Organic modification of hydrophilic sodium montmorillonite (Na+-MMT) is important for improving its compatibility with organic polymers. In the present research, (3-aminopropyl)triethoxysilane (APTES) was used to modify Na+-MMT. The effects on the basal spacing of Na+-MMT upon the premixing process with different mixing techniques were examined in detail. The resultant products (S-Mts) were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), and Fourier transform infrared (FTIR) spectroscopy. For monitoring the grafting process, FTIR was used, while the percentage of the loaded silane was calculated using TGA. Furthermore, XRD measurements were carried out to evaluate the increase in the d-spacing. The amount of grafted silane increases when a suitable premixing process, such as the mechanical mixer and homogenizer, is chosen. The same beneficial effects were observed on d-spacing, as it increases when using the mechanical mixer and homogenizer. This study demonstrates that the degree of grafting and d-spacing of the grafted products strongly depends on the mixing process before the silylation reaction. This is very important for the synthesis and application of polymer nanocomposites containing silylated layered silicate minerals.

Natural rubber (NR)/sodium-montmorillonite (Na-MMT) nanocomposites were prepared by co-coagulating the mixture of NR latex and various amounts of Na- MMT aqueous suspension. Tapping mode AFM (for the first time in the present case), TEM and XRD were applied to characterize the structure of nanocomposites. Results showed that at the low loading of layered silicates, fully exfoliated structure could be achieved by this method. Both non-exfoliated (stacked layers) and exfoliated structures were observed in the nanocomposites when the amount of Na-MMT increased to 10 phr. The mechanical results on the vulcanized nanocomposites showed that nanocomposites present initial moduli and tensile strength greater than Na-MMTfree NR compound. Furthermore, initial moduli increased with increasing the Na-MMT loading, indicating the reinforcement effect of Na-MMT on the mechanical properties of nanocomposites. The nanocomposites exhibit a higher glass transition temperature and lower tangent peak value in comparison with Na-MMT-free NR compound. TGA results indicated an improvement in the main and end decomposition temperature but there is no effect on the suppression of the initial decomposition temperature.

As the uptake of cationic drugs, such as tetracycline (TC), was attributed to cation exchange, the stability of adsorbed TC on a Ca-montmorillonite SAz-2 was studied using cationic solutions of different valence charges under different pH conditions. At the initial loading of 356 mg g-1, the amounts of TC desorbed by 0.05 M AlCl3, CaCl2, and NaCl were 133±4, 83±6, and 50±4 mg g-1, respectively, or 37, 23, and 14%. However, when the amount or percentage of TC desorbed was normalized to the equivalence of each cation, the values were in the range of 44-50 mg g−1 or 11-14% per 10 mmol of charge. The kinetics of TC desorption were moderately fast and almost reached equilibrium in 6 h. The results followed the pseudo-second-order kinetic model with reaction rate in the order of AlCl3>CaCl2>NaCl at a higher initial TC loading level. The total amount of TC desorbed after five desorption cycles followed the order of AlCl3>CaCl2>NaCl, too, suggesting that cations with higher positive charges, thus, less hydrated, are preferred to remove adsorbed cationic drugs. The FTIR analyses showed larger band shift when Al3+ was used as the desorbing reagent. The XRD patterns before and after TC desorption revealed no changes in basal spacing, even after five desorption cycles, suggesting that the removal of TC from SAz-2 was largely from the external surfaces

In the present study, the potential use of zycosil and clay nanomaterials was examined to decrease water absorption of Medium Density Fiberboard (MDF). For this, a group of MDF samples were coated by nanozycosil and in the other group, nanoclay was used to produce the MDF. Then, water absorption and thickness swelling of the MDFs were evaluated. In order to characterize the structure of the MDF, X-ray diffraction (XRD) and SEM observation were performed. The results of different tests indicated a desirable effect of nanozycosil on water resistance properties of MDF. Nanozycosil reduced water absorption by 90% because it could modify MDF surface by reacting with the board thereby imparting a molecular level hydrophobic characteristic. Regarding the effect of nanoclay, the scanning electron microscope (SEM) images and X-ray diffraction (XRD) confirmed a suitable dispersion and exfoliation of nanoclay in the modified MDF. The water absorption presented a decrease with increasing nanoclay content. The nanoclay had no effect on the thickness swelling.

