Styrene ATRP using the new initiator 2,2,2‐tribromoethanol: Experimental and simulation approach

Atom transfer radical polymerization (ATRP) is a powerful technique for the controlled synthesis of polymers, and one of the most important ATRP characteristics is the possibility to produce functionalized polymers. 2,2,2‐Tribromoethanol appears as a promising initiator for the ATRP process, because it allows the production of polymers with end hydroxyl groups, making it easy for copolymerization with biomonomers. This article explores, in experimental and computational level, the styrene ATRP using 2,2,2‐tribromoethanol to understand how this new initiator behaves, and presents a powerful tool to predict the polymer properties for different operating conditions. Simulations and experimental results showed that polymers with high molecular weight and low PDI can be simultaneously obtained using 2,2,2‐tribromoethanol as initiator. For all operational conditions, the reaction was fast and polydispersity values kept lower than 1.4, confirming the “living”/controlled characteristic. The polymers produced contain hydroxyl as functional group and in some operating conditions, PDI values of 1.1 was obtained, even at high monomer conversion. POLYM. ENG. SCI., 55:2270–2276, 2015. © 2015 Society of Plastics Engineers     

Some Issues in Rubber Nanocomposites: New Opportunities for Silicone Materials

This paper focuses on some issues regarding rubber nanocomposites especially silicone rubbers. An outstanding affinity of carbon nanotubes towards poly(dimethylsiloxane) (PDMS) has been observed. The reinforcing effect of carbon nanotubes is much more important than that imparted by in situ generated silica particles that are well known to lead to significant improvement in the mechanical properties of the elastomeric matrix. The good dispersion of carbon nanotubes in PDMS allows the formation of a conductive interconnecting filler network at a very small loading (0.05 phr).     

Reinforcement of natural rubber: use of in situ generated silicas and nanofibres of sepiolite

Natural rubber composites containing silica particles generated in situ by the sol-gel process are investigated. The sol-gel processing is conducted before and after the cross-linking reaction. A good dispersion of the inorganic particles is obtained when the sol-gel reaction takes place after curing. In each case, the level of reinforcement is assessed from the mechanical and orientational behaviors. The reinforcement provided by in situ silica is compared with that obtained with anisotropic particles such as nanofibers of sepiolite.     

Vascular corrosion casting technique steps

The vascular corrosion casting technique produces a replica of vascular beds of normal or pathological tissues. Once associated with scanning electron microscopy (SEM), this technique provides details of the three-dimensional anatomic arrangement of the vascular replica, which is the main advantage of this method. The present study is intended to describe the steps of the vascular corrosion casting technique and the different ways to perform them. them.     

A Raman Investigation of Carbon Nanotubes Embedded in a Soft Polymeric Matrix

Raman spectroscopy has been used to characterize multiwall carbon nanotubes (MWNTs) styrene-butadiene rubber (SBR) composites. Raman spectra of the MWNTs/SBR composites excited at different excitation wavelengths show that the dependence of the D band of carbon nanotubes on the laser energy has the same behavior as that of pure MWNTs. Raman spectra are shown to be sensitive to the state of dispersion of carbon nanotubes in the polymeric medium. On the other hand, analysis of Raman spectra of uniaxially stretched composites reveals a weak interface between the polymer and the nanotube surface.     

Heavy metals in edible mushrooms in Italy

The distribution of arsenic, cadmium, lead, mercury, and selenium was investigated in 1194 samples of 60 species of common, edible mushrooms collected mainly in the province of Reggio Emilia, Italy. The quantitative determination of heavy metals (mg/kg dry weight) was carried out by spectrophotometry, with the exception of Hg, which was determined by atomic absorption spectroscopy.     

Types de sites universitaires et appropriation de l'espace.

The principal aim of our research is to evaluate the impact of different academic setting types (teaching facility spread out among several sites within the city, on campus or autonomous entity) on the process of spatial appropriation developed by students enrolled at a technical university (IUT). Three hundred and twenty students answered a questionnaire regarding space appropriation and the results of the study underline the differentiated impact of the type of academic site on the three factors of our scale, namely Knowledge of the Space Environment, Easy Access, and Stimulating Effects of the Environment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A new hybrid MCDM approach for RPN evaluation for a medical device prototype

The Failure Mode and Effect Analysis (FMEA) is a useful instrument born in the aerospace industry and widely used to improve a process or product's efficiency. Over the years, this instrument has been adopted in increasingly different contexts, such as HealthCare. This paper proposes an approach aimed at improving the defects typical of the classic FMEA in the design phase, that is, in a scenario full of uncertainties and with little information available, using a new hybrid Multiple-criteria decision-making (MCDM) method in order to obtain a priority index more performant than Risk Priority Number (RPN). In the proposed method, the three assessment criteria have a different weighting in the index's final computation, differently from the classical RPN. These weights are obtained with a scientific technique, thus avoiding that excessive subjectivity influences the final result. A more efficient priority index is obtained through a new hybrid approach that solves some classical RPN gaps. A case study concerning an endoscope Ear Nose Throat Entropy (ENT) prototype is examined to illustrate the proposed method. FMEA analysis in HealthCare is increasingly used for its flexibility and reliability. This study focuses on using new techniques to eliminate certain defects or exploit some qualities better. The use of a robust and elastic innovative MCDM method to calculate a new priority index and a scientific technique to obtain the weight of the selection are the interesting insights proposed in this paper.