Pınar Acar Bozkurt

Sonochemical green synthesis of Ag/graphene nanocomposite

Recently, the popularity for green chemistry and chemical process have increased. The approach must comprehensively be considered for these principles in the design of a synthesis method, chemical analysis, or chemical process. Utilization of nontoxic chemicals, environment friendly solvents, and renewable materials are some of the important issues in green synthesis methods. The importance of green synthesis arises in the production of Ag/graphene nanocomposites, due to their future potential applications in nanomedicine and materials engineering. Herein, a simple approach to synthesizing Ag/graphene nanocomposite using sodium citrate as the reducing agent by sonochemical method has been reported. The synthesized Ag/graphene nanocomposite was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and UV-Visible spectroscopy. The results showed that graphene oxide was successfully reduced to graphene and silver ions to silver nanoparticles with sodium citrate. Spherical Ag nanoparticles with a mean particle size of approximately 20nm on graphene sheets were synthesized sonochemically. The use of sodium citrate as an environment-friendly reducing agent provided green attributes whereas the use of sonochemical processes as the synthesis method provided economic attributes to this study. The results obtained demonstrate this method to be applicable to the synthesis of other metals on graphene sheets and may possibly find various forthcoming medicinal, industrial and technological applications.

Simultaneous quantification of Myelin Basic Protein and Tau proteins in cerebrospinal fluid and serum of Multiple Sclerosis patients using nanoimmunosensor.

This study was aimed at the development of an immunosensor for the simultaneous quantification of Myelin Basic Protein (MBP) and Tau proteins in cerebrospinal fluid (CSF) and serum, obtained from Multiple Sclerosis (MS) patients. The newly developed GO/pPG/anti-MBP/anti-Tau nanoimmunosensor has been established by immobilization of MBP and Tau antibodies. The newly developed nanoimmunosensor was tested, optimized and characterized using differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). The developed nanoimmunosensor was seen to have detection limits of 0.30nM for MBP and 0.15nM for Tau proteins which were sufficient for the levels to be analysed in neuro-clinic. The clinical study performed using CSF and serum of MS patients showed that the designed nanoimmunosensor was capable of detecting the proteins properly, that were essentially proven by ELISA.

Synthesis and characterization of CdS nanorods by combined sonochemical-solvothermal method

Abstract Cadmium sulfide (CdS) nanorods with a diameter of 50 nm and length of approximately 200 nm have been synthesized using combined sonochemical-solvothermal method. Structural properties of CdS nanoparticles synthesized by this method have been compared with the CdS nanoparticles synthesized by sonochemical method alone. The synthesized CdS nanostructures have been characterized using X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM) methods. In addition, the factors affecting the formation of the structures, including reaction time, different type and ratio of precursors, such as sulphur source, have been investigated. Comparison of the results obtained by both the synthesis methods revealed CdS nanoparticles synthesized by the combined sonochemical-solvothermal method to be of high morphological homogeneity compared to the sonochemical method alone. It is interesting to note that ethylenediamine has been found to be prevented from agglomeration by using the combined sonochemical-solvothermal method as the synthesis method. A modified growth mechanism under the inducement of ethylenediamine solutions for the CdS nanorods has been suggested.

Sonochemical synthesis and characterisation of lead sulfide nanoparticles using different capping agents

Lead sulfide (PbS) nanoparticles of about 12 nm in diameter and with a single crystalline structure have been prepared by a sonochemical method. The influence of reaction time and different capping agents such as polyethylene glycol (PEG), cetylytrimethylammonium bromide (CTAB), tetraethylortosilicate on the morphology of the synthesised PbS nanoparticles have been investigated. Results revealed polyethylene glycol (PEG) was a useful capping agent to produce PbS nanostructures with a suitable size distribution. Further studies demonstrated that by increasing the polymer chain length of PEG, the size of the PbS nanoparticles decreased remarkably. The nanoparticles were characterised by X-ray diffraction, energy dispersive X-ray spectroscopy, and transmission electron microscopy and the surface areas were determined using the BET method.

Preparation, characterization, and properties of polystyrene/Na-montmorillonite composites

A series of polystyrene (PS)/unmodified Na-montmorillonite (Na-MMT) composites were prepared via in situ radical polymerization. The prepared composites were characterized using various techniques. The presence of various functional groups in the unmodified Na-MMT and PS/unmodified Na-MMT composite was confirmed by Fourier transform infrared spectroscopy. Morphology and particle size of prepared composites was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). According to the XRD and TEM results, the interlayer spacing of MMT layers was expanded. SEM images showed a spongy and porous-shaped morphology of composites. TEM revealed the Na-MMT intercalated in PS matrix. The thermal stability of PS/unmodified Na-MMT composites was significantly improved as compared to PS, which is confirmed using thermogravimetric analysis (TGA). The TGA curves indicated that the decomposition temperature of composites is higher at 24–51°C depending on the composition of the mixture than that of pure PS. The differential scanning calorimetry (DSC) results showed that the glass transition temperature of composites was higher as compared to PS. The moisture retention, water uptake, Brunauer–Emmett–Teller specific surface area, and specific pore volume of composites were also investigated. Water resistance of the composites can be greatly improved.

Co-pyrolysis of Lignite-Oil Shale Mixtures

In this study, conversion of lignite has low calorific value with oil shale have been co-pyrolysed to investigate as an energy source and chemical feedstock. Pyrolysis of Balikesir Dursunbey lignite (Turkey), Seyitomer oil shale (Turkey), and co-pyrolysis of their mixtures were carried out in a fixed bed reactor at different temperatures and mixture ratios. Pyrolysis experiments were performed in the temperature range of 400–700 °C with mixtures consisting of lignite/oil shale at a weight ratio of 33 % (w/w), 50 % (w/w) and 67 % (w/w). The effect of temperature and different ratios of lignite/oil shale in mixtures on product distribution and fuel properties were investigated. Tars obtained by different experimental conditions were characterized using spectroscopic and chromatographic techniques such as GC-MS and FTIR and the effect of experimental conditions on the formation of this valuable product was determined. The highest tar yield was obtained at 600 °C with a 67 % weight ratio of lignite to oil shale.

Synthesis and Characterization of Poly(N-Hydroxymethyl Acrylamide)/Na-Montmorillonite Composites

In this study, N-hydroxymethyl acrylamide ( HMAm ) monomer was mixed with Na-Montmorillonite (Na-MT) in different ratio. The mixture was polymerized in the presence of benzoyl peroxide (Bz 2 O 2 ) with in-situ radical polymerization to prepare poly(N-hydroxymethyl acrylamide) (PHMAm)/Na-Montmorillonite (Na-MT) composites. Purified Na-MT, and also produced composites with different ratio were characterized with Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), thermal analysis (TGA/DTA) techniques . The moisture retention, water uptake, adsorptive properties of composites was also researched. The XRD pattern demonstrated that Na-MT layers intercalated into the PHMAm matrix. The composites displayed much better thermal stability than the pure polymer.

Pyrolysis of Waste Printed Circuit Board Particles

Electrical and electronic apparatus and instruments which are obsolete value in use or completion of the life can be defined as e-waste. E-waste is one of the fastest growing types of hazardous waste. Printed circuit boards a major component of this waste. In this study, printed circuit board particles of mobile phone (MPCB) were used as electronic waste. MPCB waste was obtained from a local electronic waste factory. The elemental analysis and ICP-MS analysis were performed on these electronic wastes and thereafter pyrolysis runs were carried out between 500 and 900°C in a horizontal furnace. The liquid yields were determined and compared at different temperatures.