrared spectra indicated the interactions between Ag-NPs and κ-carrageenan. In addition, the Ag-NPs were characterized by X-ray diffraction (XRD). The peaks in the XRD pattern showed that the Ag-NPs possessed an FCC structure. The green methods by using an eco-friendly stabilizer and reducing agent provide green and economic attributes to this paper. These results demonstrate the successful synthesis of Ag-NPs in κ-carrageenan by using UV-irradiation as a green and a photochemical reducing method. Ag-NPs were obtained by using UV-irradiation at different times at room temperature, where increasing irradiation time corresponded to the formation of smaller more spherical Ag-NPs. The synthesized Ag-NPs find applications as bacteria inhibitors and can be applied in the medical field.

This study includes the synthesis of nano-sized lithium tetraborate by an innovative single step thermal treatment method and characterization of the products. The heating temperature for the synthesis was varied between 200 and 850°C with the retention time of 2h. Polyvinyl pyrrolidone (PVP) with different concentrations was used as surfactant. Characterization of the samples was achieved by thermogravimetric analysis (TGA), derivative thermogravimetry analysis (DTG), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM) techniques and UV–vis spectroscopy. Thermal analysis of initial solution allowed the optimization of the heat treatment program and showed that the thermal stability of samples is started at 460°C. FT-IR, XRD and TEM results proved the formation of pure nano-crystalline lithium tetraborate at temperature between 460 and 750°C. Furthermore, the band gap investigation was performed using UV–vis spectra in the presence of different concentrations of PVP and in variety of calcination temperatures. The estimated optical bandgap was found to be between 5.2 and 6.2eV.

In this study, talc was modified with zinc oxide nanoparticles to form a ZnO/talc nanocomposite. The nanocomposite was characterized using X-ray powder diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption/desorption, field emission scanning electron microscopy. The characterization revealed that ZnO nanoparticles were well incorporated with the talc. The adsorption efficiency of the prepared nanocomposite was evaluated for Pb(II) removal from aqueous solution. The related parameters such as agitating time, dosage and pH, were optimized. Adsorption characteristics of the talc, and ZnO/talc nanocomposite were compared and the results showed that ZnO/talc nanocomposite had the highest adsorption capacity. The kinetic sorption data were found to fit the pseudo-second-order kinetic model. The experimental isotherm data of lead adsorption were examined using the Freundlich and the Langmuir models. The maximum lead adsorption capacity of the adsorbent was determined as 48.3 mg g−1. The mechanism of adsorption was found to be controlled by electrostatic attraction on the nanocomposite. The overall results indicated the prepared nanocomposite can be employed as an alternative for Pb(II) removal from wastewater.

A chemical reduction method was employed for the synthesis of copper nanoparticles stabilized by nanocrystalline cellulose (NCC) using different concentrations of copper salt in aqueous solution under atmospheric air. CuSO4·5H2O salt and hydrazine were used as metal ion precursor and reducing agent, respectively. Ascorbic acid and aqueous NaOH were also used as an antioxidant and a pH moderator, respectively. The number of CuNPs increased with increasing concentration of the precursor salt. The formation of copper nanoparticles stabilized by NCC (CuNPs@NCC) was investigated by UV-visible spectroscopy (UV-vis), where the surface absorption maximum was observed at 590 nm. X-ray diffraction (XRD) analysis showed that the CuNPs@NCC are of a face-centered cubic structure. Moreover, the morphology of the CuNPs@NCC was investigated using transmission electron microscope (TEM) and field emission scanning electron microscope (FESEM), which showed well-dispersed CuNPs with an average particle size less than 4 nm and the shape of CuNPs was found to be spherical. Energy dispersive X-ray spectroscope (EDS) also confirmed the presence of CuNPs on the NCC. The results demonstrate that the stability of CuNPs decreases with an increasing concentration of the copper ions.

