Electrochemically polymerized 2,2-dimethyl-3,4-propylenedioxythiophene on carbon fiber for microsupercapacitor

ProDOT(Me)₂ was electrochemically polymerized onto a carbon fiber microelectrode (CFME) by cyclovoltammetry under a wide potential range (0–1.6 V) with well-defined parameters. The nano to micron scale coatings on CFMEs were characterized by cyclovoltammetry, ex situ FTIR attenuated total reflectance spectroscopy (FTIR-ATR), electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM and EDX). The existence of a capacitance behavior is shown by Nyquist, Bode phase relationship.     

Evolution of surface roughness parameters and microstructure in two-phase nanocrystalline Co–Cu films electrodeposited onto ITO coated glass substrates at different deposition potentials

In the present research, we have studied the effect of deposition potential on the film composition, structural, and morphological properties of the electrodeposited Co–Cu thin films grown onto indium tin oxide coated glass substrates. For this purpose, the properties of the films were analyzed by means of X-ray diffraction, energy dispersive X-ray spectroscopy (EDX), and atomic force microscopy (AFM) characterization techniques. Structural characterizations showed that all of the Co–Cu films consist of hexagonal close-packed (hcp) Co and face-centered cubic (fcc) Cu phases. The hcp Co (002)/fcc Cu (111) peak intensity ratio was found to increase as the deposition potential decreased towards more negative values. An increase in the Co content in the Co–Cu films was observed as the applied deposition potential was made more negative according to EDX analysis. The decrease of the applied deposition potential towards more negative values also induced a decrease in the average crystallite sizes of both Co and Cu particles. AFM study indicated that a granular structure of the electrodeposited Co–Cu films regardless of deposition potential. As the applied deposition potential was made more negative, the surface roughness and particle size decreased considerably. Besides, two additional roughness parameters, surface kurtosis and the surface skewness were also obtained and discussed by means of the obtained results under the study.     

The Use of Boron Compounds for Stabilization of Lipase from Pseudomonas aeruginosa ES3 for the Detergent Industry

This study aimed to characterize a lipase that is highly active and stable under typical washing conditions for use as a detergent ingredient by investigating the effects of various boron compounds on lipase stabilization under different conditions. In addition, the antimicrobial activity of the boron compounds used in enzyme stabilization was examined in order to obtain an effective antimicrobial detergent. A lipase‐producing bacterium was isolated from kitchen wastewater samples using Rhodamine‐B Agar medium and identified as Pseudomonas aeruginosa based on 16S rDNA sequence analysis. The ES3 lipase obtained from P. aeruginosa was purified, and the purified enzyme was found to have a molecular mass of 40 kDa. The enzyme showed optimal activity at pH 9.0–10.0 and 40 °C and remained stable in the presence of various metal ions, surfactants and oxidizing agents. Moreover, the pH stability and thermostability of the enzyme was improved by the addition of boron compounds, which, when used as stabilizers in the incubation media, also increased the stability of the enzyme towards commercial detergents. Furthermore, the enzyme displayed properties comparable with the commercial product Lipolase^®, which has shown excellent stability towards various commercial detergents. Finally, boron compounds used to stabilize the lipase were found to possess antimicrobial properties, suggesting that detergents incorporating these compounds will also exhibit antimicrobial activity when washing clothes and dishes.     

Optimization of electro-blown polysulfone nanofiber mats for air filtration applications

Durable, robust, and hydrophobic air filtration media was produced via electro-blow spinning (EBS) technique using polysulfone (PSU) due to its superior properties. To our knowledge, this is the first optimization study of PSU nanofiber production via EBS technique for air filtration applications. Concentration, air pressure, and voltage were determined as independent variables for the optimization based on “smaller is the better” approach of Taguchi Design of Experiment. The optimized values which supplied the smallest average fiber diameter (AFD) possible were obtained as 13 wt% PSU, 3 bar, and 7.5 kV. The AFD of the sample obtained from the confirmation experiment was calculated as 105 ± 34 nm. Surface morphologies, porosity values, and wettability behaviors of the samples were investigated by using scanning electron microscopy, gravimetric method, and water contact angle measurements, respectively. PSU nanofiber mats exhibited superhydrophobic behavior (water contact angle values up to 159.8°) which is important for various separation processes. Samples prepared at different deposition times (15, 30, 45, and 60 min) were investigated in terms of particle capture efficiency and pressure drop. The 0.3 μm particle filtration efficiency was found to be 98.09% at an expense of 202 Pa pressure drop which would be suitable for various respiratory and HVAC filter applications.