Synthesis of a Novel Zn-Salphen Building Block and Its Acrylic Terpolymer Counterparts as Tunable Supramolecular Recognition Systems

In this work, we present the synthesis of a novel Zn-Salphen complex containing an allyl group, which was used as building block in the further preparation of a new family of functional terpolymers. These polymers were obtained through radical co-polymerization with methyl metacrylate (MMA) and n-butyl acrylate (nBuA) in different ratios. The supramolecular recognition behavior of each polymer was evaluated via potentiometric measurements against selected anions in aqueous media. Interestingly, this proof of concept study shows that these systems were selective against only fluoride (F−) or both, fluoride and acetate (OAc−), by tailoring the relative content of Zn-Salphen monomer, thus making them a promising starting point for modular design of chemical sensors through straightforward synthetic approaches.

Poly(methyl metacrylate) Nanocomposites for Two-piece CAD/CAM Solution as an Alternative to Monolithic Removable Prosthesis

The aim of the present paper was to characterize the new pink PMMA doped with 0.4% TiO2 nanoparticles utilized for denture base manufacturing as alternative to the one-piece, single color material for removable denture. The PMMA base material was structurally characterized through XRD, SEM, EDX, and subsequently by FT-IR and Raman spectroscopy. An improvement in the thermal stability of the obtained material compared with the PMMA matrix without filler was evidenced. All performed structural analyzes are recommending the new pink PMMA with 0.4% nano-titania as an as an alternative to the one-piece, single color material for removable dentures processing.

A Facile Method for Synthesis of CdS/P(St-сo-MMA) Nanorods Composite and Characterization of its Optical Properties

Composite of Cadmium sulphide (CdS) nanoparticle on the surface of polystyrene- co- maleic anidride (St-co-MMA) were prepared via surfactant free emulsion polymerization. Methylmetacrylate (MMA) was used as auxiliary monomer which co-polymerized with styren (St) and provided the side for coordinating with Cd2+. By the coordination of Cd2+ ions to methyl metacrylate, decoration of the Cd2+ ions on the surface of copolymer were prepared successfully. With the release of S2- ions from the thioacetamide (TAA), CdS was formed on the surface of nanorods copolymer in facile method. Fourier transform infrared spectroscopy (FT-IR) of nanocomposite was confirmed the polymerization of monomers. Structure and morphology of CdS nanoparticles have been characterized using x-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD measurements suggest the cubic structure for CdS and the particles size was estimated to about 3.35 nm by applying Scherrer’s equation. The SEM analysis confirmed the nanorode structure of CdS/ (St-co-MMA) composite. The photoluminescence (PL) and UV–Vis spectroscopy revealed the quantum confinement effect in the CdS/ (St-co-MMA) nanocomposite. Using effective mass approximation (EMA) method particle sizes were calculated from the shift in optical band gap. The thermal properties of the CdS/ (MMA-co-St) were explored by thermal gravimetric analysis (TGA). The improved thermal stability of nanocomposite was attributed to the interaction of CdS nanoparticles with polymer. The CdS/ (MMA-co-St) nanocomposite exhibited a glass transition temperature around 250◦C.

Effect of Polymer Admixtures on Mechanical Properties of Alkali-Activated Slag Mortars

Alkali-activated slag (AAS) binders have lower environmental impact due to its production process, but also have disadvantages as an increased shrinkage followed by formation of microcracks. The effect of polymer admixtures based on vinyl acetate, ethylene and acrylic acid ester, methyl metacrylate and different types of polyethylene glycol (PEG) and polypropylene glycol (PPG) on properties of alkali-activated slag concrete was studied. Admixtures used for mortars were tested to improve shrinkage, workability and compressive strength, flexural strength. The analysis also showed the effect of the admixtures on microstructure of the alkali-activated slag pastes and mortars.