Polysulfone/Metal Nanocomposites by Simultaneous Photoinduced Crosslinking and Redox Reaction

A diacrylate polysulfone oligomer is synthesized and used as the acrylic oligomer for the in situ synthesis of noble metal/PSU nanocomposites through UV‐induced simultaneous radical polymerization of acrylic functionalities and NP formation by reduction of their precursors. Thus, silver or gold NPs are formed in situ during polymer network formation. FESEM analysis of the morphology of the cured systems demonstrates that the nanoparticles of the noble metals are homogeneously distributed in the network without macroscopic agglomeration.

     

Personal Information Self-Management:A Survey of Technologies Supporting Administrative Services

This paper presents a survey of technologies for personal data self-management interfacing with administrative and territorial public service providers.It classifies a selection of scientific technologies into four categories of solutions:Personal Data Store (PDS),Identity Manager (IdM),Anonymous Certificate System and Access Control Delegation Ar-chitecture.Each category,along with its technological approach,is analyzed thanks to 18 identified functional criteria that encompass architectural and communication aspects,as well as user data lifecycle considerations.The originality of the survey is multifold.First,as far as we know,there is no such thorough survey covering such a panel of a dozen of existing solutions.Second,it is the first survey addressing Personally Identifiable Information (PII) management for both administrative and private service providers.Third,this paper achieves a functional comparison of solutions of very different technical natures.The outcome of this paper is the clear identification of functional gaps of each solution.As a result,this paper establishes the research directions to follow in order to fill these functional gaps.     

Conducting polymer coated carbon surfaces and biosensor applications

This review article focuses on several approaches in the characterization and modification of carbon surfaces with electrocoated thin films which has been realized by recent progress in experimental methods. Electropolymerization and electrocopolymerization of π-conjugated polymers (pyrrole, carbazole, N-vinylcarbazole and aniline) onto carbon surfaces are reviewed with 348 references. Particular emphasis is placed on the recent nanoscale surface characterization techniques applied to the resulting electrocoated polymers onto carbon fibers (i.e., scanning electron microscopy (SEM), cyclic voltammetry (CV), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), focused ion beam-secondary ion mass spectroscopy (FIB-SIMS), Fourier transformed infrared spectroscopy (reflectance-FTIR), and Raman spectroscopic measurements).     

Ultrastructure of segmentation mitoses in cleaving newt eggs after blocking of centrospheres by quinoline

In quinoline treated blastomeres of Triturus helveticus Raz. and Pleurodeles waltlii Michah., microtubules disappear and around the centrioles markedly enlarged dense bodies accompanied by striated bodies are accumulated, from prophase beyond metaphase. It is concluded that these bodies in untreated cells play a role in the formation of the spindle microtubules. - During metaphase the chromosome are smooth-surfaced and show a pronounced tendency to stickiness. During ana-telophase they become surrounded by nuclear membranes and form caryomeres. - Qinoline does not interfere with centriole replication, but prevents the separation if diplosomes that have been already formed, if it acts before that separation. - Some centrioles exhibit different degrees of ultrastructural disarrangement.     

Polysulfone/Clay Nanocomposites by in situ Photoinduced Crosslinking Polymerization

PSU/MMT nanocomposites are prepared by dispersing MMT nanolayers in a PSU matrix via in situ photoinduced crosslinking polymerization. Intercalated methacrylate‐functionalized MMT and polysulfone dimethacrylate macromonomer are synthesized independently by esterification. In situ photoinduced crosslinking of the intercalated monomer and the PSU macromonomer in the silicate layers leads to nanocomposites that are formed by individually dispersing inorganic silica nanolayers in the polymer matrix. The morphology of the nanocomposites is investigated by XRD and TEM, which suggests the random dispersion of silicate layers in the PSU matrix. TGA results confirm that the thermal stability and char yield of PSU/MMT nanocomposites increases with the increase of clay loading.

