Synthesis and characterization of (zinc-layered-gallate) nanohybrid using structural memory effect

The memory effect of calcined zinc hydroxide nitrate, with gallate anion solutions, was studied. The layered hydroxide salt material, zinc hydroxide nitrate was heat-treated at 150–800 °C. XRD analysis showed the growth of the calcined materials in both thickness and diameter occurring simultaneously with increasing calcination temperature. Surface area analysis confirmed this growth. The rehydration behavior of the calcined material was investigated by placing the material in a solution containing gallate anions. The best result for layered hydroxide salt phase reconstruction was obtained for a sample heated at 500 °C and treated with 0.1 mol L−1 anion. PXRD analysis showed the formation of a layered structure material after rehydration process. FTIR and TG confirmed the formation of the host–guest nanohybrid material produced

Comparative study of physical properties based on different parts of sugar palm fiber reinforced unsaturated polyester composites.

This research was conducted to evaluate the potential of sugar palm residue as a raw material to produce the new green composites. The physical properties of sugar palm fibre reinforced unsaturated polyester composites from different part which are sugar palm frond (SPF/PE), sugar palm bunch (SPB/PE), sugar palm trunk (SPT/PE) and black sugar palm fibre (ijuk/PE) were studied. Samples were submerged in distilled water for 24 hours. The water absorption and thickness swelling were investigated in order to determine the dimensional stability of the composites. It is found that SPF/PE showed the higher value of water absorption and thickness swelling which are 1.57%, and 1.56% followed by SPB/PE (1.35%, 1.11%), ijuk/PE (0.65%, 0.76%) and SPT/PE (0.39%, 0.50%). Generally, this investigation is valuable for researchers in order to evaluate the potential and some possible application of sugar palm residues as a new natural composites product

LDH-intercalated D-gluconate: generation of a new food additive-inorganic nanohybrid compound

Intercalation of d-gluconate into the interlamellae of zinc–aluminum-layered double hydroxide for the formation of a food additive-inorganic layered nanohybrid was accomplished by both direct (co-precipitation) and indirect (ion-exchange) methods. Powder X-ray diffraction (PXRD) together with CHNS and Fourier transform infrared (FTIR) analyses showed that the hybridization of d-gluconate with pure phase and good crystallinity was successfully accomplished by a direct method within ranges of pH 7.5–10, Zn to Al initial molar ratio of 2–5 and DG concentration of 0.05–0.3 M. The same nanohybrid compound was also prepared using an indirect ion-exchange method by contacting the pre-prepared LDH with 0.1 M DG for 80 min. The basal spacing of the nanohybrid synthesized by the direct method ranged between 9 and 12.0 Å while that synthesized by the indirect ion-exchange method was 14.0 Å. The crystallinity of the latter was higher than the former and it inherited the crystallinity of the precursor. This work shows that a food additive, such as d-gluconate, can be hybridized into an inorganic host for the formation of a new nanohybrid compound, which can be used to regulate the release of acidity in the food industry

Chemical composition and FT-IR spectra of sugar palm (Arenga pinnata) fibers obtained from different heights

This paper deals with the study on the effect of biological degradation to chemical composition and Fourier transform infrared (FT-IR) of sugar palm (Arenga pinnata) fibers obtained from different heights (1, 3, 5, 7, 9, 11, 13, and 15 m) of the sugar palm tree. It was observed that degradation that took place at the bottom part of the sugar palm trunk affected the chemical composition of its fiber. It was noticed that cellulose, hemicelluloses, and lignin contents increased with the increase of the tree height. A good correlation between chemical composition and mechanical properties of sugar palm fiber was found where cellulose, lignin, and hemicelluloses show a significant contribution to the increase in tensile strength, modulus, and elongation at break of the fiber, respectively. For the fibers obtained from higher height, it was observed that cellulose and hemicelluloses contents slightly decreased. High ash content for fibers obtained from 1 m height resulted in low moisture content and significant increase in its thermal stability. In FT-IR study, it was determined that the relative absorbance in sugar palm fibers was no different in all fibers

Mechanical Properties and Morphology of Oil Palm Empty Fruit Bunch-Polypropylene Composites: Effect of Adding ENGAGE TM 7467.