Artificial neural networks have been widely used to solve problems because of their reliable, robust, and salient characteristics in capturing nonlinear relationships between variables in complex systems. In this study, a wavelet neural network (WNN) based on the incremental backpropagation (IBP) algorithm was used in conjunction with an experimental design. To optimize the network, independent variables including ion concentration, adsorbent dose, and removal time were used as input parameters, while the removal percentage of Pb(II), Ni(II), and Cu(II) by magnetic/talc nanocomposite were selected as outputs. The network was trained by the IBP and four other algorithms as a model. To determine the number of hidden-layer nodes in the model, the root-mean-square error of a testing set was minimized. After minimizing this error, the topologies of the algorithms were compared based on the coefficient of determination and absolute average deviation. This comparison indicated that the IBP algorithm had the minimum root-mean-square error and absolute average deviation, and maximum coefficient of determination, for the test dataset. The importance values included 35.16 % for initial ion concentration, 32.74 % for adsorbent dose, and 32.11 % for removal time, showing that none of these were negligible. These results show that the WNN has great potential ability for prediction of removal of heavy-metal ions from aqueous solution with residual standard error less than 1.2 %.

Polymer gel is a kind of radiation dosimetry system that has been applied widely in radiotherapy treatment. In this study, the samples of NIPAM-based polymer gel which posses a good potential as 3D radiation dosimetry are synthesized. The samples of polymer gel were irradiated up to 20 Gy by using gamma cell instrument with 60Co sources at a constant dose rate. Upon irradiation, then the chemical changes in polymer gel were characterized by using Raman spectroscopy. The polymerization was referred to an increment in Raman intensity at 815 cm-1, assigned for C-C stretching mode of NIPAM polymer gel, as the dose increased. The consumptions of the co-monomers were referred to a decrement in Raman intensities at 1025 cm-1 and 2353 cm-1 assigned for C=C stretching modes of NIPAM and BIS respectively, as the dose increased. Result shows that the amount of carbon single bonds increases while the amount of carbon covalent bonds decreases following irradiation.

Fe3O4/montmorillonite nanocomposite (Fe3O4/MMT NC) was synthesized for removal of Pb2+, Cu2+ and Ni2+ ions from aqueous systems. The nanoadsorbent was characterized by X-ray diffraction and transmission electron microscopy and mean diameter of magnetic nanoparticles was about 8.24 nm. The experiments were designed by response surface methodology and quadratic model was used to prediction of the variables. The adsorption parameters of adsorbent dosage, removal time, and initial heavy metal ions concentration were used as the independent variables and their effects were investigated on the heavy metal ions removal. Variance analysis was utilized to judge the adequacy of the chosen models. Optimum conditions with initial heavy metal ions concentration of 510.16, 182.94, and 111.90 mg/L, 120 s of removal time and 0.06 g/0.025 L, 0.08 g/0.025 L, and 0.08 g/0.025 L of adsorbent amount were given 89.72%, 94.89%, and 76.15% of removal efficiency Pb2+, Cu2+ and Ni2+ ions, respectively. Prediction of models was in good agreement with experimental results and Fe3O4/MMT NC was found successful in removing heavy metals from their aqueous solutions.

The sonochemical method as a green method for the preparation and size control of silver nanoparticles (Ag-NPs) formed in κ-carrageenan has been developed. κ-carrageenan was chosen because it is an eco-friendly stabilizer and ultrasonic irradiation reducing agent. Formations of Ag/κ-carrageenan were determined by electronic spectroscopy where the surface plasmon absorption maxima were observed at 437–412 nm. The FT-IR spectrum indicated the presence of κ-carrageenan in capping with Ag-NPs. The XRD analysis proved that the Ag-NPs were of a face-centered cubic structure. TEM images displayed well-dispersed Ag-NPs with an average particle size of less than 10 nm. SEM images indicated the spherical shape of the Ag-NPs.

A comparison has been made of the intercalation capacity of the stearate anions into the two different anionic clays: magnesium aluminum layered double hydroxide (Mg3Al LDH) and zinc aluminum layered double hydroxide (Zn3Al LDH). The anionic clays Mg3Al LDH and Zn3Al LDH were firstly prepared by co-precipitation method from nitrate salts solution and then modified by stearate anions through an ion exchange reaction. The properties, morphologies and ion exchange ability of these two clays have been studied by XRD, TGA, SEM, TEM and CHNS that show the ability of Zn3Al LDH to capture stearate anions is greater than Mg3Al LDH.

