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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.

A novel sodium alginate-g-poly(acrylic acid-co-acryl amide)/clinoptilolite hydrogel nanocomposite was prepared via free radical polymerization method, using N,N′-methylenebisacrylamide as a crosslinker and ammonium persulfate as an initiator. Grafting and component interactions were evidenced by Fourier transform infrared spectroscopic method. Adsorption properties of the both hydrogel samples in the aqueous solution of methylene blue (MB) dye were also investigated. Further investigations showed that methylene blue adsorption kinetic data followed pseudo-second-order kinetics. Also, adsorption equilibrium data were better fitted by a Freundlich isotherm. Finally the hydrogel nanocomposite designed in this work is distinguished by significantly higher adsorption capability, reusability, and stability making it an economical and successful adsorbent to remove MB dye from aqueous solutions.

A novel slow released NPK fertilizer encapsulated by superabsorbent nanocomposite was prepared via in-situ free radical polymerization of sodium alginate, acrylic acid, acrylamide, and montmorillonite in the presence of fertilizer compounds. Evidence of grafting and component interactions, superabsorbent nanocomposite structure and morphology was obtained by a FT-IR, XRD and SEM techniques. The water absorbency behavior of superabsorbent nanocomposite was investigated. After those characterizations, the potential application was verified through the study of fertilizer release from prepared formulations. Results indicated that the presence of the montmorillonite caused the system to liberate the nutrient in a more controlled manner than that with the neat superabsorbent. The good slow release fertilizer property as well as good water retention capacity showed that this formulation is potentially viable for application in agriculture as a fertilizer carrier vehicle.

A representative pesticide, NeemAzal was encapsulated into polyvinyl alcohol/alginate-montmorillonite (PVA/Alg-MMT) nanocomposite by cross-linking with glutaraldehyde. Different formulations of capsule beads containing NeemAzal were prepared with different concentration of materials. Evidence of cross-linking of PVA and Alg was obtained by comparison of the Fourier transform infrared spectra of the initial substrates and capsule beads. X-ray diffraction and transmission electron microscopy techniques confirmed the intercalated structure of capsule bead nanocomposites. In addition the swelling behavior of capsule beads was investigated. Results showed that swelling ratio of capsule beads decreases with introduction of MMT as well as increase of PVA content in capsule bead formulations. The release characteristics of NeemAzal from capsule beads were monitored using UV–visible spectrophotometer in distilled water. The addition of sodium MMT to these formulations was found to have a profound inhibitory effect on the release of NeemAzal. Furthermore, the release data were fitted to several empirical equations to estimate the kinetic parameters. The NeemAzal encapsulated PVA/Alg-MMT nanocomposite capsule beads, designed and discussed in this work, have the potential for controlled release of pesticide. POLYM. ENG. SCI., 54:2707–2714, 2014. © 2013 Society of Plastics Engineers

In this work, natural and modified clinoptilolite as low-cost adsorbents have been used for removal of Ni(II) from aqueous solutions in batch experiments. Modification of clinoptilolite zeolite was done with polymerization of polypyrrole in and outside of zeolite surface. The prepared polypyrrole/clinoptilolite nanocomposite was characterized using FTIR and scanning electronic microscopy techniques. The effect of various factors like solution pH, contact time, and concentration of Ni(II) solution on the removal efficiency was investigated. The optimum conditions for high removal efficiency included adjustment of solution pH value to 4, using nanocomposite for a time period of about 24 h. The adsorption isotherms and kinetic study result showed that the adsorption data were well described by the Freundlich isotherm model and pseudo-second-order reaction kinetics. It was concluded that in the case of nanocomposite, the chelating and ion exchange interactions are the governing adsorption mechanisms. ...

In this study, polyaniline/polyvinyl alcohol/clinoptilolite (PANI/PVA/Clino) nanocomposite was obtained by oxidative polymerization of anilinium cations inside and outside of the clinoptilolite channels. The structure and morphologies of the prepared nanocomposite were characterized by utilizing Fourier transform infrared spectroscopy and scanning electron microscopy. The prepared nanocomposite was used as an adsorbent for the removal of methylene blue (MB) dye from aqueous solutions. Furthermore, the adsorption kinetics studies showed that the adsorption process followed intraparticle diffusion model. Also, the investigation of adsorption isotherms showed that the equilibrium adsorption data were well described by the Langmuir isotherm model. It was concluded that chelating interaction between nanocomposite components and MB dye was the governing adsorption mechanism. Finally, desorption–adsorption cycle experiments showed that after 5 cycles; nanocomposite has a good adsorption behavior for MB d...

In this work, polypyrrole/clinoptilolite nanocomposite was synthesized by in situ surface polymerization of pyrrole using Fe3+ as oxidant, incorporated on the inner and outer surface of clinoptilolite nanoparticles. Formation of nanocomposite and deposition of polypyrrole on the clinoptilolite surface was confirmed and characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) patterns, scanning electron microscopy (SEM), and cyclic voltammetry techniques. Elemental analysis showed the loading/incorporation of 9.18 wt% polypyrrole in the clinoptilolite structure. However the electrical conductivity of polypyrrole/clinoptilolite nanocomposite pellets was higher than that of similar pure polypyrrole pellets, synthesized through the chemical oxidation polymerization method using Fe3+ as oxidant without the presence of clinoptilolite nanoparticles. Improved structural order or crystalinity of polypyrrole chains in nanocomposite structure which was confirmed by XRD and SEM results, may be the responsible of higher electrical conductivity of nanocomposite compared to pure polypyrrole although the low content (9.18 wt%) of polypyrrole in nanocomposite. Cyclic voltammetry studies showed that polypyrrole/clinoptilolite nanocomposite is electroactive similar to pure polypyrrole. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers

