Papers by Keyword: Montmorillonite

Abstract: The possibility of preparation of hybrid nanocomposites, based on Burdock Arctium Lappa L biomass, modified with enzymes and montmorillonite, was substantiated. It was founded that bio-modification allowing releasing pectin into the biomass Burdock structure that allow fixing clay mineral particles onto biomass. It was found that the increase of pore spaces occurs at the expense of increasing mesopore spaces to 93 %. It allows increasing the adsorption capacity of hybrid nanocomposites to zinc ions and methylene blue to 52.2 and 166.9 mg g^-1 respectively; that is 3.5 and 9 times more than adsorption capacity for initial plant Burdock

Abstract: Silylation, also known as silane grafting, is frequently used to organically modify montmorillonite (organo-Mt), which of properties were depended on the type of siloxane and intercalated interlayer structure of Mt, for construction of functional materials utilizing in a variety application of industry. We have synthesized organo-Mt using different siloxanes after Mt was firstly modified at three different surfactants of cationic cetyltrimethylammonium bromide (CTAB), anionic sodium oleate (So) and nonionic sorbitan monostearate (Span60) to identifying the effect of surfactants for silylation of Mt. The spectral and structural characters of the obtained products were characterized by a combination of X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), thermogravimetry (TG), and contact angle analysis. The basal spacing of the organo-Mt increased with surfactants loading. We found that CTAB can significantly increase the spacing between layers of Mt from 1.55nm to 1.90nm, load more siloxane on Mt. The average contact angles of CTAB-Mt-APTES and CTAB-Mt-PTES were 69.9±0.3° and 80.7±0.3°, which could be more prone to the interlayer locking effect. Our study showed that the charge of surfactants has significant influence for silylation of Mt, resulting in the loading amount of silane, interlayer structure, and the surface wetting properties.

Abstract: Iron-modified montmorillonite-filled polycaprolactone nanofiber mats were produced via electrospinning with varying applied voltage, flow rate, needle-tip-to-collector distance, and needle diameter. Scanning electron microscopy (SEM) was used to observe fiber morphology and characteristics. The effects of varying process parameters on various fiber characteristics were evaluated using a two-level fractional factorial experimental design. The effect of voltage on fiber diameter differed with varying flow rate. At 32 ml/hr, the average fiber diameter decreased from 518.38 nm ± 289.37 nm to 466.43 nm ± 312.36 nm when the voltage is increased. At 42 ml/hr the effect of voltage on fiber diameter was reversed. The average fiber diameter was also found to decrease from 516.03 nm ± 283.48 nm to 467.96 nm ± 318.07 nm with decreasing tip-to-collector distance at 32 mL/hr flow rate. The variation of the effect of the factors on fiber diameter was mainly due to a significant loss of material observed at 12 kV and 15 cm tip-to-collector distance. Bead formation was observed for all runs with more beads being formed at 12 kV applied voltage and 15 cm tip-to-collector distance. Spherical beads were observed at 12 kV and 15 cm tip-to-collector distance while spindle-like beads were present in nanofiber membranes spun at high voltage and at the combination of low voltage and low tip-to-collector distance. The parameter setting combination of 19 kV, 32 ml/hr flow rate, 10 cm tip-to-collector distance, and 0.514 mm needle diameter yielded the lowest fiber diameter with the least amount of beading and small bead size. Small fiber diameters and less beading provide larger surface area and more exposure of the Fe-MMT particles for more efficient adsorption.

Abstract: Nowadays, there is a need for efficiency and miniaturization in electronic products. However, in the chip level, heat dissipation can limit the performance of these gadgets. Semiconductor industries addressed this thermal management challenge by using thermal interface material. Previous studies have shown that polymer-clay nanocomposite has an enhanced thermal conductivity which can be used as a thermal interface material. In this study, the aim was to determine the effect of casting techniques on the microstructure and thermal conductivity of the polymer-clay nanocomposites. Solution intercalation method was used in fabricating the 5vol% polymer-clay nanocomposite. Organo-modified montmorillonite (MMT) was dispersed in unsaturated polyester (UP) matrix by means of high frequency ultrasonication and formed using two casting techniques; mold casting and tape casting. Results showed a slight increase in the thermal conductivity coefficient of the tape-casted samples at 2.99 W/m-K compared to the mold-casted samples at 2.87 W/m-K. Transmission electron microscopy (TEM) and x-ray diffraction (XRD) results exhibited dispersed microstructure for both casting techniques. Polymer intercalation of ~16% increase in d-spacing of clay for mold-casted samples and with a ~20% increase in d-spacing of clay for tape-casted samples were observed. With these microstructure modifications, the increase in the thermal conductivity coefficient of the tape-casted samples can be attributed to the shear force employed by the tape casting technique.