A green sonochemical method was developed for preparing silver nanoparticles (Ag-NPs) in κ-carrageenan in different concentrations of AgNO3. The κ-carrageenan was used as an eco-friendly stabilizer and ultrasonic irradiation as a green reducing agent. The number of Ag-NPs increased with increasing concentrations of AgNO3. Formation of Ag/κ-carrageenan was determined by UV–visible spectroscopy where the surface plasmon absorption maximum was observed at 410–416 nm. XRD analysis showed the Ag-NPs are of a face-centered cubic structure. TEM images showed the well-dispersed Ag-NPs with an average particle size

Galantamine hydrobromide is formulated in tablets and capsules prescribed through oral delivery for the treatment of Alzheimer’s disease. However, oral delivery of drugs can cause severe side effects such as nausea, vomiting, and gastrointestinal disturbance. Transdermal delivery of galantamine hydrobromide could avoid these unwanted side effects. In this work, galantamine hydrobromide was formulated in gel drug reservoir which was then fabricated in the transdermal patch. The in vitro drug release studies revealed that the drug release from the donor chamber to receptor chamber of Franz diffusion cell was affected by the amount of polymer, amount of neutralizer, amount of drug, types of permeation enhancer, and amount of permeation enhancer. Visual observations of the gels showed that all formulated gels are translucent, homogeneous, smooth, and stable. These gels have pH in the suitable range for skin. The gel also showed high drug content uniformity. Hence, this formulation can be further used in the preparation of transdermal patch drug delivery system.

Hydrazide derivatives have been synthesized from methyl esters, hydrazones and vegetable oils. They are important due to their diverse applications in pharmaceutical products, detergents as well as in oil and gas industries. The chemical synthesis of fatty hydrazides is well-established; however, only a few publications described the synthesis of fatty hydrazide derivatives, particularly, when produced from refined, bleached and deodorized palm olein. Here, the synthesis and characterization of N,N-dimethyl fatty hydrazides are reported. The N,N-dimethyl fatty hydrazides was successfully synthesized from fatty hydrazides and dimethyl sulfate in the presence of potassium hydroxide with the molar ratio of 1:1:1, 6 hours reaction time and 80℃ reaction temperature in ethanol. The product yield and purity were 22% and 89%, respectively. The fatty hydrazides used were synthesized from refined, bleached and deodorized palm olein with hydrazine monohydrate at pH 12 by enzymatic route. Fourier transform infrared, gas chromatography and nuclear magnetic resonance (NMR) spectroscopy techniques were used to determine the chemical composition of N,N-dimethyl fatty hydrazides. Proton NMR confirmed the product obtained were N,N-dimethyl fatty hydrazides.

Arsenic contaminated water is an environmental issue due to their toxicity. Acute arsenic poisoning has claimed the lives of many and causes adverse health risk to millions of people in several countries such as Bangladesh, India, and China. Effective removal of this contaminant can be obtained by adsorbing them onto low-cost adsorbents. In this study, hydrogel-biochar composite (HBC-RH) was successfully synthesized by embedding rice husk biochar into poly(acrylamide) hydrogel with N.N’-methylenebisacrylamide (MBA) as crosslinker. The synthesized HBC-RHs were characterized and utilized for the removal of arsenic from wastewater. The experimental parameters that influence the sorption process were investigated. The results obtained revealed that the effective removal of arsenic was found to be dependent on solution pH, sorbent dosage, initial contaminant concentration, and contact time. HBC-RH maximum monolayer sorption capacity for arsenic was 28.32 mg g −1 and the experimental data suggested that the arsenic sorption was best fitted by pseudo-second-order kinetic mode. Above all, HBC-RH can easily be separated from aqueous solution after accomplishing its mission, avoiding separation complications faced by powder adsorbents in aqueous media.

New 1,3-benzoxazine and naphthoxazine monomers were synthesized using a modified step-wise technique in which formaldehyde was replaced with methylene bromide for ring-closure reaction in the last synthetic step. Salicylaldehyde and 2-hydroxy-1-naphthaldehyde were used as the aromatic aldehydes and 4-fluoroaniline, 4-butylaniline, hexamethylenediamine, p-phenylenediamine and 2-aminothiazole were used as the primary amines. Condensation of the aromatic aldehydes and the aromatic primary amines in absolute ethanol gives imine compounds which on reduction with sodium borohydride in methanol give 2-hydroxybenzylamines/2-hydroxynaphthylamines. Ring-closure reaction between 2-hydroxybenzylamines/2-hydroxynaphthylamines and methylene bromide in absolute ethanol gives the 1,3-benzoxazines and naphthoxazines in good yields. The structures of the new 1,3-benzoxazine and naphthoxazine monomers were confirmed by FT-IR, 1H NMR and 13C NMR spectral analysis, Mass spectroscopy (GC-MS) and elemental analysis. The mass spectrum of the synthesized compounds showed molecular ion peaks centered at m/z 229, 218, 316, 317, 444 and 268 which are equivalent to the molecular weights of the new synthesized compounds a, b, c, d, e and f, respectively. Results of elemental analysis also confirm the calculated result to be in agreement with the experimental result.

