Cagri Üzüm

W. R. Grace & Co.

Low‐Q‐whispering gallery modes (low‐Q‐WGM) can be used for label‐free detection of interactions between biomolecules, measuring their binding and release kinetics or for analysis of changes in the medium in real‐time. The main advantage of the low‐Q‐WGM approach over other label‐free methods is the possibility of measurements in small cavities as t...

A new regenerable nanofiltration membrane based on LbL film assembly of PDADMAC/PSS on a ceramic support is presented. Using a constant flux coating method the large pores of the ceramic support with a diameter of about 100 nm could be covered and closed with only 3 bilayers. The performance of the presented membrane is comparable to today's nanofi...

Scanning- and colloidal-probe atomic force microscopy were used to study the mechanical properties of poly(L-lysine)/hyaluronan (PLL/HA)(n) films as a function of indentation velocity and the number of polymer deposition steps n. The film thickness was determined by two independent AFM-based methods: scratch-and-scan and newly developed full-indent...

The paper addresses the structuring and rheology of semidilute polyelectrolyte solutions with varied concentration and degree of polymer branching. The used polymer is constituted of the units of sodium 2-acrylamido-2-methylpropanesulfonate (NaPAMPS) with the branching inserts of 2-(2-bromopropionyloxy)ethyl acrylate (BPEA). The content of the bran...

The swelling/deswelling behaviour of microgel particles in the bulk and at the surface was studied and correlated to their mechanical properties. We focused on two kinds of particles: pure PNIPAM and PNIPAM-co-AAc particles. It was shown that the two step volume phase transition found for PNIPAM-co-AAc particles in the bulk disappears after the ads...

The present paper gives a deeper insight into the chain ordering in aqueous polyelectrolyte solutions under geometrical confinement as a function of degree of polymerization and polymer concentration. Colloidal probe atomic force microscopy (CP-AFM) and small-angle X-ray scattering (SAXS) are used to compare the poly(styrenesulfonate) (NaPSS) chain...

The effect of the amount of cross-linker in poly(N-isopropylacrylamide-co-acrylic acid) microgel particles on the swelling behaviour and their elasticity is studied. The distribution of the stiffness through the particle is also investigated. Therefore, the swelling ratio obtained from dynamic light scattering measurements in aqueous solutions is c...

Der Zusammenhang zwischen der Struktur und der Rheologie von salzfreien Polyelektrolytlösungen sowie die rheologischen und mechanischen Eigenschaften von adsorbierten Polyelektrolytfilmen werden erforscht. Zunächst wird die Struktur von Lösungen aus monodispersen NaPSS als Funktion der Kettenlänge analysiert. Die Lösungen werden mittels AFM in eine...

Small calibre vascular prostheses (<6 mm) still lack medium and long term patency. Inelasticity of the prosthesis is one of the characteristics, which is involved in the mechanisms of failure (e.g. the development of neointimal hyperplasia at the distal anastomosis). Here we report about covalently crosslinked poly(n-butyl acrylate) networks (cPnBA...

The review addresses the influence of polyelectrolytes on the statics and dynamics of thin liquid films. Both, changes of interfacial and bulk properties, contribute to the overall behaviour of thin films formed from aqueous polyelectrolyte solutions. Therefore, the chapter is separated into two parts: polyelectrolytes at film interfaces and polyme...

We use a thin film pressure balance to probe the rheological properties of thin liquid films. These films are made from mixed aqueous solutions of surfactants and polyelectrolytes. They drain under applied pressure in a noncontinuous way due to a stratification process of the polyelectrolytes network. The stratification kinetics was studied for fil...

This study reports the synthesis and characterization of iron nanoparticles in the presence of K10 bentonite. Introducing K10 during synthesis of iron nanoparticles resulted in a partial decrease in the aggregation of the nanoparticles. The dispersed nanoparticles showed a typical core–shell structure and were predominantly within the 10–60 nm size...

This study reports the synthesis and characterization of nano-scale zero-valent iron in the presence of kaolinite clay (nZVI-kaol). The adsorbent, nZVI-kaol, was produced at initial Fe:kaolinite mass ratios of 1:1, 0.5:1, and 0.2:1. The presence of kaolinite resulted in decreased aggregation of iron nanoparticles, yielding composites with iso-elect...

Nanosized zero-valent iron (nZVI) is increasingly gaining interest as an efficient sorbent for various types of aqueous pollutants. In this study, nZVI was synthesised by the borohydride reduction method, characterised and then examined for the removal of aqueous Co2+ ions over a wide range of concentrations, from 1 to 1000 mg/L. The size of nZVI p...

In this study, nZVI prepared by borohydride reduction was applied for the removal of Cu2+ ions under a variety of experimental conditions. The uptake experiments investigated the effects of initial concentration, contact time, pH, and repetitive loading on the extent of retardation of Cu2+ ions. Within the applied conditions, the sorbent demonstrat...

Recently, iron nanoparticles are increasingly being tested as adsorbents for various types of organic and inorganic pollutants. In this study, nanoparticles of zero-valent iron (NZVI) synthesized under atmospheric conditions were employed for the removal of Ba(2+) ions in a concentration range 10(-3) to 10(-6) M. Throughout the study, (133)Ba was u...

In this contribution, we introduce the use of metal ion (Cd(II) and Zn(II)) modified mesostructured silica as a reaction medium, to produce a solid solution of Cd1−xZnxS nanocrystals as a thin film. With this approach, a true liquid crystalline templating (TLCT) and liquid crystalline mesophase of transition metal salt ∶ oligo(ethylene oxide) non-i...