IntroductionEpoxidation of unsaturated fatty compounds is one of the main routes to synthesize valuable fatty chemicals for wide range applications, e.g. plasticizer, lubricant, and starting material for various bio-based polymeric materials 1 5 . Unsaturated fatty compounds vary in the form of triglycerides, fatty esters, or fatty acids. Epoxidation reaction with unsaturated vegetable oil triglycerides as starting material is the most common subject in epoxidation that has been intensively explored because it does not require the additional process such as hydrolysis or esterification. Fatty esters or fatty acid are usually employed for epoxidation in order to simplify the kinetic evaluation and to enhance the oleochemical product diversification. Meanwhile, amongst the various unsaturated fatty acids, oleic acid is the most frequently used for epoxidation 6 13 .It is commonly known that oleic acid is the most unsaturated fatty acid recurrently used in the wide range of research topics, from agricultural to medical, biochemical, chemistry, and other related fields. The reason behind this fact is based on the nature of oleic acid; it can be found effortlessly in most of vegetable oils and animal fats. The first major source of oleic acid is originated from olive oil which

No abstract

Dye-sensitized Solar Cells (DSSCs) have been successfully fabricated by using ZnO nanoparticles (NPs). The ZnO photoelectrode was prepared by using pastes solved in water-based and ethanol-based solvent. The ZnO NPs was synthesized by copresipitation method, prepared by reaction from Zinc Acetate with diethylene glycol (DEG). The obtained ZnO NPs has 13.93 nm particle diameter. Scanning Electron Microscopy (SEM) showed that ZnO NPs from monodisperse spherical aggregate with particle diameter of approximately 300nm. The band gap was found of 3.29eV. Variations of annealing temperature were carried out in photo-electrode fabrication. This work employs extracts from mangosteen pericarp as natural dye for fabrication of DSSCs. DSSCs were fabricated in sandwich structure with redox couple electrolyte I3-/I- and Pt-catalyst counter electrode. The best efficiency of 0.11% (Voc = 232.4 mV, Jsc = 111.6 µA/cm2, FF = 61.41 %) was obtained for DSSCs using ZnO photo-electrode prepared by ethanol-based paste and 200°C of annealing temperature.

ZnO, with direct wide band gap of 3.37 eV and high excitonic binding energy of 60 meV has been attracting much attention due to its wide range of applications, for transparent electronics, solar cells, and other optoelectronics device. We present a simple, single step process to produce ZnO nanotrees using co-precipitation method. As a precursor, zinc nitrate dehydrate was stabilized by hexamethylene tetraamine (HMTA) and 3-9 mM polyethylene glycol (PEG) was added at 180°C for 3-6 hours followed by residual polymer removal. Scanning Electron Microscopy revealed the typical rod-like branched nanostructures were achieved. For longer annealing time the PEG-assisted growth process indeed exhibited a distinctive c-direction inhibition responsible for the lateral growth and subsequent branching of ZnO, in which the branch growth in sample with PEG amount of 0.05 g is the slowest. Some amounts of PEG up to 0.03 g are sensitive to affect several parameters, such as, lattice stress, unit cell volume, density of film and dislocation density.