The aim of this paper is to report the effect of the addition of cellulose nanocrystals (CNCs) on the mechanical, thermal and barrier properties of poly(vinyl alcohol)/chitosan (PVA/Cs) bio-nanocomposites films prepared through the solvent casting process. The characterizations of PVA/Cs/CNCs films were carried out in terms of X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA and DTG), oxygen transmission rate (OTR), and tensile tests. TEM and SEM results showed that at low loading levels, CNCs were dispersed homogenously in the PVA/Cs matrix. The tensile strength and modulus in films increased from 55.1 MPa to 98.4 MPa and from 395 MPa to 690 MPa respectively, when CNCs content went from 0 wt% to 1.0 wt%. The thermal stability and oxygen barrier properties of PVA/Cs matrix were best enhanced at 1.0 wt% of CNCs loading. The enhanced properties attained by incorporating CNCs can be beneficial in various applications.

Modified rice straw/Fe3O4/polycaprolactone nanocomposites (ORS/Fe3O4/ PCL-NCs) have been prepared for the first time using a solution casting method. The RS/Fe3O4-NCs were modified with octadecylamine (ODA) as an organic modifier. The prepared NCs were characterized by using X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR). The XRD results showed that as the intensity of the peaks decreased with the increase of ORS/Fe3O4-NCs content in comparison with PCL peaks, the Fe3O4-NPs peaks increased from 1.0 to 60.0 wt. %. The TEM and SEM results showed a good dispersion of ORS/Fe3O4-NCs in the PCL matrix and the spherical shape of the NPs. The TGA analysis indicated thermal stability of ORS/Fe3O4-NCs increased after incorporation with PCL but the thermal stability of ORS/Fe3O4/PCL-NCs decreased with the increase of ORS/Fe3O4-NCs content. Tensile strength was improved with the addition of 5.0 wt. % of ORS/Fe3O4-NCs. The antibacterial activities of the ORS/Fe3O4/PCL-NC films were examined against Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) by diffusion method using nutrient agar. The results indicated that ORS/Fe3O4/PCL-NC films possessed a strong antibacterial activity with the increase in the percentage of ORS/Fe3O4-NCs in the PCL.

This study aims is to investigate the influence of different concentrations of Kappaphycus alvarezii (K. alvarezii) for the synthesis of Cu@Cu2O core–shell nanoparticles (NPs) in aqueous solution. The core–shell NPs were prepared by a chemical reduction method using K. alvarezii, CuSO4·5H2O, NaOH, ascorbic acid, hydrazinium hydroxide, as stabilizer, copper precursor, pH moderator, antioxidant and reducing agent under 120 °C temperature, respectively. Formation of Cu@Cu2O-NPs was determined by UV–Vis spectroscopy where surface plasmon absorption maxima can be observed at 390-590 nm. The synthesized core–shell NPs were also characterized by X-ray diffraction. Moreover, the morphology and structure of the K. alvarezii/Cu@Cu2O-NPs were investigated by TEM, FESEM and EDXRF. The Fourier transform infrared spectrum suggested the complexation present between K. alvarezii and Cu@Cu2O-NPs. The study clearly showed that using various amounts of K. alvarezii leads to produce different ratios and sizes of Cu@Cu2O NPs. The size of the Cu@Cu2O-NPs decreased as the amount of K. alvarezii was increased. The ratio of Cu@Cu2O increases with the increasing concentration of K. alvarezii until 0.2 wt%.

