Advanced Materials Research Vol. 576

Abstract: Cellulose cross linking is a very important textile process and has application in the crease resistant finished textile products. N-methylol cross linkers give fabrics desirable mechanical stability properties, but also reduces strength and release formaldehyde, a known human carcinogenic. Our work is based on reactions of particularly hospital green vat dyed cellulose with materials that creates an ionic character to the cellulose. These reactions produce ionic cellulose that can react with a poly ionic material of opposite charge to form cross links. The ionic content of the fabric and various features of the application procedure were varied to optimize the results.

Abstract: The CuI thin films were prepared by a spraying method with acetonitirile as a solvent and CuI as reagents. The parameter investigated in this research is the effect of spraying method either continuously or intermittently sprayed. The influence of spraying method and solution concentration on the surface morphology and electrical properties of CuI thin films were investigated by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX) and 2 point probe I-V measurement. Nanoparticle CuI was observed for all the thin films prepared. The EDX spectrum confirmed the existence of Cu and I elements. The resistivity of order 10-1 to 100 Ω cm was obtained for the CuI thin film deposited by the spraying technique. The CuI thin films also showed a photoresponse characteristic when measured under illumination condition. These results imply that the prepared CuI thin film deposited by spraying technique exhibit excellent conductivity with nanostructured particles seen.

Abstract: Multilayer ZnO/MgO was successfully deposited using sol-gel spin coating method at different MgO molar concentration. The electrical and dielectric properties of deposited multilayer films were investigated using two point probes I-V measurement and impedance spectroscopy respectively. The resistivity was calculated based on I-V curve obtained and the results show that there is increment in resistivity values from 1.04 x 105Ω.cm to 7.45 x 105Ω.cm as the MgO concentration varied from 0.2M to 1.0M. The growth of multilayer films was measured in term of their thickness using surface profiler. Moreover from the observation, the value of dielectric constant, k is decrease when the MgO concentrations increase due to non-uniform and porous structure in the films. This is proven by their surface morphology observed by field emission scanning electron microscopy, FESEM. There is also interesting view obtained in this work where the surface morphology of multilayer film with 0.2M and 0.4M MgO concentration produced nano-flower and nano-rod like structure respectively.

Abstract: Five types of selected tropical light hardwoods were chemically modified with benzene diazonium salt to improve their physical and mechanical properties. Benzene diazonium salt underwent a coupling reaction with wood which was confirmed through FT-IR analysis. The compressive modulus of the treated wood increased, whereas modulus of rupture was shown to decrease on treatment. The modified wood samples had higher hardness (Shore D) values compared to that of the control ones.

Abstract: Crosslinked polyester clay nanocomposites were prepared by dispersing originically modified montmorillonite in prepromoted polyester resin and subsequently crosslinked using methyl ethyl ketone peroxide catalyst at different clay concentration. Cure process and the mechanical properties of rubber toughened polyester clay composite have been studied. Rubber toughened thermoset polyester composite were prepared by adding 3 per hundred rubber (phr) of liquid natural rubber (LNR) was used in the mixing of producing this composite. Modification of polyester matrix was done due to the brittle problem of polyester composite. Addition of LNR will increase the toughness of composite and produce ductile polyester. Two types of composites were produced which is clay-lnr polyester composite and clay polyester composite. Addition of liquid natural rubber significantly increased the impact strength and flexural properties. Result shows that addition of 6% of clay-lnr composite give good properties on impact, strength and flexural. From the ESCR test, both composites showed good resistance to environmental.

Abstract: The nanocomposites were prepared using melt intercalation technique in an internal mixer. Particular attention was given to investigate the influence of different processing condition such as rotor speed and mixing time on the tensile properties and also phase morphology of the nanocomposites using SEM. The nanocomposites were prepared from blend of high density polyethylene (HDPE), natural rubber (NR) and organoclay. Significant improvement in tensile strength and modulus of composites were obtained with rotor speed at 80 rpm. While optimum mixing time used was 12 min. The morphology of the composites determined from the fracture surface of tensile specimen showed a large filler particle or agglomeration of organoclay in the blend at low rotor speed.

Abstract: Lead zirconate titanate nanopowder Pb(Zr0.53Ti0.47)O3 (PZT) was prepared by modified sol-gel method with 1-propanol as solvent and acetylacetone as stabilizer. The microstructure and particle size measurements at different heat treatment conditions were characterized by field emission scanning electron microscopy and x-ray diffraction analysis. It was found that the PZT nanoparticles calcinated at 600 °C showed mean diameter of 75-125 nm with high crystallinity of perovskite-type structure.

Abstract: ZnO as a semiconductor with wide direct band gap (3.37 eV) and high exciton binding energy of 60 meV. It has attracted in several applications such as solar cells, field emission, sensor, etc. In this study, different ZnO complex structures were prepared by precipitation method at different molar ratio. Zinc nitrate as zinc source, potassium hydroxide as precipitating agent and sodium dodecly sulphate as surfactant were used to synthesis the ZnO. The effect of different molar ratio on the morphology and size of final product have been investigated. The final products were characterized by X-ray diffraction (XRD) with Cu Kα radiation, field emission scanning electron microscopy (FESEM) with an attached energy dispersive x-ray spectroscopy (EDS) and photoluminescence spectrofluorophotometer (PL). From XRD patterns, all synthesized ZnO shows good crystallinity. Different morphologies of synthesized ZnO were obtained from FESEM including flower composed flakes, flower composed radial rods and single straight rods while the EDS result demonstrates elements Zn and O obtained in the product. A very strong UV emission at ~390 nm observed in PL spectra indicated that the ZnO are of high crystal quality.

Abstract: Polycaprolactone (PCL) polyol was prepared by a ring opening polymerization of ε-caprolactone initiated by palm kernel oil (PKO) based polyol and 1,6-hexanediol to form a PCL/PKO based polyol. The properties of polyol were varied by their initiator:co-initiator weight ratio. The completion of polyol formation was characterized through Fourier Transformation Infrared (FTIR) spectroscopy. Other parameters such as acid number and hydroxyl number of polyol were also studied to monitor the progress of reaction. FTIR results showed the significant changes particularly for the OH and C=O stretching peaks.

Abstract: This paper comprises of the characterizations of superabsorbent polymer hydrogels based on sago starch (SS) prepared via graft copolymerization method with acrylic acid (AA) in the presence of ammonium persulphate (APS) and N, N-metylenebisacrylamide. The morphology of sago-g-acrylic (SAG) was evidenced by scanning electron microscope (SEM) images. The remarkable feature of this SAG is the porosity distribution with different amount of crosslinker. Less amount of crosslinker leads to increment in porosity distribution as well as water absorbency. This SAG with excellent water absorbency properties, being biodegradable in nature could be useful in sanitary products, horticulture and agriculture.