In this work homogeneous and adherent nanocomposite of polypyrrole (PPY) with Na+-Cloisite nanoclays was successfully prepared by insitu electropolymerization of pyrrole monomer in the presence of Na+-Cloisite nanoclays. Formation of nanocomposite and incorporation of nanoclays in polypyrrole matrix was endorsed and characterized by FTIR spectroscopy studies, X-ray diffraction (XRD) pattern and scanning electron microscopy (SEM). The X-ray difraction patterns showed that PPY was intercalated between clay layers in the order of nanoscale. The morphology of the resulted nanocomposite was studied by scanning electron micrograph (SEM). Cyclic voltammetry experiments were carried out in different electrolytes and showed that nanocomposite is electroactive, while conductivity of the nanocomposite derived from four point probe technique indicated that the resulted nanocomposite is conductive. The anticorrosive properties of a thin layer coating of PPY/Na+-Cloisite nanocomposite on iron coupons was evaluated and compared with pure polypyrrole coating. According to the results in various corrosive environments PPY/Na+-Cloisite nanocomposite has enhanced corrosion protection effect in comparison to pure polypyrrole coating. It was observed that the corrosion protection effect was due to the dispersion of nanoclays in polymer matrix, which results in the increase in the corrosion potential and decrease in corrosion current and corrosion rate.

A novel electrically conductive nanocomposite consisting of poly(N-vinylpyrrolidone) (PVP) modified polyaniline (PANI) and cloisite clay nanoparticles was obtained via insitu polymerization method. The synthesized nanocomposite was characterized using FT-IR, XRD, conductivity measurement and cyclic voltammetry techniques. The electrical conductivity measurements of prepared nanocomposite showed that the nanocomposite is electrically conductive. Also cyclic voltammetry studies revealed that the synthesized nanocomposite is electro active. Electrochemical corrosion studies including open circuit potential measurements and tafel tests were carried out in various corrosive environments to evaluate the anticorrosive property of the nanocomposite coating on iron samples. Results showed that the coating of this nanocomposite on iron was useful in decreasing corrosion current and corrosion rate of iron in comparison with bare iron and pure polyaniline coated samples. A positive shift in corrosion potential and a significant decrease in corrosion current were observed for nanocomposite coated iron samples in sodium chloride 3.5 %, hydrochloric acid 0.1 M and sulfuric acid 0.1 M solutions.

Nanocomposites of polyaniline (PANI) with organophilic montmorillonite (O-MMT) and hydrophilic montmorillonite (Na-MMT) were prepared. The nanocomposites were characterized using FT-IR, D.C. electrical conductivity measurement and cyclic voltammetry techniques. It was found that PANI/Na-MMT nanocomposite has lower (5.8%) and PANI/O-MMT nanocomposite has higher (29.4%) conductivity compared to pure polyaniline. Cyclic voltammetry experiments showed that both nanocomposites are electroactive. The anticorrosive properties of a 100 μm thickness coating of nanocomposites on iron coupons were evaluated and compared with pure polyaniline coating. According to the results PANI/MMT nanocomposites have enhanced corrosion protection effect in comparison to pure polyaniline coating. Results showed also that the PANI/Na-MMT and PANI/O-MMT nanocomposites have considerably different corrosion protection efficiencies in various corrosive environments.

A novel slow release fertilizer hydrogel nanocomposite was prepared via free radical polymerization of sodium alginate, acrylic acid, acrylamide, and clinoptilolite using N, N΄-methylene bisacrylamide as a crosslinker and ammonium persulfate as an initiator. Evidence of grafting and component interactions was obtained by a comparison of the Fourier transform infrared spectra of the initial substrates and hydrogel without clinoptilolite with that of the hydrogel nanocomposite containing clinoptilolite. The swelling behavior of both hydrogels in solutions of various pHs (2-12) and various saline solutions such as NaCl, KCl, CaCl2 and FeCl3 as well as swelling kinetics were investigated. Results showed that the swelling of hydrogels depends on the solution pH value. Also, the swelling of both hydrogels in all salt solutions is significantly lower than that of the values in distilled water. After those characterizations, the potential application was verified through sorption and fertilizer releasing from the hydrogel with and without clinoptilolite zeolite. The presence of the clinoptilolite zeolite in the hydrogel caused the system to liberate the nutrient in a more controlled manner than that with the neat hydrogel. The results of the fertilizer release of hydrogel nanocomposite were also encouraging in order to find applications in agriculture. Consequently, the good slow release fertilizer property as well as the good water adsorption capacity showed that this formulation is potentially viable to be used in agriculture as a nutrient carrier vehicle.

The nanocomposite of polypyrrole with organonophilic montmorillonite and hydrophilic montmorillonite clays was prepared by in situ polymerization of pyrrole monomer in the presence of montmorillonite nanoclays. FTIR spectroscopy studies and X-ray diffraction pattern were used to confirm the formation of a polypyrrole/montmorillonite nanocomposite. The scanning electron microscopy image of the nanocomposite showed the homogeneous and continuous structure of the nanocomposite. Also cyclic voltammetry studies revealed that the synthesized nanocomposites were electroactive. The anticorrosive properties of nanocomposite coatings on iron coupons were evaluated and compared with pure polypyrrole coating. According to the results in corrosive environments, the polypyrrole/organonophilic montmorillonite nanocomposite has enhanced corrosion protection effect in comparison to pure polypyrrole and polypyrrole/hydrophilic montmorillonite coating. It was concluded that the better corrosion protection effect was due to the better dispersion of organophilic montmorillonite nanoclays in the polymer matrix, which results in a decrease in the corrosion current and corrosion rate. © 2013 Wiley Periodicals, Inc. Adv Polym Technol 2013, 32, 21337; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21337