The composite materials based on rice straw (RS) fiber and polycaprolactone (PCL) were prepared by a solution-casting method and characterized. The composites were prepared using different fiber loadings (1.0, 3.0, 5.0, and 7.0 wt%). The prepared composites (Cs) were characterized by using powder X-ray diffraction (XRD), scanning electron microscopy (SEM), electro-optical microscopy, Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis, and mechanical properties were investigated. The XRD results showed that the intensity of the peaks decreased with the increase of RS content from 1.0 to 7.0 wt% in comparison with PCL peaks. SEM micrographs indicated poor adhesion between RS and PCL matrices, and FT-IR spectroscopy showed that, with the increase of loading percentages of RS, the intensity of the peaks is decreased from 1.0 to 7.0 wt%, and the interaction between RS and PCL was a physical interaction. Thermal stability was decreased with increasing the RS contents. Tensile measurement showed an increase in tensile modulus from 1.0 to 7.0 wt% loading of RS into the PCL, but a decrease in tensile strength and elongation at the break as the RS contents are increased, although there is a modest increase in tensile strength of the Cs material with 3.0 wt% loading of RS.

A hydrothermal method for the synthesis of reduced graphene oxide/titanium dioxide filter (RGO/TiO2) and reduced graphene oxide/zinc oxide filter (RGO/ZnO) by using polypropylene (PP) porous filter is reported. Field emission scanning electron microscopy illustrated that the nanoparticles were uniformly distributed on the reduced graphene oxide nanosheets. Flexural tests showed that the physical properties of the modified filters have greater strength than the original filter. Thermogravimetric analysis revealed that the thermal property of the modified filters is the same as that of the original filter. Under a halogen lamp, the modified filter exhibited excellent photocatalytic degradation of methylene blue. The RGO/TiO2 filter maintained its ability to degrade MB efficiently, even after five cycles of photocatalysis.

Polystyrene was grafted onto oil palm empty fruit bunch (OPEFB) fiber in aqueous medium by using the H2O2/Fe2+ system as an initiator. Optimization of the reaction conditions was carried out by varying the reaction period, temperature, amounts of the monomer, initiator and co-catalyst. The presence of the peaks around 3026 cm-1, 698 cm-1 and 755 cm-1 in the Fourier transform infrared (FTIR) spectra of the grafted product and the presence of polystyrene on the surface of grafted OPEFB in the scanning electron micrograph provided strong evidence of the grafting. The maximum percentage of grafting (about 200%) was achieved when the reaction was carried on for 4 h at a temperature of 65°C, using 52.27 mmol monomer, 6.00 mmol initiator and 0.26 mmol co-catalyst. The thermal stability of the grafted OPEFB was found to be better than that of the ungrafted fiber, as seen from thermogravimetric analysis (TGA).

The goal of this study was to investigate the effect of modified rice straw (ORS) on the mechanical and thermal properties of modified rice straw/polycaprolactone composites (ORS/PCL-Cs). The composites (Cs) of polycaprolactone (PCL) with ORS were successfully synthesized using the solution-casting method. The RS modified with octadecylamine (ODA) as an organic modifier. The prepared composites were characterized by using powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and Fourier transforms infrared spectroscopy (FT-IR), and mechanical properties were investigated. Composites of ORS/PCL showed superior mechanical properties due to greater compatibility of ORS with PCL. The XRD results showed that the intensity of the peaks decreased with the increase of ORS content from 1.0 to 7.0 wt.% in comparison with PCL peaks. Tensile measurement showed an increase in tensile modulus but a decrease in tensile strength and elongation at break as the ORS contents are increased from 1.0 to 7.0 wt.%; on the other hand, tensile strength was improved with the addition of 5.0 wt.% of ORS. Thermal stability was decreased with the increase of ORS contents. SEM micrograph indicated good dispersion of ORS into the matrix, and FT-IR spectroscopy showed that the interaction between PCL and ORS is physical interaction.