Abstract: Polylactic Acid (PLA) has been used widely in packaging application because of its biodegradability. The aim of this study is to produce PLA nanocomposites by solvent casting incorporating montmorillonite nanoclays (MMT) and titanium dioxide (TiO2) nanoparticles. The effect of different loadings of MMT in PLA and different loadings of TiO2 on chemical structure and surface wettability were studied. The nanocomposites were prepared by solvent casting at different loadings of MMT (0, 2, 4, 6 wt %) and different loadings of TiO2 (1 and 3 wt %) respectively. The chemical structure and surface wettability were determined. The absorption peaks in the range of 3550-3200 cm-1 had increased after incorporating of TiO2 and it indicated that there is the presence of stretching vibration of O-H groups. Moreover, increasing the percentage of TiO2 mass in the nanocomposites decreased the contact angle with water which led to increasing the wettability of the nanocomposites.

Abstract: The aim of this study is to produce PLA nanocomposites by solvent casting incorporating Montmorillonite nanoclays (MMT) and titanium dioxide (TiO2) nanoparticles. The effects of difference loadings of MMT in PLA and different loadings of TiO2 on mechanical and morphology properties were studied. The nanocomposites were prepared by solvent casting at different loadings of MMT (0, 2, 4, 6 and 8 wt %) and different loadings of TiO2 (1 and 3 wt %) respectively. The properties such as tensile properties (tensile strength, elongation at break, and modulus of elasticity) and morphology were determined. The results indicate that 4 wt% of MMT loading produced the best tensile properties. However, the incorporation of TiO2 showed an improvement in the modulus of elasticity of PLA/MMT nanocomposites mainly at 1 wt % loading of TiO2.

Abstract: Composite materials are extensively used in various applications like space, aircraft, and automobile sector because of superior physical and mechanical properties even though they are costly. In recent technological innovations, using Montmorillonite (Nanoclay) to reinforce polymer-based composites has raised attention to academic and industrial sectors since small addition could enhance Mechanical properties thereby decreasing failures like delaminations. In present research work, the effect of AWJ machining parameters on delaminations of glass fibre reinforced epoxy composite is investigated. The Main objective is determining delamination factor and reduce delaminations which is major failure in laminates. This paper investigates on effects of impregnated Nanoclay epoxy in Bi-directional GFRP where previous research has been made only in changing the parameters for reduction of delaminations. The samples were machined using AWJ, delamination factors are measured using image-J software and SEM analysis for comparing micrographs. Finally with increase in nano clay weight fraction, delaminations are checked.

Abstract: The usage of biopolymers in developing biodegradable food packaging films that are sustainable and safe towards environment has been restricted because of the poor mechanical and barrier properties of the biopolymers. This study aims to enhance the limited properties of biopolymers particularly polylactic acid (PLA) for food packaging applications by investigating the effects of incorporating different types (montmorillonite (MMT) and halloysite) and concentrations (0–9 wt.%) of nanoclays on the mechanical, oxygen barrier, and transparency properties of the films. PLA with 3 wt.% concentration of nanoclays resulted in the optimum mechanical and oxygen barrier properties due to the strong interaction between nanoclays and torturous path length created by nanoclays respectively. Nevertheless, these properties reduced as more nanoclays (≥5 wt.%) was added into the films due to agglomeration of nanoclays. PLA incorporated with MMT nanoclay exhibited better properties compared to halloysite nanoclay due to the nanoclay structure in nature. Addition of 3 wt.% nanoclays into virtually transparent PLA film have only small effects on the transparency of the film whereby the reduction in light transmittance was only around 10%. This study is crucial to improve the feasibility of biopolymers usage for food packaging applications.

Abstract: Polymer-inorganic composites were obtained from montmorillonite and three types of pectin (sugar beet, citrus and nettle). The parameters of particle size, a distance between clay layers and the pore structure and also sorption capacity of composites to ions of Zn (II) and Cu (II) and the methylene blue dye were analyzed. The effect of the chemical structure of pectin to the properties of composite materials was shown.

Abstract: The synthesis of polyphenylene sulfide by nucleophilic substitution of 1,4-dichlorobenzene and sodium sulfide nine-water sulfide with varying temperature, pressure and catalysts was investigated. It is shown that lithium oxalate is the most effective among lithium catalysts. The promise of montmorillonite as a catalyst in the synthesis of polyphenylene sulfides was revealed.