     

Probing metabolic stability of CdSe nanoparticles: alkaline extraction of free cadmium from liver and kidney samples of rats exposed to CdSe nanoparticles

Cadmium selenide nanoparticles (CdSe NPs) exhibit novel optoelectronic properties for potential biomedical applications. However, their metabolic stability is not fully understood because of the difficulties in measurement of free Cd from biological tissues of exposed individuals. In this study, alkaline dissolution with tetramethylammonium hydroxide (TMAH) is demonstrated for selective determination of free Cd and intact NPs from liver and kidney samples of animals that were exposed to thiol-capped CdSe NPs. Aqueous suspensions of CdSe NPs (3.2 nm) were used to optimize the conditions for extracting free Cd without affecting NPs. Nanoparticles were found to aggregate when heated in TMAH without releasing any significant Cd to solution. Performance of the method in discriminating free Cd and intact NPs were verified by Dogfish Liver (DOLT-4) certified reference material. The samples from the animals were digested in 4 mL TMAH at 70 °C to extract free Cd followed by analysis of aqueous phase by ICP-MS. Both liver and kidney contained significant levels of free Cd. Total Cd was higher in the liver, while kidney accumulated mostly free Cd such that up to 47.9% of total Cd in the kidney was free Cd when NPs were exposed to UV-light before injection.     

A review study of (bio)sensor systems based on conducting polymers

This review article concentrates on the electrochemical biosensor systems with conducting polymers. The area of electro-active polymers confined to different electrode surfaces has attracted great attention. Polymer modified carbon substrate electrodes can be designed through polymer screening to provide tremendous improvements in sensitivity, selectivity, stability and reproducibility of the electrode response to detect a variety of analytes. The electro-active films have been used to entrap different enzymes and/or proteins at the electrode surface, but without obvious loss of their bioactivity for the development of biosensors. Electropolymerization is a well-known technique used to immobilize biomaterials to the modified electrode surface. Polymers might be covalently bonding to enzymes or proteins; therefore, thickness, permeation and charge transport characteristics of the polymeric films can be easily and precisely controlled by modulating the electrochemical parameters for various electrochemical techniques, such as chronoamperometry, chronopotentiometry, cyclic voltammetry, and differential pulse voltammetry. This review article is divided into three main parts as given in the table of contents related to the immobilization process of some important conducting polymers, polypyrrole, polythiophene, poly(3,4-ethylenedioxythiophene), polycarbazole, polyaniline, polyphenol, poly(o-phenylenediamine), polyacetylene, polyfuran and their derivatives. A total of 216 references are cited in this review article. The literature reviewed covers a 7 year period beginning from 2005.     

Electrolyte type and concentration effects on poly(3-(2- aminoethyl thiophene) electro-coated on glassy carbon electrode via impedimetric study

In this study, 3-(2-Aminoethyl thiophene) (2AET) monomer was electropolymerized on glassy carbon electrode (GCE) using various electrolytes (lithium perchlorate (LiClO₄), sodium perchlorate (NaClO₄), tetrabutyl ammonium tetra fluoroborate (TBABF₄) and tetraethyl ammonium tetra fluoroborate (TEABF₄) in acetonitrile (CH₃CN) as solvent. Poly(3-(2-aminoethyl thiophene) (P(2AET))/GCE was characterized by cyclic voltammetry (CV), Fourier transform infrared reflectance spectrophotometry (FTIR-ATR), scanning electron microscopy, energy dispersive X-ray analysis (EDX), and electrochemical impedance spectroscopy (EIS) techniques. The electrochemical impedance spectroscopic results were given by Nyquist, Bode-magnitude, Bode-phase, capacitance and admittance plots. The highest low frequency capacitance (C _LF) value obtained was 0.65 mF cm^?2 in 0.1 M LiClO₄/CH₃CN for the initial monomer concentration of 1.5 mM. The highest double layer capacitance (C _dl = ~0.63 mF cm^?2) was obtained in 0.1 M LiClO₄/ACN for [2AET]₀ = 0.5, 1.0 and 1.5 mM. The maximum phase angles (θ = 76.1^o at 26.57 Hz) and conductivity (Y″ = 3.5 mS) were obtained in TEABF₄/ACN for [2AET]₀ = 0.5 and 1.0 mM, respectively. An equivalent circuit model of R(Q(R(Q(R(CR))))) was simulated for different electrolytes (LiClO₄, NaClO₄, TBABF₄ and TEABF₄)/P(2AET)/GCE system. A good fitting was obtained for the calculated experimental and theoretical EIS measurement results. The electroactivity of P(2AET)/GCE opens the possibility of using modified coated electrodes for electrochemical micro-capacitor electrodes and biosensor applications.