The purpose of this study was to investigate the effect of OH concen- tration on the size of Fe3O4 nanoparticles (Fe3O4-NPs). Fe3O4-NPs with different cubic nanocrystal structure and percentage Fe3O4 content were successfully pre- pared, by use of the chemical co-precipitation method, on the exterior surface of talc, as solid substrate, by an environmentally friendly process. Ferric chloride, ferrous chloride, and sodium hydroxide were used as iron oxide precursors and reducing agent. The results showed that the morphology of the Fe3O4-NPs can be adjusted by changing the reaction conditions, for example volume of reducing agent and concentration of iron salts. Different size, dispersal, and the magnetic properties were obtained by changing the concentration of iron salts and NaOH. The products were characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy. The reaction was conducted in a non- oxidizing, oxygen-free environment. Because the interlamellar spacing of the talc was almost unchanged (ds = 0.94-0.87 nm), the Fe3O4-NPs were formed on the exterior surface of the talc. The average diameter of the Fe3O4-NCs could be varied from 6.62-8.13 nm in adjusting the concentration of NaOH. The size of the nanoparticles decreased as the amount of reducing agent was increased. These talc- Fe3O4 nanocomposites (talc-Fe3O4-NCs) may have potential applications in the chemical and biological industries.

In this research, the effect of SiO2 particles on the dispersion behavior of montmorillonite (MMT) in polyimide(4-APS/BTDA)/SiO2–MMT nanocomposite film(where 4-APS is 4-aminophenyl sulfone and BTDA is 3,3′,4,4′-benzophenonetetracarboxylic dianhydride), and the changes in the molecular structure and morphology of the polymer matrix during thermal imidization were characterized by means of temporal analyses. For this purpose, the X-ray diffraction (XRD) patterns of PI/MMT and PI/SiO2–MMT nanocomposite films prepared at different heating steps under ambient atmosphere were studied. The MMT d-spacing in the polymer matrix was determined using Bragg’s equation. The XRD results showed that modified organophilic MMT (OMMT) is initially exfoliated in the poly(amic acid) for both nanocomposite films. The results showed that, with increasing temperature and duration of thermal imidization, the peak of the MMT layers moved to slightly higher angle and also the peak intensity increased concurrently for both nanocomposite films. Comparison of the temporal XRD patterns of PI/MMT and PI/SiO2–MMT nanocomposite films revealed that the increase in the peak intensity as well as the displacement of the peak position of MMT layers were less for the latter film. Indeed, the obtained results indicated that, in the presence of SiO2 particles, there was more dispersion of MMT layers in the polymer matrix. The morphology of all the specimens was investigated by atomic force microscopy. The obtained results showed that presence of SiO2 particles can cause the surface of nanocomposite film to become smoother. The temporal ultraviolet–visible spectra of both nanocomposite films showed a bathochromic shift with increase of the thermal treatment temperature and duration.

Silver nanoparticles (Ag NPs) have been synthesized by using a chemical reducing method in the external space of talc layers as a solid support at room temperature. NaBH4 and AgNO3 were used as a reducing agent and silver precursor, respectively. The interlamellar space limits were without many changes and, therefore, Ag NPs formed on the exterior surface of talc composites with mean diameters 7.60–13.11 nm for different silver nitrate concentrations. The antibacterial effects of different sizes of Ag NPs in talc were investigated against Gram-positive (i.e. Staphylococcus aureus and methicillin-resistant S. aureus) and Gram-negative (i.e. Escherichia coli) bacteria by the disk diffusion method using Mueller–Hinton Agar. The AgNO3 was found to have significant antibacterial activity against Ag NPs that did not indicate any antibacterial effects. These results showed that Ag NPs entrapped in the surface of talc layers cannot be used as effective growth inhibitors in different biological systems.

Hydrofluoric acid has been used as a stripping agent for molybdenum(VI) using a mixture of N,N’-carbonyl difatty amides (CDFAs) synthesized from palm oil as a extractant. The CDFAs was characterized by Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance technique. In the extraction step, the effects of parameters, such as type of diluent, hydrochloric acid, metal concentration, and temperature, have been studied. The effects of various stripping agents on stripping efficiency have also been investigated. This work presents the development of a low-cost and environmentally friendly extractant to recover molybdenum.

