Arménio C Serra has completed his study in Biochemistry from the University of Coimbra and has completed his Doctorate in Organic Chemistry. His research area includes sulfonyl radical reactions, synthesis of porphyrin macrocycles as photooxidation catalyst, photodynamic therapy, supported organic catalysts for carbon-carbon condensation reactions and carbon dioxide activation. Presently, he is the Professor of the Engineering Chemical Department in Coimbra University. His research topics are centered on the study of polymerization processes and in the use of biomolecules in material science.
Polyethylene Terephthalate (PET) is a very versatile polymer mainly used in the manufacture of bottles for water. Due to its rigidity, oxygen barrier effect and thermal stability PET can improve the mechanical and thermal properties of other common polymers (polyolefins), if efficiently blended. Also, recycled PET is available in the market large amounts. Polypropylene (PP) is one of the major polyolefins produced worldwide used in a variety or articles from packaging to fibers. With relative low price, its uses could be expanded if some modifications of its mechanical properties are achieved. One of the possibilities is the use of blends with polymers or particles that could improve the PP mechanic weaknesses. The major difficulty to surpass is the compatibilization process between the immiscible and polar polyester and the apolar polyethylene. In order to improve blending process two major strategies to create covalent bonds between the two polymers were described by using PP grafted glycidyl methacrylate or maleic anhydride grafted PP. These are the routes followed by the commercial compatibilizers. In this work, we synthesized copolymers containing different amounts glycidyl methacrylate and ethyl-hexyl acrylate and evaluate the effect of these copolymers on the compatibilization of polypropylene and recycled PET. The effect of the synthesized copolymers in the mechanical and thermal properties of the blends will be discussed.
Hengwei Qiu has completed his Master’s degree from Shandong Normal University in 2016. He is now studying for a PhD degree in Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, Shaanxi Engineering Research Center of Advanced Energy Materials and Devices, Xi’an Jiaotong University. His research interests are design and synthesis of noble-metal nanostructures and their applications, especially for biosensors.
Surface-Enhanced Raman Scattering (SERS) spectroscopy is one of a few techniques that are capable of ultimately detecting matter at single molecule scale. The SERS activity of Noble-Metal Nano-Particles (NM-NPs) depends mainly on their shapes, as this determines the number and position of hot spots and, therefore, it is critical to have a purposeful control over the shapes in order to maximize their performance. Herein, using the control variate technique in the solution reaction process, various highsymmetrical Ag Meso-Particles (Ag-MPs) with well-tuned morphology were prepared for ultrasensitive SERS activity, which include polyhedron, urchin-like, multi-branched and meatball-like. Multi-branched Ag-MPs were shown to have the strongest SERS sensitivity in rhodamine B (RhB) detection in all samples as particle-array substrates with a detection limit of 10-13 M and an enhancement factor greater than 108, which can be undoubtedly applied to the molecular trace-detection. In order to verify the practical effectiveness, these Ag-MPs were used as the SERS materials for the in situ detection of a widely used growth regulator (forchlorfenuron) on an apple surface, showing clear Raman peaks at 0.01 ppm. Moreover, we investigated the influence of different variates on the morphology of Ag-MPs and propose a complete growth mechanism for these various Ag-MPs. This can provide a promising synthetic