Composites of polypropylene and oil palm empty fruit bunch (OPEFB) were prepared by melt blending using ENGAGE™ 7467 (polyolefin elastomer) as an impact modifier. ENGAGE™ 7467 is a polyolefin elastomer. The mechanical properties and morphology of composites have been studied. Tensile tests showed that addition of ENGAGE™ 7467 improved the elasticity of the composite, thus reducing the stiffness of the composites but no significant changes on tensile strength. The impact strength was also improved with the addition of ENGAGE™ 7467, but no significant effect on flexural test was observed. This result indicates that the ENGAGE™ 7467 forms a flexible interphase around the OPEFB particles, giving the composites better impact strength for both notched and unnotched samples without degrading the fiber and matrix interaction. The ENGAGE™ 7467 composites characterized using Fourier transmission infrared spectroscopy showed that there is no shifting of peaks, indicating that the addition of ENGAGE™ 7467 does not affect the interaction between matrix and filler

Effects of alkali treatments on the tensile properties of pineapple leaf fibre reinforced high impact polystyrene composites

A study on the effects of alkali treatment and compatibilising agent on the tensile properties of pineapple leaf fibre (PALF) reinforced high impact polystyrene (HIPS) composite is presented in this paper. The tensile properties of natural fibre reinforced polymer composites are mainly influenced by the interfacial adhesion between the matrix and the fibres. In this study, several chemical modifications were employed to improve the interfacial matrix-fibre bonding and this resulted in the enhancement of tensile properties of the composites. In this study, the surface modification of pineapple fibre with alkali treatments and compatibilizer were used to improve the adhesion between hydrophilic pineapple fibre and hydrophobic polymer matrix. There are two concentrations of NaOH treatments and compatibilizer used in this study, namely, 2 and 4 wt. %. The results show that the alkali treated fibre and the addition of compatibilising agent in PALF/HIPS composites have improved the tensile strength and tensile modulus of the composites

Equilibrium isotherm studies for the uptake of Pb(II) and Cd(II) onto Lignocellulosic Biosorbent from waste water.

The removal of Pb(II) and Cd(II), by treated rubber wood fibre, a low-cost material, has been found to be concentration, pH and contact time dependent. The adsorption parameters were determined using both Langmuir and Freundlich isotherm models and the Langmuir model was found to be in better correlation with the experimental data with a maximum adsorption capacity, Pb(II) (52.38 mg/g) and Cd(II) (5.64 mg/g) respectively. Surface complexation is the major removal mechanisms involved. The adsorption isotherm studies clearly indicated that the adsorptive behaviour of metal ions on treated rubber wood fibre satisfies not only the Langmuir assumptions but also the Freundlich assumptions. Results of kinetic experiments demonstrated that the adsorption was effective and rapid. Two different kinds of kinetic models (Lagergren-first-order and second-order equations) were used to investigate the adsorption mechanisms. The kinetic adsorption data can be described by the second-order equation and the adsorption might be a rate-limiting control. The results indicate the potential application of this method for effluent treatment in industries and also provide strong evidence to support the adsorption mechanism proposed

Rapid removal of Cu(II) ion by chemically modified rubber wood fiber

This article describes a study of the adsorption conditions of Cu(II) ions onto polyacrylamide-grafted rubberwood fiber. Preparation of the adsorbent was carried out via graft copolymerization of acrylamide (Am) onto rubberwood fiber (RWF), using ceric ammonium nitrate as an initiator. Fourier transform infrared spectroscopy was used to confirm the formation of PAm-g-RWF. Various variables affecting the adsorption capacity such as pH of the solution, adsorption time, initial metal ion concentration, and temperature were investigated. Cu(II) was removed by PAm-g-RWF up to 92% from an initial concentration of 10 mg/L at pH 6.0. Kinetic adsorption data can be described by the second-order equation. Equilibrium parameters for adsorption isotherms of the metal ions on the grafted fiber were obtained using the Langmuir and Freundlich models, and the Langmuir model was found to be in better correlation with the experimental data with a maximum adsorption capacity of 142.85 mg/g. Thermodynamic parameters such as enthalpy change (ΔH°), free energy change (ΔG°), and entropy change (ΔS°) were calculated; the adsorption process was spontaneous and endothermic. The results showed that PAm-g-RWF developed in this study could be an economical and effective adsorbent for application in removal of copper ions from water and wastewater

Synthesis and mesomorphic properties of non-symmetric liquid crystalline dimers containing azobenzene groups

Four novel nonsymmetric dimers containing azobenzene mesogenic groups were synthesized. The nonsymmetric dimers compounds namely, ethyl 4-[(4-{4-(4-((4-nitrophenyl)diazenyl)phenoxy)alkyloxy}phenyl)diazenyl]benzoate were obtained from the alkylation of ethyl 4-[(4-(4-bromoalkyloxy)phenyl)diazenyl]benzoate with 4-[(4-nitrophenyl)diazenyl]phenol. The mesomorphic properties of the compounds were determined by DSC and polarizing optical microscopy. The first member of the series was nonliquid crystalline while all other homologues display nematic and smectic A phases. The trans-azobenzene groups of the dimers display a high-intensity –* transition at about 365nm and a low-intensity n–* transition at around 465 nm, therefore, photochromism can be achieved by the introduction of the azo linkage to the dimeric liquid crystalline molecules