A novel nano-adsorbent SiO2/(3-aminopropyl)triethoxysilane-coated magnetite nanoparticles was synthesized for the adsorption of lead ions from water samples. Its structure and magnetic characteristics were characterized, by FTIR, powder X-ray diffraction, scanning electron microscope (SEM), transmission electron microscope (TEM) and vibrating sample magnetometry (VSM). Amino-functionalized SiO2 coated Fe3O4 magnetite nano-adsorbent exhibited superparamagnetic behavior and strong magnetization at room temperature. The efficiency of the nano-adsorbent in separation of the metals was evaluated by adsorption technique. Kinetic data were analyzed using the pseudo-first-order and pseudo-second-order equations. The data fitted very well to the pseudo-second-order kinetic model.The linear Langmuir and Freundlich models were applied to describe equilibrium isotherms and Langmuir model fitted well. The monolayer adsorption capacity was found as 17.65 mg/g at pH 4.0. Thermodynamic parameters such as free energy change (ΔG°), enthalpy change (ΔH°) and entropy change (ΔS°) were also calculated. These parameters showed that the adsorption of Pb(II) onto nano-adsorbent was feasible, spontaneous and endothermic. The amino-functionalized SiO2 coated Fe3O4 magnetic nano-adsorbent shows high adsorption capability for metal ions from aqueous solutions via the chelation mechanisms. The Pb(II) loaded nano-adsorbent can be easily recovered from aqueous solution with magnetic separation and regenerated readily by acid treatment. The product of this work can be used as an effective and recyclable nano-adsorbent for the removal of metal ions in wastewater treatment.

Biosynthesis of noble metal nanoparticles is a vast developing area of research. In the present study, silver nanoparticles (Ag-NPs) were synthesized from aqueous silver nitrate through a simple and biosynthetic route using water extract of Curcuma longa (C. longa) tuber powder, which acted simultaneousl as a reductant and stabilizery. The as-prepared samples are characterized using UV–Visible, XRD, TEM, SEM, EDXF, and FT-IR techniques. The formation of Ag-NPs is evidenced by the appearance of the signatory brown color of the solution and UV–vis spectra. Formation of Ag/C. longa was determined by UV–Vis spectroscopy where surface plasmon absorption maxima can be observed at 457–415 nm from the UV–Vis spectrum. The XRD analysis shows that the Ag-NPs are of a face-centered cubic structure. Well-dispersed Ag-NPs with anisotropic and isotropic morphology for 5, 10, and 20 mL of C. longa water extract having a size less than 10 nm are seen in TEM images. The optimum volume extraction to synthesize smallest particle size was 20 mL with mean diameter and standard division 4.90 ± 1.42 nm. FT-IR spectrum indicates the presence of different functional groups in capping the nanoparticles with C. longa. The zeta potential analysis results indicated that the charge of C. longa was negative and increased in Ag/C. longa emulsion with increasing of volumes of extract used (10–20 mL). The most needed outcome of this work will be the development of value-added products from C. longa for biomedical and nanotechnology-based industries.

The purpose of this study was to investigate the antibacterial effect of silver nanoparticles in chitosan–poly(ethylene glycol) suspension. The silver nanoparticles (AgNPs) were prepared by use of an environmentally benign method from chitosan (Cts) and poly(ethylene glycol) (PEG) at moderate temperature and with stirring for different times. Silver nitrate (AgNO3) was used as the metal precursor and Cts and PEG were used as solid support and polymeric stabilizer, respectively. The antibacterial activity of silver–chitosan–poly(ethylene glycol) nanocomposites (Ag–Cts–PEG NCs) against Staphylococcus aureus, Micrococcus luteum, Pseudomonas aeruginosa, and Escherichia coli was tested by use of the Mueller–Hinton agar disk-diffusion method. Formation of AgNPs was determined by UV–visible spectroscopy; surface plasmon absorption maxima were observed at 415–430 nm in the UV–visible spectrum. The peaks in the XRD pattern confirmed that the AgNPs had a face-centered cubic structure; peaks of contaminated crystalline phases were not observed. Transmission electron microscopy (TEM) revealed that the AgNPs synthesized were spherical. The optimum stirring time for synthesis of the smallest particle size (mean diameter 5.50 nm) was 12 h. The AgNPs in Cts–PEG were effective against all the bacteria tested. Higher antibacterial activity was observed for AgNPs with smaller size. These results suggest that AgNPs can be used as an effective inhibitor of bacteria and can be used in medical applications. These results also suggest that AgNPs were successfully synthesized in Cts–PEG suspension at moderate temperature with different stirring times.