In the present study, Anionic polymerization of Butyl Methyl acrylate has been carried out in oxygen atmosphere over different heterogenic prepared catalytic systems which is composed of a group of three metal oxides ( Ti, Mn Cu ) assembled on thin layers of clay ( Bentonite ) as hydrogenating/dehydrogenating activation for the polymerization reaction. The prepared catalysts and polymeric products were distinguished by different spectroscopic techniques such as XRD , 1HNMR, ,energy-dispersive X-ray spectroscopy (EDX), SCN TEM, IR, and gel permeation chromatography(GPC). we deduced that the dimensions of the efficiency of each catalyst as well as whole composites on the polymerization of Butyl Methyl acrylate of process, also, we approach the reaction mechanism of the polymeric process, furthermore, studying the variation and factors affecting on anionic polymerization like polydispersity index and tactility properties, we approached more details and discussion were deeply investigated in blow throughout figures and applicable data analysis.

In the present study, dyes derived from the Hibiscus sabdariffa flower (Hs) were successfully entered into the space inside the sodium montmorillonite clay layer (Na+-MMT) caused by the ion exchange reaction, and a hybrid nano-pigment called (Hs-MMT) was formed. To investigate and characterize the morphology of the Hs-MMT nano-pigment, Fourier transform infrared spectroscopy (FTIR), small angle X-ray scattering (SAXS), field emission scanning electron microscope (FESEM), and energy dispersive spectroscopy (EDS) were used. Also, both the thermal and antimicrobial behavior of Hs-MMT nano-pigment was evaluated by thermogravimetric analysis (TGA) and well and disc methods, respectively. The results of FTIR, SAXS, and EDS analyses showed that after the interaction of two organic and inorganic phases, the functional groups of Hs appeared on the nanoclay, and also the insertion of Hs dyes in the spaces between the layers of the nanoclay increased the surface by 5.72 angstrom .The TGA results indicated that the nanoclay plates prevented heat loading on the structure of Hs dyes and caused the thermal stability of Hs-MMT nano-pigments. Finally, the results of the antimicrobial test confirmed that Hs-MMT nano-pigment could hinder and destroy two types of gram-positive bacteria and two types of gram-negative bacteria, in such a way that the minimum bactericidal concentration of gram-positive bacteria i.e., Staphylococcus aureus and Streptococcus pyogenes was equal to 250 and 31.25 microgram per milliliter, respectively, while the minimum bactericidal concentration of gram-negative bacteria i.e., Escherichia coli and Salmonella paratyphi was equal to 1000 microgram per milliliter.

Background and Objectives: Cationic dye malachite green is one of the most important toxic compounds in industrial wastewater. Typically, physicochemical or biological methods are used to water treatment and wastewater containing high concentrations of malachite green. In the present study nanocomposite hydrogels based on carrageenan and sodium alginate in the presence of sodium montmorillonite as Nano clay were synthesized and then used to study the absorption of malachite green from aqueous samples. Methods: Acrylamide was used as a monomer, methylene base acrylamide as an organic cross linker and potassium sulfate as an initiator. The adsorption of cationic dye malachite green by the nanocomposite hydrogels was investigated. The structures of nanocomposite hydrogels were investigated by (FTIR, XRD and SEM) techniques. The effect analytical parameters such as pH, contact time for the removal of dye material by synthesized nanocomposite hydrogels were investigated and optimal conditions were obtained. Finding: According to the results, synthesized nanocomposite hydrogels are sensitive to pH and changes in the amount of carrageenan and sodium alginate. Equilibrium absorption time is 3 hours. The absorption isotherm with Langmuir model and absorption kinetics was more suitable for pseudosecond order kinetic models. Discussion & Conclusion: The rate of removal of malachite green dye increases with increasing amount of Nano clay in the acidic medium. Finally, it can be concluded that the bio-polymer mixture of carrageenan and sodium alginate in the presence of sodium montmorillonite nanoclay is a suitable absorbent to remove the malachite green dye from aqueous solutions.