The aim of this paper is to investigate the possible application of the cavitation phenomenon as efficient method to modify the surface properties (e.g. the surface roughness) in the nano and micro levels. Aluminum alloy (AlSiMg) specimens were subjected to high speed submerged cavitating jets under various working conditions, for short time periods between 15 and 30 seconds. The force generated by the cavitating jet is employed to modify the surface roughness of the specimen. The target surface was analyzed with optical microscopy, white light interferometry, atomic force microscopy (AFM) and also with electrostatic force microscopy (EFM). The results show the possibility to use the cavitation bubbles as a nanofabrication method e.g. for shotless surface peening. With AFM, the deformation mechanism and the formation of planar or wavy slip were also investigated. EFM shows that the changes in the surface roughness also have a strong influence on the electrostatic field above a biased sample.

The application of poly(acrylamide‐co‐sodium methacrylate) hydrogel for the removal of Cu2+ and Cd2+ ions from aqueous solutions has been investigated as a function of pH, adsorbent dose and temperature. FTIR spectra showed that –NH2 and –COOH groups are involved in both metal ions adsorption which followed pseudo‐first order kinetics. Non‐linear regression analysis of six isotherms, Langmuir, Freundlich, Redlich‐Peterson, Toth, Dubinin‐Radushkevich and Sips, have been applied to the sorption data, while the best interpretation was given by Redlich‐Peterson. Based on the separation factor, RL, the Cu2+ and Cd2+ ions adsorption is favorable. The maximum adsorption of 24.05 mg/g (48%) for Cu2+ ions and 32.99 mg/g (66%) for Cd2+ ions has been obtained at pH 5.0 and sorbent dosage of 300 mg. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 824–834, 2014

Izvod U ovom radu predstavljeno je uporedno ispitivanje karakteristika baznog i novog nanofotoničnog materijala koji je dobijen inkorporiranjem nanomaterijala u bazni materijal za meka kontaktna sočiva. Bazni (SL38) i nanofotonični materijal (SL38-А) za meka kontaktna sočiva dobijeni su radikalnom polimerizacijom 2-hidroksietil-metakrilata, odnosno 2-hidroksietil-metakrilata i fulerena koja je izvedena pо tеhnоlоgiјi i u prоizvоdnim lаbоrаtоriјаmа kоmpаniје Soleko (Milano, Italija). Fulereni su dodati zbog apsorpcionih transmisionih karakteristika u ultraljubičastom, vidljivom i bliskom infracrvenom spektru. Od dobijenih materijala napravljena su meka kontaktna sočiva u kompaniji Optix (Beograd, Srbija). Izračunati su parametri mreže, urađena je SEM analiza i merene su optičke karakteristike ispitivanih mekih kontaktnih sočiva. Utvrđeno je da transport tečnosti kroz hidrogel prati Fikov zakon i da bazni i nanofotonični materijal spadaju u grupu neporoznih hidrogelova. Dobijeni rezultati pokazuju bolja optička svojstva sintetisanih nanofotoničnih mekih kontaktnih sočiva u poređenju sa baznim sočivom.

This paper presents a comprehensive method to evaluate the mixture of dicyclohexilamine and oleylamine (DCHA+OA) as corrosion inhibitor for mild steel in CO2 environment in liquid and vapor phase. Corrosion inhibitor volatile properties were investigated in order to determine if DCHA+OA can be used to control the severity of the top of the line (TLC) corrosion attack. Corrosion measurements were performed using electrochemical impedance spectroscopy, linear polarization resistance, potentiodynamic sweep measurements, as well as the electrical resistance measurements and weight loss measurements, in order to determine the inhibitive performances of dicyclohexilamine and oleylamine. In order to define surface morphological characteristics scanning electron microscopy technique was applied. The electrochemical study and weight loss measurements indicated that DCHA+OA significantly decreased the corrosion rate in liquid phase when 50 ppm of DCHA+OA was added. Scanning electron microphotographs indicated protective inhibitor film has formed on the steel surface and revealed that good protection was achieved, along with the decrease in the corrosion rate determined by weight loss and electrochemical techniques. Using electrical resistance measurements in vapor phase it was shown that concentration of 1000 ppm DCHA+OA significantly decreased the corrosion rate at the top of the line, only when it was carried there within its own foam and not due its volatility