In this study, the effects of epoxidized palm oil (EPO) on the mechanical and morphological properties of a blend of two types of biodegradable polymer, poly(lactic acid) (PLA) and polycaprolactone (PCL), were investigated. The solution-casting process, with chloroform as a solvent, was used to prepare samples. Addition of EPO reduced the tensile strength and modulus but increased elongation at break for the PLA–PCL blend. The highest elongation at break was observed for the blend with 10 % (w/w) EPO content. Scanning electron microscopy (SEM) indicated that the fractured surface morphology of the PLA–PCL blend became more stretched and homogeneous in PLA–PCL–EPO. Possible interactions between the PLA–PCL blend and EPO were also characterized by use of Fourier-transform infrared (FTIR) spectroscopy. Thermal stability was studied by differential scanning calorimetry and thermogravimetric analysis. The results from FTIR and SEM revealed that the miscibility of the PLA–PCL blend was improved by addition of EPO.

Nanocomposites of poly-3-hydroxybutyrate/poly(butyleneadipate-co-terephthalate)/layered double hydroxide (PHB/PBAT/LDH) were prepared from a binary blend of PHB/PBAT and stearate-Zn3Al LDH via a solution casting method using chloroform as solvent in this study. The pristine Zn3Al LDH was synthesized from nitrate salts solution at pH 7 by using coprecipitation technique and then was modified by stearate anions surfactant via ion exchange reaction. As a result, the basal spacing of the LDH was increased from 8.77 to 24.94 Å after the modification. Intercalated nanocomposites were formed due to the presence of diffraction peak in XRD diffractograms. The infrared spectrum of stearate-Zn3Al LDH exhibited the existence of stearate anions in the synthesized Zn3Al LDH. Mechanical properties with 2 wt% stearate-Zn3Al LDH loading nanocomposites showed 56 wt% improvements in elongation at break compared to those of the blend.

Nanocomposites of zinc oxide loaded on a zeolite (Zeolite/ZnO NCs) were prepared using co-precipitation method. The ratio effect of ZnO wt.% to the Zeolite on the antibacterial activities was investigated. Various techniques were used for the nanocomposite characterization, including UV-vis, FTIR, XRD, EDX, FESEM and TEM. XRD patterns showed that ZnO peak intensity increased while the intensities of Zeolite peaks decreased. TEM images indicated a good distribution of ZnO-NPs onto the Zeolite framework and the cubic structure of the zeolite was maintained. The average particle size of ZnO-nanoparticles loaded on the surface of the Zeolite was in the range of 1–10 nm. Moreover, Zeolite/ZnO NCs showed noticeable antibacterial activities against the tested bacteria; Gram- positive and Gram- negative bacteria, under normal light. The efficiency of the antibacterial increased with increasing the wt.% from 3 to 8 of ZnO NPs, and it reached 87% against Escherichia coli E266.

Fatty methylydrazides (FMHs) have been successfully synthesized from palm oil. Glycerol was produced as a by-product. The synthesis was carried out by reflux palm oil with methylhydrazine in hexane. FMHs have been characterized using elemental analysis, Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance technique. The results showed that a 6:1 molar ratio of palm oil to methylhydrazine, a round 78 % maximum conversion of palm oil into FMHs and a 10 h reaction time are the optimum reaction conditions.

Solutions of carboxymethyl sago pulp (CMSP) of various degree of substitution were irradiated with electron beam of various radiation doses. The gelation dose (Dg) and po/qo ratio (po is degradation density, qo is crosslinking density) is dependent on CMSP concentration and degree of substitution. In the range of concentrations of 10% to 80% (w/v) CMSP with degree of substitutions of 0.4, 0.6, and 0.8, the po/qo ratio decreases with increasing %CMSP showing that crosslinking processes are dominating and increasing the gel network of the CMSP hydrogel. The fourier transform infrared spectra of CMSP hydrogels of degree of substitutions of 0.4, 0.6, and 0.8 with percentage of gel fractions 25, 35, and ≥ 40 show differences in the intensity of the absorption bands at 1020–1100, 1326, and 1422 cm−1 with different degree of substitutions and percentage of gel fraction (%GF) that correspond to different extents of chain scission and crosslinking. The swelling behavior in water shows that CMSP hydrogels could absorb 3500–5300% of water by 1 g of CMSP hydrogel. The ability to absorb water increases with the decrease of degree of substitution and %GF of the CMSP hydrogels. It is also observed that the optimum pH for swelling CMSP hydrogel is at pH 7. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013