a simple and sensitive method has been developed for the preconcentration and determination of trace level of co(ii) using uv-vis spectrophotometry. β-cyclodextrin polymer modified with 1-(2-pyridylazo)-2-naphthol (pan) is used for the preconcentration of co(ii) from samples at ph 8.5. the polymer is synthesized and characterized using elemental analysis, ft-ir and sem analysis. the factors aff...

a new method for the synthesis of water soluble polyaniline (pani) using hemin chloride (h.c) in the presence of hydrogen peroxide (h.p) is presented. hemin chloride is an effective catalyst for the oxidative polymerization of aniline in the presence of hydrogen peroxide at room temperature. the uv- vis absorption spectra of the product show a distinct absorption peak at 430 nm in ph 4.0 b...

The soft fundamental-measure theory, which was based on the additive colloid-polymer mixture [M. Schmidt, Phys. Rev. E 62, 3799 (2000)] has been employed to investigate the adsorption of a colloid-polymer mixture within a hard slit pore. The calculated results show that the adsorption for the confined colloid-polymer mixture is very different from those of the colloid-colloid and polymer-polyme...

Polymer translocation through a nanopore in a membrane is investigated theoretically. Recent experiments on voltage-driven DNA and RNA translocations through a nanopore indicate that the size and geometry of the pore are important factors in polymer dynamics. A theoretical approach is presented which explicitly takes into account the effect of the nanopore length and diameter for polymer motion...

Precise synthesis of polymer brushes to modify the surface of nanoparticles and nanodevices for targeted applications has been one of the major focuses in the community for decades. Here we report a self-assembly-assisted-grafting-to approach to synthesize polymer brushes on flat substrates. In this method, polymers are pre-assembled into two-dimensional polymer single crystals (PSCs) with func...

the difficult to handle and store zinc borohydride, zn(bh4)2, is stabilized by supporting it on polyvinylpyridine. this new mild, efficient, selective, and regenerable polymer supported borohydride reducing agent reduces a variety organic compounds such as, aldehydes, a-b-unsaturated carbonyl compounds, acid chlorides, epoxides, disulfides, as well as reductive acetylation of carbonyl compounds...

conclusions retrograde laparoscopic appendicectomy using single polymer clip makes easy access to operating in complicated and non-complicated appendicitis. results four patients (15.4%) were converted to open surgery; three patients in group i and one in group ii. four patients developed postoperative complications; three patients in group i and one in group ii. operative time was less in grou...