Optimization Process Of Biodiesel Production With Ultrasound Assisted By Using Central Composite Design Methods

The objective of this research is to optimize of biodiesel production with ultrasound assisted. Optimization was used central composite design methods. Biodiesel was produced from frying oil with KOH catalyst and ultrasonic assisted. The variables were investigated temperature, catalyst concentration and ratio of methanol to oil. Biodiesel was separated from reactant and impurities with decantation process and distillation process. The results of research obtained optimum conversion 85.95% in operation condition are methanol/oil 5.05:1, catalyst concentration 1.65% and temperature reaction 50 o C. Mathematic modeling for describe in this process like expressed; Y= 86.2107 -7.4287X +1.0661X + 0.6289X 2.5319X -2.0603X -1.0618X − Keywords: biodiesel; central composite design; ultrasonic assisted; yield biodiesel

Development of nanocatalytic-based assay for the detection of an endocrine disrupting compound in aqueous solution

Endocrine disrupting compound (EDC) pollutants raise a concern among researchers as these pollutants are implicated in the increasing incidence of testicular, breast and thyroid cancers. Some of these chemicals are widely used for plastics production and discharged into the water system as industrial effluents that could harm the ecosystem as well as plant, animal and human life. Thus, rapid detection and quantification of EDCs in water is desired for screening and investigative purposes. For this purpose, nanoparticle-based methods appear to be potentially efficient, quick and cost-effective techniques to rapidly assess this toxic pollutant. The main focus of this study was to synthesize heterogeneous nanoparticles, iron oxide/gold nanoparticles (IONPs/AuNPs) and to manipulate their synergistic effects for the development of a nanoparticles-based assay, specifically for the EDC compound, 17β-estradiol. As the first step, IONPs and AuNPs were synthesized separately and heterogeneous nanoparticles were formed by a simple electrostatic- self- assembly technique. The unique physiochemical properties of this hybrid nanoparticle were investigated as a supporting material for biomolecules, as well for its intrinsic peroxidase-like activity using a hydrogen peroxidase dependent system. The formation of the IONPs/AuNPs was verified using several characterization tools such as UV-Vis spectrophotometry, Dynamic Light Scattering (DLS), Transmission Electron Microscope (TEM), Energy Dispersive X-ray (EDX) and X-ray Photoelectron Spectroscopy (XPS). The diameter calculated from TEM was 16.1 ± 11.1 nm and EDX confirmed the presence of the Fe and Au elements. From a heterostructural analysis using HRTEM and XPS data, an alloy-like morphology (Fe/Au) was suggested for the heterogeneous nanoparticles, rather than a core-shell structure. The Fe/Au nanoparticles showed good potential for the basis of a colorimetric assay for glucose detection using glucose oxidase immobilized on the Fe/Au surface. In addition, the Fe/Au nanoparticles also showed a significant peroxidase-like activity. A nanocatalytic-based assay was developed by modifying the nanoparticles surface with an aptamer in order to specifically “capture” the target molecule, 17β-estradiol. The formation of a Fe/Au-17β-estradiol complex significantly hampered the peroxidase-like catalytic activity resulting in the development of a unique nanosensor system based on the extent of loss of peroxidase activity. Development of the nanocatalytic-based assay suggests the potential application of Fe/Au nanoparticles to capture, separate and detect a selective target as well as a basis for the development of a rapid, simple and reliable detection tool. The heterogeneous Fe/Au nanoparticles show a remarkable synergistic property for application in nanosensor system. Therefore, some of the work presented here can be extended in certain major directions such as heterostructure formation and optimization of nanocatalytic-based assay

The electrocatalytic response of metallophthalocyanines when clicked to electrodes and to nanomaterials

Conjugates of nanomaterials and metallophthalocyanines (MPcs) have been prepared and their electrocatalytic activity studied. The prepared nanomaterials are zinc oxide and silver nanoparticles, reduced graphene oxide nanosheets and semiconductor quantum dots. The MPcs used in this work are cobalt (II) (1a), manganese(III) (1b) and iron (II) (1c) 2,9(10),16(17),23(24)- tetrakis 4-((4-ethynylbenzyl) oxy) phthalocyaninato, 2,9(10),16(17),23(24)- tetrakis(5-pentyn-oxy) cobalt (II) phthalocyaninato (2), 9(10),16(17),23(24)- tris-[4-tert-butylphenoxy)-2- (4-ethylbezyl-oxy) cobalt (II) phthalocyaninato (3), 9(10),16(17),23(24)- tris-[4-tertbutylphenoxy)-2-(pent-4yn-yloxy)] cobalt (II) phthalocyaninato (4), cobalt (II) (5a) and manganese (III) (5b) 2,9(10),16(17),23(24)- tetrakis [4-(4-(5-chloro-1H-benzo [d]imidazol-2-yl)phenoxy] phthalocyaninato and 9(10),16(17),23(24)- tris tert butyl phenoxy- 2- [4-(4-(5-chloro-1H-benzo[d]imidazole-2-yl)phenoxy] cobalt (II) phthalocyaninato (6). Some of these MPcs (1a, 3 and 4) were directly clicked on azide grafted electrode, while some (1b, 1c, 2, 5a and 5b) were clicked to azide functionalised nanomaterials and then drop-dried on the electrodes. One phthalocyanine (5b) was drop-dried on the electrode then silver nanoparticles were electrodeposited on it taking advantage of metal-N bond. Scanning electrochemical microscopy, voltammetry, chronoamperometry, electrochemical impedance spectroscopy are among electrochemical methods used to characterise modified electrodes. Transmission electron microscopy, X-ray photoelectron spectroscopy, Xray diffractometry, Raman spectroscopy and infrared spectroscopy were employed to study surface functionalities, morphology and topography of the nanomaterials and complexes. Electrocatalytic activity of the developed materials were studied towards oxidation of 2-mercaptoethanol, hydrazine and hydrogen peroxide while the reduction study was based on oxygen and hydrogen peroxide. In general, the conjugates displayed superior catalytic activity when compared to individual materials. Complex 2 alone and when conjugated to zinc oxide nanoparticles were studied for their nonlinear optical behaviour. And the same materials were explored for their hydrazine detection capability. The aim of this study was to develop sensitive, selective and affordable sensors for selected organic waste pollutants. Conjugates were found to achieve the aim of the study compared to when individual materials were employed